Draft 11-10-77
DEVELOPMENT, OBSERVATION, AND EVALUATION

        OF PERFORMANCE TESTS

                 AT
      ASPHALT CONCRETE PLANTS
Prepared by:

James W. Peeler
Entropy Environmentalists, Inc.
P. 0. 12291
Research Triangle Park, N. C.
Prepared for:

The Division of Stationary Source Enforcement
U.S. Environmental Protection Agency
                  NOTICE

   This draft document has not been

   formally reviewed by EPA.   It is

   being circulated for review and

   comment on its technical accuracy.

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                                  Draft 11-10-77
DEVELOPMENT, OBSERVATION, AND EVALUATION


        OF PERFORMANCE TESTS

                 AT

      ASPHALT CONCRETE PLANTS
Prepared by:

James W. Peeler
Entropy Environmentalists, Inc.
P. 0. 12291
Research Triangle Park, N. C.
Prepared for:

The Division of Stationary Source Enforcement
U.S. Environmental Protection Agency
                  NOTICE

   This draft document has not been

   formally reviewed by EPA.  It is

   being circulated for review and

   comment on its technical accuracy.

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                  TABLE OF CONTENTS

I    Introduction                                      1
II    Process and Control System Description           3
      2.1   Basic Process Description                  3
      2.2   Emission Points                            6
      2.3   Air Pollution Control Equipment            7
III   Emission Control Regulations                     15
      3.1   Federal Regulations                        15
      3.2   State Regulations                          16
IV    Process Parameters Affect Potential Emissions    19
      4.1   Process Variables and Their Relation to    19
            Dust Loading
      4.2   Normal Range of Process Parameters         23
            Plant Capacity
      4.3   Process Modifications                      26
V     Control System Parameters Affecting Emissions    29
      5.1   Control System Parameters                  29
      5.2   Control System Modifications               33
VI    Representative Conditions - Test Protocol -
      Pretest Meeting                                  36
      6.1   Determination of Representative Conditions 36
      6.2   Test Protocol                              38
      6.3   Pretest Meeting                            39
VII   Emission Test Methods and Acceptable Alternatives  41
      7.1   Emission Test Methods                      42
      7.2   Commonly Encountered Sampling Problems     45
            and Acceptable Alternatives
VIII  Monitoring Process and Control System Parameters 51
      8.1   Monitoring the Process                     51
      8.2   Monitoring Control System Parameters       55
      8.3   Additional System Parameters               62

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IX    Visible Emission Observations                    66
X     Review and Evaluation of Performance test
      Reports                                          68
      10.1  Review of Test Reports                     68
      10.2  Checking Test Data                         70
Appendix A - NSPS Regulations
Appendix B - EPA Test Methods
Appendix C - Blank Data Forms
Appendix D - Isokinetic Sampling in Non-Parallel
             Flow Systems - Cyclonic Flow
                             11

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                     LIST OF FIGURES


2-1   Typical Pulse-Jet Configuration                   10

2-2   Venturi Scrubber                                  12

2-3   Low-Energy Scrubber System                        14

7-1   Air-Water Vapor Psychrometric Chart               48

8-1   Process Flow Diagram                              53

8-2   Nomograph For Estimating Flue Gas                 56
      Composition - Excess Air Or Type Of Fuel

8-3   Measurement Of Static Pressure Drop               57

8-4   Measurement Of Static Pressure Drop               57

8-5   Flow Meter Installation                           60

8-6   Pressure Gage Installation                        60

10-1  Air-Water Vapor Psychrometric Chart               73

10-2  Moisture From The Ambient Air                     75

10-3  Determining Moisture In The Flue Gas From         75
      Combustion of Fuel
                           111

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              LIST OF TABLES


2-1    Primary And Secondary Control          8
       Devices Used In The Asphalt
       Hot-Mix Industry

3-1    Summary Of State Regulations           17

4-1    Mix Compositions                       24
                      iv

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                          Chapter I
                         INTRODUCTION

     The Standards of Performance for New Stationary Source
(NSPS), promulgated by the U.S. Environmental Protection Agency
(EPA) under Section 111 of the Clean Air Act, require performance
tests to be conducted on any new or modified sources affected
by the standards.  A determination of compliaace with the stand-
ards is made based on the written report of the test results
submitted to the EPA Regional Office or State Air Pollution Con-
trol Agency delegated NSPS authority.
     This manual presents practical information for use by State
and Federal field enforcement personnel in planning, observing,
and evaluating performance tests at hot-mix asphalt concrete
plantsi  The source sampling manual for hot-mix aspahlt concrete
plants ia one of a series of technical manuals being prepared
by the Division of Stationary Source Enforcement, EPA, which
address the individual performance testing needs and problems
of the various source categories for which NSPS have been promul-
gated.  These manuals are designed to provide source-specific
background information, guidelines, test procedures, and solutions
to special emission testing problems to aid agency personnel in
ensuring that valid and representative results are obtained
from performance tests at new stationary sources.
     The source-specific material presented in this manual re-
garding techniques and procedures for evaluating performance
tests at hot-mix plants should be used in conjunction with the
general procedures outlined in the DSSE Compliance Testing Manual
series entitled "Development, Observation, and Evaluation or
Performance Tests."    This manual is also intended to be sup-
plemental to the DSSE Stationary Source Enforcement Manual entitled,
"Inspection Manual for Enforcement of New Source Performance
                                       2
Standards - Asphalt Concrete Plants."
  Development, Observation, and Evaluation of Performance Tests,
  currently being prepared by the DSSE,U.S.EPA.
  Inspection Manual for Enforcement of New Source Performance
  Standards-Asphalt Concrete Plants, U.S. EPA, 340/1-76-003, March 1976.

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For more in-depth information on the EPA reference test methods and
their proper application, the EPA publication "Quality Assurance
Handbook for Air Pollution Measurement Systems, Volume Ill-
Stationary Source Specific Methods " should be consulted.
     This manual deals with conventional hot-mix asphalt concrete
plants.  Drum-mix plants will be covered in a later manual, as
information about this relatively new process becomes available.
Although the manual primarily applies to performance tests at
sources subject-to NSPS it also has general application to existing
plants subject to state regulations. .However, due to the diversity
of state regulations and tests.procedures, and for the sake of'
brevity, this manual will not cover all the problems related to
testing existing sources.  .,     ..>•      '-.=•;.       ; r           r'^-
     Chapter II-provides a brief-description of  the hot-mix asphalt
concrete manufacturing process and':its. operation.  Chapter III
summarizes the NSPS regulations and gives- examples of typical   -.
state regulations..Chapters IV and.V describe process and control
system parameters which affect:emissions.  Suggested agency pre-
paration and procedures.for selection,of representative.conditions
for performance tests are described in Chapter VI.  Emission ;  •,
testing methods and solutions to-special sampling- problems are-
provided in Chapter.: VI11...  Procedures for monitoring .process..and *
control system.parameters during .performance tests are; included-.,
in Chapter VIII.  Concurrent visible emission observations are ';
discussed in Chapter IX.  Chapter, X contains procedures for
review and evaluation of the test report.  Recommendations for...
future surveillance of plant operation are included in Chapter,XI.
Applicable NSPS regulations and EPA test methods are included  in
Appendices A and B.  Data forms for use by agency observers are
included in Appendix C.                                       -
   uality Assurance Handbook  for Air  Pollution Measurement Systems;
   plume III  -  Stationary  Source Specific Methods,currently
  being prepared  by the  Environmental Monitoring  and  Support
  Laboratory, U.S. EPA.

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                         Chapter II
           PROCESS AND CONTROL SYSTEM DESCRIPTION

2.1  Basic Process Description
     Asphalt concrete is basically a mixture of crushed stone,
sand, and mineral dust which is dried, heated, and then coated
with hot asphalt cement.  The principal use for asphalt concrete
is surfacing of roads and parking lots and other paving operations.
For a more complete description of the hot-mix process, the reader
should consult "Inspection Manual for Enforcement of New Source
                        A:
                        2
Performance Standards - Asphalt Concrete Plants"   or the
"Asphalt Plant Manual."

2.1.1  Raw Materials
     The raw materials used in the production of asphalt concrete
are asphalt cement, various sizes and types of aggregate, and
fuel for the dryer.
     Aggregate. Asphalt mixes may be produced from a wide range
of aggregate combinations.  Each mix has particular characteris-
tics which are suited to specific applications.  Mixtures are
generally classified according to the relative amount of coarse
aggregate, fine aggregate, and mineral filler.
     Coarse Aggregate - crushed stone, slag, or gravel  (material
                        retained on No.8-mesh sieve)  3
  Inspection  Manual  for Enforcement  of New Source Performance
  Standards -  EPA  341/1/76-003, March, 1976
 2
  Asphalt  Plant  Manual, The Asphalt  Institute Manual Series, No.  3,
  fourth edition,  December, 1974.
  No.  8-mesh  sieve -  (2.38 mm  or  .094 in.)

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     Fine Aggregate - natural sand or finely crushed stone
                      or gravel (material passing No. 8-
                      mesh  seive)
     Mineral Filler - (mineral dust) - very finely ground
                      particles of crushed stone, limestone
                      Portland cement, or other non-plastic
                      mineral materials.(material passing No.
                      200-mesh sieve)  4
     Asphalt Cement.  Asphalt cement, a residual by-product
of the petroleum cracking process, makes up from 3% to 8% of the
product weight.  Normally a solid at ambient tmeperatures, the
cement must be heated to 135-177°C  (275-350°F) to be used as a
liquid.  Cut-back asphalt, used in the production of "cold
patch" asphalt mixes, is produced by adding mineral oils or
solvent to regular asphalt cement.          '   :
     Fuel.  The rotary dryer is usually gas or oil-fired.  Natural
gas and No. 2 fuel oil are the most commonly used fuels.  LPG
and heavy fuel oils  (no. 5, no. 6) are sometimes used as alternative
fuels.                                                    ,   .

2.1.2  Process Description

     Asphalt concrete is produced in both batch plants and
continuous plants.  The two types of plants are similar  in  most
respects, differing mainly in the feed mechanisms to the mixer
and in the mixer itself.  Drum-mix plants will be" covered in a
supplemental manual currently being prepared.
     The Batch Process.   The process begins as raw  aggregate
is transferred from stockpiles to the cold bins.  There are
usually three or four cold  bins, each containing a  different
grade of aggregate.  The aggregate  is metered from the cold  bins
onto a conveyor and  is then transferred either directly or by
means of a bucket elevator to the rotary dryer.   The dryer is an
inclined revolving cylinder usually  ranging from  .9-3 meters
(3 to 10 feet) in diameter and from  4.6-12.2 meters  (15 to 40 feet)
 No.  200 mesh  sieve  -  (.074 mm  or  .0029  in.)

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long.  The dryer performs two functions: 1)removal of moisture
from the aggregate, and 2) heating of the aggregate to mixture
temperature, 121-177°C (250-350°F).  The conventional rotary
dryer is either gas or oil fired with the burner being located
at the aggregate exit; thus, the air and combustion gases flow
counter-current to the aggregate flow.  The term "direct-fired"
is often used to describe conventional dryers, since the aggregate
is in direct contact with the burner flame and combustion gases.
The rotating cylinder is equipped with longitudinal channels
called "flights" which lift the aggregate and drop it in veils
through the hot gases to facilitate maximum heat transfer,  the
slope of the dryer, its rotational speed, diameter, length,
and number of flights control the length of time required for
the aggregate to pass through the dryer.
     The aggregate leaving the dryer is transported by a hot
bucket elevator to a set of vibrating screens at the top of the
mixing tower.  The aggregate is classified by size into several
grades by the screens and is then stored in hot bins.  Aggregate
from each of the hot bins is weighed in the weigh hopper to obtain
the desired size distribution for the mixture.  The weigh hopper
discharges to the mixer or "pugmill" where the aggregate is mixed
dry for about 30 seconds, after which asphalt cement is pumped in
from heated storage tanks to complete the mixture.  When the
asphalt and aggregate are thoroughly mixed, the product is loaded
into trucks or held in heated storage silos.
     The Continuous Plant.   The major difference between the
continuous plant and the batch plant is seen in  the operation of
the mixer or "pugmill".   In the continuous plant, aggregate from
the hot bins is metered and transported by a set of feeder-con-
veyors to the mixer.  Hot asphalt cement is also metered to the
inlet end of the mixer.  Flow through the mixer  is continuous and
retention time is  controlled by an adjustable dam at the outlet
end of the mixer.  The completed product flows to a holding hopper

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from which the trucks are loaded.  Some plants have heated
storage facilities for holding the product.

2.1.3  Typical Operations
     Plant capacities range from 90 to 800 tons per hour; a
180 tons per hour plant is considered average.    Currently, batch
plants are much more common than continuous plants.  Typical
plants produce 5,000 pound batches although some newer plants
produce 8,000 pound batches.
     There are an increasing number of portable asphalt plants,
(plants which can be temporarily located at maj or paving sites).
Currently, portable plants constitute approximately 151 of- the
total.
     Various degrees of automation are encountered at asphalt
plants:  Some plants are completely automated so that all op-
erations are controlled from a central control center.  Batch
programmers are often employed to control the weighing and mixing
operations.  Older plants typically have fewer automatic or remote
controls and are operated manually.  The use of automatic controls
generally provides smoother plant operation and a more consistent
product.

2.2 Emission Points
     The rotary dryer is the major source of particulate emissions
at hot-mix asphalt plants.  The  exhaust gases from the dryer are
almost  always ducted to a primary control device.  Most plants use
either a cyclone or multicyclone as the primary collector.  The
dust collected in the cyclone is returned to the hot bucket elevator
or weigh hopper to serve as additional mineral filler in the mix-
ture.  In order to comply with air pollution regulations, the
effluent gases from the primary  collector are ducted to a seco	,
air cleaning device with a relatively high collection efficiency.
  ' Personal communication, Fred Kloiber, Director,Engineering  §
   Operations, National Asphalt Pavement Assoc., Riverdale, Md.

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     The hot elevator, vibrating screens, hot bins, weigh hopper
and mixer are also sources of particulate emissions at hot-mix
asphalt plants.  Particulate emitted directly to the atmosphere
from these sources is referred to as fugitive dust.  The particulate
emissions from these sources are controlled by enclosing the
sources with a scavenger ducting system and conveying the dust-
laden gas to a control device.  Usually the scavenger system is
connected to the dryer exhaust system before the primary collector.
A few plants employ a separate control device for the scavenger
system.  It should be emphasized that the particulate and opacity
standards apply to emissions from all control systems.

2.3  Air Pollution Control Equipment
     An asphalt plant equipped only with a primary collection
device (cyclone) will typically release 5.0 to 7.5 kg of par-
ticulate per metric ton of asphalt produced, (10-15 Ibs of
                              1
particulate/ton of asphalt).     A plant so equipped operating
at 150 metric tons per hour (165 tons/hr) would emit 748 to
1122 kg (1650-2475 Ibs) of particulate per hour of operation.
To comply with the concentration standard, 90 mg/dscm, prescribed
by the New Source Performance Standards, such asphalt plants must
reduce potential emissions by approximately 99.6%.  Relatively high
efficiency collectors are required to achieve the required degree
of control.  The best systems for emission reduction, taking into
account the cost, are considered to be well-designed, well operated,
                                                     g
and well maintained baghouses and venturi scrubbers.    In addition
to baghouses and venturi scrubbers, multiple low engery scrubbers
in series are often used to control particulate emissions from
the asphalt industry.  Table 2-1 shows the types and frequency of
application of various control devices used at hot-mix asphalt
plants.
 Background Information for New Source Performance Standards,
 U.S. EPA  (APTD-135Za) Vol. 1, p.9.
8Ibid.,  (APTD-1352c), Vol. 3, p.13.

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                          Table 2-1
           Primary and Secondary Control Devices
            Used in the Asphalt Hot-Mix Industry

TYPES OF EQUIPMENT                         PERCENT OF INDUSTRY
Primary Collectors
  Settling Chambers                                4
  Cyclones                                        58
  Multicylones                                    35
  Other                                            3
Secondary Collectors
  Baghouses                                       40
  Venturi Scrubbers                               16
  Low Energy Scrubbers                            40
  Other                                            4
2.3.1  Primary Collection Devices
     Hot-mix asphalt plants usually employ a primary collection
device to recover dust from the exhaust stream, which is returned
to the process, and to reduce the dust loading on. secondary air
cleaning devices. Almos't  all asphalt plants employ either simple
cyclones or multicyclones as primary collection devices.  These
devices collect from 50% to.90% (by weight) of the dust in the
gas stream.
     Many design factors affect the collection.efficiency of cy-
clones.  Generally, higher pressure drop, greater flow rate, and
smaller cyclone  radius increase collection efficiency.  An upper
limit on the flow rate is established by the development of
turbulent flow which re-entrains the collected material. Also,
poor design or construction practices can yield a high pressure
drop and a low collection efficiency.  The improved collection
efficiency of smaller radius cyclones is utilized in the multi-
cyclone where a number of small cyclones are operated in a parallel
arrangement.  The performance of cyclones collectors is directly
Q
 "Controlling Air Pollution in Asphalt Paving", Fred  Kloiber,
 Pollution Engineering, September  1977, p. 48.

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related to the particle size distribution in the gas stream;
collection efficiency decreases with decreasing particle size.
Cyclones and multicyclones alone cannot achieve the  degree
of control required of asphalt plants by NSPS.

2.5.2 Baghouses
     Almost all baghouses  used to control emissions from asphalt
plants are the reverse-pulse or reverse flush type.  Usually
the bags are supported on a wire cage with the interior of the
bag being the clean side. (Figure 2-1).  The fabric bags are
usually 14 to 16 oz. (weight per square yard) felted or felted-
woven Nomex* bags.
     The term "air-to-cloth ratio" refers to the ratio of the
volumetric flow rate through the baghouse to the total filter area
of the bags (acfm/ft2).  The terms "superficial face velocity"
and "filter velocity" are also used, since cancelling units in
the ratio .results in ft/min.  For reverse-pulse and reverse
flush baghouses at asphalt plants, air-to-cloth ratios range from
4 to 7 acfm/ft.  10
     In the reverse-pulse type baghouse, removal of the accumulated
dust cake is accomplished by directing a pulse of compressed air
into the interior of individual bags.  The high pressure air causes
the bag to snap from a collapsed condition on the wire support
cage to an expanded (ballooned) position.  The abrupt change in
the bag configuration causes the dust cake to fall from the bag
to a hopper at the bottom of the baghouse.  In the reverse-flush
baghouse, cleaning is facilitated by isolating a group of bags
by means of dampers.  Compressed air is introduced to the exhaust
chamber above the bags which causes the bags to expand rapidly,
thereby removing the dust cake.  The frequency and duration of
the cleaning cycle can usually be adjusted by the plant operator.
Sometimes the cleaning cycle is automatically controlled by a
device which senses the pressure drop across the bags.
*
  Trade name
  Operation of Exhaust Systems  in  the Hot-Mix  Plant, National
  Apshalt Pavement Association,Information  Series  52, p.  34.

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                         FIGUR? 7 2'-1



              TYPICAL PULSE-JET CONFIGURATION
                            Soiiis
Source:  Handbook of Fabric Filter Technology,GCA Corp., Dec.  1970
                                10

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     An older type of baghouse using woven fabric filters and
air-to-cloth ratios in the range of 1 to 4 acfm/ft  is sometimes
encountered.  This type of baghous relies on the collected dust
cake to act as part of the filter.  Periodic cleaning is ac-
complished by mechanically shaking the bags.  Only a few older
asphalt plants employ this type of baghouse.

2.5.5  Wet-Collection Devices
     Wet-collection devices, or scrubbers, employ two principal
mechanisms for the removal of particulate matter from gas streams:
l)Dust particles are wetted by contacting them with a liquid.
Wetting the particles increases their effective  mass, which
facilitates collection by impingement on centrifugal devices.
2) Dust particles are  contacted'.'. with a collection surface by im-
pingement or other.means and are then removed by a liquid flush.
In some cases, the collection surface is the scrubber water.
Many wet-collection devices employ both of these mechanisms for
particulate collection.
     High Energy Venturi Scrubbers.  High Energy venturi scrubbers
are the most effective wet-collection devices for controlling
particulate emissions at asphalt plants.  In the venturi scrubber,
the dust laden gases are passed through a venturi which consists
of a convergent section, throat, and a divergent section  (Figure 2-2),
Gas velocities in the throat range from 76 to 102 meters per second
(15,000 - 20,000 fpm) with pressure drops across the venturi ranging
from 254 to 762 mm (10-30 inches) of water column.      Low
pressure water is injected either directly into the throat or in
the convergent section.  Turbulence created by the high velocity
gas stream atomizes the liquid  into a very fine mist.  The dust
particles collide with the liquid droplets due to the high relative
velocities in the throat, thus  increasing the mass of the  par-
ticles.  Further agglomeration  occurs in the divergent section
creating relatively large particles which are removed in a
cyclonic or other inertial separator.
11Air Pollution Engineering Manual, U.S. EPA,AP-40, May,1973,p.104.
                              11

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               Figure 2-2.   Venturi Scrubber
Source:  Air Pollution Engineering Manual, U.S. EPA AP-40, 1973
                             12

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     Low Energy Scrubbers.  Low-energy wet collectors are
devices with pressure drops of less then 15" we and include such
devices as spray systems, centrifugal scrubbers, orifice scrubbers,
and wet fans.  Alone, none of these devices are capable of achiev-
ing the required degree of control.  However, tests have shown
that the  NSPS emission standard can be met with the use of two
or more low-energy scrubbers in series.
     There is considerable variability in low-energy scrubber
design among the various manufacturers.  There is even greater
variability in the combinations of these devices at aspahlt
plants.  Improvised systems are frequently used in an attempt
to meet the required emission standard.  Several low-energy
scrubber systems are shown schematically in Figure 2-3.
12
  Background Information for New Source Performance Standards,
  U.S. EPA  (APTC-1352c) Vol. 3, p. 10)
                             13

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 Scavenger \Svstem
                                                 Spray Nozzles
  :Dryer   x  Exhaust
                                                       Wet Fan
                                Cyclone
                                                                Freeleaner
                                                                                                   f
                                                                                                      stack
H^
)
1 -~
i — .
i 	

x'

1 1
1



                                                                                                  • Spray
                                                                                                  Wet
                                                                                               Centrifugal
                                                                                                Collector
                                                    Exhaust Fan
Scavenger
v.   oysuein
 Dryer
    Exhaust
               \
  Multiple
.Centrifugal
 Scrubber
                                                                                                 r
                                                                                                               Stack
                                                                                                     ->-
                                        Figure 2 - 3•   Low-Energy Scrubber  Systems

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                        Chapter III
                EMISSION CONTROL REGULATIONS
     State and Federal regulations have been established to limit
particulate emissions to the atmosphere at asphalt plants.

3.1  Federal Regulations- Standards of Performance for New or
     Modified Asphalt Concrete Plants
     The current standards regulating particulate emissions from
asphalt plants were published March 8, 1974 (39 FR 9308).  These
standards apply to hew sources, plants whose construction or
modification* was undertaken after June 11, 1973.  The standards
limit particulate emissions to:
     (1)  No more than 90 mg/dscm (0.04 gr/dscf)
     (2)  Less than 201 opacity2
     "The concentration standard applies to emissions of parti-
culate matter from the control system, as evidenced by the test
methods required for determining compliance with this standard."•*
The regulations also require the operators of asphalt plants to
conduct a performance test and submit the results within 60 days
after achieving the maximum production rate at which the affected
facility will be operated, but not later than 180 days after ini-
tial start-up (40 CFR 60.8).  The appropriate test methods for
determining compliance are described in Chapter VI.
     lit should be noted that relocation, change of ownership, and
upgrading of emission controls are not, by themselves, modifications
(40 CFR 60.14  (e) ).  These occurrences are particularly common  at
asphalt plants.
     2Qccasionally a plant operator will add small amounts of as-
bestos to asphalt mixes to increase the cohesion and  abrasion re-
sistance of the product.  Asbestos is usually supplied in sealed
plastic bags which are added directly to the mixer.
     Any new or existing asphalt plant which uses asbestos in the
production of  asphalt concrete is subject to the National Emission
Standards for  Hazardous Air Pollutants (40 CFR  61.22  Cll).  The
standard for asbestos manufacturing operations  allows no visible
emissions of asbestos-containing particulate matter to the outside
air unless a specified fabric filtration device is employed (40 CFR
61.23) .
      ^Background Information for New Source Performance Standards,
 U.S.  EPA (APTD-1352C),  Feb.  1974,  p. ^"~

                            15

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     The opacity standard, to ensure that emissions of parti-
culate matter are properly collected and vented to a control
system4, applies to "dryers, systems for screening, handling,
storing, and weighing hot aggregate; systems for loading, trans-
ferring, and storing mineral filler; systems for mixing asphalt
concrete; and the loading, transfer and storage systems associated
with emission control equipment" (40 CFR 60.90).  The opacity
standard applies to all of the above named fugitive dust sources
and to stack emissions from all control systems.

3.2 State (SIP) Regulations for Asphalt Concrete Plants
     All states have laws which affect the ;hot-mix asphalt
industry.  Many states have dual standards;  one for existing
plants and a more stringent standard for new plants.  Table
3-1 is a tabulation of state, (SIP), particuiate and opacity
regulations;  The values listed are illustrative only 'arid should
not-be used for enforcement purposes.
     Most states limit particuiate emissions in terms of Ibs/hr
where the allowable emission rate is determined from'process
weight rate tables. 5"- Some states employ concentration standards
Cgr/dscf) or other means of limiting emissions.  The basis for
the particuiate emission standard often affects the test
method(s) which are used to determine compliance with the
standard.  For example, a mass emission rate standard' (Ibs/hr)
requires that the tester determine the stack volumetric flow
rate, however, a concentration standard does not.  Most states
employ EPA Methods 1-5 for particuiate sampling, however test-
ing details vary from state to state.  For example, most
states count only the particuiate collected in the front half
of the Method 5 train, however, some states also count parti-
cuiate collected in the impingers.  Factors in the state
     4Ibid.  .       .           .                 ••'.-.:
      Air Pollution Regulations Study, Information Series 49,
      National Asphalt Paving Association, 1973.
                            16

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                                          Table 3-1.  Summary of State Regulations
  State
Allowable Emission Rates        % Opacity
Ibs/hr,process wt. depen-       Provisions
dent except where noted         	
State
Allowable Emission Rates    % Opacity
Ibs/hr,process wt. depen-  Provisions
dent except where noted       •	
Alabama              9.76-46.79/12.05-68.96           20
Alaska                   0.05/0.10  a                 20
Arizona                    12-69                      40
Arkansas                9.73-46.72                  20/40
California      Each county has its own  regulations
Conn.       0.3 lbs/1000 Ibs dry discharge gas      .  20
Delaware                   10-50                      20
D. Colum.                  10-40                       0
Florida                 9.73-46.72                    20
Georgia               5.52-43/5.0-91                  20
Hawaii                  13.6-40                     20/40
Idaho                    12-69                      20/40
Illinois                 6-67/12-69                   30
Indiana                     12~6|                     40
Iowa                       0.15                       40
Kansas                      12-69                   20/40
kentUcky                    12-69                   20/40
Louisiana                   12-69                     20
Maine                    9.73-46.72                   40
Maryland                    0.03                       0
Mass.                   4.5-18.1/9.0-36.2             20
Michigan   0.3-0.6 lbs/1000 Ibs wet flue gas          20
Minnesota               0.1-0.042 a'                  20
Miss.                      12-264                     40
Missouri                   12-69                    20/40
                                                  Montana                     12-69               20/40
                                                  Nebraska                    12-69                20
                                                  Nevada                      12-69                20
                                                  N. Haopsh.                  10-47                20
                                                  N. Jersey                0.02 a'c               20
                                                  New Mexico                  10~59                20
                                                  New York            0.03-0.05a' /10.8-71.1      20
                                                  N. Car.                     10-60               20/40
                                                  N. Dakota                   12-69                20
                                                  Ohio              4-220 lb/hre or 12-69         20
                                                  Oklahoma                    12-69                20
                                                  Oregon                      10-69               20/40
                                                  Penn.             3.18-13.3  or  0.02           20
                                                  Rh.-Is.                     12-69                20
                                                  S, Car&lina             22-65/30-94            20/40
                                                  S. Dakota                   21-69               20
                                                  Term.             9.7-46.7 and 0.25S/12-51.2   20/40
                                                  Texas                   14.5-60.4              20/30
                                                  Utah         Maintain 85% collection effici;   20/40
                                                  Vermont              0.07 S/6.67-40            NA/40
                                                  Virginia                   10-50                20
                                                  Washingt.                  0.10 a               20
                                                  W. Vir.                    10-50                20
                                                  Wisconsin      9.73-46.72/some areas differ    20/40
                                                  Wyoming           9.73-46.72/12-69             20/40
         gr/dscf
         dependent upon source gas volume(scfm)
                                                     dependent upon Ib/hr emission rate
                                                     uncontrolled mass rate basis
         or control equipment of 99% efficiency, whichever is less

                                        1
                                                     whichever is greater

                        Whenever available listed according to new source standard,existing source

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regulations which affect how a source test is to be con-
ducted must be ascertained in the developmental stages of
the test.
     Opacity regulations vary from "no visible discharge'
to 40% opacity.  Many state regulations allow opacities
greater than the standard for short time periods.  Many
states also have regulations for fugitive dust and odor
emissions.  These emissions are often dealt with on a
nuisance  basis.
                            18

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                         Chapter IV

     PROCESS PARAMETERS AFFECTING POTENTIAL EMISSIONS

     The first section of this chapter explains how process
variables and operational parameters are related to the dust
loading on control equipment.  Section 4.2 describes commonly
encountered values of important process parameters.  Examples
of process modifications and operational practices which are
sometimes employed to achieve short term emission reductions
are provided in section 4.3.

4.1 Process Variables and Their Relation to Dust Loading.
     Rotary Dryer.   The dryer is the major source of potential
particulate emissions at asphalt plants.  There are several
operational parameters which affect the dust discharge rate
from the rotary dryer.  The two major factors affecting
particulate emissions are: (1) the quantity of fine material
in the dryer, and (2) the flow rate of gases through the dryer.
These two factors are directly related to process variables
such as:  production rate, aggregate size distribution,
aggregate moisture content, firing rate and excess air.
     The aggregate size distribution in the dryer feed has a
significant effect on the dust emissions.  Dust carryover increases
as the particle size decreases.  In addition to the mineral dust
in the dryer feed, very fine particles are created in the dryer
by breakup of coarser aggregate.  Tests have shown that approx-
imately 55$ of the mineral dust (material less than 74 microns)
in the dryer feed may be lost in,the processing.     The amount
of small particles in the dryer,  is dependent on both
the percentage of fines in the dryer feed and the total production
rate.
     Pollution Engineering Manual,U.S. Environmental Protection
 Agency, AP-40, May, 1973" p. 328.
                              19

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     The volume flow rate of gases through the dryer has a
major effect on the dust discharge rate.  A study by Barber-
Greene reported that dust carryover was proportional to the
                                               2        •
square of the gas velocity through the dryer.     Therefore,
the"gas flow rate should be kept to the minimum necessary
for proper operation of the dryer to reduce particulate
entrainment.       .
     The firing rate of the dryer is directly related'to the
aggregate feed rate, the percent moisture in the cold aggregate
feed, and the required hot aggregate temperature.  If any of
these factors increases, the amount of heat supplied to the
dryer must be increased.  This is accomplished by increasing   '
the firing rate.
     To increase  the firing rate, the quantity- of vfuel, supplied
to the burner is  increased.  At the same time, the amount of air
supplied to the burner, which, is brought in by a forced-draft
fan in the burner itself and by the induced draft of the
exhaust fan following the dryer, must be increased to maintain
proper combustion conditions.  Thus, the flow rate-of gases
through the dryer is related to the rate and moisture content
of the aggregate  feed.     	
     Excess air is defined as the quantity of air in excess of
the theoretical amount necessary for complete combustion of the
fuel.  Due to less than ideal combustion conditions a certain
amount of excess  air must always be present in combustion
processes to ensure .complete combustion of the fuel.  Normally..
10 to 25% excess  air is sufficient for the operation .of gas or
oil-fired burners.  In aggregate dryers with low exhaust
temperatures, additional excess air may be required to prevent
dryer gases from becoming saturated with water vapor.  A state
of saturation or high relative humidity in the dryer gases will
retard the evaporation of water from the aggregate.
     In direct fired rotary dryers, too much excess air lowers
the flame temperature, reduces the effective heat transfer to
  "Dryer Principles", The Barber-Greene Co., Aurora, 111. (1969)

                             20

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'the aggregate, wastes the fuel required to heat the excess air,
and increases the gas flow rate through the dryer.  This in turn
increases the dust emissions.
     In order to maximize the efficiency of the dryer and to min-
imize the amount of dust lost, the firing rate of the burner and
the draft must be balanced carefully.  For a given process rate
and aggregate moisture content, the firing rate should be
adjusted to provide the minimum amount of heat necessary to
dry and heat the aggregate properly.  The draft should be
regulated to provide the correct amount of air for complete
combustion and, when necessary, sufficient excess air to ensure
that a state of high relative humidity does not occur in the
dryer gases.
     Most hot-mix plants have controls which allow modulation
of the burner to provide the required firing rate.  Part of the
air for combustion is supplied by the forced draft blower, which
forces air- through the burner to ensure thorough mixing of the
fuel and air.  The quantity of air supplied by the forced draft
blower is regulated by the burner controls.  The remainder of
the air flow through the dryer (approximately 70%) is provided
by the exhaust fan.  Exhaust fans are usually located either
immediately before or after the secondary control device.  The
flow of gases through the dryer is regulated by a damper in the
ducting between the dryer and exhaust fan.  A procedure commonly
used to obtain the proper air flow is to close the damper until
puffback occurs (visible emissions of dust and smoke from the
air inlet end of the dryer).  The damper is then slightly re-
opened.
     On almost all hot-mix plants, the hot aggregate temperature
is monitored to ensure that the aggregate is at the desired
mixture temperature.  Many plants also monitor the dryer exhaust
gas temperature.   An exhaust gas temperature from 90 to 120°C
(200-250°F) desired.  3  Some plants have little ability to
  The Operation of Exhaust Systems  in  the Hot-Mix Plant,
  National Asphalt Paving Association,  Information Series
  52., 1975, p. 14
                            21

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regulate the firing rate and do not have a damper or other
means of regulating air flow.  These plants are usually run
wide open (maximum production rate) with little attention
given to maintaining the correct firing conditions in the
dryer.
     The type of fuel used can have a noticeable effect on
emissions from the dryer.  Usually gaseous fuels or fuel oil
are used to heat the dryer.  The use of heavy fuel oil may
result in unburned fuel droplets or soot particles in the
dryer exhaust due to poorly maintained burners or improper
combustion conditions.  Tests have shown that emissions were
increased more than 5 Ibs. per hour when No. 6 fuel oil was
used in place of natural gas at a plant controlled by multiple
centrifugal scrubbers.   Frequently, the added increment of
particulate emissions from a misadjusted or defective oil
burner will cause the standard to be exceeded.  The combustion
of fuel oil containing sulfur will produce sulfur oxides
(SO-, SO,).  The presence of these compounds, especially when
   £,.  • - 3 •       - _       , • •   .        "              (
the gas stream is wet, increases the corrosion problems in
the system.  When high sulfur fuels are used at plants
equipped with wet-collection systems, water treatment may be
necessary to prevent the scrubber water from becoming acid.
     The rotational speed of the dryer and the number of
flights may also affect the amount of dust discharge from the
dryer.  An addition of flights or an increase in rotational
speed increases the amount of time the particles are in the
veil suspension. Particles in the veil suspension are the most
susceptible to entrainment in the gas stream.
4 Air Pollution Engineering Manual, U.S. EPA, AP-40, May 1973,
  p. 330.
                               22

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'Secondary  Sources.   Particulate  emissions  from secondary
 sources,  (hot  elevator,  screens,  hot  bins, weight hopper,
 and  mixer)  are controlled by  enclosing  the aggregate
 handling equipment with  a scavenger ducting system.  The
 particulate loading  in the  scavenger  system varies with
 the  condition  of  the aggregate handling equipment and  the
 quantity of fine  material in  the  mix.   The design and  physical
 condition  of the  scavenger  system (particularly the effective-
 ness  of the seals) affects  both  the required volumetric flow
 rate  for the system  and  the amount of dust which is entrained.
 For  a typical  plant  the  ventilation requirements of the
 scavenger  system  are on  the order of  5100  to 5950 m /hr
 C3000-3500 cfm).5
 4.2  Normal Range  of  Process Parameters  - Plant Capacity
      The following values of  process  parameters indicate the
 normal or  typical ranges encountered  at most asphalt plants.
 However, considerable deviations  from the  given ranges are
 observed at some  plants.

 Aggregate  Size Distribution  The  compositions of various
 asphalt mixes  are summarized  in  Table 4-1.  The values
 given in the table are percent by weight of.the aggregate
 passing the given screen.
 5  Air Pollution Engineering Manual,  U.S.  EPA,  AP-40,
    May 1973, P.  328.
                                 23

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                Table 4-1 Mix  Compositions
Ml.1
Type
1 a
II a
II b
II c
II d
II e
III a
III b
III c
III d
III e
IV a
IV b
IV c
IV d
V a
V b
Via
VI b
VII a
~ VIII a
2K
in.
100




















I'/i in.
35-70




100




100



100






1 in.




100
70-100



100
75-100


160
80-100






% in.
0-15


100
70-100
50-80

100
100
75-100
60-85

100
66- )00
70-90

100

160


'/i in.


100
70-100


100
75-100
75-100


100
80-100


100
85-1 OO
100

-

Hin.

10O
70-100
45-75
35-60
25-60
75-100
60-85
60-85
45-70
40-65
80-100
70-90
60-80
55r75
85-100

85-100
85-100
.100

#4

40-85
20-40
20-40
15-35
10-30
35-55
35-55
30-50
30-50
30-50
55-75
50-70
48-65
45-62
65-80
65-80


85-100
100
#8
0-5
5-20
5-20
5-20
5-20
5-20
20-35
20-35
20-35
20-35
20-35
35-50
35-50
35-50
35-50
50-65
50-65
65-78
65-80
80-95
95-100
#16















37-52
37-52
50-70
47-68
70-89
85-98
#30






10-22
10-22
5-20
5-20
5-20
18-29
18-29
19-30
19-30
25-40
25-40
35-60
36-55
55-80
70-95
#50






6-16
6-16
3-12
3-12
3-12
13-23
13-23
13-23
13-23
18-30
18-30
25-48
26-46
30-60
40-75
#100






4-12
4-12
2-8
2-8
2-8
8-16
8-16
7-15
7-15
1 0-20 *
10-20
1 5-30
16-25
10-35
20-40
#900
0-3
'0-4
0-4
0-4
0-4
0-4
2-8
2-8
0-4
0-4
0-4
4-10
4-10
0-8
0-8
•3-10
3-10
6-12
3-8
4-14
8-16
Percent
A»ph*n
3.0-4.5
4.0-5.0
4.0-5.0
3.0-6.0
3.0-6.0
.3.0-6.0
3.0-6.0
3.0-6.0
3.0-6.0
3.0-6.0
3.0-6.0
3.5-7.0
3.5-7.0
3.5-7.0
3.5:7.0
4.0-7.5
4.0-7.5
4.5-8.5 .
4.J-8.S
7.0-1 1.0
7.5-12.0
         Coarse Aggregate
Fine Aggregate
                                                      Mineral
                                                         Dust
             I Macadam
          i   II Open Type
          i   CD Coarse Graded
          i   IV Dense Graded
             V Fine Graded
          i   VI Stone Sheet
          .  VD Sand Sheet (Sand Asphalt)
            VIII Fine Sheet (Sheet Asphalt)


Aggregate Moisture Content - usually 3-71.   Aggregate moisture

content  varies  depending on source  of material and storage

conditions.  Moisture content  can be expected to increase

following rainy weather.

Hot Aggregate Temperature - normally 93  to  150°C (200-300°F).

Required hot aggregate temperature  varies with the type of

mix produced and the distance  to the paving site.



Dryes Exhaust Temperature.  The desired  dryer exhaust tempera-

ture is  93 to 190°C  (200-375°F).  The actual exhaust temperature

is often higher.'  In"no case can'the dryer.exhaust temperature

be less  than the hot aggregate temperature.
  The Asphalt Handbook, Asphalt Institute,  Manual Series No. 4,

  March 1966, p.  68.
                               24

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Fuel - Natural gas, No. 2 - No. 6 fuel oil.  Fuel consumption
typically varies from 1.7 to 4.9 gal per ton of aggregate.

Heat Distribution of Dryer Exit
             Hot Aggregate        40 - 50%
             Water Vapor          30 - 45%
             Combustion Gases     2.5-5%
             Excess Air           7  - 15%
Heat losses from the dryer (casing losses) typically 10-25%
of the gross heating value of the fuel burned.

Excess Air.  Minimum necessary for proper combustion, 25%
typical range encountered, 25% - 60%.  Excess air values
greater than 300% are sometimes encountered at plants with
little ability to regulate draft and firing rate.

Plant Capacity.  The maximum production rate or plant capacity
is usually limited by the quantity of aggregate that the rotary
dryer can process.  Only in rare cases is plant capacity limited
by screening, mixing, or other aggregate handling operations.
     Dryer capacity is the quantity of aggregate which can be
dried and heated in a specified time interval (tons/hour).
Manufacturers normally specify the rate (capacity) of dryers at
a specified aggregate moisture content, usually 5%.   In
practice, dryer capacity is limited by the capacity of the
exhaust  fan or by the amount of heat which can be supplied
by the burner.  Many plants have a limited exhaust system
capacity due to the addition of air cleaning equipment without
a corresponding increase in fan capacity.
   The Operation of Exhaust Systems at Hot-Mix Asphalt Plants,
   National Asphalt Pavement Association Information, Series 52,
   1975, p. 2.
                              25

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     For a given heat input rate, the quantity of aggregate
which can be processed is largely dependent on the moisture
content of the feed.  For a typical plant, an increase of 1%
in the moisture content decreases as the process weight rate
by approximately 10 to 15%   based on a fixed heat input rate.
If the dryer capacity is limited by the exhaust system capacity,
the firing rate cannot be increased without unbalancing the
combustion process.  Under these conditions, an increase in
moisture content requires reduction, of the process weight
rate to achieve the proper heat input per ton of aggregate
processed.  A further reduction in process weight rate is
necessary in order that the exhaust fan can handle the additional
volume of water vapor.

4.5 Process Modifications
     Almost any of the process variables and operational
parameters which .have been discussed in the preceding .•sections
can be adjusted or modified to' achieve short term reductions
in the dust loading on air pollution control equipment.  The
most common operational modification is "fine tuning" of the
process using existing -.plant controls to (1) minimize the
firing rate, (2); increase combustion efficiency or (3) reduce
the quantity of/excess air used in the rotary dryer.   Testing
under these conditions may or may not'Constitute .representative
conditions for the performance test.  In most cases,  it is
difficult to prevent "fine tuning" of the process up  to the
point where the operational modifications affect the  production
capacity of the plant.  If "fine tuning" procedures are
employed to reduce potential emissions during the performance
test, then the same operational procedures and conditions
must be maintained during future day-to-day operation of the plant,
   Heating and Drying of Aggregate, Dr. P. F. Dicerson,
   National Asphalt Pavement Association, May, 1971.
                              26

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     Examples of temporary process modifications which can
be employed to reduce the gas flow rate through the dryer
and thus the dust loading on control equipment are:
(1)  reduction of fan speed, (2) increasing the flow rate
through the scavenger system thereby reducing the flow rate
through the dryer or (3) introducing dilution air to the
dryer exhaust system to reduce the draft on the dryer.  All
of these modifications also reduce the production capacity
of the dryer for those plants were exhaust system capacity is
the limiting factor.
     A minor process parameter which is often overlooked is
the hot aggregate temperature.  The desired hot aggregate
temperature varies with the type of mix being produced.
Lowering the hot aggregate temperature allows the firing
rate and the gas flow rate through the dryer per ton of product
to be reduced.  Therefore, if a relatively low temperature
mixture is produced during the performance test, then the
production rate should be increased to accurately reflect
plant capacity.
     For tests requiring measurement of the production rate,
it is to the source's advantage to start the test with the hot
bins empty.  Thus, if the quantity of material in the hot bins
and/or storage facilities can not be accurately determined
before and after the test, then the apparent production rate
nay be greater than the actual production rate.
     Many states have emission standards based on the ratio
of the emission rate (Ibs/hr), to the process weight rate
(tons/hr - cold aggregate feed rate plus the quantity of
asphalt cement used).  For a fixed emission rate (Ibs/hr),
the  particulate emissions in terms of the standard  decrease
as the process weight rate increases.  The process weight
                               27

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can be significantly increased with little affect on emissions
by adding a substantial amount of large aggregate to the cold
aggregate feed.  The coarse aggregate may be rejected in the
screening operation or may result in overflow of the coarse
aggregate hot bin.  In either case, a portion of the large
size aggregate is included in the process weight but is not
included in the asphalt product and contributes little to the-
emissions from the dryer.
     It should be emphasized that by carefully and completely
monitoring the process during the performance test almost
all significant operational modifications can be eliminated
or at least, documented.
                              28

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                      CHAPTER V
   CONTROL SYSTEM PARAMETERS AFFECTING EMISSIONS

     The first section of this chapter explains how control
system variables affect emissions and describes the typical
parameters ranges for various control devices.  The second
section provides examples of control system modifications
which can be employed to achieve short term emission
reductions.

5.1 Control System Parameters
     Pressure Drop.  The pressure drop across a control
device is an important operational parometer for all control
equipment found at asphalt plants.  The pressure drop is a
measure of the power expended in forcing the system gases
through a collection device.  The pressure drop (the difference
between inlet and outlet static pressures) is a function of
both the flow resistance of the device and the volumetric
flow rate through the device.  For a given flow rate, the
pressure drop increases if the resistance to flow increases.
For a given flow resistance, the pressure drop decreases as
the flow rate decreases.  The three variables, flow resistance,
flow rate, and pressure drop are inseparably related, at least
one  of the three variables must be specified to establish
a known relation between the other two.  It should be noted
that the same principles apply to the water supply lines for
wet-collectors.
Baghouses.  The parameters which affect or are indicative of
the operation of baghouses are the pressure drop, air-to-
cloth ratio, and cleaning cycle frequency.  The particulate
collection efficiency of the reverse-pulse and reverse-flush
                               29

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baghouses is usually dependent only on the condition of the
filter bags.  Tests have shown that the particle size distri-
bution has little affect on the emission rate.
     Pressure drop across baghouses normally ranges from 10
to 15 CM (4-6 in.)of-water column.  The pressure drop is
dependent on the air-to-cloth ratio and on the thoroughness
and frequency of the cleaning cycle. The air-to-cloth ratio
is typically 1.2 to 2.1 m/min (4-7 ft/min.).
     The frequency of the cleaning cycle is usually controlled
by either a timer or by a device which senses the pressure
drop across the baghouse.  The thoroughness of the cleaning
cycle for reverse-pulse baghouses is in part dependent on the
pressure of the compressed air used to clean .the bags..  In-
sufficient cleaning results in large pressure drops across
the baghouse and may reduce the capacity of the exhaust system.
Excessive cleaning often results in rapid wear of the filter
bags, particularly where the bag contacts the wire support
cage,  torn or severely worn bags or leaks in the baghouse
greatly reduce the collection efficiency of the baghouse
and are usually accompanied by insufficient pressure drop
across the baghouse.
     Temperature and moisture limitations are extremely
important in the—ope-r-ation of baghouses.  Protective devices
and operating procedures are designed to.ensure that the gas
temperature in the baghouse does not exceed the filte.r
temperature limit, normally 232°C (450° F) for Nomex* bags.
Care must also be taken that the gas temperature does not
fall below the dew point.   If this occurs, water will condense
on the bags resulting in blinding of the filters.  The temp-
erature and moisture limitations of the baghouse restrict the
   Background Information for New Source Performance Standards,
   U.S. EPA (APTC-1352a) Vol. 1, p. 12.
   Tiade name.
                              30

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range of dryer operating variables to those which produce
exhaust gases within the acceptable limits.
Wet-Collection Devices.  The principal factors governing
collection efficiency include the condition of the inlet gases
(dust loading, particle size distribution), the kinetic energy
energy of the gas stream (velocity head), and the kinetic
of the collection liquid.  For a given inlet  dust loading and
particle size distribution, it is commonly felt that collection
efficiency is directly related  to the total power expended
in forcing the gases through the collector and in generating
            2
water spray.
     Most asphalt plants which are equipped with wet-collection
devices recirculate the scrubber water.  A settling pond is
almost always employed to remove the -"fcotafeegEspr particulate
material from the scrubber water.  Particulate emissions
may be increased if the water used in the scrubber system
contains a large amount of solid material (silt).  In addition,
the pressence of large amounts of solids in the inlet scrubber
lines leads to rapid deterioration of spray nozzles, pressure
gages, water flow meters and other components of the scrubber
system.
Venturi Scrubbers. The venturi design, pressure drop, water
injection rate, and particle size affect the collection
efficiency in venturi scrubbers.  Some venturi designs include
adjustable throat openings.  Decreasing the throat area
increases the gas velocity in the throat which increases both
the extent of liquid atomization and the relative velocity
between the dust particles and liquid droplets.  These
conditions increase the frequency of collisions between
particles and droplets which increases collection efficiency.
   AIR POLLUTION ENGINEERING MANUAL U.S. EPA (AP-40)
   May, 1973, P.100.
                               31

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     Constricting the throat area increases the pressure drop
across the collector.  Also, an increase in the volume flow
rate will increase the pressure drop.  The collection efficiency
for a given dust concentration and particle size distribution
is directly related to the pressure drop across the device.
Collection efficiency can usually be increased if additional
fan horsepower is available.
     It should be noted that at a fixed throat opening,
reducing the volumetric flow rate of exhaust gages through
the venturi will reduce the pressure drop and the collection
efficiency of the device.  Therefore, operating an asphalt
plant equipped with a venturi scrubber at reduced load may
increase the particulate emissions per ton of product.
     Generally, an increase in the water injection rate will
create more liquid droplets which increases collection efficiency.
An increase in water injection rate is usually accompanied by a
slightly increased pressure drop across the collector.  Typical
                           .  -.                   7            i
water injection rates range from .80 to 1.34 1/m  (6-10 gal/
        3                                                  3
1000 ft.  of gas).  Water usage rates in excess of 1.35 1/m
(10 gal/1000 ft. ) produce only slight increases in collection
efficiency.
     As in most collection devices, the collection efficiency of
the venturi scrubber is directly related to particle size; de-
creasing particle size decreases efficiency;  For a typical
venturi scrubber with a 20" WC pressure drop and 8 gal/ 1000 ft
water injection rate,  95% to 98% collection for l/i to 5/x particles
is expected.   Efficiency falls off sharlply below ]/u  (50%
collection for . 5/t particles) .
   Operation of Exhaust Systems in the Hot Mix Plant, National
   Asphalt Pavement Association- Information Series 52, p.26.
                               32

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Low-Energy Scrubbers.  There is great diversity and variability
among the low-energy scrubber systems found at hot-mix asphalt
plants.  The most commonly encountered components of these systems
include: wet-fans, spray systems, wet-centrifugal collectors
and orifice scrubbers.
     Often, spray systems are used before existing exhaust fans
to provide wet-fan collectors.  Water sprays are also used in
centrifugal devices to provide wet washers.  The ability of the
spray systems to wet the dust particles is related to water usage
rate, water pressure, and the degree of atomization provided
by the spray nozzles.
                  >
     The same operating principals apply to orifice scrubbers with
adjustable throats.  Decreasing the size of the orifice increases
the pressure drop across the device, increases the effective fan
horsepower required to operate the device, and increases the
collection efficiency of the device.  The efficiency of wet-
impingement and wet-centrifugal collection devices is generally
proportional to pressure drop, gas velocity and water usage rate.
Particle size distribution in the gas stream has a m-ajor effect
on the collection efficiency of low-energy scrubbers.  These
devices generally have poor collection efficiencies for particles
smaller than Sjj.
5.2 Control System Modifications.  The following paragraphs
describe control system modifications which can be employed to
achieve short term emission reductions.
   Operation of Exhaust Systems  in the Hot Mix Plant, National
   Asphalt Pavement Association,  Information Series 52, p. 24.
                              33

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Baghouses.   The frequency of the cleaning cycle can be adjusted
to decrease emissions from baghouses during performance tests.
Either the time interval between cleaning cycles or the pressure
drop across the baghouse required to activate the cleaning
cycle can be increased.  This allows the accumulated dust cake
on the bags to act as part of the filter thereby increasing
particulate collection efficiency.
     At some plants the clean air plenum of the baghouse is
inspected prior to the performance test.  Accumulated dust in
"the clean air plenum is indicative of torn or severly worn bags
or leaks in the interior of the baghouse.  Leaks are then
patched and torn bags are either replaced or in some cases,
wooden plugs are used to effectively seal off individual bags.
These procedures obviously increase collection efficiency.
It should- be noted that plugging individual bags increases
the air-to-cloth ratio for the remaining bags which generally
reduces the useful life of the filters.
West-Collection Devices.  There are several methods which can
be used to temporarily increase..the collection.efficiency of
scrubber systems.  .Examples of these methods are provided in
the following paragraphs.
     Particulate emissions are increased if the water used in
the scrubber system contains a large amount of solid particles.
Two different methods are used to reduce the solids content
of the scrubber water.  First, the settling pond  or lagoon
can be cleaned out to remove oil and accumulated silt prior
to the performance test.  This procedure increases the effectiveness
of the settling pond and is considered part of the periodic
maintenance required for wet-collection systems.  A second
procedure which is sometimes employed is to use tap water in
the scrubber system during the performance test.  The use of
tap water should not be allowed unless the scrubber system will
use only  tap water during future operation.  If a relatively
small settling pond is used, the use of tap water can be
detected by noting the water level in the pond.
                              34

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     An increase in the water pressure OT water usage rate
usually increases the collection efficiency of scrubber systems.
Auxiliary or stand-by pumps are sometimes used to increase the
water pressure and/or water flow rate to the scrubber.  An
increase in pump speed at a constant delivery pressure will
also increase the water flow rate.
     Due to the pressence of solid material in the scrubber
water, rapid deteroration (erosion and/or plugging) of spray
nozzles is to be expected at asphalt plants.  Spray nozzles
are sometimes replaced prior to performance tests to increase
the effectiveness of water spray systems.  This procedure is
difficult to prevent since replacement of spray nozzles is
considered normal maintenance.  However, spray systems should
be inspected during performance tests to establish "normal
operating conditions" as a baseline for comparison during
future follow-up inspections.
     The collection efficiency of venturi scrubbers with
adjustable throat openings can be increased by decreasing the
size of the opening.  It should be noted that decreasing the
size of the throat increases the pressure drop across the
device and increases the fan capacity required to operate the
device, at a constant flow rate.  If additional fan capacity
is not available, reduction in the size of the throat opening
will reduce the production capacity of the plant.  The same
principals apply to orifice scrubbers with adjustable orifice
openings.
     From the previous discussion it may appear that it is
relatively easy to temporarily increase the collection efficiency
of control devices at asphalt plants.  However, it should be
emphasized that almost all control system modifications can
be eliminated or documented by carefully monitoring the control
system parameters during the performance test.
                              35

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                         Cihapter YI

 REPRESENTATIVE CONDITIONS - TEST PROTOCOL - PRETEST MEETING

     Detailed procedures for determining representative
conditions, developing test protocol, and conducting pretest
meetings are provided in Volume I, "Development, Observation,
and Evaluation of Performance Tests".
6.1 Determination of Representative Conditions
     One of the most important tasks for the enforcement agency
in developing performance tests is the determination of repre-
tative conditions.  Paragraph 60.8 (c) of NSPS states:
         "Performance tests shall be conducted under such
    conditions as the Administrator shall specify to the
    plant operator based on representative performance of
    the affected facility.  The owner or operator shall
    make available to the Administrator such records as
    may be necessary to determine the conditions of the
   .performance tests.  Operations during periods of start-  .
    up, shutdown, and malfunction shall not constitute
   : representative conditions of performance tests unless
    otherwise specified in the applicable standard.**   '
Many states have similar requirements for compliance tests.  The
determination of what "conditions based on represantative per-
formance of the facility" means for "asphalt plants is at best
very difficult.  The operating conditions of a particular plant
can be expected to vary due to fluctuations in the demand for
the product, changes in the type or grade of asphalt concrete
produced, changes in the type, source or moisture content of
the raw aggregate, or changes in the operating procedures or
control system parameters at the plant.  Performance tests
conducted to determine compliance with NSPS are usually con-
ducted at the "normal" operating conditions which represent the
  Development, Observation and Evaluation of Performance Tests,
  currently being prepared by The Division of Stationary Source
  Enforcement, U.S., EPA
                              36

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greatest particulate emission potential.  In the simplest
of terms, the maximum production rate anticipated using the mixture
generally produced which contains the greatest percentage of
very fine aggregate.  (See chapters IV and V for additional
parameters which must be considered.)  For asphalt plants
subject to state regulations, the permit issued by the state
enforcement agency may stipulate testing conditions.  Most
state regulations are based on process weight:  the emission
standard becomes more stringent as the process weight rate
is increased.  This also requires testing at the maximum
production rate.
     The agency personnel responsible for determining rep-
resentative conditions must have a thorough understanding of
how all process and control system parameters affect the
operation and emissions of the particular asphalt plant being
considered.  This requires correspondence with the source and
may require a trip to the source if unusual conditions are
encountered.  When possible, representative conditions should
be based on past production records.  Production records
for new; sources.will of course be very limited.
     The agency has two options to consider in determining
representative conditions:  (1) Specify to the source the
conditions which will be maintained during the test.  (2) Request
the source to suggest the conditions which will be maintained
during  the test.  The first option requires a great deal of
information to be obtained and documented to fairly assess
what constitutes representative conditions for a particular
plant.  The second option requires that the agency reviews the
sources suggested conditions to determine  if the conditions
are both reasonable and enforceable.  If the second option is
employed the plant should be informed that future operation of
the asphalt plant at conditions which represent greater
potential emissions will require the plant to be retested.
                               37

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  Regardless of which option is employed, when  the represent-
  ative conditions  are finally established  the  agency should
  specify the  conditions of the test in a formal  letter to
  the source.
  6.2 Test Protocol
       The test protocol submitted by the source  is a complete
  description  of  what will be done to satisfy the performance
  testing requirements.   The agency should  be careful to request
  only the information which is necessary for the evaluation
  of the proposed performance testing program at  the particular
  installation being considered.  A summary of  what should be
  included in.  the test" protocol is provided below.
           Test,, Protocol ^ Asp.halt Concrete Plants
' . 1 . Proces-s •  Opera't ing Goadi'feiionsc During ' Te s t  -  the test
-\  • j-pfotbcQl ^should; .coiEtaTin> exp.e'ct^d values and/or ranges of
 :  . < values^ /fqipthe^fo^lo^^^                         Product iun
  •'"'  rate-; .a'gg.^e."gate?--nfei-&tu^^.tt^t-e'n-t^-' mixture  compositio'n and
  ' '  *      „"' ~ '"' '  .   ''•'-?>" '• •'* - •'"•' ' '  '-   -   • -      -  .. -
  ' ';  ...tempeTa^ure^  typeC^O'f^-fu?i^'ii!s;e'dJi. fuel  con-sumption,  and
   .'•*•'.'  •   '  .'  »•'"   »>-"* ?••"•'•««. ~, .jjV,-"'/^'"  • .. •
   "  "drye-r ex^ausitifVfeeJnp'e'fatiEcSe^J:. Thfe "source 'may also wish to
   " '. %  '  *  '    '       * -  ' j   **• '/>; '. f '   *-        v
     propose alternate- operating conditions  in  the  event : that
     the maximum production rate^  or. other-, conditions specified
     as "representative",  can- not be obtained p.n the day: of the-
     - test.
  2.  Control System Conditions During Test  - The  test protocol,
     should  contain estimated  values of- control  system parame-
     ters for  the  appropriate control device:
        A.   Baghouses -  type of bags, frequency of  cleaning
             cycle,  cleaning air supply pressurej  fan speed,
             Fan Ap .
        B.   Scrubbers -  Pressure drops (s) , water flow fate,
            water  pressure, source of scrubber  water, and
             venturi or orifice throat size  (if  adjustable) .
  3.  Procedures for Monitoring Operating  Conditions  - The
                                 33

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   protocol should contain a list of the process and control
   system parameters which will be monitored during the
   performance test.  A description of the equipment and pro-
   cedures which will be used to perform the monitoring
   should be included.
4. Sampling and Analytical Procedures - The test protocol
   should describe the test procedures which will be used to
   determine the emission rate.  Reasons for any deviations
   from the specified methods and a detailed description of
   any alternate.sampling and/or analytical methods should
   be provided.  Detailed drawings of the sampling site
   should be included.
5. Performance Test Report - A description or list of what
   will be included in the test report (See Chapter X, Source
   Test Report Format) should be included in the test
   protocol.
6. Tentative Schedule - The anticipated testing and reporting
   schedule should be outlined in the test protocol.
     The agency must review and determine the acceptability
of the test protocol submitted  by the source.  The process
and control system conditions contained in the test  protocol
should agree with the representative conditions specified by
the agency.  Careful consideration should be given to pro-
posed alternate operating conditions in the event "represent-
ative conditions" can not be maintained at the time of the
test.  Similarly, alternate sampling procedures should be
examined to ensure that test results will be equal to or
higher than the actual emissions.  Admendments to the sub-
mitted protocol may be necessary to obtain an acceptable test
protocol.
6.5 Pretest Meeting
     The need for a pretest meeting is a function of the agen-
ies familiarity with the source and the number of questions
left unanswered  by the test protocol review.  A pretest
                              39

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meeting between the agency, source and test team is the last
opportunity to resolve problems before the performance test.
In many cases, a pretest meeting with only the agency and
source or with only the agency and test team may be sufficient,
If all problems are resolved with the review of the protocol,
then the pretest meeting need not be conducted.
                              40

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                       Chapter VII

    EMISSION TEST METHODS AND ACCEPTABLE ALTERNATIVES



    Acceptable sampling methods and procedures must be employed

to accurately determine the particulate emission rate during

performance tests.  Alternative sampling methods must sometimes

be used when standard sampling procedures are not directly appli-

cable.  In order to effectively review the test protocol sub-

mitted by the source, agency personnel must be familiar with

the test methods which may be encountered.  The observer in the

field must also have a working knowledge of sampling procedures

to be able to ensure that proper methodology is employed.

Procedures for actually observing tests are detailed in Volume

II of "Development, Observation and Evaluation of Performance

Tests".  An "Observers Sampling Checklist" is available in

Appendix C of this manual.  This chapter describes the EPA

reference methods which are used to determine the particulate

emission rate at asphalt concrete plants.  Commonly encountered

sampling problems and acceptable alternatives are also

discussed.
  "Development, Observation and Evaluation of Performance Tests'
  Currently being prepared by the Division of Stationary Source
  Enforcement, U.S. EPA.
                              41

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7.1 Emission Testing Methods
     The reference methods as  published in the Federal Register,
Volume 42, No. 160, August 18, 1977, should be used to determine
compliance with Federal New Source Performance Standards.   The
applicable reference methods for testing at asphalt concrete
plants are:
     Appendix A - Reference Methods.
     Method 1   - Sample and Velocity Traverses for Stationary
                  sources.
     Method 2   - Determination of Stack Gas Velocity and
                  Volumetric Flow Rate.
     Method 3   - Gas Analysis for Carbon Dioxide, Oxygen, Excess
                  Air, and Dry Molecular Weight.
     Method 5   - Determination of Particulate Emissions From
                  Stationary Sources.
Copies of the above sampling methods are included in Appendix B
of this manual.
7.1.1 Method 1 - Sample and Velocity Traverses for Stationary
                 Sources
     Method 1 provides criteria for selection of the sampling
location, determining the required number of sampling points, and
determining the locations of the sampling points.  This method
can not be used where cyclonic flow occurs.  At asphalt plants,
cyclonic flow often occurs after inertia! demisters following
wet scrubbers and in stacks with tangential inlets.  Paragraph
2.4 of Method 1 provides explicit instructions for determining
when unacceptable flow conditions exist.  In short, the angle
(between the pitot orientation and the plane perpendicular to
to the stack axis) required to produce a null reading is
measured for each sampling point.  If the average of the absolute
values of the angles is greater than 10°, unacceptable flow
2
  On August 18, 1977 the EPA promulgated revisions to reference
  methods 1 through 8.  The revised methods contain significant
  changes from the methods which were previously in effect.
                              42

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conditions exist.  Procedures for sampling cyclonic flow are
described in section 7.2.3 and in Appendix D.
     The August 18, 1977 revisions of the reference methods
may require moving sampling port locations at some asphalt
plants when retested.  The revised Method 1 requires that for
particulate traverses of round stacks, one of the traverse
diameters must be in the plane of the greatest expected
concentration variation.  The length-to-width ratio requirement
of 2:1 for cross-sectional equal areas in rectangular ducts
has been replaced by a "Balanced matrix" scheme, which is
provided in table form.
7.1.2 Method 2 - Determination of Stack Gas Velocity and
                 Volumetric Flow Rate
     Method 2 is not applicable to cyclonic flow systems.
Procedures for sampling cyclonic flow systems are discussed in
section 7.2.3 and in Appendix D.
     Method 2 is performed concurrently with Method 5 to obtain
velocity measurements which are required to determine isokinetic
sampling rates.  It should be noted that to determine compliance
with NSPS for asphalt concrete plants (concentration standard)
it is not necessary to calculate the stack volumetric flow rate.
However, it is suggested that the volumetric flow rate be
determined since it is an important operational  parameter  for
asphalt plants.  The cross-sectional area of the stack is the
only additional data required to calculate the stack gas
volume flow rate.
7.1.3 Method 5 - Gas Analysis for Carbon Dioxide, Oxygen, Excess
                 Air, and Dry Molecular Weight
     At asphalt plants method 3 is employed only to determine the
dry molecular weight of the effluent stream.  Any of the sampling
techniques described in Method 3, grab sampling, single point
integrated sampling, or multi-point sampling, can be used for
                               43

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this determination.  Either an orsat or Fyrite* analyzer may be
used for the analysis.
     Paragraph 1.2 provides examples of alternative procedures
which may be used, including (1) a method using %C09 or %09
                                                   £* .     £ .
and stoichiometric calculations to determine molecular weight,
and (2) assigning a value of 30.0 for dry molecular weight in
lieu of actual measurements for processes burning gas or oil.
These methods may be used but are subject to approval by the
Administrator.
7.1.4  Method 5 - Determination of Particulate Emissions from
                 Stationary Sources
     Although it is not explicitly stated in the method,
Method 5 is not applicable to cyclonic flow systems since the
method relies directly on Method 1 and Method 2.
     Subpart I - Standards of Performance for Asphalt Concrete
Plants, (60.93) provides additional requirement for Method 5:
"The sampling time for each run shall be at least 60 minutes
and the sampling rate shall be at least 0.9 dscm/hr  (.'053 dscf/
rnin-) except that shorter sampling times, when necessitated by
process variables or other factors' may be approved by the
Administrator".  The intent of this section, in addition to
specifying the duration of the test,is to ensure that the
minimum sample volume be 0.9 dscm (31.8 dscf) rather than
imposing a sampling rate restriction.  As stated, the sampling
rate limitation implies that the test would be unacceptable
if the sampling rate falls below 0.9 dscm/hr (0.53 dscf/min)
at any time-.  The' sample volume restiction is necessary to
ensure enough particulate is collected to have a significant
weight.         :
     Other problems which are commonly encountered in the
application of Method 5 at asphalt plants are discussed in the
following section.
*  Tradename
                              44

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7.2 Commonly Encountered Sampling Problems and Acceptable
    Alternatives
     There are several areas which often present sampling
problems when performance tests are conducted at asphalt plants.
Insufficient attention to these areas can easily result in
invalid sampling results.  A large expenditure of time and effort
may result in little information being obtained.  The most
commonly occuring problems relate to:
     (1) intermittent process operation
     (2) determination of the moisture content in the
         effluent stream
     C3) cyclonic flow

7.2.1 Intermittent Process Operation
     Start ups and shut downs are common occurences at asphalt
plants.  The hot-mix asphalt process is basically a series or
chain operation.  A failure of any part of the operation almost
always requires the plant to shut down.  Most plants do not
have any provisions for storing the completed asphalt mixture.
The flow of trucks used to haul the asphalt product is often
sporadic and the lack of available trucks often causes the plant
to shut down for a brief period.  Failure of paving machines or
poor weather at the paving site may cause the plant shut down for
extended periods.
     Both the test team and the observer should continually
watch the process and be prepared to cease sampling during plant
shut downs.  Particular attention should be paid to the cold
aggregate feeder system and the number of available  trucks. If
production is halted or if the aggregate feed for the dryer is
interrupted, sampling should be discontinued immediately.  The
sampling train should be removed from the stack, and the time the
shut down occurred and the dry gas meter reading should be noted.
If the shut down is expected to last more than a few minutes,
the sampling train should be sealed to prevent loss or contam-
                              45

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ination of the sample.  When production is resumed, sufficient
time should be allowed for the process to stabilize before
sampling is commenced.  For plants equipped with baghouses,
the fan is usually turned on before the burner is fired and the
baghouse is allowed to warm up before the aggregate feed to the
dryer is resumed until the first batch of asphalt is completed
and the stack temperature has returned to within 5.5°C (10°F)
of the pre-shut down value.
     If sampling is inadvertantly continued for some time after
the process is shut down, the sampling results will be biased
low.  The observer should provide the testing team with the
option of repeating the sample run or applying an, adjustment
to the results.  Subtracting the portion of the sample volume
which was collected while the process was not. operating, from
the total sample volume will provide results equal to-or greater
than the actual emissions from the plant.  This is simply -an
application of the "bias concept".
     Under good conditions and if the plant, production is nearly
continuous,, an experienced sampling-team can conduct a perfor-
mance test in one day in"the field (not necessarily 8 hours).
Intermittent plant operation often extends the time'required to
perform 'the test.  Although the sampling can be performed in
the rain, asphalt paving can not.  Rainy weather can postpone
a test for several days.  The observer and test team should' be
prepared for several:days of testing.
7.2.2 Determination of Moisture Content in Stack Gases
     At asphalt plants, the moisture content of the stack
gases is dependent on the firing rate of the dryer burner, the
air flow rate through the system, the moisture content of the
cold aggregate feed and the type of control equipment employed.
     The moisture content of the stack gases can easily be as
low as 4% or as high as 301.
                               46

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     In the EPA Method 5 sampling train, the water vapor
in the sample stream is collected by the impingers in the,
sampling box.  The instruments in the meter box measure only
the flow of. dry sample gases.  Therefore  to perform isokinetic
sampling, an estimate of the percentage of moisture in the
effluent stream is necessary.  Note that the sampler is
interested in the actual percent moisture (absolute humidity),
and not relative humidity.   An absolute error of 1% in  esti-
mating moisture will generate  "a relative error" of approxi-
mately 1% in the sampling rate.
     Asphalt plants controlled with baghouses typically have
higher moisture contents in the stack gases than plants
controlled with scrubbers.   Baghouses must be maintained above
the dew point to prevent blinding of the filter bags.  For
plants equipped with baghouses, the stack temperature usually
ranges from 88°C to 138°C (190-280°F) and the percent moisture
usually falls between 14% and 30%.  Plants equipped with wet-
collection devices normally have saturated stack gases but at
a lower stack temperature.   Stack temperature is usually within
the range of 32°C to 71°C (90-160°F) and the percent moisture
ranges from 4% to 20%.
     The wet bulb, dry bulb method provides the simplest means
of estimating percent moisture.  Many stack samplers distrust
this method because it has  given them erroneous data.  This is
usually due to neglecting to make pressure corrections.  To
obtain good results with this method, the sensing portion of
the wet bulb thermometer must be completely covered with a
wetted wick and the wet bulb temperature must be determined
before the wick dries out.   A psychrometic chart which corrects
for absolute pressure changes, Figure 7-1, is included for
field estimations.
     Wet-collection devices rely on intimate contact between
the dust-laden gases and the scrubber water to collect particu-
late.  The effluent from scrubber systems is usually saturated
with water vapor.  Under saturated conditions, the wet bulb and
dry bulb temperatures are the same.  Often, the stack gases
                               47

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25-
16-
Z7-
Z8-
59-
      Ul
      oc
      8
      3
(1 -
3-
                                                                    i—SO
                                                                    -40
                                                                    -30 °
r°
      ui

-200  |


-400  5


-6OO  2
      Q£

-800  |
_      Ul
      ^*

-1000


-1200
20
   O
                                                                        an

                                                                        *-
                                                                        VI
                                                                    -10
                                Figure 7-1
                  AIR - WATER VAPOR PSYCHROMETRIC CHART
            Conventional psychrometric charts provide values of moisture
       content based-on wet bulb and dry bulb temperature measurements,.
       but they generally apply only to measurements made at standard
       barometric pressure (29.92 inches Hg).  The above nomograph
       allows you to determine the moisture  content for a wide range
       of system (or atmospheric) pressures.                  '
            To use the nomograph, line up the absolute pressure of  the
       system (or atmosphere) with the wet bulb temperature.  Where it
       crosses the "saturation" line is the  value of the moisture
       content if the system is saturated with water vapor  (i.e., the
       dry bulb temperature equals the wet bulb temperature).  If the
       system is not saturated, line up the  saturation moisture
       content with the difference between the wet bulb and dry bulb
       temperatures, which yields the value  for the moisture content
       on the far right scale.  Example: while testing an asphalt
       plant cpntrolled with a baghouse, the following measurements
       were made:

       Absolute stack pressure - 29.30" Hg.
       Dry bulb temperature - 240°F
       Wet bulb .temperature 140°F

       Then, moisture content at saturation  = 20%
             moisture content of stack gas   = 16%
                                      48

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after scrubber systems will contain entrained liquid droplets.
Consequently, the water collected in the sample box may be
greater than the quantity of water necessary to saturate the
sample gas stream at stack conditions.   For this case, assume
saturation and calculate the precent moisture using either
the psychrometric chart [wet bulb + dry bulb temperature] or
saturated steam tables.  To use the steam tables, find the
saturated vapor pressure corresponding  to the stack tempera-
ture.  The fraction of the gas stream which is water vapor
is determined as the ratio of the saturated vapor pressure to
the absolute stack pressure.  Under no  conditions can the
percent moisture be greater than saturated conditions.
     The moisture content of the effluent stream may vary
during the test due to variations in the process.  Repeated
checks of the assumed moisture content  are necessary to
maintain isokinetic sampling conditions throughout the test.
For sources with saturated effluent, the moisture content
estimation must be changed as the stack temperature changes.
As an example, consider a scrubber controlled plant with
saturated effluent at 29.9 in. Hg., absolute stack pressure.
If the stack temperature changes from 140°F to 150°F, the
moisture content will vary from 19.7% to 25.31.  Changes in
moisture content must be considered when calculating isokinetic
sampling rates.
     If a standard EPA nomograph is used to set isokinetic
sampling rates, it is usually advantageous to pre-calculate  s
a number of C-Factors based on the expected range of moisture
contents.  This facilitates rapid adjustments of the sampling
rate during the performance test.
7.2.5 Cyclonic Flow
     Cyclonic flow constitutes the most difficult particulate
sampling problem which is encountered at asphalt plants.
Stacks attached to centrifugal inertial demisters following
venturi scrubbers and/or low-energy wet scrubbers and stacks
                            49

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with tangential  inlets are the most common causes of
cyclonic flow at asphalt plants.  Many of the stacks with
cyclonic flow at asphalt plants are large diameter stacks
(3.3m, 10 feet).  Often these stacks have little straight
run, approximately 2 diameters is typical.  These conditions
make modification of the stacks, (straightening vanes and/
or stack extensions) difficult.  In addition, many of the
stacks at asphalt plants with cyclonic flow have entrained
water droplets in the effluent.  This further complicates
particulate sampling in these stacks.
     Appendix D provides a paper which discusses three.
sampling approaches for isokinetic particulate testing in
cyclonic flow systems.  The biases associated with each
sampling technique  are described.  Source modifications
which can be employed are also described.
                             50

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                          Chapter VIII
       MONITORING PROCESS AND CONTROL SYSTEM PARAMETERS

      Monitoring and documenting the appropriate process and
control system parameters during a performance test is important
for several reasons.  First, only by monitoring the important
operating parameters during the test can it be determined whether
or not the performance test is conducted at the prescribed
representative conditions agreed upon during the developmental
stages of the test  (see Chapter VI).  Testing at other than
representative conditions is of little use for determining compliance
with the applicable regulations.  Secondly, determining the process
and control system parameters during the performance test estab-
lishes a baseline for future comparison of operating conditions
during follow-up inspections.  Such a baseline greatly increases
the effectiveness of follow-up inspections.  Finally, for states with
emission standards expressed as the ratio of particulate emissions
to process weight rate, the determination of the process rate
is of fundamental importance.  Thus, monitoring the operational
conditions of the source during the performance test is as import-
ant as the actual stack sampling.

8.1  Monitoring the Process
      This section details procedures which may be used to
monitor the process rate and conditions.

8.1.1  Process Rate
      The process rate may be described in terms of the pro-
duction rate, process weight rate, or the cold  aggregate feed
rate.  The production rate is the quantity of asphalt concrete
produced per unit of time.  The process weight rate is defined
as the sum of all material inputs per unit of time.  The production
rate is a sufficient indicator of process rate for tests to de-
termine compliance with NSPS.  However, most state regulations
                              51

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require that the process weight rate be determined.  Figure 8-1
provides a schematic diagram of the flow of materials at an asphalt
plant.
      Production Rate.  Since asphalt concrete ;is sold by weight,
monitoring the production rate is relatively simple.  Two
methods may be used to determine produciton rate:
      (1) The quantity of asphalt sold is monitored by weighing
each truck.  Records of sales are kept by the weigh scale operator.
To determine the production rate, total the amounts of asphalt
loaded into each truck and divide by the length of time the plant,.
was operating.  If the plant has heated facilities for storing
the completed product, the quantity of asphalt concrete in storage
must be estimated both before and after the test period.
      (2) To ensure that the product complies with mixture speci-
fications, the quantities of the various sizes of aggregate and
of asphalt are controlled by the plant operator.  Consult with the
operator to determine the weight per batch.  The control panel
contains a batch integrator which counts the number of batches pro-
duced.  The production rate is the weight per batch times the.
number of batches, divided by the length of time the plant, was
operating.
      Cold Aggregate Feed Rate,  the cold aggregate feed rate
can be estimated as the production rate plus the moisture content
of the cold aggregate, minus the amount of asphalt cement added
to the mixture. Usually, both the moisture content and asphalt ce-
ment are approximately 5%.  This allows estimation of the cold
aggregate feed as equal to the production rate.  Dust loss from
the system can be considered negligible for the purposes of this
estimation.  To use this method, the plant should be operating at
steady state conditions (constant level in hot bins).  If the
hot bins oyer.flow, an error is introduced.  The cold aggregate
feed rate can be measured directly ,by measuring ,the quantity of
aggregate on a section of the feed conveyor and determining the
conveyor speed.
                              52

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Aggregate Bins
                         Primary
                         Collecto
                                                      Secondary
                                                      Collector
Stack
                                                                                                       Screens


                                                                                                     Hot  Bins
                                                                                                     (storage)
                                                                                                       Asphalt
                                                                                                       Cement
                                      Figure 8-2..   Process Flow Diagram

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8.1.2  Aggregate Feed - Size Distribution and Moisture Content
      The plant operator can provide the relative quantities of
the various aggregate sizes used in the mixture.  These quan-
tities, the amount of asphalt  cement used, and the type of mixture
produced should be noted.  Since.a large percentage of the fine
material and mineral dust introduced into the dryer is lost in
the processing, the aggregate size distribution should be deter-
mined by sampling the cold aggregate feed.
      To sample the aggregate feed, have the plant operator
briefly stop the feed conveyor.  Remove all material from a
section across the conveyor and place in a clean, dry, air-tight
container.  Repeat this procedure several times.  The samples may
be collected in the same container.
      Percent moisture is determined by weighing the sample, drying
the sample at 100°C, and again weighing the sample.

      percent moisture.- (wet weig^ weig£tWeight) * 100

      The size distribution is determined by performing a sieve
analysis.  Most plants have the facilities to perform the analysis.
Of particular interest are the relative quantities of fine aggre-
gate (material passing No. 8 mesh seive) and mineral dust (material
passing No. 200 mesh seive).  Classification of the aggregate into
several additional grades is sufficient.

8.1.5  Additional Dryer Performance Parameters
      1) Hot Aggregate Temperature - usually monitored in plant
         operator's control room.  Note temperature and location
         of measurement device.
      2) Dryer Exhaust Gas Temperature  - usually monitored in con-
         trol room.  Note temperature and location of measurement
         device.
      3) Type of Fuel and Fuel Consumption- The type of fuel used
         should be noted.  Fuel consumption per hour or per ton of
         aggregate should be noted if monitored by the plant or if
         easily determined.
                               54

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      4) Damper Position - note or sketch the damper opening if a
         damper exists in the dryer exhaust system.

8.1.4  Excess Air
      Excess air should be determined at plants where production
capacity is limited by exhaust system capacity or when a plant is
being retested after failing marginally.
      A simple procedure exists for determining excess air:
      1) Obtain a sampling site (3/8" hole) in the dryer exhaust
         duct as close as possible to the dryer exit.
      2) Using a 1/4" stainless steel probe, obtain a grab sample
         of the combustion gases.
      3) Determine the %COj or %02 in the exhaust gases using
         either a fyrite or orsat analyzer. (The fyrite  is
         sufficiently accurate for this measurement and much
         easier to use).
      4) Referring to Figure 8-2, the amount of excess air can be
         determined using either %C09 or %09, and the type of fuel
                                    £*       £t
         being burned.

8.2  Monitoring Control System Parameters
      This section details specific methods which may be used
to determine the important operational parameters for various control
devices.

8.2.1  Pressure Drop
      The pressure drop  ( Ap) across air pollution control equip-
ment is expressed in height of water column (mm or inches).  The
pressure drop across a control device can be measured directly as
shown in Figure 8-3.  The upstream side is  always higher pressure.
      If the inlet and outlet cannot be reached simultaneously,
the pressure differences between the inlet  and the atmosphere
(Ap^) and between the outlet and the atmosphere (AP0) may  be
determined separately as  shown in Figure 8-4.  The pressure drop
is then:     Ap = Ap. -   Ap
                               55

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                           ENTROPY ENVIRONMENTALISTS INC.
1500-1
                                       in, *£oaita»
                         Example:  Known:  240% excess air burning Pentane
                                   Answer:  15%
                   —  1
                                                   & 4% CO  in flue gas
                   —  2
                   —  3
                   —  4	
                         Q
                      5  g
                      6   *
                   _     8
                      8  *'

                    -10
                      15

                      20
                                       Refuse,' Bark -
                                         and Wood
—  Methane

_  Average Natural Gas

—  Ethane
—. Propane
—  Pentane
—  Gasoline.
-  #2 Fuel Oil
   Bunker,."C" Oil
    (#6 Fuel Oil)
 - Bituminous Coal
" T-Sub-bituminous & Lignite
 F Anthracite
   Coke
          NOMOGRAPH FOR ESTIMATING FLUE GAS COMPOSITION,
                    EXCESS AIR OR TYPE OF FUEL

                          Figure   8-2
                                       56

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Inlet
               Collection
                 Device
High
                        T.nw
                 (&
                  Gage
                   Ap
               Figure :g-3
               Collection
                  Device
                    Outlet
    Gage
               Ap = Ap •  ~  Ap
               Figure 8-4
  MEASUREMENT OF STATIC PRESSURE DROP -  Ap
                      57

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If the exhaust fan is before the collector, then both the inlet
and outlet duct pressures will be higher than or equal to at-
mospheric pressure (positive).  If the exhaust fan is after the
collector, the inlet and outlet duct pressures will be lower than
atmospheric pressure (negative).
     To obtain accurate static pressure measurements, the pressure
probe must be perpendicular to the direction of flow.  The probe
and connecting tubing must be kept free of dirt and moisture.
Be careful to connect the high pressure side of the gage to the
high pressure source and not to exceed the range of the instrument.
When using manometers, make sure the gage is level and zeroed.
Spare gage fluid is often handy due to the large pressure drops
across some devices, which can blow the fluid out of the instrument,

8.2.2  Cyclones - Multicyclones
     The pressure drop, cyclone diameter, and, when  multicyclones
are used, the number of collectors should be determined.

8.2.3  Baghouses
     The pressure drop across" the baghouse should be determined.
If the pressure drop varies during the cleaning cycle, then the
range of fluctutation should also be noted.
     The cleaning cycle frequency should, be determined.  The
plant operator usually controls the cleaning cycle frequency  from
the control room.  Note the setting on the cleaning  timer.  If
the cleaning cycle is automatically controlled by a  pressure
sensing device, the pressure setting should be noted if it is
available.
     The area o.f the filter cloth can sometimes be determined by
checking the baghouse nameplate or by referring to the state
permit.  If not available, the observer  should request the plant
official to furnish or obtain the effective cloth area from the
manufacturer.
                                58

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8.2.4  Wet-Collection Devices
     The operating parameters which are important for most
wet-collection devices are pressure drop, water flow rate, and
water pressure.
     The pressure drop across venturi scrubbers and across each
component in multiple scrubber systems must be measured.
     For venturi scrubbers with adjustable throats, the throat
opening should be measured.  When this is physically impossible,
the position of the adjustments should be permanently marked as
a reference for future site inspections.  Some orifice scrubbers
used in low-energy systems have adjustable orifice openings either
mechanically adjusted or dependent on the water level in the
device.  An attempt should be made to measure or mark the size
of the opening.
     Water Flow Rate. Measurement of water flow rate presents
several problems. Very few plants are equipped with water flow
meters on the  scrubber equipment.  The plant owner may be
required to install equipment to measure water flow under 40 CRF
60.8e; however, such an action may be of  questionable  effective-
ness.  Some plants equipped with low-energy wet-collectors have
multiple water pumps and supply lines, thus requiring several flow
meters which may constitute a considerable expense.  Scrubber water
is almost always recycled through a settling pond.  The scrubber
water can contain a significant amount of solid particles (silt)
which can lead to the rapid deterioration of flow measuring
device.  If flow devices are installed,  they must be cleaned and
calibrated periodically.  Flow measuring devices should be in-
stalled as shown in Figure 8-5.  This permits removing the
instrument from the flow steam when not  in use.  This set-up
reduces the frequency of cleaning and calibration and increases
the  life of the meter.  Either a flow rate meter or quantity
totalizing meter and stopwatch can be used to determine the flow
rate.
                                 59

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  Valves
Figure 8-5.   Flow Meter Installation
                     Gage
                                   Figure 8-6
                          Pressure Gage Installation
                       60

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     The water flow rate can sometimes be determined by ob-
serving the water discharge from the scrubber system.  If the
discharge pipe is horizontal and above the surface, the following
method is applicable:
                        •Discharge  Pipe
                    .  .X.
                    • .   X
                   .  '.   N. •
                    X   •   \
                     \     V
                      \  •.  -
                    -x-    \
I.  Measure the distance (x) between a point P (located one
    foot below pipe centerline) and the center of the discharge
    stream.
2.  Determine the cross-sectional area (A) of flow leaving dis-
    charge pipe (if pipe is full, then pipe exit area is used).
3.  Calculate the water discharge rate (Q) as:

             Q (m3/min) =240  • A (m2) ' x(m)
           .  Q (gal/min) = 1800 ' A(ft2) ' x(ft)

A relative measure of water flow rate can be made by measuring
the speed  (rpm) of the water pump or pump drive.  At a constant
delivery pressure, the flow rate is directly proportional to  the
pump speed.
     Water Pressure.  Some plants have water pressure gages
on the scrubber supply lines,  particularly the water lines which
feed spray systems.  These gages are often broken or filled with
dust and silt.  The following  procedures are recommended for  checking
existing pressure gages:
                               61

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1.   Check general condition of the gage.  Look for possible
    contamination by ambient dust.
2.   Turn off water supply, or if gage is equipped with valves,
    isolate and drain water from gage.  Check gage zero.
3.   Turn on water supply and note gage reading, drain gage and
    repeat.  Gage should read consistently.
     Gages which are contaminated with dust or silt generally
indicate less than real pressure.  Gages which do not zero cor-
rectly or do not read consistently should be removed and cleaned,
and replaced if necessary.  When new gages are required, they should
be installed as shown in Figure 8-6.  When not in use, the
proper gage should be isolated and drained by operating the
proper valves.
     On spray systems, it is important to check to see if all
nozzles are clear.  High delivery pressure is not necessarily
indicative of proper operation for spray nozzles.

8:3  Additional System Parameters
     This section applies to the operational variables which
concern the combined system of plant and control equipment.  A
method to determine the amount of dilution air added to the
system, a method for determining the flow rate at different points
in the system, and several methods fo'r estimating' the system
volumetric flow rate are provided.

8.3.1  Dilution Measurements --, Local Flow-Rate Determinations
     The procedures outlines in this section should be utilized
when: 1) insufficient flow in the scavenger system is suspected',
2) the production rate is lower than expected and the plant oper-
ator claims that production is limited by dryer exhaust capacity,
3) when dilution air is added to the system and the applicable
emission regulation is expressed in terms of concentration.
     To determine (1)> the amount of leakage or dilution air  added
to the system,(2), the flow rate at any point in the system,  or
(3),the flow rate through the scavenger system,the following
procedures are applicable:
                              62

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Consider  the flow diagram  shown below:
                                        Baghouse
                  scavenger
                   system
Cyclone
     The  volume flow rate,  Qz (dscfm),  and the %  CO-
at the  stack(point 3)  are measured in the course of a  per-
formance  test.   If the ICO~ at several  other points is determined,
then the  quantity of air added  to the system between these points
and the flow rate at these  points can be determined.   For example,
if I C02  is known at points 1, and 2, then:
(1)   the flow rate at point 2 is   Q2  =  Q3
                                                 ICO,
                                                 ICO,
                         '(dscfm)
 (2)   the air leakage  between points  2  and 3 is
         Leakage Air  (dscfm) =  Q3-Q2  =   Q
 Similarly, the flow  rate at point  1  is :
                                                     ICO,
               1  -
                                                     ICO
                                                        2  (2)
 (3)   Q1(dscfm) =  Q2  x
                          ICO
                             2  (2.
             ICO,
                          ICO
   =  Q- x
                             2   I
             ICO,
 and the flow rate  in  the scavenger system is  :
                               1  -
                                    ICO,
                                    ICO
                                       2 1
                 ICO,
                                                 ICO-
                   2  (2
                                                          1 -
                                                              ICO,
                             ICO,
Note:  The values of Q,  volumetric flow rate, in the above equations, must be
expressed at dry standard conditions (dscfm).  To calculate the volume flow
rate at actual conditions, use the equation:
       Q acfm = Q (dscfm,
                           100
                                           29.92
  460
where:   %H20 = moisture content of gas stream, volume percent
        T    = absolute gas temperature (R°)
        P    = absolute gas pressure (in Hg.)
                                63

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     To determine the flow rate at the actual conditions, the
percent moisture, gas temperature and gas pressure must be
measured.  The volume percent moisture is most easily determined
by using the wet bulb, dry bulb method and psychrometric nomo-
graph which is included in section 6.4.1.  These procedures assume
that the leakage air and scavenger system air contain negligible
C0_.  The method does not apply if leakage out of the system
occurs.  Also, this procedure should not be used after a wet-
collection device since the water can absorb a portion of .the
CO., and the moisture content of the gases will change.
  £* '
 8.3.2  Air Flow Measurements
     During a performance test, the volumetric flow rate is
measured.  Measuring certain system parameters during the per-
formance test provides methods of estimating the flow rate during
subsequent site inspections.  Several procedures are applicable.

Method 1 - Cyclone Pressure Drop
     The pressure drop across a cyclone or multicyclone is related
to  the flow rate _by:
      kO P/o
Ap  =  • "• t              where:  Ap = cyclone pressure drop
        T
                                 k  = proportionality constant
                                 Q  = volumetric flow rate
                                 P  - absolute gas pres'sure
                                 T  = absolute gas temperature
                                 /?  =. gas density
If  the pressure, density and temperature are assumed to be
constant for similar operating conditions, then  Q= F -^Ap and
F is a new  proportionality constant.  Measuring Q and Ap during
the test allows determination of F.  The value of F and the
pressure drop .across the cyclone can be used to estimate the flow
rate during future site inspections if relatively consistent
process conditions are maintained.
Method 2- Fan Speed
     Exhaust fans used at 'asphalt plants are essentially constant
volume devices.  Volumetric flow rate through the fan varies directly
with the fan speed.  It is important to recognize that although
                             64

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 the  volume flow rate is  constant at cons±ant speed, the mass flow
 rate is dependent on the temperature,  pressure,  and density of the
 gas  stream.
      The fan speed can be determined using a hand-held tachometer.
 Access through the belt  guard to the fan shaft must be provided.
      Caution should be used in applying this method since
 erosion of the fan blades by the entrained dust  will affect the
 flow rate to speed relationship.  This is particularly important
 if the fan is located before the secondary control device.  This
 method should not be used if the exhaust fan serves as  a wet-fan
 in a scrubber system, since blade wear can be expected.
 Method 5 - System Pressure Drop
      The system pressure drop is the sum of all the pressure drops
 across the individual components of the air handling system (dryer,
 ductwork, damper, and control devices).  Since the dryer inlet and
 the stack are open to the atmosphere, the algebraic sum of the
 system pressure drop and the increase in static pressure across
-the exhaust fan must be equal to zero.  It is much easier to
 measure the pressure rise across the fan than summing the in-
 .dividual pressure drops.  If the system resistance to flow is
•constant, the static pressure rise across the fan is directly pro-
 portional to the square of the volume flow rate through the system.
      The static pressure rise across the fan can be measured
 using the procedures given in section 6.6.1.  Obviously, the fan
 outlet pressure is always greater than the inlet pressure.
      Caution should be exercised in interpreting fan pressure
 rise data ,since the pressure rise will also change  with any change  in the
 flow resistance at a constant flow rate.
                              65

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                      Chapter IX
            VISIBLE EMISSION OBSERVATIONS

     Alone, opacity measurements constitute an enforceable
emission standard for both Federal and State regulations.  The
opacity of emissions must be determined in accordance with EPA
Method 9 by a certified observer.  (A copy of Method 9 'is
included in Appendix B of this report).  At asphalt plants,
visible emission observations should be conducted at all
emission points including the rotary dryer, fugitive-dust
control system, and the stack.  The appr.opriate.-data should., be
recorded on the "Opacity Observation, Form" which is .-included
in Appendix C of this report.
     Stack emissions from asphalt plants .equipped with scrubber
systems are normally .accompanied by extensive  attached sjteam
plumes.  Asphalt plants controlle.d with b.aghouses usually
have detached steam plumes although .attached plumes ar.e some-
times encountered.-For attached steam plumes, Method. 9; requires
that opacity observations are made beyond,the point in- the
plume where the water vapor .is no longer visible.  .The observer
must record the distance from the .stack, outlet, to the;, point in
the plume where observations are made.. In some cases,
condensed water vapor is visible in the,plume, several hundred
feet from the stack outlet.  Since the plume dissipates., with
distance, visible emissions are at best very difficult, in,
these instances.
     Opacity readings of stack emissions during performance
tests (where the mass emission rate is accurately measured),
provide a valuable baseline for comparison of visible emission
observations during subsequent follow-up inspections.
     A considerable amount of data exists  which indicates
that asphalt plants meeting the NSPS particulate emission  stand-
ard (90 mg/dscm or 0.04 gr/dscf) have virtually no visible
                             66

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emissions.   Some success has been obtained with mass emission
opacity correlations at asphalt plants.   Further research is
required before the results of these correlations can be
applied to  asphalt plants in general.   Additional information
on these correlations will be included in the final report.
                           67

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                          Chapter X
    REVIEW AND EVALUATION OF PERFORMANCE TEST REPORTS

     An importance task for the enforcement agency, once a
performance test has been conducted, is the review and evaluation
of the test report.  Detailed procedures for reviewing test
reports are provided in Volume III - Development, Observation.
and Evaluation of Performance Tests.

10.1  Review of Test Reports
     Copies of the test protocol, the "Observer's Report",
the "Observer's Sampling Checklist", the "Observer's Process and
Control System Data Form" and any other applicable information,
such as state permits, should be obtained before reviewing the
actual test report.  The test report must be examined both for
completeness in reporting all the pertinent sampling and process
data and for accuracy in the calculation procedures used to deter-
mine the emission rate.  All sampling reports should contain copies
of the original field sampling data.  Computer printouts of the
raw field data are unacceptable since there is no way to determine
if the information was correctly entered into the computer.  A
check on the accuracy of the calculated emission rate is accom-
plished by simply recalculating the emission rate using only the
raw field data and laboratory analytical results.  The percent
isokinetic, (%I), should also be calculated from the test data.
Tests where II is between 90% and 110% are acceptable.  Volume
V,Development, Observation, and Evaluation of Performance Tests,
provides criteria  or. accepting or rejecting tests outside the
normal acceptable isokinetic range.
     The process and control system information contained in the
test report and the information on the "Observer's Process and
Control System Data Form"  should be reviewed to determine if the
test was conducted at the representative conditions specified in
  currently being prepared by the Division of Stationary Source
  Enforcement, U.S. EPA.
                            68

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                Source Testing Report Format


Cover
   1.  Plant name and location
   2.  Source sampled
   3.  Testing compnay or agency, name, and address
Certification
   1.  Certification by team leader
   2.  Certification by reviewer (e.g., P.E.)
Introduction
   1.  Test purpose
   2.  Test location, type of process
   3.  Test dates
   4.  Pollutants tested
   5.  Observers' names (industry and agency)
   6.  Any other important background information

Summary of Results
   1.  Emission results
   2.  Process data, as related to determination of compliance
   3.  Allowable emissions
   4.  Description of collected samples
   5.  Visible emissions summary
   6.  Discussion of errors, both real and apparent

Source operation
   1.  Description of process and control devices
   2.  Process and control equipment flow diagram
   3.  Process data and results, with example calculations
   4.  Representativeness of raw materials and products
   5.  Any specially required operation demonstrated

Sampling and Analysis Procedures
   1.  Sampling port location and dimensioned cross section
   2.  Sampling point description, including labeling syste-
   3.  Sampling train description
   4.  Brief description of sampling procedures, with discussion
       of deviations from standard methods
   5.  Brief description of analytical procedures, with discussion
       of deviations from standard methods

Appendix
   1.  Complete results with example calculations
   ?.  Raw field data (original, not computer printouts)
   3.  Laboratory report, with chain of custody
   4.  Raw production data, signed by plant official
   5.  Test log
   6.  Calibration procedures and results
   7.  Project participants and titles
   8.  Related correspondence
   9.  Standard procedures
                           69

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the test protocol.  In short, if the test was conducted at
representative conditions, if all sampling procedures which were
used are acceptable, if the test  report is complete and accurate
(both data and calculations), then the performance test is ac-
ceptable.  Determination of compliance is based on the average
emission rate for the three sampling runs.

10.2  Checking Test Data
     The following paragraphs describe methods which may be
used to crosscheck sampling data included in the performance test
report.
     Barometric Pressure: Incorrect barometric pressure measure-
ment will not generally cause errors of more than 10-15%, but it
is a very common error.  The value reported by the tester can be
checked in.two separate ways.  First, the value reported should
be reasonable, with respect to the elevation at the plant site.
At sea level, the barometric pressure is almost always between
29 and 31 inches of mercury, and usually close to 30.  For every
1000 feet above sea level, the value will decrease 'by 1.1 inches
of mercury.  As. a more accurate check, the reviewer can call
                                  r" ' .   .      '     '   '
the airport closest to test site, and ask for the "station"
pressure (not corrected to sea level) for the date of the test.
     Stack Pressure:  Since almost all sampling at asphalt plant
is conducted near the exit of the stack, the stack pressure
should be essentially the same as, or slightly less than, at-
mospheric pressure.
     Stack Temperature: The stack temperature for plants controlled
by baghouses typically ranges from 88°C to 138°C  (190-280°F).
In any case, the stack temperature is approximately the same as the
baghouse temperature, which must be maintained above the dew
point.  This provides a lower limit for the stack temperature.
An upper limit for the stack temperature is provided by the dryer
exhaust temperature.  For asphalt plants controlled by wet-
collection devices, the stack temperature normally ranges from
90°F to 160°F.
                            70

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     Dry Molecular Weight:  The dry molecular weight of the stack
gases at asphalt plants typically ranges from 29.0 to 29.5 due to
the high excess air and dilution  by the scavenger system.
     The orsat data can be checked by using Figure 8-2.  Data
reported by aligning the type of fuel with the fcCO? and I02
can be checked by aligning the type of fuel with the % CC^ and
checking the 102 from the nomograph with the reported value.
The reviewer is cautioned that if the orsat data was taken after
a scrubber, the nomograph may not work, since the scrubber will
remove an indeterminate amount of carbon dioxide.
     Leak Tests:  Leak tests are required after each sample run
and prior to filter changes during the run.  Most testers also
perform leak tests immediately prior to each sample run.  The
observer should have witnessed each leak test and recorded the leak-
age rate on the "Observer's Sampling Checklist".  If the observer
failed to record leakage rates and the report claims that leak
tests were performed, either after each test or before filter
changes, the dry gas meter readings on the data sheet would indi-
cate this.  In other words, it is unlikely that a leak test was
done after run #1 if  the final volume reading for run #1 is the
same as the initial volume reading on run #2.  If a leak test
was made in the middle of the run (because of a filter change, for
example), the volume readings before and after the leak test
would be shown on the data sheet, so that the computed meter volume
could be adjusted accordingly.
     If the sampling train fails to meet the acceptable leakage
rate criteria,  (.57 1/min, .02 cfm), then the tester has the
option to subtract the product of the measured leakage rate and
the duration of the test from the sample volume or repeat the test.
Adjusting the sample volume for an excessive leakage rate intro-
duced a high bias (in the agency's favor) in the calculated
emission rate.
                             71

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     Sample Volume:  The sample volume should be checked by
referring to the initial and final dry gas meter readings re-
corded on the "Observer's Sampling Checklist".  Any discrepancies
between the values given by the observer and the test report
must be resolved.                      '
     Moisture Data: There are several procedures which may be
used to check moisture data.  The first check is to compare the
assumed moisture content recorded on the field data sheet or
"Observer's Sampling Checklist" to the actual measured value.
Normally, an absolute error of 1% in estimating the moisture
content of the stack gas (It^O actual - IH20 estimated) will
introduce a relative error of approximately 1% in the sampling
rate.  Thus isokinetic sampling conditions will be off by 1%.
     The stack gases at asphalt plants controlled "by scrubbers
are normally saturated.with water vapor and may contain en-
trained water,droplets.,  .Entrained droplets of liquid water in
the stack gases can yield an erroneously.high moisture content.
All moisture data should be che.cked  (even if there are no entrained
water droplets) to ensure that the reported' value is not higher
than the saturation moisture content.  Figure 10-1 gives the
moisture content at saturation as a  function of stack absolute
pressure and stack gas, temperature (at saturation 'conditions,
the wet bulb temperature is equal to the 'dry'bulb temperature).
If. the reported value  is higher than the maximum shown in Figure
10-1, the data is suspect.  Generally, if the high reading was
caused by entrained water droplets,  the value is adjusted to the
saturation moisture content.                     r
     At asphalt plants.controlled by baghouses, a water balance
across the process may be used to check both moisture data and
process data if sufficient  information is available.  The mass
balance requires determination of the volumetric flow rates  (dscfm)
at the stack and dryer exit.  A method for determining these
values is provided in  section 8.3.1.  The type of fuel used,
                               72

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                                                                                                           J3
                          8
                          UJ
                          e:
                          3
                          in

                      10  I
                                       AIR - WATER VAPOR  PSYCHROMETRIC CHART

-------
excess air at dryer exist  (section 8.1.4), cold aggregate feed
rate and percent moisture  in the aggregate feed must also be
known.
     The mass rate of water leaving the stack, A,  is:
         lb H70                      !H90 -  A
      A C	—) = Q stack  (dscfm)   (—	)  (.0456)
          min                        100 - %H20
where the %H20 - A is the percent moisture of the  stack gases
given in the report.

     The mass rate of water supplied by the ambient  air,  B,  is
approximately:  lb „ Q                       %H,0  -  B
            (B  	±- )= Q stack (dscfm) ( 	.	 )  (.0467)
                 min                        100 -  %H0
where the %H70 - B  is the percent moisture.in .the  ambient  air,
determined from Figure: 10-2.
     The mass rate of water supplied by combustion  of  the fuel,
C, is:
           lb H70                    IH-0  - C
        C (———) = Q dryer(dscfm) (-^-	)  (.04-67)
            min                      100 - H0
where the ..%H70 - (T is the percent moisture  from  the  combustion
of the fuel, determined from Figure 10-3.
     The mass rate of water supplied by the aggregate,  D,  is:
  lb H20
D(	—) = %H20     x  aggregate feed rate (rfpfr) x 33.3
    min          °°                           nour

where the percent moisture in the aggregate is determined  by the
procedure given in section 8.1.2.  A mass balance  of the water
requires that:       A = B + C  + D
                               74

-------
10 —I
                              I—0
                              — 50
X
a
a
                                    U
                                •100
      MOISTURE FROM THE AMBIENT AIR
          Figure 10-2









•
M
<

m
U)
u
u
X
H

*







— 0
•
• 7!
O
; «
c- 50 *• >•
r•.
" ,

•
- 0.5



,




I SKS'.-HStur.l Ga.

. Propane
. Gasoline
. «2 Fuel 01-1

. Bunker "C" oil
J

• Bituminous Coal
f
.


1 Subbituninoua and
J Lignite


• Anthracite



—i

-Coke

  FOB DETERMINING MOISTURE U) FLUE GAS
      FROM COMBUSTION OF FUEL
          Figure 1O3
                75

-------
     Volume Flow Rate:  The volumetric flow rate is difficult
to cross-check.  Normally, 185 to 315 scm/metric ton of product
(6000 - 10,000 scf/ton) is typical.  However, values as high
as 470  scm/metric ton (15,000 scf/ton) are sometimes encountered.
     Miscellaneous Data:   The data provided by the sampling report
should be consistent with values listed on the "Observer's
Sampling Checklist",
                               76

-------
                                            APPENDIX  A
                                      NSPS  REGULATIONS
; 60.8  IVrformjiiirr IcMs.
   R i  Wi .hin 60 days after achieving the
maximum production rate at which the
affected facility will'be oi>erated. but not
alcr than 180 days after initial startup
of  such facility and at such other times
as  may be required by the Administrator
under section '114 of the Act, the owner
or  operator of such facility shall conduct
>erformance test's) and furnish the Ad-
ministrator a written report of the results
of  such performance test (s >.
   (b)  Performance tests shall be con-
ducted and data reduced in accordance
with the test methods and procedures
contained  In  each applicable  subpart
unless the Administrator (1) specifies
or approves, in specific cases, the use of
a  reference method with minor changes
in methodology.  (2)  approves  the  use
of an  equivalent method,  (3)  approves
the use of an alternative method the re-
sults of which he has determined to be
adequate for indicating  whether a spe- •
cific source  is  in compliance, or  (4)
waives the requirement for performance
tests because  the owner or operator of
a  source has demonstrated by  other
means .to the  Administrator's satisfac-
tion that the affected facility is in com-
pliance with the  standard. Nothing in
this paragraph shall be  construed  to
abrogate the  Administrator's authority
to require testing under section 114 of
the Act.
     The  owner or  operator  of ar.
 affected  facility  shall  provide the Ad-
 ministrator 30 days prior notice of  the
 performance  test to aflord the Admin-
 istrator the opportunity to have an  ob-
 server .present.
    >e>  The  owner or  operator  of ar.
 affected facility shall provide, or cause 10
 be provided,  performance  testing  facil-
 ities as follows:
   .il > Sampling ports adequate for  tes:
 methods applicable to such facility.  .
    <:> Safe sampling platform 151.
    '3> Safe -access to  sampling  plat-
 form   Utilities for sampling  and  test;r.£
 equipment.
  
-------
                 Appendix B

EPA TEST METHODS FOR ASPHALT CONCRETE PLANTS

                 Method  1
                 Method  2
                 Method  3
                 Method  5
                 Method  9

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 41754
      RUIES AND REGULATIONS
   TWe 40—Protection of Environment
     CHAPTER I—ENVIRONMENTAL
         PROTECTION AGENCY
              [PHI. 754-5]

 PART  6O—STANDARDS OF  PERFORM-
 ANCE  FOR NEW STATIONARY SOURCES
    Revision to Reference Methods 1-8
 AGENCY:  -environmental   Protection
 Agency.
 ACTION: Final Rule.
 SUMMARY: This rule revises Reference
 Methods 1 through 8. the detailed re-
 quirements used  to measure emissions
 from  affected faculties to  determine
 whether they are In compliance with a
 standard of performance. The methods
 were originally promulgated December
 23. 1971. and since that time several re-
 visions became apparent which would
 clarify, correct and Improve the meth-
 ods. These revisions make the methods
 easier to use. and improve then* accuracy
 and reliability.
 EFFECTIVE DATE: September 19,1977.

 ADDRESSES:  Copies of the comment
 letters are available for public Inspection
 and copying at the U.S. Environmental
 Protection Agency. Public Information
 Reference  Unit (EPA Library), Room
 2922. 401 M Street. S.W., Washington.
 D.C. 20460. A summary of the comments
 and EPA's responses may be obtained
 upon written request from the EPA Pub-
 lic information Center (PM-215),  401
 M Street. S.W.. Washington, D.C. 20460
 (specify "Public  Comment. Summary:
 Revisions to Reference Methods 1-8 In
 Appendix A of Standards of Performance
.for New Stationary Sources").
 FOR PUUTHKU INFORMATION CON-
 TACT:
   Don R. Goodwin, Emission Standards
   and Engineering  Division,  Environ-
   mental Protection Agency, Research
   Triangle Park. North Carolina 27711,
   telephone No. 919-541-5271.

 SUPPLEMENTARY  INFORMATION:
 The amendments were proposed on June
 8, 1976 (40 FR 23060). A total of 55 com-
 ment  letters  were  received during the
 comment period—34 from Industry, 15
 from governmental agencies, and 6 from
 other Interested parties. They contained
 numerous suggestions which were incor-
 porated in the final revisions.
   Changes common to all eight of the
 reference methods are:  (1) the clarifica-
 tion of procedures and equipment spec-
 ifications resulting from the comments,
 (2)  the addition  of guidelines for  al-
 ternative procedures and equipment to
 make prior approval of the Administra-
 tor unnecessary and (3) the addition of
 an introduction to each reference meth-
 od  discussing the general  use of the
 method and  delineating the procedure
 for using alternative methods and equip-
 ment.
   Specific changes to the methods are:

               METHOD 1
   1.  The provision for the  use of more
 than two traverse diameters, when spec-
ified by  the Administrator, has  been
deleted. If one traverse diameter Is hi a
plane containing the greatest expected
concentration variation,  the intended
purpose of the deleted paragraph will be
fulfilled.
  2. Based on recent data from Fluidyne
(Participate  Sampling  Strategies for
Large Power Plants Including Nonunl-
form  Flow.  EPA-600/2-76-170.  June
1976)  and  Entropy  Environmentalists
(Determination of the Optimum Number
of Traverse Points:  An  Analysis  of
Method 1 Criteria (draft), Contract No.
68-01-3172).  the number  of  traverse
points for velocity measurements has
been reduced and the 2:1 length to width
ratio requirement for cross-sectional lay-
out of rectangular ducts has been re-
placed by a "balanced matrix" scheme.
  3. Guidelines for sampling In stacks
containing   cyclonic  flow  and  stacks
smaller than about 0.31 meter In diam-
eter or 0.071 m* hi cross-sectional area
will be published at a later date.
  4. Clarification has been made  as to
when a check for cyclonic flow is neces-
sary;  also, the suggested procedure for
determination of unacceptable flow con-
ditions has been revised.

              METHOD 2
  1. The calibration of certain pilot tubes
has been made optional. Appropriate con-
struction and application guidelines have
been included.
  2. A detailed calibration procedure for
temperature gauges has been Included.
  3. A leak check procedure for  pilot
lines has been included.

              METHOD 3
  1. The applicability of the method has
been confined to fossil-fuel combustion
processes and to other processes where It
has been determined that components
other than O,, CO,, CO. and N.  are not
present in concentrations sufficient to
affect the final results.
  2. Based on recent research informa-
tion (Particulate Sampling Strategies for
Large Power Plants  Including' Nonuni-
form   Flow,  EPA-600/2-76-170,  June
1976), the  requirement for proportional
sampling has been dropped and replaced
with the requirement for constant rate
sampling. Proportional and constant rate
sampling have been found to give essen-
tially the same result.
  3. The  "three  consecutive" require-
ment has been replaced by "any three"
for  the   determination  of  molecular
weight, CO, and O,.
  4. The equation for excess air has been
revised to account for the presence of CO.
  5. A clearer distinction has been made
between molecular weight determination
and   emission  rate  correction  factor
determination.
  6. Single  point, Integrated sampling
has been included.
              METHOD 4

  1. The sampling time of 1 hour has
been changed to a total sampling time
which will span the length of time the
pollutant emission rate Is being deter-
mined or such time as specified  in an
applicable subpart of the standards.
  .2. The requirement  for  proportional
sampling has been dropped and replaced
with the requirement for constant rate
sampling,
  3. The leak check before the test run
has been made optional; the leak check
after the run remains mandatory.
              MXTROD 5
   1. The  following alternatives  have
been Included hi the method:
   a. The use of metal probe liners.
   b. The use of other materials of con-
struction  for filter holders and probe
liner parts.
   c. The use of polyethylene wash bot-
tles and sample storage containers.
   d. The use of deslccants other  than
silica  gel or calcium sulfate,  when
appropriate.
   e. The  use of stopcock grease other
than sflicone  grease, when appropriate.
   f. The drying of filters and probe-niter
catches at elevated temperatures, when
appropriate.
   g. The  combining of the  filler and
probe washes into one container.
   2. The leak check prior to a test run
.has been made optional. The post-test
leak check remains  mandatory. A meth-
od for correcting sample volume for ex-
cessive leakage rates has been included.
   3. Detailed leak check and calibration
procedures for the metering system have
been included.
              METHOD  6
   1. Possible  interfering agents of the
method have been delineated.
   2. The options of: (a) using a Method
8 Impinger system, or (b) determining
SOi  simultaneously  with  particulato
matter,  have been  Included   In  the
method.
   3. Based on recent research data, the
requirement for proportional sampling
has been dropped and replaced with the
requirement for constant rate sampling.
   4. Tests have shown that isopropanol
obtained  from commercial sources oc-
casionally has peroxide impurities that
will cause erroneously low SO, measure-
ments. Therefore,  a test for detecting
peroxides  hi  isopropanol  has been in-
cluded hi the method.
   5. The leak check before the test run
has been made optional; the leak check
 after the run remains mandatory.
   6. A detailed calibration procedure for
 the metering system has been included
 in the method.

              METHOD  7

   1. For variable wave length spectro-
 photometers,  a scanning procedure for
 determining the point of maximum ab-
sorbance  has been Incorporated as an
 option.
              METHOD  8

   1. Known interfering compounds have
 been listed to avoid misapplication of
 the method.
   2.  The determination  of  filterable
 particulate matter (Including acid mist)
simultaneously with SO,  and SO, has
 been allowed  where applicable.
   3. Since occasionally some commer-
 cially available quantities of isopropanol
                              FEDERAL REGISTER, VOL 42, NO. 160—THURSDAY, AUGUST 13, 1977

-------
                              RULES AND tEMULATIONS
                                                                41755
have peroxide impurities that wffl cause
erroneously high sulfuric add mist meas-
urements, a test for peroxides In Isopro-
panol has been Included In the method.
   4. The gravimetric technique for mols-.
ture content  (rather  than volumetric)
has been specified because a mixture of
Isopropyl alcohol  and  water will have a
volume less than the sum of the volumes
of Its content.
   5.  A  closer correspondence has  been
made between similar parts  of Methods
8 and 5.
               MISCELLANEOUS

   Several  commenters  questioned  the
meaning of the term "subject to the ap-
proval of the Administrator" in relation
to using alternate test methods and pro-
cedures. As defined In § 60.2 of subpart
A, the "Administrator" Includes any au-
thorized representative  of the Adminis-
trator of the Environmental Protection
Agency. Authorized  representatives are
EPA officials in EPA Regional Offices or
State, local,  and regional governmental
officials who have been delegated the re-
sponsibility of enforcing regulations un-
dergo CFR 60. These officials in consulta-
tion with other staff  members  familiar
with technical aspects of source .testing
will render decisions  regarding  accept-
able alternate test procedures.
   In accordance with  section 117 of the
Act, publication of  these methods was
preceded by  consultation with appropri-
ate  advisory, committees,  Independent
experts,  and Federal  departments  and
agencies.

(Sees. Ill, 114  and 301 (a) of the Clean All
Act. aec. *(») of Pub. L. No. 91-604. 84 8tat
1683; >ec. *(») of Pub. U No. 91-604, 84 Stat.
1687; sec. 2 of Pub. L. Mo. 00-148, 81 Stat. 504
 142 U.S.C. 18670-6,  1857C-9. 1857g(»)J.)

   NOTE.—The   Environmental  .Protection
Agency has determined  that this document
 does not contain a  major  proposal- requiring
preparation of an Economic Impact Analysis
under Executive Orders  11821 and 11949 and
OMB Circular A-107,           '          ..

   Dated: August 10,1977.

                 DOUGLAS  M.  COSTLE,
                           Administrator.

   Part 60 of Chapter I of Title 40 of the
Code of Federal Regulations Is amended
by revising Methods 1 through  8 of Ap-
pendix   A—Reference    Methods   as
 follows:

        APPENDIX A— REFERENCE' METHODS
  The reference methods in this appendii are referred to
in J60.8 (Performance Tests) and 160.11 (Compliance
With Standards and Maintenance Requirements) of 40
CFR Part 60, Subpon A (General Provisions). Specific
uses of these reference  methods are described in the
standards  of perforniam-e contained iu the subparts,
beginning with Subpart l>.
  Within each standard of performance, a section titled
"Test Methods  and  Procedures" is  provided to  (1)
identify the test methods applicable to  the  facility
subject to  the respective standard and 12.1 identify any
special instructions or conditions to be followed when
applying a method to the respective facility. Sucb in-
 structions (for eiample, establish sampling rates, vol-
 umes, or temperatures) are to be used either in addition
 to, or as a substitute for procedures in a reference method.
 Similarly, for sources subject to emission monitoring
 requirements, specific instructions pertaining to any use
 of a reference method arc provided in the subpart or in
Appendii B.
   Inclusion of methods In this appendli b not Intended
 M mn endorsement >or denial of their applicability to
 BomcM that •mint subject to standards of performance.
 The methods weyotentlany applicable to other sources:
 however, applicability should be confirmed by careful
 and appropriate evaluation of the conditions prevalent
 at such sources.
   The approach followed In the formulation of the ref-
 erence methods Involves specifications for equipment,
 procedures, and performance. In concept, a performance
 specification approach would be preferable In all methods
 because this allows the greatest flexibility to the user.
 In practice, however, this approach Is Impractical in most
 cases because  performance  specifications  cannot be
 established.  Most of the methods described herein,
 therefore, Involve specific equipment specifications and
 procedures, and only a few methods in this appcndii rely
 on performance criteria.
   Minor changes  In the reference methods should not
 necessarily affect the validity of the results and it is
 recognized that alternative  and equivalent  methods
 esist. Section 60.8 provides authority for the Administra-
 tor to specify or approve (1) equivalent methods, (2)
 alternative  methods, and (3)  minor  changes In the
 methodology of the  reference methods.  It should be
 clearly understood that unless  otherwise identified all
 such methods and changes must have prior approval of
 the Administrator. An owner employing such methods or
 deviations from the reference methods without obtaining
 prior approval does so at the risk of subsequent disap-
 proval and retesting with approved methods.
   Within the reference methods, certain specific equip-
 ment or procedures are recognized as being acceptable
 or potentially acceptable and are specifically Identified
 In the methods. The items identified as acceptable op-
 tions may be used without approval but mist be identi-
 fied In the test report. The potentially approvable op-
 tions are cited  as "subject to the  approval of the
 Administrator" or as "or equivalent."  Such potentially
 approvable techniques or alternatives may be used at the-
 discretion of the owner without prior approval. However.
 detailed  descriptions (or  applying these  potentially
 approvable techniques or alternatives are cot provided
 In the reference methods. Also; the potentially approv-
 able options are not necessarily acceptable in all applica?
 tions.  Therefore, an owner  electing  to  use such po-
 tentially approvable techniques or alternatives-is re-
 sponsible, for:  (1). assuring  that the-techniques or
 alternatives are' in fact  applicable and are properly
 executed;  (2) Including a written description of the
 alternative method:  In  the  test report (the  written.
 method must be clear and most be capable of .being per-
 formed without additional instruction, and the'degree
 of detail should be similar to the detail contained in the
 reference methods); and (3) providing any rationale or
 supporting data necessary to show the validity of Jhe
 alternative.in  the particular application. 'Failure to
 meet these requirements can result  in  the Adminis-
 trator's disapproval of the alternative.

 JlETnoD 1—SAMPLE  AKD VELOCITY  TRAVERSES TOE
               STATtONABT SOCEIES

 1. rrinciflt and Applicability

..  r.l' Principle. To  aid in the  reprr-s.-maiivo measure-
 ment of pollutant emissions and/or total volumetric flow
' rate from a stationary source, a measurement site .where
 the effluent stream is'fiowing in a known direction is
 selected, and the cross-section of the stack is divided Into'
 a number of equal areas. A traverse point is then located <
 within each of these equal areas.
   1.2  Applicability.  This method is ari|)l:i:aule to flow-
 ing gas streams in ducts, stacks, and Hues. The method'
 •cannot be used'whcu: (1) flow is cvcloiiic or swirling (see
 Section 2.4), (2) a stack Is smaller"thni  about 0.30 mewr
 (12 in.) in diameter, or 0.071 m" (113 in:1) in cross-ser-
 tional area, or. (3) the measurement site-is less than' two
 stack or duct diameters downstream or less than a bait
 djameter upstrc-am from a flow disturL'an'.v.
   The requirements of this method must be considered
 before construction of a new facility from which emissions
 will be measured; failure to do so may require subsequen t
 alterations to the stack or deviation from the standard
 procedure. Cases involving variants are subject to ap-
 proval  by the Adminis'.raK-r.  I'.*. Knviroriinei)!^
 Protection Agency.

 2. Frotfdurt

   2.1  Selection  of Measurr::v.<-nt  ?:;*-.  Piuupling or
 velocity measurement is performed a;  a site located at
 least eight stack or duct diameters downstream and two
 diameters upstream from any flow disturbance such as
 a bend, eipansion, or contraction in the stack, or from a
 visible flame. If necessary, an alternative location mav
 be selected, at a position at least two stack or duct di-
 ameters downstream  and a ha!' diame:er upstream from
 any flow disturbance. For a rectangular cross section.
 an equivalent diameter (U.I shall be ca^iiiateu from the
 following eqnation,  to  determine the upstream  and
 downstream distances:
                  D.=
ZLW
L-rW
             FEDERAL  REGISTER, VOL 42,  NO.  160—THURSDAY, AUGUST  It, 1977

-------
41756
                              RULES AND  REGULATIONS
    50
       0.5
DUCT DIAMETERS UPSTREAM FROM FLOW DISTURBANCE (DISTANCE A)

                 1.0                         1.5                        2.0
2.5
                                                                              I
                                                                           I
     40
 o
 a.
 UJ '
 V)
 cc
 UJ

 ^ .30
 cc

 u_
 O
 cc
 UJ
 §  20

 Z
 s
 D
 S

 Z  10
\
T
A
i
~L
B
i
—



—
I
k
'DISTURBANCE

MEASUREMENT
p- SITE

•
DISTURBANCE

              * FROM POINT OF ANY TYPE OF
                DISTURBANCE (BEND, EXPANSION. CONTRACTION. ETC.)
                      I
                      3             4             56            78            9

                DUCT DIAMETERS DOWNSTREAM FROM FLOW DISTURBANCE (DISTANCE B)


                 Figure 1-1. Minimum number of traverse points for particulate traverses.
                                                                                                      10
                                          where £=leugtb and H'=widtb.
                                           2 .2 Determining the Number of Traverse Points.
                                           2.2.1  Particulate Traverses.  When the eight- and
                                          two-diameter criterion can lie met, the minimum number
                                          of traverse points shall be: (1)  twelve, for circular or
                                          rectangular stacks with diameters (or  equivalent di-
                                          ameters) greater than 0.61 meter (24 in.); '(2) eight, for
                                          circular stacks with diameters  between 0.30 and 0.61
                                          meter (12-24 in.); (3) nine, for rectangular stacks with
                                          equivalent diameters between 0.30 and 0.61 meter (12-24
                                          in.).
                                           When the eight- and two-diameter criterion cannot be
                                          met, the minimum number of traverse points is deter-
                                          mined  from  Figure 1-1. Before referring to the figure,
                                          however, determine the distances from the chosen meas-
                                          urement site to the nearest upstream and downstream
                                          disturbances, aud divide  each  distance by tho stack
                                          diameter  or equivalent diameter,  to  determine the
                                          distance in terms of the number of duct diameters. Then,
                                          determine from Figure 1-1 the minimum number of
                                          traverse points that corresponds: (17 to the number of
                                          duct diameters upstream: and  (2)  to the number of
                                          diameters downstream. Select the higher of the two
                                          minimum numbers of traverse points, or a greater value,
                                          so that for circular stacks the number is a multiple of 4,
                                          and for rectangular stacks, the number is one of those
                                          shown in Table 1-1.

                                          TABLE 1-1. CroM-xctfaiial layout far rfCtnnff'.ilur sliekt

                                                                               .Ma-
                                                                               trix
                                                                               lay-
                                                                               out
                                                                          ..... 3*3
                                                                          ..... 4i3
                                                                          ..... 4x4
                                 \aatbtr oftrtutrtt pointt;
                           12.
                           16.
                                             30..
                                             as..
                                                                                oxo
                                                                                6l5
                                                                                7l6
                                                                                7i7
                                FEDERAL REGISTER, VOl. 47,  NO. 160—THURSDAY. AUGUST  18, 1977

-------
    50
    40

5
o.
UJ

<
       o.s
                                 RULES  AND  REGULATIONS


DUCT DIAMETERS UPSTREAM FROM FLOW DISTURBANCE (DISTANCE A)


                    1.0                          1.5                          2.0
                                                                                                                           41757
                                                                         2.5
O
tc
     20
i   10
                       I
                      I
I
I
\
                                                                                                   ^   /DISTURBANCE
                                                                                        MEASUREMENT
                                                                                      •>-'  SITE
                                                                                                         DISTURBANCE
                                                                    I
         ;              3             4              5              67              8             9             10


              DUCT DIAMETERS  DOWNSTREAM FROM FLOW DISTURBANCE (DISTANCE R)




          Figure 1-2.  Minimum number of traverse points for velocity (nonparticulate) traverses.


                                             2.2.2  Velocity (Non-Particulate)  Traverses.  When
                                            velocity or volumetric flow rate is to be determined (but
                                            not paniculate matter), tbe same procedure as that for
                                            paniculate  traverses (Section 2.2.1)  is followed,  except
                                            that Figure 1-2 may be used instead of Figure 1-1.
                                             2.3 Cross-Sectional Layout and Location of Traverse
                                            Points.
                                            • 2.3.1  Circular Stacks. Locate the traverse points.on
                                            two perpendicular diameters adcording to Table 1-2 and
                                            the example shown in Figure 1-3. Any equation  (for
                                            examples, sec Citations 2 and 3 in tbe Bibliography) that
                                            Rives tbe same values as those in Table. 1-2 may be used
                                            in lieu of Table 1-2.
                                             For paniculate traverses, one of the diameters must be
                                            in a plane containing the greatest expected concentration
                                            variation, e.g.. after bends, one diameter shall be in the
                                            plane of the bend. This requirement becomes'less critical
                                            as the disiancc from the disturbance increases; therefore,
                                            other diani'Her locations may be used, subject to approval
                                            Oi'tlie Administrator.
                                             In addi:ion, for stacks having diameters greater than
                                            0.61 m (24 in.) no traverse points shall be located within
                                            2.5 centinu-iers (1.00 in.) of tbe stock walls; and for stack
                                            diameters f-fjual to or less than 0.61 m (24 in.), no traverse  .
                                            point* shall be located will.in 1.3 cn> (0.50 in.) of the stack
                                            walls. To u;eet these criteria,  observe the  procedures
                                            given below.
                                             2.3.1.1 Stacks With Diameters Greater Than 0.61 m
                                            (21 in.). When any of the traverse poinrs as located in
                                            Section Q.3.1 fall within 2.5 cm (l.OOin.) of the stack walls,
                                            relocate th«*m away from the stack walls to: (I) a distance
                                            of 2.5 cm (1.00 in.); or (2) a distance equal to the nozzle
                                            inside diaxeter, whichever  is  larger. These relocated
                                            traverse points (on each end of a diameter) shall be the
                                            "adjusted'1  traverse points.
                                             \\ heneviT two successive traverse points are combined
                                            to form a single adjusted traverse point,  treat the ad-
                                            justed poi": as two separate traverse points, both in the
                                            sampling kor velocity measurement) procedure, and in
                                 FEDERAL REGISTER, VOL 42, NO.  160—THURSDAY,  AUGUST 18,  1977

-------
41758
       imES *3&  BIGULAT10NS
    TRAVERSE
      POINT

        1
        2

        4
        S
        6
                  Figure 1-3.  Example showing circular stack cross section divided into
                  12 equal area*, with location of traverse points indicated.
                                                                                                      '«)in stacta having tangmUil Inlets or other duet con-
                                                                                                      flgrmitliTin wUeh tend to Indues swirling;  In  then
                                                                                                      Instances, on pnauuco or absence of cyclonic flaw at
                                                                                                      the sampling location must be determined. The following
                                                                                                      tecbniqaea ore acceptable tor this determination.
                                                                           I
                                                                      0,0,0

                                                                   	1-—-J---

                                                                    .0    J    O J   O


                                                    Figure 1-4. Example showing rectangular stack cross
                                                    section divided into 12 equal area* with a travane
                                                    point at centroid of each area.

                                                                               '
     Table 1-2. LOCATION OF TRAVERSE POINTS IN CIRCULAR STACKS

             (Percent of stack diameter from inside wall to traverse point)
Traverse
point
number
on a •
diameter
1
2
3
«l
5'
6
7
8
9
10
11
«!
13
U
15
16
17
18
19
20:
. 21
22
23
24
Number of traverse points on a diameter
2
14.6
85.4




•







i







'

4
6.7
25.0
75.0
33.3




















6
4.4
14.6
29.6
70.4
85.4
95.6
•

















8
3.2
10.5
19.4
32.3
67.7
80.6
89.5
96.8





*






.
"


10
2.6
8.2
14.6
22.6
34.2
65.8
77.4
85.4
91.8
97.4














12
2.1
6.7
11.8
17.7
25.0
35.6
64.4
75.0
82.3
88.2
93.3
97.9












14
1.8
5.7
9.9
14.6
20.1
26.9
36.6
63.4
73.1
79.9
85.4
90.1
94,3
98.2










16
1.6
4.9
8.5
12.5
16.9
22.0
28.3
37.5
62.5
71.7
78.0
83.1
87.5
91.5
95'. 1
98.4








18
.1.4
4.4
7.5
10.9
14.6
18.8
23.6
29.6
38.2
61.8
70.4
76.4
81.2
85.4
89.1
92.5
95.6
98.6






20
1.3
3.9
•6.7
.9.7
12.9
16.5
20.4
25.0
30.6
38.8
61.2
69.4
75.0
79.6
83.5
87.1
90.3
93.3
96. 1
98.7




22
1.1
3.5
6.0
8.7
11.6
14.6
18.0
21.8
26.2
31.5
39.3
60.7
68.S
73.8
78.2
82.0
85.4
88.4
91.3
94.0
96.5
98.9


24
1.1
3.2
5.5
7.9
10.5
13.2
16.1
19.4
23.0
27.2
32.3
39.8
60.2
67.7
72'. 8 '
77.0
80.6
83.9
86.8
89.5
92*. 1
94.5
96.8
98.9
   JJ.U  Stacks With Diameters Equal to or Less Than
 0.61 m (24 In.). Follow the procedure In Section 2J.1.1,
 noting .only that  any. "adjusted" points should  be
 relocated away from the stack walls to: (1) a distance of.
 1.3 cm  (0.50 in.); or (2) a distance equal to the noule
 Inside diameter,  whichever Is larger.
   2.3.2   Rectangular  Stacks. Determine the number
• of traverse points as explained In Sections 2.1 and 2.2 of
 tnis method. Fronj Table 1-1, determine the grid con-
 figuration. Divide  the stack cross-section- Into as many
 eo.ua! rectangular  elemental areas as traverse points.
 and then locate a traverse point, at the rentrold of each
 equal ana according to the example In Figure 1-4.
   The situation of tnverae points being too close to the
 atack walls Is not expected to arise with rectangular
 «fa**V" If this problem should ever arise, the Adminis-
. tntor must be contacted for resolution of the matter,
   2.4  Verification of Absence of Cyclonic Plow. In  most
 stationary  sources, the direction of stack gas flow is
 essentially   parallel  to  ibe stack  walls.  However,
 cyclonic flow may exist (1) after such devices as cyclones
 and inertial demisten following venturi scrubbers, or
                                                     Level and nto the manometer. Connect a Type 8
                                                   pilot tube to the manometer. Position the Type V^dtot
                                                   tube at each traverse point. In succession, so that  the
                                                   planes of the face openings of the pi tot tnbe are perpendic-
                                                   ular to the stack cross-sectional pjanrwtum the Ttoe 8
                                                   pilot labels In this position. It Is at "0" reference.*'Note
                                                   the differential pressure (Ap) reading at each Inverse
                                                   point. U a null (zero)  pilot reading  Is obtained at 0*
                                                   reference at a given traverse point, an acceptable flow
                                                   condition exlttrat that fioint. If the pttot raiflliij {• not
                                                   «ero «tO* reference, rotate the flttot tone (op to ±90^ yaw
                                                   angle),an tHanuareadlnxIsobtalned. Caremlly'determine
                                                   and record the value  of the rotation angle (a) to  the
                                                   nearest degree. After the mill technique has been applied
                                                   at each travrse point, calculate the average of the abso-
                                                   lute values of 
-------

                                             RULK AND  REOULATIONS
41759
10.2.54 em«
(0.75-1.0 in.)
       * "jr*™"™* tiBS£S&f353£^3DP^

         T    ,  7.62 cm (3 in.)'
                                         TEMPERATURE SENSOR
                                                                                       LEAK-FREE
                                                                                     CONNECTIONS
                  •SUGGESTED (INTERFERENCE FREE)
                   PITOT TUBE • THERMOCOUPLE SPACING
                                  Figure 2-1.  Type S pilot tube manometer assembly.
                                          2.1 Typ« S Pilot Tube.  The Type 8 pilot tube
                                         (Figure 2-1) shall be made of meta) tubing (e.g.. stain-
                                         less sleel). It is recommended that the external lubing
                                         diameter  (dimension D,. Figure 2-2b) be between 0.48
                                         and 0.95 centimeters (Me and H inch). There shall be
                                         an equal distance from the base of each leg of the pilot
                                         tube to its face-opening plane (dimensions PA and PB,
                                         Figure 2-2H); It is recommended that this distance be
                                        ' between 1.05 and 1.50 times the external tubing diameter.
                                         The face openings of the pilot tube shall, preferably, be
                                         aligned as shown in Figure 2-2; however, alight misalign-
                                         ments of the openings are permissible (see Figure 2-3).
                                          The Type S pitot tube shall have a known coefficient,
                                         determined as outlined in Section 4. An Identification
                                         number shall be assigned to the pitot to be; this number
                                         shall be permanently marked or engraved on the body
                                         of the tube.
                                      IEGISTH, VOL. 42, NO.  160—THU*SDAY, AUGUST 18. 1977

-------
ffTDO
                               JBttES *«& SEOUIAT1OHS
                    TRANSVERSE
                     TUBE AXIS
                              \
                                         FACE
                                     h*~ OPENING
                                        PLANES

                                           (a)
LONGITUDINAL
                      Dt
                                         A SIDE PLANE
   TUBE AXIS
                                8
                                                                    NOTE:
                                                                         PA-PB
                                         B-SIDE PLANE

                                           (b)
                                         A ORB
                                           (c)
                 Figure 2-2.  Properly constructed Type S pitot tube, shown
                 in: (a) end view; face opening planes perpendicular to trans-
                 verse axis; (b) top view; face opening planes parallel to lon-
                 gitudinal axis; (c) side view; both legs of equal length and
                 center lines coincident, when viewed from both sides. Base-
                 line coefficient values of 0.84 may be assigned to pitot tubes
                 constructed this way.
                      KOERAi REGISTER, VOL 42, NO. 160—THURSDAY, AUGUST ) 8, 1977

-------
TRANSVERSE
 TUBtAXB ,r
1UIES A>JD REGULATIONS
'-•'''''^•.^£^L  ,".:,;.,.•-  /.
            fv      |«i;     \«2
               r   rf¥     V^l
            b;         /       v;
            • I'.'-'. t..-
                                                                          41761
                                      (f)
                                      W

    Figure 2-3. Types of face-opening misalignment that can result from field use or im-
    proper construction of Type S pitot tubes. These will not affect the baseline value
    of Ifpfe) so long as 01 and a2 < 10°. 01 and fa < 5°. z < 0.32 cm (1/8 in.) and w <
    a08 cm (t/32 in.) (citation 11 in Section 6).
           f&EML tECISTW, VOL 42, NO. 16O—THUMOAt. AUGUST 18, 1977

-------
 41762
        RtflH AfSO REGULATIONS
   A standard pftct tab« mar be nsed Instead of a Type 8,
 Provided that It n*ets the specifications of Sections 17
 and  4.2; note, btwever, that  th«  static and Impact
 pressure holes oT c&ndord pi tot tubes are susceptible to
 plucking in part: rt late-laden gas streams.  Therefore,
 whenever a sia^-iArd pitot tube  Is used to  perform  a
 traverse.  adequv.*  proof must be furnished that the
 openings of Ihe p:'->t tube hare not plugged up during the
 traverse period: :i;' can be done by taking  a Telocity
 head (Ap) readin. •  the final traverse point, cleaning oat
 the impact and si* x holes of the standard pitot tube by
 "bark-punting" ».  i pressurized  air, and then taking
 another Ap readi-   If the AD readings made before ana
 after the air purr  .t the same (tS percent), the traverse-
 is acceptable. Oi.-Krwise, reject the run.  Note- that ft Ap.
 at the anal  tro-.-rw point is unsuitably low, another
 point may  be  stated.  If  *'back-purging" at regular
 Intervals is pan cJ :he procedure,  then comparative Ap
 readings shall be uktn, as above,  for the last two back
 purges at which nimbly high  Ap readings are observed.
  2.2 Differential Pressure Gauge. An inclined manom-
 eter  or eqnivalpr.i device is used. Most sampling trains
 are equipped wi:h  a 10-in.  (water column)  inclined-
 vertical manomelf?, having 0.61-in. HjO divisions on the
 0- to 1-ln. Inclined scale, and 0.1-in. HiO divisions on the
 1- to 10-in. vertical scale. Thia type of  manometer (or
 other gauge  of equivalent sensitivity) Is satisfactory far
 the measurement of Ap values as tow as 1.3 mm (0.06 In.)
 HiO. However, a differential  pressure gange  of greater
sensitivity shall be toed  (subject to the approval of the
Administrator), if any of tbe  following  Is, toond to be
true: (I) the arithmetic average of all Ap readings at the
traverse points in the stack is less than 1.3 mm (0.05 Uk)
HiO; (2) for trave»» of 12 or more points, more than 10
percent of the Individual Ap readings an below IS mm
 (0.05 in.) BiO: (3; lor traverses of fewer  than  12 points,
more than one Ap reading is below 1.3 mm (0.06 in.) HiO.
Citation 18 in Section 6 describes commercially available
instrumentation for the ineasnremen t of low-range gas
velocities.
  As an alternative to criteria (1) through (3) above, the
following calculation may be performed to determine the
necessity of using  a more sensitive differential pressure
gauge:
where:
  Ap(=Individual velocity head reading at a traverse
       point, mm BiO (in. H.O).
    n=Total number of traverse points.
   K=0.13 jnm U.-O when metric units are tued and
       0.005 In HrO when English units are used.

If T  is greater than 1.05, tbe velocity head data are
unacceptable and a more sensitive differential pressure
gauge must be used.
  NOTE.—If  differential pressure  gauges  other  than
inclined manometer: are used (e.g., magncbelic gauges),
their calibration must be checked after each test series.
To check the calibration of a differential pressure gauge,
compare Ap readings of the gauge with those of a gauge-
oil manometer at i ninimum of three points, approxi-
mately representing ;iie range of Ap values in the stack.
If. at each point, the values of Ap as read by the differen-
tial pressure gauge and gauge-oil manometer agree to
within 5 percent. *:.? differential pressure gauge shall be
considered to be !.-. proper calibration. Otherwise, the
test scries shall pi::..?.- be voided, or procedures to adjust
the measured Ap vaiucs and final results shall be used.
subject to the a^provrJ of the Administrator.
  2.3  Temperature  Gauge. A thermocouple, liquid-
rilled  bulb UienconM-ter, bimetallic thermometer,  mer-
cury-in^lass  thermometer, or other gauge capable of
measuring teir.pi-ra-.ure to within 1.5 percent of the mini-
mum  absolute E;S.£  temperature  shall be used.  The
temperature gaufc s::all be ailttched to the  pitot  tube
such that the SPIGOT tip does not touch any  metal; the
gauge shall be in a^ interference-free arrangement  with
respect to the pitci lube fcce openings (see Figure 2-1
and also Figure 2-7 :n Section 4). Alternate positions may
bo used if the i'-;:.-:  '.abe-Urr.pcrature gauge system ia
calibrated accord:^ to the procedure of Section 4.  Pro-
vided that a difference of not more than 1 percent in the
average. velocity ^.easurcment is introduced, the  tcm-
 perature gangs need not be attached to the pitot tube;
 this  alternative  ii  subject to  the approval of  tbe
 Administrate:-.
  2.4  Pressure Probe and Gauge. A pleiometer tube and
 mercury- or water-filled TJ-tube manometer capable of
 measuring stack pressure to within 2.5 mm (0.1 in.) Hg
 Is used. The static tap of a standard type pitot tube or
 one leg of a Type X pitot tube with the face opening
 planes positioned parallel to the gas flow may also  be
 used as the pressure probe.
  2.5  Barometer. A mercury, aneroid, or other barom-
 eter  capable  of  measuring atmospheric  pressure  to
 within 2.6 mm Hg (0.1 in. Hg) may be used. In many
 cases, the barometric reading may be obtained from a
 nearby national weather oervioe station,  in which 'case
 the station value (which Is  the absolute  barometric
 pressure)  shall be requested and an adjustment for
 elevation  differences between the weather station  and
 the sampling point shall be applied at a rate of minus
 2.5 mm (0.1 In.)  Eg per 30-meter (100 foot) elevation
 Increase, or vice-versa for elevation decrease.
  2.6  Gas Density Determination Equipment. Method
 3 equipment, if needed (see Section 3.6), to determine
 tbe stack  gas dry  molecular weight, and Deference
 Method 4 or Method 5 equipment for moisture content
 determination; other methods may be used subject to
 approval of tbe Administrator.
  2.7  Calibration Pitot Tuba. When calibration of tbe
 Type S pitot tube to necessary (see Section 4), a standard
 pitot  tube Is and as a reference. The standard pitot
tube shall, preferably, have aknown coefficient, obtained
 either 0) directly from the National Bureau of Stand-
ards,  Boute 270, Quince  Orchard Road, Galthersburg,
                                                                                                          Maryland, or (2) by calibration against another standard
                                                                                                          pttot'*jbe with' an NBS-traoeable coefficient. Alter-
                                                                                                          natively, a standard pitot tube designed according to
                                                                                                          the criteria given In 2.7.1 through 2.7.5 below and Illus-
                                                                                                          trated In Figure 2-4 (see also Citations 7, 8, and 17 In
                                                                                                          Section 6) may be used. Pitot tubes designed according
                                                                                                          to these specifications will have baseline coefficients of
                                                                                                          about 0.09±0.01.
                                                                                                            2.7.1  HemtspherIcaUshownlnFlgure2-4).elllpsoIdal.
                                                                                                          or conical tip.
                                                                                                            2.7 J  A minimum of six diameters straight run (based
                                                                                                          upon D, tbe external diameter of the tube) between the
                                                                                                          Up and tbe static pressure holes.      .-'
                                                                                                            2.7.3  A minimum of eight diameters  straight run1
                                                                                                          between the static  pressure holes and the centerline of
                                                                                                          tbe external tube, following tbe 90 degree bend.
                                                                                                            2.7.4  Staliepressure.holesofequalslze (approximately
                                                                                                          0.1 D), equally spaced In a piezometer ring configuration.
                                                                                                            2.7.5  Ninety degree bend,  with curved or  mltered
                                                                                                          junction.
                                                                                                            2.8 Differential Pressure Gauge for Type  S Pilot
                                                                                                          Tube Calibration. An inclined manometer or equivalent
                                                                                                          Is used.  If the single-velocity calibration  technique Is
                                                                                                          employed (see  Section  4.1.&3), the calibration differen-
                                                                                                          tial pressure gauge shall be readable to tbe nearest 0.13
                                                                                                          mm HiO WMtin. JIiO). FormulUveloctty calibrations,
                                                                                                          the gauge shall be readable to tbe nearest 0.13 mm HrO
                                                                                                          (0.005 In HiO) for Ap values between 1.3 and 25 nun HtO
                                                                                                          (0.05 and 1.0 In. BiO),  and to the nearest L3 mm HiO
                                                                                                          (0.05 in. H*0) for Ap values above S mm  HjO (1.0 in.
                                                                                                          *">>. A tstOA more «em«rn cram wlD be required
                                                                                                         to read""AT°varaM'belowT.» mm
                                                                                                         (see Citation 18 In Section t).
I (0.05 In. HiO]
                                                                                                               CURVED OR
                                                                                                          MITERED JUNCTION
                                                                                                                            STATIC
                                                                                                                            HOLES
                                                                                                                           (-0.1DJ
                                                                                                              . HEMISPHERICAL

                                                                                                                      T"
                                                                Figure 2-4. • Standard pitot tube design specifications.
                                                    3.  Procedure

                                                      3.1  Set op the apparatus as shown in Figure 2-1.
                                                    Capillary tubing or surge tanks installed between the
                                                    manometer and pitot tube may be used to dampen Ap
                                                    fluctuations. It is recommended, but not required, that
                                                    a pretest leak-check be conducted, as follows: (1) blow
                                                    through the pitot impact opening until at least 7.6 cm
                                                    (3 in.) IliO velocity pressure registers on tbe manometer;
                                                    then, close  off the impact opening. The pressure shall
                                                    remain stable for at least 15 seconds; (2) do the same for
                                                    the static pressure side, eicept using suction to obtain
                                                    the minimum of 7.6 cm (3 in.) HtO. Other leak-check
                                                    procedures, subject to the approval of the Administrator,
                                                    may be used.                                     -
                                                     3.2  Level and zero the  manometer. Because the ma
                                                   nometer level and zero may drift due to vibrations and
                                                   temperature changes, make periodic checks during  the
                                                   traverse.  Record an necessary data as  shown in  the
                                                   example data sheet (Figure 2-5).
                                                     3.3 Measure the velocity head and temperature at the
                                                   traverse points specified by Method 1.- Ensure that  the
                                                   proper differential pressure gauge is being used (or  the
                                                   range of Ap values encountered (see Section 2.2). If it la
                                                   necessary to change to a more sensitive gauge, do so, and
                                                   remeasnre tbe Ap and temperature readings at each tra-
                                                   verse point. Conduct a post-test leak-check (mandatory),
                                                   as described in Section 3.1 above, to validate We traverse
                                                   run.
                                                     3.4 Measure the  static pressure In the stack. One
                                                   reading is usually adequate.
                                                     3.5 Determine the atmospheric pressure.
                                       FEDEBA1  REGISTER. VOL 41, NO.  160—THURSDAY,  AUGUST  18, 1977

-------
      RULES AND REGULATIONS
41763
MAPfT .
pftTP RUM an
STACK DIAME
BAROMETRIC
CROSS SECTIO
OPERATORS _
WTOTTUBtU
AVG.COEF
LAST DATE
Travcnt
Ptllo.


-





-









TER OR DIMENSION*
PRESSURE, mm Kg (i
BAt ARFA m2(ftZ)
? m(ttt) , _^
" "af


n-im
pIMPMT p. • as .
fAIIRRATFn

VtI.Hl.Aj.
mnrftUHzO


















Cfa* k T«niM*r«inm

%,°cm
^
















-
Avtnp
Tfc»K{«W

,



	












-.

SCHEMATIC OF STACK
CROSS SECTION
wnHft'tuUti)



•
'

-










•

.«•



















Figure 2-5.  Velocity traverse data
      , VOL 42, NO. 1«0—TKUtSDAY, -AUGUST II. 1477

-------
  41764
      RUUS AND  REGULATIONS
   ».«  Determine «n» stack 31* flry motoauar jwfcbt.
  For oombtKtitm tncean* or procesaoa that emit eoan-
  tlaDy CO*. Ofc CO, and Ni. oao Method a. For processes
  omitting resentfully air, an analysis need not be con-
  ducted; use • dry auleealar weight of 29.0. For other
  processes, other methods, subject to the approval of the
  Administrator, xunst be used.
   3.7  Obtain U»  nioistnra  content bom Reference
  Method 4 (or equivalent) or from Method ft.
   3.8  Determine the aosMectlonalarea of the stock
  or duct at the tr ojpHng location. Whenever possible,
  physically mease . the stack dimensions rather than
•using Uuenrloav
   4.1  Type 8 Pftot Tub*. Baton its Initial use, care-
  fully examina the Type 8 pitot tube hi top, ride, and
  end vtows to verify that the face openings of the tube
  are aligned within the specifications illustrated In Figure
  2-S orMTTbe pttot tube abaB not be and If it bib to
  meet these alignment spedflcsttons.
   After verifying the taoe opening alignment, measure
  and record thefBQowing dimensions of the pilot tube:
AO the eitams! tnbuu dtametar (dimension D,, Figure
z-zb); and (b) the Dose-to-opanlnf plane distances
(dunenstaB PA and P*. Figure iMo). lfx>, b between
0.48 and 0.91 «m (Mt and H tn.) and If J>4 and PC an
equal and between 1.05 and 1.50 KI, there are two possible
options: (I> the pttot tube may be calibrated according
to the procedure outlined  In  Sections 4.1.2 through
4.14 below, or (2) • baseline (Isolated tube) coefficient
value of 0.84 may be assigned to the pltot tube. Note,
however, that if the pltot tube is part of an assembly,
calibration may still be required, despite knowledge
of the baseline coefficient  value (see Section  4.1.1).
  If D,, Pf.faAPatat outside the specified limits, the
pitst tube mast be calibrated as outlined in 4.1.2 through
4.1J below.
  4.1.1 Type 8 Pttot Tube Assemblies. During sample
and Telocity traverses, the isolated Type 8 pltot tube is
not always oaed: In many Instances, the pilot tube is
used In combination with other source-sampling compon-
ents (thermocouple, sampling probe, noiile) as part of
an "assembly." The presence of other sampling compo-
nents can sometimes affect the baseline value of the Type
8 pilot tube coefficient (Citation 8 In Section 6); therefore
an assigned (or otherwise known) baseline coefficient.
                                                     TYPE SPtTOT TUBE
                                                                          vatae may or may not be rand for • given assembly. The
                                                                          baseline and assembly coefficient value* will be Identical
                                                                          only -when the relative placement of the components In
                                                                          the assembly b such that aerodynamie Interference
                                                                          effects are eliminated. Figures 2-6 through 2-8 Illustrate
                                                                          Interference-free component arrangements for Type 8
                                                                          pltot tubes having external tubing diameters between
                                                                          0.48 and 0.85 cm (Mi and H In.). Type 8 pltot tube assem-
                                                                          blies that fad to meet any or all of the specifications of
                                                                          Figures 2-6 through 2-6 snail be calibrated according to
                                                                          the procedure outlined In Sections 4.1.2 through 4.1.8
                                                                          below, and prior to calibration, the values of the Inter-
                                                                          component spaolngs (pltot-nonle, pilot-thermocouple,
                                                                          pilot-probe sheath) ahan be measured and recorded.
                                                                            Norm.—Do not its* any Type 8 pilot tube assembly
                                                                          which is constructed such that the Impact pressure open-
                                                                          ing plane of the pltot tube b below the entry plane ofthe
                                                                          notie (see Figure S-6b).         :
                                                                            4.1.2  Calibration Setup. If the Type 8 pltol tube is lo
                                                                          be calibrated, one leg of the tube shall be permanently
                                                                          marked A, and the other, 3. Calibration shall be done in
                                                                          a flow system having the following essential design
                                                                          features:

                                                                            I
                                               i
     r£ IJ3 OR (1/4 M FOR 0, -'1.3 cm {1/2 faj
                                   SAMPLIWGHOZZLE
                           A. BOTTOM VIEW; SHOWING MINIMUM PITOT-NOZZLE SEPARATION.
SAMPLING
  PROBE
                                                       SAMPLING
                                                        NOZZLE
                                                        STATIC PRESSURE
                                                         OPENING PLANE
                                                                                                        IMPACT PRESSURE
                                                                                                          OPENING PLANE
                               B.  SIDE VIEW; TO PREVENT PITOT TUBE
                                  FROM INTERFERING WITH GAS FLOW
                                  STREAMLINES APPROACHING THE
                                  NOZZLE. THE IMPACT PRESSURE
                                  OPENING PLANE OF THE PITOT TUBE
                                  SHALL BE EVEN WITH OR ABOVE THE
                                  NOZZLE  ENTRY PLANE.
                          Figure 2-6.  Proper pitot tube • sampling nozzle configuration to prevent
                          aerodynamic interference; buttonhook • type nozzle; centers of nozzle
                          and pitot opening aligned; Dt between 0.48 and 0.95 cm  (3/16 and
                          3/8 in.).                                                                     .
                                    FEDERAL REGISTER,  VOL 42, NO. 160—THURSDAY, AUGUST  18, 1977

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                                                       8UIES
                                                                                                                   41765
                                                                                             mmUICOUPU
                                                                                                     TYrtSPITOTTUBE
                                                                                    SAMPLE  PROBE
                                   Figure 2-7. Proper thermocouple placement to prevent interference;
                                   Dt between 0.48 and 0.95 cm (3/16 and 3/8 in.).   -
                                                                            TYPE SPITOT TUBE
                                                                                      Y>7.62cm(3inJ
                                   n;yi  HI
                             SAMPLE PROBE
  Figure 2-8.   Minimum pitot-sample probe separation needed to prevent.injterference;
  Dt between 0.48 and 0.95 cm  (3/16 and 3/8  in.).
  4.1.2.1  The flowing f«3 stream must be confined to •
duet a! definite croci nnniniml an*, tuber circular or
netauKola?. For eimdur eross-aectlana, the minimum.
duet diameter shall be 30.5 em (13 In.); for rectangular
riws-eocUoni, the width febortor side) shall b« at least
25.4 cm (10 in.).
  4.1.2 J  The eross-Geettonal area of the calibration duct
most be constant over a distance of 10 or more duet
dianuters. For a "ytft"g"T"' cross-section, use an equiva-
lent diameter, calculated from the following equation,
to determine the number of duct diameters:
                />.=
 2LTV
(L+W)
                                Equation 2-1
where:
  .».=Equivalent diameter
  i= Length
  »'=Widtb

  To ensure the presence of stable, fully developed flow
patterns at  the calibration site, or "test section," the
site must be located at least eight diameters downstream
and two diameters upstream from the nearest disturb-
ances.
  NOTE.—The eight- and two-diameter criteria are not
absolute; other test section locations may be used (sub-
ject to approval of the Administrator), provided that the
flow at the test site Is stable and demoustrably parallel
to the duct ails.
  4.1.2.3 Tbe flow system shall  have the capacity to
generate a test-section velocity around 915 m/min (3,000
ft/min). This velocity must be constant with time to
guarantee steady  flow during calibration. Note that
Type 8 pitot tube coefficients obtained by single-velocity
calibration at 915 m/min (3,000 ft/min) will generally be
valid to within ±3 percent  for  the measurement of
velocities above 305 m/min (1,000 ft/mln) and to within
±6 to 6 percent for the measurement of velocities be-
tween 180 and 305 m/mtn (MO and 1,000 ft/min). If a
more precise correlation  between C, and velocity is
desired, the flow  system shall have the capacity to
generate at least four distinct, time-invariant test-section
velocities covering the .velocity range from 180 to 1,525
m/min (600 to 5,000 ft/mln), and calibration data shall
be taken at regular velocity Intervals ever this range
(see Citations 9 and 14 in Section < for details).
  4.1.2.4 Two entry ports, one each for the  standard
and Type S pilot tubes, shall be, cnt in the test section;
the standard pitot entry port shall be located slightly
downstream of the Type B port,  so that the  standard
and Type S impact openings will lie in the same crass-
sectional plane during calibration. To  facilitate align-
ment of the pitot tubes during calibration, it is advisable
that the test section be constructed of pleiiglas or some
other transparent material.
  4.1.3  Calibration Procedure. Note that this procedure
Is a general  one and must not be used without first
referring to the special considerations presented in Sec-
tion 4.1.5. Note also that this procedure applies only to
single-velocity calibration. To obtain calibration' data
for the A and B sides of the Type S pitot tube, proceed
as follows:
  4.1.3.1  Make sure that the manometer  is  properly
filled and that the oil is free from contamination and is of
the proper density. Inspect and leak-check all pitot lines;
repair or replace if necessary.'
  4.1.3.2 Level and tero the manometer. Turn on Hie
fan and allow toe flow to stabilise. Seal tbe Type S entry
port.   •                - '    —    -
  4.1.SJ Ensure that the manometer is level and leroed.
Position the standard pitot tube at the calibration point
(determined as outlined in Sction 4.U.I), and align the
tube so that its tip is pointed directly into the flow. Par-
ticular care should be taken in aligning the tube to avoid
yaw and pitch'angles. Make sure that the entry port
surrounding the tube is properly sealed.    .'
  4.1.3.4 Read Ap.td and record,its value in a'data table
similar to tbe one shown in 'Figure 2-9. Remove the
standard pitot tube from the duct and disconnect it from
the manometer. &eal the standard entry port.
  4.1.3.5 .Connect the Type S pilot tube to the manom-
eter. Open the Typo S entry port. Check the manom-
eter level and tero. insert and align the Type S pitot tube
so that its A side impact opening is ax the same point as
was the standard pitot tube and is pointed directly into
tbe tlow. Make sure that the entry put surrounding the
tube is properly sealed.
  4.1.3:6 Read Ap, and enter its value in the data table.
Remove the Type 8 pitot tube from the duct and dis-
connect it from the manometer.
  4.1.3.7 Repeal steps 4.1.3.3 through 4.1.3.6 above until
three pairs of Ap readings have beer, obtained.
  4.1.3.8 Repeat steps 4.1.3.3 through 4.1.3.7 above for
the B side of the Type S pitot tube.
  4.1.3.9 Perform calculations, as described in Section
4.1.4 below.
  4.1.4  Calculations.
  4.1.4.1 For each of the sii pairs of ap readings (i.e.;
three from side A and three from side B) obtained in
Section 4.1.3 above, calculate the value  of tbe Type S
pitoi ml* t'x-flicimt as follows:
                                     F&KIAL REGISTEI,  VOL 42, NO.  160—THUtSDAY, AUGUST J«,  1977

-------
41766
                                                         RUIES AND  REGULATIONS
 PirOTTUBE IDENTIFICATION NUMBER:

 CALIBRATED BY?	
                                                                     .DATE:.

RUN NO.
1
2
3
"A" SIDE CALIBRATION
' APstrf
crnHjO '
(in. HjO)




Ap(j)
cmH20
(in.HaO)



CpfilDEA)
CpW





DEVIATION
CpM-CpjA)




,
RUN HO-.
1
i
3
"B" SIDE CALIBRATION
Apjtd
craHjO
(In. HzO)



- .-" " - ' '
APW
ernHjO
(in.HzO)



Cp(SIDEB)
CpW





' DEVIATION
CpM-CpW
•



      AVERAGE DEVIATION = cr(AORB)
                                                S|Cp(i)-Cp{AORB}|
                                                                              -foUSTBE<0.01
      |  Cp (SIDE AJ-Cp (SIDE B) J-*-MU$T BE<0.01
                        Figure 2-9.  Pitot tube calibration data.
          Calculate the deviation of each of the three A-
 dde-rahMaof C,(.) from (?, WdeA), and the deviation of
 each B-elde value of C,M from C, (side B). Use the fol-
 lowing equation:

         Deviation=C,(.) — f?p(A of B)  •

                                  Equation 2-3

   4.1.4.4  Calculate », the average .deviation from the
 mean, for both the A and B sides of the pilot tube. Use
 the following equation:

                        3
                                                                                                      a (side A or B) =
•here:
                                 Equation 2-2
        'Type 8 pilot tube coefficient
        =Standard pitot tube coefficient: use 0.99 if the	
         coefficient is unknown and the tube Is designed   values.
                                                           according to the criteria of Sections 2.7.1 to
                                                           .2.7.5 of this method.
                                                          -Velocity bead measured by the standard pilot
                                                           tube, em HiO On. H|O)
                                                       Aj>.=Velocity bead measured by the Type 8 pilot
                                                           tube, em HjO On. HiO)
                                                    4J.4J  Calculate C, (side AX the mean A-slde coef-
                                   Equation 2-4

   4.1.4.5  Use the Type S pitot tube only If the values of
 • (side A) and * (side B) are less than or equal to 0.01
 and If the absolute value of the difference between  C,
 (A) and C, (B) Is 0.01 or less.
   4.1.4 Special considerations.
   4.1.4.1  SelooUon of calibration point
   4.1.S.1.1 When an Isolated Type 8 pitot tube Is cali-
 brated, select a calibration point at or near the center of
 the duct, and follow the procedures outlined In Sections
 4.1.3 and 4.1.4 above. The Type S pitot coefficients so
 obtained, Le., 
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                                                         BOIES  AND REGULATIONS
                                                                                 41767
                                                         ESTIMATED
                                                         SHEATH
                                                         BLOCKAGE
              F   lxw     1
              [pUCTAREAJ
                                                                                                                       (b)
x  100
                            Figure 2-10.   Projected-area models for typical pltot tube assemblies.
  4.1.9 Field Use and Recalibratton.    .   .   .
  4.1.8.1  Field Dse.                       "
  4.1.6.1.1  When m Type 8 pltot tube (Isolated tube or
assembly) la used In the field, the appropriate coefficient
Talue (whether assigned or obtained by calibration) shall
be used to perform velocity calculations. For calibrated
Type 8 pilot tabes, the A side coefficient shall be used
when the A side of the tube faces the flow, and the B side
coefficient shall be used when the B side faces tbe flow;
alternatively, tbe arithmetic average of the A and B side
coefficient values may be used, irrespective of which side
faces tbe flow.                 •
  4 1.6.1.2  When a probe assembly is used to sample a
small duct (12 to 38 In. in diameter), tbe probe sheath
sometimes blocks a significant part  of the duct cross-
section, causing*a reduction in the effective  value of
 percent, the temperature data
taken in the field shall be considered valid. Otherwise,
the pollutant emission tesl shall either be considered
invalid or ad]ustmenls (if appropriate) of the test results
shall be. made, subject to tbe approval of the Administra-
tor.
  4.4  Barometer.  Calibrate tbe barometer used against
a mercury barometer.

5. Calculation!

  Carry out calculations, retaining at least ono extra
decimal figure beyond lhal of Ihe acquired data. Round
oil figures after llnal calculation.
  5.1  Nomenclature.
   X=Cross-sectional area of stack, m'(fl'). .
  B«,=Water vapor in the gas stream (from Method 5 or
       Reference  Method 4),  proportion by volume.
   Cp=Pitol rube coefficient, dimensionless.
  A',=Pilot tube constant,

     ?A 07  m r(g/g-mole)(minHg)'

     J4-97^L  c

for the inelric system and
          °K)(mmHjOj   J
      for tbe English system.
         Af j=Molecular weight of slack  gas, dry  basis (set
            Section 3.6) g/g-mole (Ib/lb-mole)	
      . .  if,—Molecular weight of stack gas, wet basil, g/g-
            mole (Ib/lb-mole).

            **Afrf (1—BM)-f-18.0 Bwt          Equation 2-5

        Pb,i=Barometric pressure al measurement site, mm •
            Hg (in. Hg).       . .'  •
         P,=fitack static pressure, mm Hg (In. Hg).
          P,*=Absolute slack, gas pressure, mm Hg (in. Hg);

       . .    =.Pb.r+Pi     .  ••   •          Equation 2-fl

        PI«=Standard absolute pressure, "60 mm Hg (29.92
            in. Hg).
         Q,i=Drv volumelric slack gas Eow rate corrected to
            standard conditions, dscm/hr (dscf/br).
           (,=Stack lemperalurc', °C (°F).
          T.=Absolule stack temperature, °K (°R).

                                           Equation 1-7

                                           Equation 2-8
                                                    f. for metric

                                              =400+1. for English
                                           Taj=S!andard absolute temperature, 293 °K- (528* R)
                                             F,=Average stack gas velocity, m sec (ft 'sec;.
                                            Ap=V«locity head of slack gas, mm UiO (in. HiO):
                                          3,600= Conversion factor, sec/hr.
                                           18.0=Mo!ecular weight  of water,  g.'g-mo'.e   flb-lb-
                                              mole'1.
                                          5.2  Avorsgc slack gas velocity.
       5.3  Avi-:\i£0 tic
                                                                         Equation 2-9

                                                         i (j;"L5 dry volumeiric flow rate.
ft  r(lb/lb-mole)(in.Hg)-|'/'
sccL   (°l{)(in. H,6)    J
                                                                        Equation 2-10
       1. Mark. L. S. Mechanical Encineers' Handbook. Now
     Yorkj McGraw-Hill Book Co., Inc. 1»M.
       2. Perry. J. H. Chemical Engineers' Handbook. New
     York. ilc
-------
47768
KU£S AND BE&UUUIONS
                          3. Solgehara, R. T., W. F. Todd, and W. 8. Smith.
                        Significance of Errors In Stack Sampling Measurements.
                        U.S.  Environmental  Protection  Agency.  Research
                        Triangle Park, N.C. (Presented at the Annual Meeting o(
                        the Air Pollution Control Association, St. Louis, Mo.,
                        June 14-19,19m)
                          4. Standard Method tor Sampling Stacks (or Farttcnlate
                        Matter. In: 1971 Book of ABTM  Standards. Part 23.
                        Philadelphia, Pa. 1871. A8TM DesignatiorTD-2928-71.
                          S. Vennard, J. K. Elementary Fluid Morfinni.-^ New
                        York. John Wiley and Sow, Inc. 1947.
                          6.  Fluid Meiers—Their Theory  and  Application.
                        American Society of Mechanical Engineers, New York,

                          7. ASURAE Handbook of Fundamentals. 1972. p. 208.
                          8. Annual Book of ABTM Standards, Part 26.1974, p.
                        648.
                          9. Vollaro, K. F. Guidelines for Type 3 Pilot Tube
                        Calibration. D.8. Environmental Protection Agency.
                        Research Tiangle Park, N.C. (Presented at 1st Annual
                        Meeting, Source Evaluation Society, Dayton,  Ohio,
                        September 18.1375.)
                          10. Volhm. R. F. A Type 8 Pilot Tub* Calibration
                        Study. U.S. Environmental Protection Agency, Emis-
                        sion  Measurement  Branch,  Research Tctangle  Park,
                        N.C. July 1371.
                          11. Vollaro, B. f. The Eflects of Impact Opening
                        Misalignment on the Varna of the Type 8 Pilot Tube
                        Coefficient.  U.8.  Environmental  Troteethro Agency,
                        Emission  Measurement  Branch   fiesearch  Triangle'
                        Park, N.C. October 1978.
                          12. Vollaro, R. f. Establishment of a Baseline Coeffi-
                        cient  Value for  Properly Constructed Type 8  Pilot
                        Tubes. U.S. Environmental Protection Agency, Emis-
                        sion Measurement  Branch,  Research Triangle  Park,
                        N.C.  November 1976.
                          13. Vollaro, R. T. An Evaluation of Single-Velocity
                        Calibration Techniques as a Means of Determining Type
                        S Pilot Tube Coefficients. U.S.  Environmental Protec-
                        tion Agency, Emission Measurement Branch. Research
                        Triangle Park, N.C. August 1975.
                          14. Vollaro, B, F. The Use of Type 8 Pilot Tabes for
                        the Measurement of Low Velocities. U.S. Environmental
                        Protection Agency  Emission  Measurement  Branch,
                        Research Triangle Park, N.C. November 1970. ,
                          15.  Smith. .Marvin L. Velocity  Calibration of EPA
                        Type  Source Sampling  Probe. United  Technologies
                        Corporation,  Pratt  and  Whitney  Aircraft  Division,
                        East Hartford. Conn. UTS.
                          16. Vollaro, R. F. Recommended ProeednmJbr Simple
                        Traverses in DncU Smaller than 12 laches In I>iatnet4r.
                        U.S.  Environmental  Protection  Agency,  Emission
                        Measurement Branch, Research Triangle Park,  N.C.
                        November 1976.
                          17. Over, E. and R. C. Pankhnrst. The Measurement
                        of Air Flow, 4th Ed. London, Pergamon Press. 1968.
                          18. Vollaro, B. F. A survey of Commercially Available
                        Instrumentation for the Measurement of low-Bang)
                        Gas Velocities. U.S. Environmental Protection Agency,
                        Emission Measurement  Branch,  Research  Triangle-
                        Park, N.C. November 1976. (Unpublished Paper)
                          19.  dnyp. A.  W, C. C. St. Pierre. D. & Smith, D.
                        ilazzon, and J. Steiner. An Experimental Investigation
                        of the Effect of Pilot Tube-Sampling Probe Configura-
                        tions on  the Magnitude of the 8 Type Piutt Tube Co-
                        efficient for Commercially Available Source BamnUng
                    Probes. Prepared by the Tfolmrslty of Windsor tor th»
                    Ministry of the Environment,' Toronto, Canada. Feb-
                    ruary 1975.'

                    METHOD  3—OAS ANALYSIS rom CABBON DIOXIDE,
                     OXYOEN, EXCESS AIR, AND DBT MOLECULAB WEIGHT

                    1. Principle and ApfOalMtUf

                     1.1 Principle. A gas sample Is extracted from a alack,
                    by one of the following methods: (1) single-point, grab
                    sampling; (2) single-point, Integrated sampling; or (S)
                    multi-print, Integrated sampling. The  gas sample li
                    analysed for percent carbon dloxwe (CO>), percent oxy-
                    gen (O>). and, U necessary, percent carbon monoidae
                    (CO). U a dry molecular weight determination is to be
                    made, either an Orsat or a i'yrile • analyzer may be used
                    for the analysis: for excess air or emission rate correction
                    factor determination, an Orsat analyzer must be used.
                     1.2 Applicability. This method is applicable for de-
                    termining COi and  Oj concentrations, excess air, an'd
                    dry molecular weight of a sample from a gas stream of a
                    fossil-fuel combustion process. The method may also he
                    applicable toother processes whereith»been determined
                    that compounds other than COi, Oi, CO, and nitrogen
                    
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                               RULES AND REGULATIONS
41769
                         PROBE
                 FILTER (GLASS WOOL)
                                                                         TO ANALYZER
                                      SQUEEZE BULB
                                  Figure 3-1. Grab-sampling train.
                                                  RATE METER
PROBE
           AIR-COOLED
           CONDENSER
        FILTER
     (GLASS WOOL)
                                       RIGID CONTAINER
                           Figure 3-2. Integrated gas-sampling train.
                   fOERAL REGISTH, VOL 42, NO. 160—THURSDAY, .AUGUST It. 1977

-------
41770
SUtB AND  REGULATIONS
   2,2.2  Condenser. An air-cooled or water-cooled eon-
 denser, or other condenser  that win not remove O*
 COt, CO, and Xt, may be used to remove excess mnbtnre
 which would Interfere with tbe operation of tbe pomp
 and flow .meter.
   2.2.8  Valve. A needle valve Is used to adjust sample
 gas flow rate.
   2.2.4  Pnmp. A  leak-free,  diaphragm-type pomp, or
 equivalent. Is csed  to transport sample gas to the fl»**Trii»
 bag. Install a ratal! surge tank between tbe pomp mnd
 rate meter to eliminate the pulsation effect of  tbe dia-
 phragm pumr on the rotameter.
   2.2.8  Jut,  Meter. Tbe rotameter, or equivalent rat*
 meter,  used  jonld be capable of measuring flow nta
 to within dt-> percent of the selected flow rate. A flow
 rate range of 500 to 1000 cm'/mln is suggested.
   2.2.6  Flexible Ban. Any leak-free plastic (e.g., Tedlar.
 Mylar,  Teflon) or plastic-coated aluminum (e.g., alumi-
 nized  Mylar) beg, or equivalent, having a  capacity
 consistent with the selected  flow rate and time length
 of tbe test ran. may be used. A capacity in the  range of
 65 to 90 liters is snggested.
   To leak-check tbe bag, connect It to a water manometer
 and pressurize tbe bag to S to 10 cm HiO (2 to 4 In. HiO).
 Allow to stand lor  10 minutes.  Any displacement In the
 water manometer Indicates a leak. An alternative leak-
 check method is to pressurize the bag to £ to 10  cm HiO
 (2 to 4 In. HiO) and allow to stand overnight. A deflated
 bag Indicates a leak.
   2.2.7  Pressure Gauge. A water-filled U-tnbe  manom-
 eter, or equivalent, of about 28 cm (12 in.) is  used  for
 tbe flexible bag leak-check.
   223  Vacuum  Gauge.  A  mercury manometer,  or
 equivalent, of at least 760 mm Hg (30 in. Hg) to used tor
 the sampling train leak-check.
   2.3  Analysis. For Orsat and Fyrlte analyzer  main-
 tenance and operation procedures, follow tbe instructions'
 recommended by  tbe manufacturer, muecs otherwise
 specified  herein.
   2.3.1  Dry Molecular Weight Determmstkm. An Omt
 analyzer or Fyrite type combustion gas analyzer may be

   2.3.2  Emission Rate Correction Factor or Excess Air
 Determination. An Orsat analyzer must be used. For
 low COi  (less tban 4.0 percent) or high Ot (greater than
 15.0 percent) concentrations, tbe measmtng tjurette of
 tbe Orsat must have at least OJ percent subdivisions.

 3. Dn Moltcalar BVfJM Dttcrmtnatim

   Any of the three sampling and analytical procedures
 described below may be used tor determining tbe dry
 molecular weight.
   3.1  Single-Point,  Grab  Sampling  end Analytical
. Procedure.
   3.1.1  The sampling point In the duct shall either be
  at the eentroid of the cross section or at a point  no closer
  to the walls than 1.00m (3.3 ft), unless otherwise specified
 by tbe Administrator.
   3.1.2 Set up tbe equipment as shown  in Ftetm 8-1,
  making sure all connections ahead of the analyzer  are  .
  tight and leak-free. II an Orsat analyzer is used, it is
  recommended that tbe analyzer be  leaked-checked by
  following the procedure in Section 5; however,  tb* leak-
  check Is optional.
    3.1.3  Place tbe  probe in the stack, with tbe tip of tb*
  probe positioned at tbe sampling point; purge the sampl-
  ing line. Draw a  sample  into the analyzer and  imme-
  diately analyze it for percent COiand percent Ot. Deter-
  mine the percentage of the gas that is Nt and CO by
  subtracting tbe sum of tbe percent COt and percent Ot
  from 100 percen:. Calculate the dry molecular weight as
 • Indicated In Section 6.3.
    3.1.4  Repeat the sampling, analysis, and calculation
  procedures, until the dry molecular weights of any three
  grab samples differ from  tbelr mean by no more tban
  0.3 g/g-mole (OJ Ib/lb-mole). Average these three molec-
  ular weights, and  report  tbe results to the nearest
  0.1 g/g-mole (lb,1b-mole).
    3.2  Single-Point, Integrated Sampling  and Analytical
  Procedure.
    3.2.1  Tbe sampling point In tbe duct shall be located
  as specified in Section 3.1.1.
    3.2.2 Leak-check  (optional) the  flexible bag as In
  Section 2.2.6. Set  up the equipment as shown  in Figure
  3-2. Just prior to sampling,  teak-check  (optional)  tbe
  train by placing a vacuum gauge at the condenser inlat,
  pulling a vacuum of at least 250 ™™ Hg (10 in. Hg),
  plugging the ouUet at the quick disconnect,  and then
  turning off the pump. The vacuum should-remain stable
  for at least 0.5 miaute. Evacuate the flexible bag. Connect
  tbe probe and place It in the stack, with the  tip of the
.  probe positioned at the sampling point; purge tbe sampl-
  ing line. Next, connect the bag and make sure that all
  connections are tight and leak free.
     3.2.3  Sample at a constant rate. The sampling: run
  should be simultaneous  with, and for  the same total
   length of time as, the pollutant emission rate determin*r
   tion. Collection of at least 30 liters (1.00 ft') of sample gas
   is  recommended; however.  «mmn«r volumes may Da
   collected. If desired.
     3.2.4  Obtain one Integrated flue gas sample during
   each  pollutant emission rate determination.  Within g
   hours after the sample is taken, analyze it for percent
   CO, and percent Ot using either an Orsat analyzer or a
   Fyrite-type combustion  gas  analyzer. If an Orsat  ana-
   lyitr  is used, it  is recommended that the Orsal leak-
   check described  in Section 5 be performed before this
   determination; however, tbe check is optional. Deter-
   mine the percentage of the gas that is Ni and CO by sub-
   tracting tbe sum of tbe percent CO. and percent Oi
                                                     m°||^l*J^C
-------
 than (a) OJ percent by volume whan Oi Is less than 15.0
 percent or (6) 0.2 percent by volume when Oi la greater
 than 15.0 percent. Average the three acceptable values of
 percent Oj and  report the  results to the nearest 0.1
 ' percent.
   4.2.6.3  For percent CO, repeat the analytical proce-
 dure until the results of any three analyses differ by no
 more than 0.3 percent.  Average the three  acceptable
 values of percent CO and report the result* to toe nearest
 0.1 percent.
   4.2.7 After the  analysis  b  completed,  leak-check
 (mandatory) the Orsat analyzer once again, as described
< in Section 6. For the results of the analysis to be valid, the
 Orsat analyzer must pass this leak test before and after
 the analysis. Note:  Although In most Instances only COi
 or Oi Is required, it is recommended that both Cut and
 Oi be measured, and that Citation 5 in the Bibliography
 be used to validate the analytical data.      .   "
   4.3  Multi-Point, Integrated Sampling and Analytical
 Procedure.
   4.3.1  Both the minimum number of sampling point*
 and the sampling point location shall be as specified in
 Section 3.3.1 of this method. The use of fewer points than
 specified is Mbject  to the approval of the Administrator.
   4.3.2 Follow the procedures outlined in Sections  4.2.2
 through  4.2.7, except for the following: Traverse all
 eampirnjj points and  sample at each point for an equal
 length of time. Record sampling data as shown in Figure
 3-3.

 8. Xeei-CftMi Proctdunfar Ontl Andyim

   Moving an Orsat analyzer frequently causes It to leak.
 Therefore, an Great analyzer should be thoroughly teak-
 checked on site before the flue gas sample is introduced
 Into It. The procedure for leak-checking an Orsat analyser
 is:
   5.1.1. Bring the liquid level in each pipette up to the
 reference mark on the capillary tubing and then close the
 pipette stopcock.
   8.1.?  Raise the leveling bulb sufficiently to bring the
 confining liquid meniscus onto the graduated portion of
 tbe burette and then close the manifold stopcock.
   5.1.3 Record the meniscus position.
   5.1.4 Observe the meniscus In the bnrette and tbe
 liquid level in the pipette for movement over the next 4
 minutes.
   S.1.6 For the  Orsat analyzer to pass the  leak-check,
 two conditions must be met.
   6.1.5.1  The liquid level in each pipette must not fan.
 below  the bottom of the capillary tubing during this
 4-mlnnte Interval.
   5.1.5.2  The meniscus in the burette must not change
 by more than 0.2 ml during thls4-minuteinterval.
   5.1.6  If the analyur fails the leak-check procedure, all
 rubber connections and  stopcocks should be cheeked
 until the cause of the leak is Identified. Leaking stopcocks
 must be disassembled, cleaned, and regressed. I^»»Mne
 rubber connections must be replaced. After the anaryter
 Is  reassembled, the leak-check  procedure must 'be
 repeated.
                                                             RULES  AND  REGULATIONS
0. CalevlaOont

 4.1  Nomenclature.
     Mi=Dry molecular weight, g/g-mok (Ib/lb-intfh).
  %EA<=< Percent excess air.
 %COt=Percent COiby volume (dry bads).
   %Oj=Percent Oj by volume (dry bests).
  %CO=Percent CO by volume (017 basts).
   %Ni=Percont Ni by volume (dry basis).
   0.284=Ratio of Oi to Nt In air, v/v.
   0.2SO=Molecu!ar weight of N, or CO, divided by 100.
   0.320=Moleeular weight of Oj divided by 100.
   0.440=Molecular weight of CO, divided by 100. .
  6.2 Percent Excess Air. Calculate the percent  excess
air  (it  applicable), by substituting  the appropriate
Tames of percent Ot, CO, and N) (obtainedtrom Section
4.1.3 or 4.2.4) into Equation 3-1.  .
                                                                                              41771
                   %O,-0.5%CO
-1,
           0.264 %NV( %0,-0.5 %CO)

                                   Equation 3-1

  NOTE.— The equation above  assumes  that ambient
air is used as the source of Oj and that the fuel does not
contain appreciable amounts of Nt (ts do coke oven or
blast furnace gases).  For those coses when  appreciable
amounts of Ni are present (coal, on, and  natural gas
do not contain appreciable amounts of  Nt) or when
oxygen enrichment Is used, alternate methods, subject
to approval of the Administrator, are required.
  6.5  Dry Molecular Weight.  Use Equation  8-2 to
calculate the dry  molecular weight of the stack gas

   Jtfj=0.4«0(%COi)+0.320(%Oj)-H).280(%>I»+%CO)

                                   Equation 3-2

  NOTE.— The above equation does not consider argon
In air  (about  0.9  percent, molecular weight of 37.7).
A negative error of  about 0.4  percent 'Is  introduced.
The tester may opt to include ftrgoa In the analysis using
procedures subject to approval of the Administrator.

1.
  i. AUshuUer, A. P. Storage of Gases and Vapors in
 Plastic Bags.  International Journal of Air and Water.
 Pollution. 6:75-81. 1963.        "
  2. Conner, William D/and J. 8. Nader. Air Sampling
 Plastic Baps. Journal of the American Industrial Hy-
 giene Association. f«:291-297. 1964.
  3. Burrell Manual for 'Gas Analysts; Seventh edition.
 Burrell Corporation,  2223 Fifth Avenue, Pittsburgh,
 Pa. 15219. 1951.
  4. Mitchell. W. J. and M. R. Midfrett. Field Reliability
 of the Orsat Analyzer. Journal of Air Pollution Control
 Association *6:491-*95. May 1970.
  5. Shigehara, R. T., R. M. Neollcht, and W. S. Smith.
 Validating Orsat Analysis Data from Fossil Fuel-Fired
 Units. Stack Sampling News. 4(2)21-28: August, 1976.
                                         rBMEIAl KEGISTEt, VOL 42,  NO. 160—THURSDAY, AUGUST  It,  1977

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41776
RULES  AND REGULATIONS
                                                                            IMffcon 5—DKTEEHTNATION or PABTICULATB EMISSIONS
                                                                                        FBOM STATIONAET SOURCES

                                                                           ~\~PrtncipU ana Applicability

                                                                              1.1  Principle, Paniculate matter Is withdrawn tso-
                                                                            Hnetteally from the source and collected  on a glass
                                                                            fiber film maintained at a temperature In the range of
                                                                            12u±U* C Q48±25° F) or  soon other temperature as
                                                                            specified by an applicable snbpart of the standards or
                                                                            approved by the Administrator, U.S. Environmental
                                                                            Protection Agency, for a particular application. The
                                                                            partienlate mass,  which includes any material that
                                                                            condenses at or above the filtration  temperature, is
                                                                            determined gravimetrically after removal of unoombined
                                                                            water.
                                                                              1.2  Applicability. This method Is applicable for the
                                                                            determination of paniculate emissions from stationary
                                                                            sources.
                                                                              2.1  Sampling Train.  A schematlo of the sampling
                                                                            train used in this method is shown in Figure 5-1. Com-
                                                                            plete  construction  details are given in  APTD-0681
                                                                            (Citation 2 in Section 7); commercial models of this
                                                                            train are also available.  For changes from  APTD-Q581
                                                                            and for allowable modifications of the train shown in
                                                                            Figure 5-1, see the following subsections. _
                                                                              The  operating and maintenance procedures for the
                                                                            sampling train are described in APTD-0576 (Citation 3
                                                                            In Section 7). Since correct usage is Important in obtain-
                                                                            ing valid results, all users should read APTD-0576 and
                                                                            adopt the operating and maintenance procedures out-
                                                                            lined in it, unless otherwise specified herein. The sam-
                                                                            pling train consists of the following components:
                                      FEDERAL REGISTEB,  VOL  41. NO. I4O—THURSDAY, AUGUST  18, 1977

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                                                         RULES AND REGULATIONS
                                                                                                     41777
                           TEMPERA
TURESENSOR
                                         PROBE
                                                                                    SWINGER TRAIN OPTIONAL, MAY BE REPLACED
                                                                                            BY AN EQUIVALENT CONDENSER
                    P1TOTTUBE
                           'PROBE
                   BEVERSE-TYPE
                   "fltOTTUBt
                                        TEMPERATURE
                                            SENSOR
                      HEATED AREA
                            A
           THERMOMETER
THERMOMETER

FILTER HOLDER
                                                                           IMPINGERS                       ICE BATH
                                                                                         BY-PASS VALVE
                                                                                                 CHECK
                                                                                                 VALVE
                                                                                                                                        VACUUM
                                                                                                                                           LINE
                                                                                                                  VACUUM
                                                                                                                   GAUGE
                                   THERMOMETERS
                                                       DRY GAS METER
                                             AIR-TIGHT
                                                PUMP
                                                      Fjgure 5 1.  Paniculate-sampling train.
  ZU  PiobeNoi^8t»tatas«teeI or glass with
 •burp, tapered leading edge. The angle of toper shall
 be SV* *»d the taper •half be on the outside to preserve
 • constant internal diameter. The proble nfltrlo 8h&U be
 «f the button-book or «Ibow design, unless otherwise
 •pacified by  the Administrator. If made of •tainless
 •tmi_ the noule •hall be constructed from gam^ia^ tnb-
 Ing; other materials of construction ma; be used, subject
 to the approval of the Administrator. .
  A range of noule aises suitable for isokinetic sampling
 should be available, e^, OS2 to 1.Z7 cm (M to  H in.)—
 or larger if higher volume p*mp*lng trains are used—
 iivdfiA diameter (ID) n"f**pft in Increments of 0.16 cm
 (H« In.). Each noule shall be calibrated according to
 the procedures outlined in Section &
  2.1.2  Probe Liner. Borosillcato or qnarU glass tubing
 with a beating system capable of maintaining a gas tem-
• peratnre at the exit end during sampling of 120±14° C
 (248db25° F), or such other temperature as specified by
 on applicable subpart of the standards or approved by
 the Administrator far a particular application. (Tbe
 tester may opt to operate the equipment at a temperature
 lower than that specified.) Since the actual temperature
 at the outlet of the probe is not usually monitored during
 aampling, probes construe ted. according to APTD-0581
 and ntUUing the calibration curves of AFTD-0576 (or
 calibrated  according to  the procedure outlined in
 APTD-0578) will be considered acceptable.
  Either borosilicUe or quarts glass probe liners may be
 used  tor stack temperatures up to about 480" C  ,900° F):
 quartz liners shall be used for temperatures between 480
 and 900° C (900 and 1.650° F). Both types ol liners may
 be used at higher temperatures than specified lor short
 periods of time, subject U> the approval of the Adminis-
 trator.  The softening temperature  tor borosilicate is
 890° C (1,308° F),and~av quartz it is 1^«° C (2,732° F).
  Whenever practical, ever; effort should be made to use
 borosfUcate or quartz glass probe liners. Alternatively.
 metal liners (e-g., W6 stainless steel, Inooloy 825,' or other
 corrosion w»g»g*ni»t imrtytK) made of seamless tuning may
 b* used, subject to the approval of the Administrator. •
  Z.I3  Pilot Tube. Type 8, as described  in Section 2.1
 of Method 2, or other device approved by  the Adminis-
 trator. The pilot tube shall be aliacbed to the prolx (as
 •hown In Figure S-l) to allow constant monitoring of the
 •tack gas  velocity Tbe impact (high pressure) opening

   > Mention ol trade names or specific product  does not
 constitute endorsement by the Environmental Protec-
 tion Agoncy.
            plane of the pttot tnbe shall be even with or above the
            noule entry plane (see Method  2, Figure 2-6b) during
            sampling. The Type 8 pilot tnbe assembly shall have a
            known coefficient, determined as outlined In Section 4 of
            Method 2.
            ' 2,1.1  Differential Pressure  Gauge. Inclined manom-
            eter or equivalent dev%c > it
            about 1.3 cm  04 In.) from the bottom ol the flask. The
            second impinger shall be ol the Oreenburg-Smilb design
            with the standard Up. Modifications (e.g.. using flexible
            connections between  the impingers, using  materials
            other titan glass, or using flexible vacuum lines to connect
            the filter bolder  to the condenser) may be used, subject
            to  the approval of the Administrator. Tbe first and
            second  impingers shall contain  known quantities ol
            water (Section 4.1.3). the third shall be empty, and the
            fourth shall contain a known weight of silica gel. or
            equivalent desiccant. A thermometer, capable of measur-
ing temperature to within 1° C (2° F) shall be placed
at the outlet of the fourth Impinger for  monitoring
purposes.
  Alternatively, any system that cools the  sample gas
stream and allows measurement of the water condensed
and  moisture leaving the condenser, each  to within
1 ml or 1 g may be used, subject to the approval of the
Administrator. Acceptable means are to measure the
condensed water either gravimeirlcaUy or volumetrically
and to measure the moisture leaving the condenser by:
(1)  monitoring the temperature and pressure at the
exit of the condenser and using Daltos's law of partial
pressures; or (2) passing the sample gas stream through
a tared silica gel (or equivalent desiccant)  trap with
exit gases  kept below 20° C (68° F; and determining
the weight gain.
  If means other than silica gel are used to determine
the amount  ol moisture  leaving th? condenser, it  is
recommended that  silica gel  (or equivalent)  still  be
used between the condenser system and pump to prevent
moisture condensation in the pump and metering devices
and to avoid the need to make corrections for moisture In
the metered volume.
  NOTE.—If a determination of the paniculate matter
collected la the Impingers is desired in addition to mois-
ture content, the impinger system drscribcd above shall
be used, without modification. Individua. Stales or
control agencies  requiring  this information  shall  be
contacted as to the sample recovery and analysis ol the
impinger contents.
  2.1.8 Metering  System.  Vacuum  gange,  leak-free
pump, thermometers capable oi measuring temperature
towlthin3°C(5.4°F),drygas mctercapableol measuring
volume to within 2 percent, and related equipment, as
shown In Figure 6-1. Other metering systems capable of
maintaining sampling rates within 10 percent of iso-
kiuetic and ol determining sample volume* to within 2
percent may be  used, subject to the approval o' the
Administrator. When the metering system  is used in
conjunction with  a pilot tube, the system shall enable
checks oi isokinetic rates.
  Sampling trains utilizing raeteringsystems designed for
higher flow rates than that described in APTD-0581 or
APTU-OoTu may be used provided that the specifica-
tions o. this method are met.
  2.1.y Barometer. Mercury, aneroid, or other barometer
capable o! measuring atmospheric pressure to within
2.5 nun Ue (0.1 in. llg). In many casts, the  barometric
reading may be obtained from a nearby national weather
service station, in which case tbe station value (which a
                                      FEDEtAl CEdSTER. VOL. «. NO.  16O—IHUUDAY,-AUGUST 16, 1977

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 41778
        RULES AND  REGULATIONS
 the absolute bar^ni^tric pressure) shall be requested and
 an adjustment  for elevation  differences between the
 uvaihir station and sampling point shall be applied at n
 rat.; of minus i.i mm Hg (0.1  in. Hg) per 30 m (100 ft)
 elevation incr-i£» or vice versa Tor elevation decrease.
   C'1.10  Gas  Density   Determination  Equipment.
 Temperature s>:uor and pressure gauge, as described
 in Sections 23 B rid 2.4 of Method 2, and gas analyzer,
 if necessary, as •'•scribed in Method 3. The temperature
 sensor  shall,  preferably, be permanently attached  to
 the pitot tubVr-  .unpling probe in a fixed configuration,
 such that the f'  jl the sensor extends beyond the leading
 edge of the pr  •» sheath  and does not touch any metal.
 Alternatively, ibe sensor may be attached just  prior
 to use i n t he f id. Note, however, that if the temperature
 sensor is attached in the field, the sensor must be placed
 in an i:itcrfcreco*-free arrangement with  respect to the
 Type S pilot tube openings (see Method  2, Figure 2-7).
 As a second alternative, if a difference of  not more than
 1  percent in ib? average  velocity measurement is to be
 introduced, th* winperatnre gauge need not be attached
 to the  probe cr pitot  tube. (This alternative is subject
 to the approval of the Administrator.)
   2.2  Sample Recovery.  The following  items  are
 needed:
   2.2.1  Probe-Uner and Probe-Nozzle Brushes. Nylon
 bristle  brushes with stainless steel wire handles. The
 probe brash shall have extensions (at least as long as
 the probe) of stainless steel. Nylon, Teflon, or similarly
 inert material. The brushes shall be properly sized and
 shaped to brush out the probe  liner and noule.
   2.2.2  Wash Bottles—Two.  Glass wash bottles are
 recommended: polyethylene wash bottles may be used
 at t be option of tbe tester.  It is recommended that acetone/
 not be  stored ic polyethylene  bottles for longer than a
 month.
   2.2.3  Glass Sample Storage Containers. Chemically
 resistant, boroaiicate  glass bottles, for acetone washes,
 600 ml or 1000 ml. Screw cap liners shall either be rubber-
 backed Teflon or shall be constructed so as to be leak-free
 and resistant to chemical attack by acetone.  (Narrow
 month  glasr. Nettles have been found to be less prone to
 leakage.) Alternatively,  polyethylene bottles may be
 used.
   2.2.4  Pelri Dishes. For filter samples, gla::one to glass bottles from metal containers;  thus,
 acetone blanks shall be run prior to field use and only
 acetone with low blank values (<0.001 percent) shall  be
" used. In no -i« shall  n blank value of greater than 0.001
 percent of the weight of act-lone used be subtracted from
 vl:e sample »££lu.'
   3.3  Analysis. Two reagents are required for the analy-
 sis:
   3.3.1  Acetone. Same as 3.2.
   3.3.2  Desiceant. Anhydrous calcium sulfato, Indicat-
 ing type. Alternatively, other types of deslccanu may be
 used, subject to the  approval of the Administrator.   •

 4. Procedure

   4.1  Sampling. The complexity of this method Is such
 that, In order to obtain reliable results, testers should be
 trained and experienced with the test procedures.
   4.1.1  Pretest Preparation. All the components shall
 be maintained and calibrated according to the procedure
 described  in APTD-0578,  unless otherwise specified
 herein.
   Weigh several 200 to 300 R portions of silica gel In air-tight
 containers to the nearest 0.6 g. Record the total weight of
 the silica gel plus container, on each container.  As an
 alternative, the silica gel need not be preweighed, but
 may be weighed directly in its impinger or sampling
 holder just prior to train assembly.
   Check filters visually against light (or irregularities and
 flaws or plnhole teaks. Label filters of the proper diameter
 on the back side near the edge using numbering machine
 Ink. As an alternative, label tbe shipping containers
 (glass or plastic petri dishes) and keep the filters in these
 containers at all  times except during sampling and
 weighing.
   Desiccate the niters at 20±S.6° C (68*10° F) and
 ambient pressure for at least 24 boors and weigh at In-
 tervals of  at least 6 hours  to a constant weight, I.e.,
 <0.5 nig change from previous weighing; record  results
 to the nearest 0.1 ing. During each weighing the filter
 must not be exposed to the laboratory atmosphere for a
 period greater than 2 minutes and a relative humidity
 above 50 percent. Alternatively (unless otherwise speci-
 fied by the Administrator), the filters  may  be oven
 dried at 105° C (220° F) for 2 to 3 hours, desiccated for 2
 hours, and weighed. Procedures other than those de-
 scribed, which account for relative humidity effects, may
 be used, subject to the approval of the Administrator.
   4.1.2  Preliminary Determinations. Select the sam-
 pling site and the minimum number of sampling points
 according to Method 1 or as specified by the Administra-
 tor. Determine the stack pressure, temperature, and the
 range of velocity beads using Method 2; it b recommended
 that a leak-check of  the pitot lines (see Method  2, Sec-
 tion 3.1) be performed. Determine the moisture content
 using Approximation Method 4 or its alternatives  for
 the purpose of making isokinetic sampling rate settings.
 Determine the stack gas dry molecular weight, as des-
 cribed in Method 2,  Section 3.6; if Integrated Method 3
 sampling is used for molecular weight determination, the
 integrated bag sample shall be taktn simultaneously
 with, and  for the same total length of time as, the par-
"ticulate sample run.
   Select a nozzle size based on the range of velocity heads,
 such that it is not necessary to change the nozzle size in
 order to maintain isokinetic sampling rates. During the
 run, do not change the nozzle size. Ensure that the
 proper differential pressure gauge is chosen for the range
 of velocity heads encountered (see Section 2.2 of Method
 2).
   Select a suitable probe liner and probe length such that
 all traverse points can be sampled. For large stacks,
 consider sampling from opposite sides of the stack to
 reduce the length of probes.
   Select a  total sampling time greater than or equal to
 the minimum total sampling time specified in the test
 procedures for  the specific industry such that (1) the
 sampling tune per point is not less than 2 min (or some
 greater time interval as specified by the Administrator),
 and (2) the sample volume taken (corrected to standard
 conditions) will exceed the required minimum total gas
 sample volume. The latter  is based on an approximate
 average sampling rate.
   It is recommended that the number of minutes sam-
 pled at each point be an integer or an integer plus one-
 half minute, in order to avoid timekeeping errors.
   In some circumstances, e.g., batch cycles, it may be
 necessary  to sample for shorter times at the traverse
 points and to  obtain smaller gas  sample volumes. In
 these cases, the  Administrator's approval  must first
 be obtained.
   4.1.3  Preparation  of Collection .Train. During prep-
 aration and  assembly of the sampling train,  keep  all
 openings where contamination can occur covered until
 just prior to assembly or until sampling is about to begin.
   Place 100 ml of water in each of the first two unpingcrs,
 leave the third impinger empty, and transfer approxi-
 mately 200 to  300 g of preweighed  silica gel  from  Its
 container to the fourth impinger. More silica gel may bo
 used, but  care  should  be taken to  ensure that it is not
 entrained  'and  carried out  from tbe impinger  during
 sampling.  Place tbe  container In a clean  place for later
 use in the sample recovery. Alternatively, the weight of
 the silica gel plus impinger may be  determined  to the
 nearest 0.5 g and recorded.
   Using a tweezer or clean disposable surgical gloves,
 place a labeled .(identified) and weighed filter  in tbe
 filter holder. Be sure that the filter is properly centered
 and the gasket properly  placed so  as to prevent the
 sample gas stream from circumventing the Alter.  Check
 the niter for tears after assembly is completed.
   When glass liners are used, install the selected nozzle
 using a Viton  A O-ring when stack temperatures are
 less than 2>JO° C (500° F) and an asbestos string  gasket
 when temperatures are higher. See APTD-0576  for
aaetatls. Other connecting systems using either 316 stain
 less-steel or Teflon ferrules may be used. When metal
 liners are used, Install the nozile as above or by a leak-
 free direct mechanical connection. Mark the*probe with
 heat resistant tape or by some other method to denote
 tbe proper distance into tbe stack or duct for each sam-
 pling point.
   Set up the train as In Figure 6-1, usfng (If necessary)
 a very light coat of silicone grease on all ground glass
 Joints, greasing only the outer portion (see APTD-0576)
 to avoid possibility  of contamination by the silicone
 grease. Subject to the approval at the Administrator, a
 glass cyclone may be used between the probe and finer
 bolder when the total- paniculate catch Is expected to
 exceed 100 mg or when water droplets are present In tbe
 stack gas.
   Place crushed ice around tbe Impingers.
   4.1.4   Leak-Check Procedures.
   4.1.4.1  Pretest Leak-Check. A pretest leak-check is
 recommended, but not required. If the tester opts  to
 conduct the pretest leak-chock, the following procedure
 shall be used.
   After the sampling train  has been assembled, turn on
 and set the filter and probe heating systems at the desired
 operating temperatures. A Dow time for the temperatures
 tostabiliie. If a Vlton A O-rtng or other leak-free connec-
 tion Is used In assembling the probe noule to the probe
 liner, leak-check the train at the sampling site by plug-
 plug-
. Hg)
     ,
 ging the nozzle and pulling a 380 nun Hg (15 in.
 vacuum.
   NOTE.— A lower vacuum may be used, provided that
 It Is not exceeded during the test.
   If an asbestos string is used, do not connect the probe
 to the train during tUe leak-check. Instead, leak-check
 tbe train by first plugging the inlet to tbe finer bolder
 (cycldne, if applicable) and pulling a 380 mm Bg (15 In.
 Hg) vacuum (see Note immediately above). Then con-
 nect the probe to the train and leak-check at about 25
 mm Hg (lln. Hg) vacuum; alternatively, tbe probe may
 be leak-checked with the rest of tbe sampling train, in
 one step, at 380 mm Hg (15 In. Hg) vacuum. Leakage
 rates in excess of 4 percent of the average sampling rate
 or 0.00057 m'/niin  (0.02 elm),  whichever is less, are
 unacceptable.
   Tbe following leak-check Instructions for the «ampM»»«
 train described in APTD-0576 and APTD-0681 may be
 helpful. Start tbe pump with bypass valve fully open
 and coarse adjust valve completely closed. Partially
 open the coarse adjust valve and slowly close the bypass
 valve until the desired vacuum is reached. Do not reverse
 direction of bypass valve; this will cause water to back
 up into the filter bolder. If the desired vacuum Is ex-
 ceeded, either leak-check at this higher vacuum or end
 tbe leak check as shown  below and start over.
   When the leak-check is completed, first slowly remove
 the plug from the inlet to  the probe, filter bolder, or
 cyclone (if applicable)  and immediately turn off the
 vaccum pump. This prevents the water in the impingers
 from being forced backward into the filter holder and
 silica gel from being entrained backward into tbe third
 impinger.
   4.1.4.2  Leak-Checks During Sample, Run. If, during
 the sampling run, a component (e-g., filter assembly
 or impinger)  change becomes necessary, a leak-check
 shall be conducted immediately before tbe change is
 made. The leak-check shall be  done according to the
 procedure outlined in Section 4.1 .4.1 above, except that
 It shall be done at a vacuum equal to or greater than tbe
 maximum value recorded up to that point in tbe test.
 If the leakage rate is .found to be no greater than 0.00057
 mVmin (0.02 cfiu) or 4 percent of the average sampling
 rate (whichever is less),  tbe results are acceptable, and
 no correction will need to be applied to the total volume
 of dry gas metcred; if, however, a higher leakage rate
 is obtained, the tester shall either record the leakage
 rate and plan to correct the sample volume as shown in
 Section 0.3 of this method, or shall  void the sampling
 run.
   immediately after component changes, leak-checks
 are optional; if such leak-checks are done, tbe procedure
 outlined in Section 4.1.4.1 above shall be used.
   4.1.4.3  Post-test Leak-Check. A leak-check is manda-
 tory at the conclusion of each sampling run. The leak-
 check shall be done in accordance with the procedures
 outlined in Section 4.1.4.1. except that it shall be  con-
 ducted at a vacuum equal to or greater than the maxi-
 mum value readied during the  sampling run. If the
 leakage rate is found to be no greater than 0.00057 ms/min
 (0.02 cfm) or 4 percent  of  the 'average sampling  rate
 (whichever is less),  the  results are acceptable, and no
 correction need be applied to the total volume, of dry gas
 motcrcd. If, however, a higher leakage rate is obtained,
 the tester shall either record tbe leakage rate and correct
 the sample volume as shown in Section 6.3 of this method,
 or shall void tbe sampling run.
   4.1.5  Paniculate  Train   Operation.   During   the
. sampling run, maintain an Isobinetic sampung  rate
 (within 10  percent of true  isokinetic unless otherwise
 specified by the  Administrator) and a  temperature
 around the tiller of 120±14° C (248±25° F), or such other
 temperature as specified by an applicable snbpart of the
 standards or approved by the Administrator.
   For each run, record the data required on a data sheet
 such as the one shown in Figure 5-2. Be sure to record tbe
 initial dry gas meter reading.' Record the dry gas meter
 readings at the beginning and end of each sampling time
 increment, when changes in flow rates an made, Defore
 and after each leak cheek, and when sampling is baltedi
                                         FEDERAL  REGISTER, VOL 42,  NO. 160—THURSDAY, AUGUST 16,  1977

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                                                           RULES AND  R'EGULATO&SS
                                                                                              41779
Take other readings required by Figure 5-2 at least once
at each sample point during each time Increment and
additional readings when significant changes (20 percent
variation in velocity head  readings) necessitate addi-
tional adjustment in flow rate,  level and wro the
manometer. Because the manometer level and eero may
drift due to vibrations and temperature changes, make
periodic cheeks during the traverse.
  Clean the portholes prior to th* test ran to mlntaSB»
the chance of sampling deposited rnnterttO. WSssln
sampling, remove the noztle cap, verify that -the Slier
and probe beating systems an np to temperature, and
that the pilot tube and probe are properly positioned.
Position the nozzle at the first traversepolnt with the tip
pointing directly Into the gas stream. Immediately start
the pomp and adjust the flow to laoUnetts conditions.
Nomographs are available, which aid In the rapid adjust-
ment of the tsoHnetio sampling rate without excessive
computation*. These nomographs are designed for use
whan the Type 8 pilot tube coefficient is O.S5±0.02, and
the stack gas equivalent density (dry molecular weight)
to equal to 29=fc4. APTD-0576 details the procedure for
using the nomographs. If C, and Ut are outside the
above stated ranges do not use the nomographs unless
appropriate steps (see Citation 7 in Section 7) are taken
to compensate for the deviations.
  PLANT
   LOCATION.

   OPERATOR,.

   DATE	

   RUN NO. _
  SAMPLE BOX N0._

  METER BOX DO. _

  METEBAHq

  CFACTOR	
                                           AMBIENT TEMPERATURE.

                                           BAROMETRIC PRESSURE.

                                           ASSUMED MOISTURE, X_

                                           PROBE LENGTH, m (ft)	
  PITOT TUBE COEFFICIENT, C.
                                                   SCHEMATIC OF STACK CROSS SECTION
                                           •NOZZLE IDENTIFICATION NO..	

                                           AVERAGE CALIBRATED NOZZLE DIAMETER, en M.

                                           PROBE HEATER 5ETTIMC	

                                           LEAK RATE, m3/ram.(efra)	

                                           PROBE LINER MATERIAL	'
                                           STATIC PRESSURE, mm Hi tin. Kg),.

                                           FILTER NO.	
TRAVERSE POINT
.NUMBER



• '-' :
— ' • *

':• . .' .





TOTAL
SAMPLING
TIME,
(01. min.


'








1

AVERAGE . ,
VACUUM
mmHg
(in. Ha)


', '

'•__'' . 1 ' " '
--_• ,« . ; •
f'~' ' ,
-; . ; .. ;






STACK
TEMPERATURE
(Tsl
•C ("Fl


'
-
'••'• :•!•..".'
'•-•
' '. ' " "







VELOCITY
HEAD
(AP$).
mmf.fn.lHjO
.,-



"'



i " ':
,




PRESSURE
DIFFERENTIAL
ACROSS
ORIFICE
' 'METER :
nmUjO '
(in.H20)



.. ,."„.'

.,.,-,•. • '
'., •


- ' V •
'-.• ' ••


' j
CAS SAMPLE
VOLUME .
i^lltS)




„;•.

• ..-. : • '-.


'.-, --

., •


GAS SAMPLE TEMPERATURE
AT DRY GAS METER
INLET
•C <»F)











•' '• :
Avg.
OUTLET
•C («F>
•











Avg.
Avg. • .
FILTER HOLDER
.TEMPERATURE.
•C ("F)



-.- • .1';
-i • . .<•••/









TEMPERATURE
-'. Of GAS '
- LEAVING
CONDENSER OR
LAST IMPINGER.
'Cl8?!

. ,




\




1 •- .
'-L.I' •'

  When the stack is under significant negative pressure
(height of implnger stem), take care to close the coarse'
adjust valve before inserting the probe into the stack to
prevent water from backing into the filter bolder. If
necessary, the pump may be turned on with the coarse
adjust valve closed.
  When the, probe is In position, block oB the openings
around the probe and  porthole to  prevent unrepre-
sentative dilution of the gas stream.
  Traverse the stack cross-section, as required by Method
1 or as specified by the Administrator, being careful not
to bump the probe nozzle into the stack walls when
sampling near the walls or when removing or Inserting
the probe through the  portholes;  this minimizes the
chance of extracting deposited material.
  During the test run,  make periodic adjustments to
keep the temperature around  the  filter holder at the
proper level: add more ice and. If necessary, salt to
maintain a temperature of less than 20° C (GS° F) at the
condenser/silica  gel outlet. Also,  periodically  check
the level and zero of the manometer.
  If the pressure drop across the filter becomes top high,
making isokinetic sampling difficult to  maintain, the
filter may be replaced in the midst of a sample run. It
is recommended that  another complete filter assembly
be used rather than attempting to change the filter itself.
Before a new filter assembly is installed, conduct a leak-
check (see Section 4.1.4.2). The total paniculate weight
shall include the summation of all filter assembly catches.
  A single train shall be used for the entire sample run,
except in cases where simultaneous sampling is required
in two or more separate ducts or at two or more different
locations within the same duct, or, in cases where equip-
ment failure necessitates 8 change of trains. In all other
situations, the use of two or more trains will be subject to
the approval of the Administrator.
         Figure  5-2.  Participate field data.


  Note that when two or more trains are used, separate
analyses of the front-half and (If applicable) impinger
catches from each train shall be performed, unless identi-
cal nozzle sizes were used on all trains, in which case, the
front-half catches from the individual  trains may  be
combined (as may the impinger catches) and one analysis
of front-half catch and one analysis of Impinger catch
may be performed. Consult with the-Admmistrator  for
details concerning the calculation of results when two or
more trains are used.
  At the end of the sample run, turn oft the coarse adjust
valve, remove the probe and nozzle from the stack, turn
off the pump, record the final dry gas meter reading, and "
conduct a post-test leak^heck,  as outlined in Section
4.1.4.3. Also, leak-check the pitot lines as described in
Method 2, Section 3.1; the lines must pass this leak-check,
in order to validate the velocity head data.
  4.1.6  Calculation of Percent  Isokinetic.   Calculate
percent isokinetic (see Calculations, Section 6f to deter-
mine whether the run was valid or  another test run
should be made. If there was difficulty in maintaining
isokinetic rates due to source conditions, consult  with
the Administrator for possible variance on the  isokinetic
rates.
  4.2  Sample  Recovery.  Proper cleanup  procedure
begins as soon as the probe is removed from the stack at
the end of the sampling period. Allow the probe to cool.
  When the probe can be safely bandied, wipe off  all
external paniculate matter near the  tip of tne probe
nozzle and place a cap over it to prevent losing or gaining
participate matter. Do not cap off the probe tip tightly
while the sampling train is cooling down as this would
create a vacuum in the filter holder, thus drawing water
from the impingers into the filter holder.
  Before moving the sample train to the cleanup site,
remove the probe from the sample train,  wipe on the •
 sillcone grease, and cap the open outlet of the probe. Be.
 careful not to lose any condensate that 'mieht be present;
 Wipe ofl the silicone grease from the filter inlet where the
 probe  was fastened and cap it. Remove the umbilical
 cord from the last impinger and cap the impinger. If a
 flexible line is used between the first teptaper or con-
 denser and the filter holder, disconnect the fine at the
 filter  bolder and let any condensed water or Liquid
 drain into the impingers or condenser. After wiping off
 the silicone grease, cap ofl the filter holder outlet and
 impinger  inlet.  Either ground-glass stoppers,  plastic
 caps, or serum caps may be used to close these openings.
  Transfer the probe and filter-impinger assembly to '.ho
 cleanup area. This area should be clean and protects
 from the wind so that  the chances oi' toi-iuminaiir^'  or
 losing  the sarcple will be minimized.
  Save a portion of the acetone  used for  o'.r-rtnup. as a
 blank. Take 200ml of this acetone din:c;]v fr/tii  In-,1 wi:-h
 bottle  being used and place it in a glass Msiple container
 labeled "acetone Wank."
  Inspect the train prior to and durinp di-:a3*r:nWy and
 note any al'nonnal conditions. Treat the  samples  as
 follows:
  Container \o. I. Carefully remove the filter  from the
 filter holder and place it In its identified petri dish con-
 tainer, tise a pair of tweezers and/or cleja disposable
 surgical gloves to handle the filter. If it is necessary  to
 fold  the filler, do so such that the parr.ruiate cake is
 inside  the f&H.  Carefully transfer to the pciri  dish any
 paniculaie mauer and/or filter fibers wL>a adhere  to
 the filter  holder gasket, by  using a  dry  cylon bristle
 brush and.-'or a sharp-edged blade. Seal the container.
  Container \o. I. Taking care to see tea: dust on the
 outside of the probe  or other exterior sonices  does no:
 get inio the sample,  quantiiatively roe-over  parUcuia'-e
 matter or ar.jr conJensate from the probe  tazzle, probe
                                        FEDERAL  REGISTER,  VOL.  42, NO.  160—THURSDAY,  AUGUST  18, 1977

-------
41780
     BUtES  AND REGULATIONS
filling, probe Siner, and front hall of tin fitter bolder by
washing tbw components with soutane and plating the
wash in a gtass container. Distilled water may to used
instead of acetone when approved by the Administrator
and snail be «d wbeo specified by the Administrator;
in these cases, save a water blank and follow the Admin-
istrator's directions on analysis. Perform the acetone
rinses as follows:
  Carefully r*s:ove the probe noule and clean the inside
surface by rirjinx with acetone from a wash bottle and
brushing wi'h a nylon bristle brush.  Brush until the
acetone tin'? shows no  visible particles, after which
make a final rinse of the inside surface with acetone.
  Brush fl"' rinse the inside parts of  the Bwagtlok
fitting  wit .  sc»tone  in a similar way  until no visible
panicles r.n^in.
  Rinse the probe liner  with acetone by  tilling and
rotating the probe while s/iuirliiif* acetone into its upper
end so that an inside surfaces will be wetted with aoe-
tone. l*t the scetone drain from the  lower end Into the
snicple roiHsfr-T. A funnel (glass or polyethylene) may
be used 10 a:j in transferring liquid washes to the con-
tainer.  Follow the acetone rinse with a probe brush.
Hold the prot« in an inclined position,  spurt acetone
into the up|*r end as the probe brush Is being pushed
with a  twisting action through  the probe; hold a sample
container underneath the lower end of the probe. and
catch aiiy  acetone, and  paniculate matter which  Is
brushed fros the  probe. Hun the brush through tin
probe three  uses  or more until  no  visible paniculate
matter is carr.td out with the acetone  or until none
remains in ihe prone Hner on visual inspection. With
stainless steel or other metal  probes, run the brash
thrcuah in \t? above  prescribed  manner at least six
limss'tincc r-^-al proles  have small crevi? container so that acetone will not leak:  •
out when it is shipped  to the laboratory. Mark the
height  of tbe £uid level  to determine whether or not
leakage occurred during transport. Label the container
to clearly ider.ufy its contents.
  Container -Vo. 3. Note t he color of the indicating silies
Eel to deterameif it has been completely spentand make
a notation ofi:-* condition. Tramfer the  silica gel from
the foiirth ta;pii!irer to its original container and seal.
A funnel may make it easier to pour the silica pel without
spiUmg. A rubber politoii.au may be used as an aid in
removing  t!ie  silii-a  eel from  the improper. It is not
necessary to i&cove the small amount of dust panicles
that n;ay.adh«re to the impinger wall  and are diflk-uit
to remove. £ir.<*e the gain in weight is to be used for
moisr.ire cak-.Nations, do not  use any waur or other
liquids to tra/o.Vr the silica gel. If a balance is available
in the field, fc-ow the procedure for  container No. 3
in Section 4.3.
  ImpingfT ifc.'rr. Treat the impuigers  as follows: Make
ft notation of ar.y color or lilm in the liquid catch. Measure
the liquid wt:ch is in the lirst three iiupingers to within
a. 1 ml by us:.-.? a graduated cylinder or by weighing it
to within •*('.•' B by using a balance (if one is available).  ,
Record the  voUime or weight of liquid present. This
information is required to calculate the moisture content
of the effluent gas.
  Discard the liquid after measuring and recording the
volume or weight, unless analysis of the impioger catch
is required is« Note, Section 2.1.7).
  If  a  different type of condenser is used, measure the
amount of moisture condensed either volujuetrkally or
gravimetricaiiy.
  Whenever possible, containers should  be shipped in
such a way that they remain upright at all times.
  4.3 Analysis. Record  the data required on a sheet
such as the one shown in. Figure A-3. Handle each sample
container as follows:                     .   ,.
   Container .Vo. /.  Leave the content* in the shipping
container or transfer the  filter and any loose paniculate
from the sample container to a  tared glass weighing dish-
Desiccate for 24 hours in a desiccator containing anhy-
drous  calcium sulfate. Weigh to a constant weight and
report the results to the nearest 0.1 mg. For purposes 01
this Section, «.3, the term "constant weight' means a
difference of no more than 0.6 mg or 1 percent of total
 weight less tare weight,  whichever Is  greater, between
 two consectrjve weighings, with no lea than 6 boors of
 desiccation time between weighings.
Rent.
 Date.
 Run Mo..
Filter No..
Amount liquid lost during transport

Acetone blank volume, ml	

Acetone wash volume, ml	
Acetone blank concentration, mg/mg (equation 5-4).

Acetone wash blank, mg (equation 5-5)	
CONTAINER
NUMBER
1
2
TOTAL
WEIGHT OF PARTICULAR COLLECTED,
mg
FINAL WEIGHT


^xd
TARE WEIGHT


^>~<^
Less acetone blank
Weight of paniculate matter
WEIGHT GAIN




-

FINAL
INITIAL
UQUID COLLECTED
TOTAL VOLUME COLLECTED
VOLUME OF LIQUID
WATER COLLECTED
IMPINGER
VOLUME,
ml.




SILICA GEL
WEIGHT,
9



g'F mi
         CONVERT WEIGHT OF WATER TO VOLUME BY DIVIDING TOTAL WEIGHT
         INCREASE BY DENSITY OF WATER (10/ml);
                                                 INCREASE, g  a

                                                     1 g/ml
                                   Figure 5-3.  Analytical data.

                                       ftOERAL BEGISTHt,  VOL  42. NO. 160—THUISDAV, AUGUST >»*,  1977

-------
                                                          RULES  AND  REGULATIONS
                                                                                             41781
  Alternatively, the sample may be oven dried at 105° C
(220° F) for 2 to 3 hours, cooled In the desiccator, and
weighed to a constant weight, unless otherwise specified
by the Administrator. The tester may also opt to oven
dry the sample at 105° C (220° F) for 2to3hoars,weigh
the sample, and use this weight as a final weight.
  Container No. 8. Note the level ofllquid In the container
and confirm on the analysis sheet whether of not leakage
occurred during transport. If a noticeable amount of
leakage has occurred, either void the sample  or use
methods, subject to the approval of the Administrator,
to correct the final results. Measure the liquid in this
container  either volumetrlcally to ±1 ml  or gravi-
metricaUy to ±0.5  g. Transfer the contents to a tared
250-ml beaker  and evaporate to dryness at ambient
temperature and pressure. Desiccate for 24 hours and
weigh to a constant weight. Report the results to the
nearest 0.1 mg.
  Container No. S. Weigh the spent silica gel (or silica gel
plus Implager) to the nearest 0.5 K using a balance. This
step may be conducted in the field.
   Acetone -Blank"  Container. Measure acetone In this
container  either volumetrically  or  gravimetrlcally.
Transfer the acetone to a tared 250-ml beaker and evap-
orate to dryness at  ambient temperature and pressure.
Desiccate for 24 boon and weigh to a contsanC weight
Beport the results to the nearest Oa mg.
  No«.—At the option of the tester, the contents of
Container No. 2 as well as the acetone blank container
may be evaporated at temperatures higher than ambi-
ent. It evaporation Is done at an elevated temperature,
the temperature must be below  the boiling point of the
solvent; also, to  prevent "bumping," the evaporation
process must be closely supervised, and the contents of
the beaker most be swirled occasionally to maintain an
even temperature. Use extreme care, as acetone Is highly
flammable and has a low flash point.

5. CaUonttm
  Mointain a laboratory log of all calibrations.
  5.1  Probe Nonle. Probe nozzles shall be calibrated
before their Initial use in the field. Using a micrometer,
measure the inside diameter of the nozzle to the nearest
0.025 mm (0.001 In.). Make three separate measurements
using different diameters each time, and obtain the aver-
age of the measurements. The difference between the high
and low numbers shall not exceed 0.1 mm (0.004 in.).
When nozzles become nicked, dented, or corroded, they
shall be reshaped,  sharpened, and recalibrated before
use.  Each nozzle shall be permanently ud uniquely
identified.
  5.2  Pilot Tube. The Type 8 pltot tube assembly shall
be calibrated according to the procedure outlined in
Section 4 of Method 2.
  5.3  Metering System. Before Its initial me In the field,
the metering system shall  DC calibrated according to the
procedure outlined In APTD-0576. Instead of physically
adjusting the dry gas meter dial readings to correspond
to the wet test meter readings, calibration factors may be
used to mathematically correct the gas meter dial readings
to the proper values. Before calibrating the metering sys-
tem, it Is suggested that a leak-check be conducted.
For metering systems having diaphragm pumps, the
normal leak-check  procedure  will not  detect leakages
within the pump.  For these cases the following leak-
check procedure is suggested: make a 10-mlnute calibra-
tion run at 0.00057 m >/min (0.02 cfm); at the end of the
run, take the difference of the measured wet test meter
and dry gas meter volumes: divide the difference by 10,
to get the leak rate. The leak rate should not exceed
0.00057 m >/min (0.02 elm).
  After each field use, the calibration of the metering
system shall be checked by performing three calibration
runs at a single,  Intermediate orifice setting (based on
the previous  field  test), with the vacuum set at the
maximum value reached doting the test series.  To
adjust the vacuum, insert a valve between the wet test
meter and the inlet of the metering system. Calculate
the average value of the calibration factor. If the calibra-
tion  has changed by more than 5 percent, recalibrate
the meter over the full range of orifice settings, as out-
lined in APTD-0576.
  Alternative procedures,  e.g., using the orifice meter
coefficients, may be used, subject to the approval of the
Administrator.
  NOTE.—If the dry gas meter coefficient values obtained
before and after a test series differ by more than 5 percent,
the test series shall either be voided, or calculations for
the test series shall be performed using whichever meter
coefficient value  (I.e..  before or after) gives the lower
value of total sample volume.
  5.4  Probe Beater Calibration. The  probe healing
system  shall be calibrated before Its Initial use In the
field according  to the procedure outlined in APTD-0576.
Probes constructed according  to APT1MB81 ne*d not
be calibrated If the calibration  curves in  APTD-0578
are used.
  5.5  Temperature Gauges.  Use  the procedure  In
Section 4J of Method 2 to calibrate In-stack temperature
gauges.  Dial thermometers, such as are used for tbe dry
gas meter and condenser outlet, shall be  calibrated
against mercury-in-glass thermometers.
  5.6  Leak Check of Metering System Shown In Figure
5-1. That portion  of the sampling train from the pomp
to the orifice meter should be leak checked prior to initial
use and after each shipment. Leakage after the pump will
result in less volume  being recorded than Is actually
sampled. The following procedure is  suggested (see
Figure 5-4): Close the main valve on the meter box.
Insert a one-hole  rubber stopper with  rubber  tubing
attached Into the  orifice exhaust pine. Disconnect ana
vent the low side of the orifice  manometer. Close ofl the
low side orifice tap. Pressurize the system to 13 to 18 on
(5 to  7 In.) water column by  blowing Into the  rubber
tubing.  Pinch off the tubing and observe the manometer
tor one  minute. A loss of pressure  on the manometer
Indicates a leak in the meter box; leaks, U present, must
be corrected.        .         .
  6.7  Barometer.  Calibrate against a mercury barom-
eter.

6. Calmlvliont

  Carry out calculations, retaining at  least one extra
decimal figure beyond that of the acquired data.  Round
off figures after the final calculation. Other forms of the
equations may be used as long as they give equivalent
results.
                      RUBBER
                      TUBING
                                       RUBBER
                                      STOPPER
      ORIFICE
                                                                                                               VACUUM
                                                                                                                GAUGE
   BLOW INTO TUBING
   UNTIL MANOMETER
  READS S TO 7 INCHES
     WATER COLUMN
                                  ORIFICE
                               MANOMETER
                                                       Figure 5-4.  Leak check of meter box.
  B. 1  Nomenclature
  A,    —Cross-sectional area of nozzle, m' (ft1).
  £—   -Water vapor in the gas stream,  proportion
          by volume.
  C,    -Acetone blank residue concentrations, mg/g.
  c,     —Concentration of paniculate matter in stack
          gas, dry basis, corrected to standard condi-
          tions, g/dscm (g/dscf).
  /     —Percent of isokinetlc sampling. .
  L,    —Maximum acceptable leakage rate for either a
          pretest leak check or for a leak check follow-
          ing  a  component change; equal to 0.00057
          m'/mln (0.02 cfm) or 4 percent of the average
          sampling rate, whichever is less.
  Lt    — Individual leakage rate observed  during the
          leak check  conducted prior  to  the *'<">"
          component  change  ((=1, 2,  3 .... n),
          m'/mln (cfm).
  L,    -Leakage rate observed during the post-test
          leak check, m'/mln (cfm).
  m.    —Total amount of paniculate matter collected,
          mg.
  U,    —Molecular weight  of  water,  18.0 g/g-mole
          (18.0 Ib/lb-mole).
  •.    -Mass of residue of acetone after evaporation,
          TTlg,
  Pb«  -Barometric  pressure at the sampling site,
          mm H( (in. fig).
  Pi    — Absolute stack gas pressure, mm IIg (in.Hg):
  J*M4   —Standard absolute  pressure  700 mm  Bg
          (28.92 In. Hf).
  R    • = Ideal gas constant, 0.06236 mm Hg-m'/°K-g-
          mole (21.85 in. Hg-ft>/°R-lb-mole).
  Tm   —Absolute average dry gas meter temperature
          (see Figure 5-2), °K (°R).
  T,    —Absolute average stack gas temperature (see
          Figure 5-2), °K(°R).
  T,a   —Standard  absolute  temperature,  293°  K
          (528° R).
  Vm    —Volume of acetone blank, mL
  V..   =Volume of acetone used In wash, ml.
     Vi,=Total volume of liquid collected in unpingers
          and silica gel (see Figure 5-3), ml.
     V«=Volume of gas sample as measured by dry gas
          meter, dcm (dcf).
  V.(.u)=Volume  of gas sample measured by the dry
          gas meter, corrected to standard conditions,
          dscm (dscf).
  V.(.rj)=Volume  of water vapor in the gas sample,
          corrected to standard conditions, scm (get).
      V".=Stack gas velocity, calculated by Method 2,
          Equation  2-0,  using data obtained  from
          Method 5,  m/sec (ft/sec).
     IP.=Weight of residue in acetone wash, mg.
       X=Dry gas  meter calibration factor.
     A//=Average pressure differential across the orifice
          meter (see  Figure 5-2), mm HiO (in. HiO).
      P.= Density  of acetone,  mg/ml  (see label on
          bottle).
      p.= Density  of  water,  0.9982 g/ml  (0.002201
          Ib/ml).
       9=Total sampling time, min.
       0j=Sampling time interval, from the beginning
          of a run until the. first component change,
          min.
       fc^Sampling time  Interval, between two suc-
          cessive component changes, beginning with
          the Interval between  the  first and second
          changes, min.
       0,=Sampling time Interval, from the final 'n">>
          component  change  until  the  end of  the
          sampling run, min.
     13.6= Specific gravity of mercury.
       GO=Sec/min.
      100= Conversion  to percent.
  6.2  Average dry gas meter temperature and average
orifice pressure drop. See data sheet (Figure 5-2).
  6.3  Dry Gas Volume.  Correct the sample voliime
measured by the dry gas meter to standard conditions
(20" C, 760 mm Hg or 08° f, 29.92 in. Hg) by using
Equation 5-1. .-•
                                                                                                                                            Equation S-l
                                       FEDERAL REGISTER, VOL 42,  NO.  160—THURSDAY,  AUGUST 18,  1977

-------
41782
                               BUlfS AND  REGULATIONS
                             	'Kftmn Hg far metric onlU
                             —17.64 "Rfln. Hg fir English, unite

                           Norm.—Eqnstlon 6-1 can be and fc§ vtitteD ante*
                         tbe leakage rate observed during any of tbe mandatory
                         Jeek checks (l.e-, the post-test leekTc&eck of leak check)
                         condneted prior to component changes) exceeds £.. If
                         •, or & exceed* £„ Equation 6-1 must be modified at
                           <•)  Case I.  No component changes mad* daring
                         sampling ran. la this cose, replace V. ID Equation 5-1
                         with tbe expression;
                           (b) Case tt. On* or more component changes made
                         during tbe sampling run. In  this owe, replace V. in
                         Equation 6-1 by the expression:
                        I
 r,,-(£,-
                         and rabstitute only tor those leakage rate* (Z« ot £»)
                         which exceed I*.
                           6.4 Volume of water vapor.
                                                              Equation 8-2
                                                   Non.—In  artorated or  water droplet-laden  pe
                                                 •tremns, two calculations oHhemotetore content of the
                                                 gtaek wa shall be made, one from the tmpfnger analysis
                                                 (Equation 5-3), and a second bom the assumption of
                                                 saturated conditions. Tbe lover of the two values of
                                                 B. aball be considered correct. Tbe procedure (or deter-
                                                 mining tbe moisture content based upon assumption of
                                                 Batorated conditions Is given In (he Not* of Section 1J
                                                 at Metbod 4. For tbe purposes of this method, the avenge
                                                 (tack gas temperature from Figure 6-4 may be used to
                                                 make oils determination, provided that the accuracy of
                                                 the uvelack temperature sensor l»±l°C (ft).
                                                   «.« Acetone Blank Concentration.
                  C.=


 6.7  Acetone Wash Blank.
                                                                                      Equation 5-4
                                                   6.8
                                    Equation (-5
      Total Paniculate Weight. Determine the total
                                                  partteulate catch from the sum of the weights obtained
                                                  from containers 1 and 2 less tbe acetone Wank (Be Figure
                                                  S-8X Non.—Refer to Section 4.1.6 toaatittin eafculatton
                                                  of results Involving two or more fitter assemblies or two
                                                  or more sampling frains.'
                                                   6.9 Particulate Concentration:

                                                          c.= (0.001 g/mg)


                                                   640 Conversion Factors:
                                                                            Jfttmx
                                                                                            To
rhere:
 K,=0.001833 mi/ml for metric units
    -0.04707 tWml far English units.
 6£ Moisture Content -

             n          *l»(«tj)
                                                                                                                 Multiply By
                                                              EcjoationS-s

g/ft«
g/ft*
                                                                                            m«

                                                                                            &
                                                                                            e/m<
'1ft, 48
 2.205X10-*
 3S.31
                                                                             6.11 laoklnetlo Variation.
                                                                             cUJ-1  Calculation From Raw Data.
                          where:
                           .Ka-0.003454 mm Bg-m'/ml-'K for metric units.
                              -0.002069 in. IIg-ff/ml-°B for English units.
                           6.11.3  Calculatioa From latennedlato values.  •
                                                    S. VeDaro, R. F. A Survey of Commerolally Available
                                                  Insteumentatlon For the MAflfflrii™*">t of Low-Ranee
                                                  Gas Velocities. U.S. Environmental Protection Agency,
                                                  Knxlasion • Measurement  Brancn. ReBeoreii Xnaoua •
                                                  Park, N.C. November, 1976 (unpubliihed paper).
                                                    9. Annual Book of A8TM Standards. Fart 26. Oasoom
                                                  Fuels; Coal and Coke; Atmospheric Analysis. American
                                                  Society  tat Testing  and Materials. Philadelphia, Pa.
                                                  1974. pp. 617-622.
                                                              Equation 5-8
                          where:
                            jfi=4.320 for metric units
                              -0.094JO for English units.
                            6.13  Acceptable Results. If 90 percent < 7<110 per-
                          cent, tbe results are acceptable. If the results are tow In  .
                          comparison to the standard and / Is beyond the accept-
                          able range, or, if / is less than 90 percent, the Adminis-
                          trator may opt to accept the results. Use Citation 4 to
                          make ] udgments. Otherwise, reject the results and repeat
                          toe test.


                            1. Addendum to Specifications for Incinerator Testing
                          at Federal Faculties. PH8, NCAPC. Doe. 6.19W.
                            t. Martin,  Robert M. Construction Details of Iso-
                          kJnette  Source-Sampling Equipment. Environmental
                          Protection Agency.  Research Triangle  Park,  N.C.
                          APTD-0581. April, 1971.
                            S. Rom, Jerome >. Maintenance, Calibration, and
                          Operation of IsoMnrtlc  Source Sampling  Equipment.
                          Environmental Protection Agency. Research Triangle
                          Park. N.C. APTIXB70. March. 1972.
                            4. Smith,  W. B.. B. T. Shigehara, and W. F. Todd.
                          A Method of Interpreting Stack Sampling Data. Paper
                          Presented at the 63d Annual Meeting of the Air Pollu-
                          tion Control Association, St. Louis, Mo. June  14-19,
                          1970
                            8. Smith, W. B^et aL  Stack Oas Sampling Improved
                          and Simplified With New Equipment. APCA Paper

                            it Specifications tor Incinerator Testing at Federal
                          Fteffltiea. PHB.NCAPO. 1967.          	
                            7. BUgebara,^. T. Adjustments m tbe EPA Humo-
                          •rapb lor Different  Pltot Tube Coefficients and Dry
                          jfcjfri-rilnr Weights. Stack  Sampling News  M-ll.
                          October, 1974.
                                        FEDEIAL lEGISTEfl, VOL  4J, NO. 160—THUtSDAY,  AUGUST -li. 1977

-------
 THOO  B—VISUAL DBTEEMlNAnOt*  O» THE
 >PACITT  or  XUISSIONS FROM  BTATIONABT
 (OCBCE3  10                  .        '

 rfany stationary sources discharge visible
 isslons Into the atmosphere; these emis-
 03 ore usually  In the shape of a plume.
 13 method  Involves the determination of
 ime opacity by qualified observers. The
 •thod Includes procedures for the training
 d certification of observers, and procedures
 be used In the field for determination of
 jme opacity. The appearance of a plume aa
 iwed by an observer depends upon a num-
 r of variables; *ome of which may be con-
 >UabIe and  eome of which may not  be
 atrollable In the field. Variables which can
 controll&a.to an extent to which they no
 nger exert  a significant Influence  upon
 ome appearance Include: Angle of the ob-
 rver with respect to the plume; angle of the
 'server with respect to the sun; point of
 uanratlon of attached  and detached steam
 ume; and  angle of  the  observer with re-
 ect to a plume emitted from a rectangular
 ack with • large length to width ratio. The
 ethod Includes specific criteria applicable
 > these variables.
 Other variables which  may not be control-
 bio in the field are luminescence and color
 ntrast between the plume and the back-
 ound against which the plume is viewed.
 less variables exert  an Influence upon the
 ipearance of a plume as viewed by an ob-
 rver. and can affect the ability of the ob-
 rver to  accurately  assign opacity values
 ' the observed plume. Studies of the theory
 ; piume opacity and field studies have dem-
 istrated that a plume is most visible and
 •esents the greatest apparent opacity when
 awed against a contrasting background; It
 Hows from  this,  and Is confirmed by field
 lals, that the opacity  of a  plume, viewed
 ider conditions where  a contrasting back-
 ound Is  present  can' be assigned with the
 •eatest degree of accuracy. However, the po-
 ntlal for a positive error la also the. greatest
 ben a plume Is viewed under such contrast*
 g conditions. Under conditions presenting
 less contrasting background, the apparent
 >adty of a  plume la less and approaches
 ro as the color and  luminescence contrast
 crease toward zero.  As a result, significant
 igative  bias and negative  errors  can  be
 Ado  when  a plume la viewed  under less
 intrastlng conditions.  A negative bias do-
 eases rather than Increases the possibility
 at a plant operator  will be cited for a ylo-
 tion of opacity standards due to observer
 ror.
 Studies have been undertaken to determine
 le magnitude of positive errors which can
 a made by qualified observers  while  read-
 >g plumes under contrasting conditions and
 sing  the procedures  set forth In this
 lethod. The results of these studies  (field
 •lals) which Involve a total of 769 sets of
 S readings each are as follows:
 (I)  For  black plumes  (133 sets at a smoke
 enerator),  100 percent of  the sets were
 :ad with a positive error1 of less than 7.5
 ercent_opaclty: 89 percent were read with
 positive error of less than 5 percent opacity.
 (2)  For white plumes  (170 sets at a smoke
 enerator, 168 seta at a coal-fired power plant,
 98 sets at a sulfurlc acid plant). 99 percent
 r the sets were read with a positive error of
 >ss than 7.5 percent opacity; 95 percent were
 ead with a positive error ofless than 5 per-
 ent opacity.
 The positive observational error associated
 rtth  an average of  twenty-five readings Is
 therefore  established. The accuracy of- the
aethod must be  taken Into account-when
letennlning  possible violations  of  appll-
 able opacity standards.

 'For a sst, positive error=average opacity
 letermined  by observers' 35 observations—
 .verage opacity determined from transmla-
 ometer's  25 recordings.
  1. Principle and applicability!

  l.t  Principle. The opacity of emissions
from  stationary sources  is determined  vis-
ually  by a qualified observer. -
  1.2  Applicability.  This method Is  appli-
cable  for the determination  of the opacity
of emissions from stationary sources pur-
suant to |60.11(b)  and  for  qualifying ob-
servers  for visually  determining  opacity of
emissions.
  2.  Procedures. The observer qualified in
accordance with paragraph 8  of this method
shall  use the following procedures for  vis-
ually  determining the opacity of emissions:
  3.1  Position,. The qualified observer shall.
stand at a distance  sufficient to provide a
clear  view  of the emissions with the  sun
oriented In the 140* sector to bis back. Con-
sistent with maintaining tba above require-
ment, the observer shall, as much as possible.
make his observations from a position such
that  bis  Una  of vision is  approximately
perpendicular to the plume direction., and
when observing opacity  of emissions from
rectangular outlets (e.g. roof monitors, open
Doghouses,   nonclrcular  stacks), approxi-
mately  perpendicular to  the longer axis of
the outlet. The observer's line of sight should
not Include more than one plume at a time
when multiple, stacka are involved, and in
any case the observer should make his ob-
servations with his line of sight perpendicu-
lar to the longer axis of such a set of multi-
ple stocks  (e.g. stub stacks on baghouses).
  2.2  Field  records.  The  observer shall  re-
cord the name of the plant, emission loca-
tion,  type  facility,   observer**  name  and
affiliation, and the date on a field date sheet
(Figure 9-1). The time,  estimated  distance
to the «i^i««i«»t location, approximate wind
direction, estimated  wind speed, description
of the sky condition (presence and color of
clouds), and plume background are recorded
on a field data sheet at the time opacity read-
ings are initiated and completed.
  2.3   Observations.   Opacity  observations
shall  bo made at the  point of greatest opacity
In that 'portion of  the  plume  where con-
densed  water vapor  is not present. The ob-
server, shall  not look continuously at the
plume,  but  instead shall observe the plume
mome'ntarUy at 15-*econd intervals.
   2.3.1  Attached steam  plumes.  When con-
densed water vapor is present within  the
plume as it emerges from the emission out-
let, opacity observations shall be made  be-
yond the point in the plume at which con-
densed water vapor is no longer visible. The
observer shall record the approximate dls-
tanca from  the emission outlet to the point
In the plume at which the observations are
made.
   2 35  Detached steam  plume. 'When water
vapor in the plume condenses and becomes
visible at a distinct  distance from the emis-
sion  outlet, the opacity of emissions should
be evaluated at the  emission outlet prior to
the condensation of  water vapor and the for-
 mation of the steam plume.        •
   2.4  Recording observations. Opacity  ob-
servations shall be recorded to the* nearest S
percent at 15-second intervals  on an  ob-
servational record sheet. (See Figure 9-3 for
an example.) A minimum of 34 observations
shall be recorded. Each momentary observa-
 tion  recorded shall  bo deemed to represent
the  average opacity  of emissions for s 15-
 second period.
   2.S Data Reduction. Opacity shall be de-
 termined as  an  average of 24 consecutive
 observations recorded at 15-second intervals.
Divide the observations recorded on the rec-
 ord sheet Into sets  of 24 consecutive obser-
 vations. A set is  composed  of any  24  con-
 secutive observations. Sets need not be con-
 secutive In time and In no case shall  two
 sets overlap. For each set of  24 observations,
 calculate the average by summing the opacity
 of tbe 24 observations and dividing this sum.
 by^4. If an applicable standard specifies an
 averaging time requiring more tb»^ 24 ob-
 servations, calculate the average for all ob-
 servations  made  during the specified time
 period. Record the average opacity on a record
 sheet. (See Figure 9-1 for an example.)
   3. Qualifications and testing.
   3.1  Certification requirements. To receive
 certification as a qualified observer, a can-
 didate must be tested and demonstrate the
 ability to assign opacity readings in 5 percent
 increments to 35  different black plume* and
 3S different  whit* plumes, with  SA  •nor
 not to exceed IB percent opacity on any one
 reading and an average error not to exceed
 7.5 percent opacity in each category. Candi-
 dates shall be tested according to the pro-
 cedures described In paragraph 8.3, Smoke
 generators, used  pursuant  to paragraph 3.2
 shall be equipped with a smoke meter which
 meets the requirements of paragraph  3.3.
   The certification shall be valid for a period
 of 6 months, at which time the qualification
 procedure must be repeated by any observer
 in order to retain certification.           _   :
 •  3.2  Certification procedure. The certifica-
 tion test consists  of showing the candidate a
 complete run of 60 plumes—25 Mack plumes
 and 25 white plumes—generated by a smoke
 generator. Plumes within each set of 25 blade
 and 25 white runs shall be presented In ran-
 dom order. Tbe candidate assigns an opacity
 value to each plume and records his  obser-
 vation on a suitable form. At tbe completion
 of each run of CO readings, the score  of the
 candidate is determined. If a candidate falls
 to qualify, the complete run of 50  readings
 must  be repeated In any retest. The  smoke
 teat may be administered as part of a smoke
 school or training program, and may be pre-
 ceded by training or familiarization runs  of
 the smoke generator during which candidates
 are shown black and white  plumes of known
 opacity.
 .  33  Smoke  generator specifications.  Any
 smoke generator  used for the purposes  of
 paragraph 3.2 shall be equipped with u smoke
 meter  Installed  to measure opacity  across
 the diameter of  the smoke generator stack.
 The smoke meter output  shall display In-
 stack opacity based upon a pathlength equal
 to tbe atock exit diameter, on a full 0 to 100
 percent  chart  recorder  scale. The  smoke-
 meter optical design and performance shall
 meet the- specifications shown In Table 9-1.
 The smoke meter shall be calibrated as pre-
 scribed in paragraph 3 J.I prior to the con-
 duct of  each smoke reading  test. At the
 completion of each test, the zero and span
 drift shall be checked and if the drift ex-
 ceeds 2:1 percent opacity, the condition cv»»n
 be corrected prior to conducting any subse-
 quent test runs.  The smoke meter shall  bo
 demonstrated, at  the time of installation,  to
 meet the specifications listed  in Table 9-1.
 This demonstration shall  bo  repeated  fol-
 lowing any subsequent repair or replacement
 of the photocell or associated electronic cir-
 cuitry Including the chart recorder or output
 meter, or every 8 months,  whichever occur*
 flrmt.
   3.3.1  Calibration. Tbe ' omoke  meter  1*
 calibrated  after  allowing a minimum of  80
 minutes warmup by alternately producing
 simulated opacity of 0 percent and 100 per-
 cent.  When stable response at  0 percent  or
 100 percent is noted, the smoke meter is ad-
 justed to produce an output of 0 percent  or
 100 percent, as appropriate. This calibration
 shall be repeated until stable 0 percent and
 100 percent readings are produced  without
 adjustment. Simulated 0  percent and 10O
 percent opacity values may be produced by
 alternately switching the power to the light
 source on and off vhile the smoke generator
.Is-not producing  smoko.

-------
    TABU •— I— «MOXK VETO DCSXGK AND
                    SPECIFICATIONS
Incandescent    lamp
  operated at nominal
  rated voltage.
Fhotoplo    (daylight
  spectral response of
  the  Human  eye—
.  reference 4.3).
15*  «^-»imnm total
  angle.
15*  ™
-------
       Appendix C





   Blank Data Forms




Field Observation Checklist




Process and Control System Evaluation Form




Opacity Observation Record

-------
                                                                  PAGE     OF
                               FIELD OBSERVATION CHECKLIST
GENERAL/ADMINISTRATIVE
PLANT NAME
PLANT ADDRESS
SOURCE TO BE TESTED



PLANT CONTACT
OBSERVERS
REVIEWED TEST PROTOCOL?
          AFFILIATION
       COMMENTS
                             DATE
                             PHONE
REVIEWED PRETEST MEETING NOTES?
         COMMENTS
REVIEWED CORRESPONDENCE?
COMMENTS
TEST TEAM COMPANY NAME



SUPERVISOR'S NAME 	



OTHER MEMBERS
              ADDRESS



              TITLE
                              PHONE

-------
                                                                    PAGE	OF

GENERAL/SAMPLING SITE

STACK/DUCT CROSS SECTION DIMENSIONS	  EQUIVALENT DIAMETER	
MATERIAL OF CONSTRUCTION	  CORRODED?	.__  LEAKS?
INTERNAL APPEARANCE- CORRODED?	  CAKED PARTICULATE?	  THICKNESS
INSULATION?  	  THICKNESS            LINING?         THICKNESS
NIPPLE?	  I.D.	  LENGTH	FLUSH WITH INSIDE WALL?
STRAIGHT RUN BEFORE PORTS	  DIAMETERS	
STRAIGHT RUN AFTER PORTS                 DIAMETERS
PHOTOS TAKEN?	  OF WHAT
DRAWING OF SAMPLING LOCATION:
MINIMUM INFORMATION ON DRAWING:  STACK/DUCT DIMENSIONS, LOCATION AND DESCRIPTION OF
MAJOR DISTURBANCES AND ALL MINOR DISTURBANCES (DAMPERS, TRANSMISSOMETERS, ETC.), AND
CROSS SECTIONAL VIEW SHOWING DIMENSIONS AND PORT  LOCATIONS.

-------
                                                                   PAGE      OF
GENERAL/SAMPLING SYSTEM
SAMPLING METHOD (e.g., EPA 5)
SAMPLING TRAIN SCHEMATIC DRAWING:
MODIFICATIONS TO STANDARD METHOD
PUMP TYPE:  FIBERVANE WITH IN-LINE OILER	  CARBON VANE	  DIAPHRAGM
PROBE LINER MATERIAL                      HEATED?            ENTIRE LENGTH?
TYPE "S" PITOT TUBE?             OTHER
PITOT TUBE CONNECTED TO:  INCLINED MANOMETER 	OR MAGNEHELIC GAUGE _
      RANGE               APPROX. SCALE LENGTH	  DIVISIONS
ORIFICE METER CONNECTED TO:  INCLINED MANOMETER 	 OR MAGNEHELIC GAUGE
      RANGE               APPROX. SCALE LENGTH    	    DIVISIONS
METER BOX BRAND                       SAMPLE BOX BRAND
RECENT CALIBRATION OF ORIFICE METER-DRY GAS METER?  	  PITOT TUBES?
      NOZZLES	THERMOMETERS OR THERMOCOUPLES?	  MAGNEHELIC GAUGES?
NUMBER OF SAMPLING POINTS/TRAVERSE FROM FED.  REG.             NUMBER TO BE USED _
LENGTH OF SAMPLING TIME/POINT DESIRED	  TIME TO BE USED	

-------
                                                                  PAGE     OF
TRAIN ASSEMBLY/FINAL PREPARATIONS  (USE ONE SHEET PER RUN IF NECESSARY)      RUN #
FILTER HOLDER CLEAN BEFORE TEST?   	  FILTER HOLDER ASSEMBLED CORRECTLY?
FILTER MEDIA TYPE	  FILTER CLEARLY IDENTIFIED?	  FILTER INTACT?
PROBE LINER CLEAN BEFORE TEST?	  NOZZLE CLEAN?	  NOZZLE UNDAMAGED?	
IMPINGERS CLEAN BEFORE TEST?	  IMPINGERS CHARGED CORRECTLY? 	
BALL JOINTS OR SCREW JOINTS?           GREASE USED?           KIND OF GREASE
PITOT TUBE TIP UNDAMAGED? 	  PITOT LINES CHECKED FOR LEAKS?        PLUGGING?
METER BOX LEVELED?	  PITOT MANOMETER ZEROED?	  ORIFICE MANOMETER ZEROED?
PROBE MARKINGS CORRECT? 	  PROBE HOT ALONG ENTIRE LENGTH? 	
FILTER COMPARTMENT HOT?         TEMPERATURE INFORMATION AVAILABLE?
IMPINGERS ICED DOWN? 	  THERMOMETER READING PROPERLY?
BAROMETRIC PRESSURE MEASURED? 	  IF NOT,  WHAT IS SOURCE OF DATA
AHfl FROM MOST RECENT CALIBRATION	  AHn FROM CHECK AGAINST DRY GAS-METER
  (d                              	    (d
NOMOGRAPH CHECK:
    IF AH@ = 1.80, TM =100° F, % HgO - 10%, Ps/Pm =1.00,  C =	 (0.95)
    IF C = 0.95, TS = 200° F^ DN = 0.375, Ap REFERENCE =	_ (0.118)
    ALIGN Ap = 1.0 WITH AH = 10; @ Ap = 0.01, AH =	 (0.1)
FOR NOMOGRAPH SET-UP:
    ESTIMATED METER TEMPERATURE :	°F ESTIMATED VALUE OF Ps/Pm	
    ESTIMATED MOISTURE CONTENT         %  HOW ESTIMATED?
    C FACTOR	  ESTIMATED STACK TEMPERATURE       ° F  DESIRED NOZZLE, DIAMETER
STACK THERMOMETER CHECKED AGAINST AMBIENT TEMPERATURE?         '.
LEAK TEST PERFORMED BEFORE START OF SAMPLING? 	•  RATE	CFM @	  IN.  Hg.

-------
                                                                  PAGE	OF

SAMPLING (USE ONE SHEET FOR EACH RUN IF NECESSARY)                    RUN #
PROBE-SAMPLE BOX MOVEMENT TECHNIQUE:
    IS NOZZLE SEALED WHEN PROBE IS IN STACK WITH PUMP TURNED OFF?
    IS CARE TAKEN TO AVOID SCRAPING NIPPLE OR STACK WALL?
    IS AN EFFECTIVE SEAL MADE AROUND PROBE AT PORT OPENING?
    IS PROBE SEAL MADE WITHOUT DISTURBING FLOW INSIDE  STACK?
    IS PROBE MOVED TO EACH POINT AT THE PROPER TIME?
    IS PROBE MARKING SYSTEM ADEQUATE TO PROPERLY LOCATE  EACH  POINT?
    ARE NOZZLE AND PITOT TUBE KEPT PARALLEL TO STACK WALL AT  EACH  POINT?
    IF PROBE IS DISCONNECTED FROM FILTER HOLDER WITH PROBE  IN THE STACK ON A
        NEGATIVE PRESSURE SOURCE, HOW IS PARTICULATE MATTER IN THE PROBE  PREVENTED
        FROM BEING SUCKED BACK INTO THE STACK?      	    	
    IF FILTERS ARE CHANGED DURING A RUN, WAS ANY PARTICULATE LOST? 	
METERBOX OPERATION:
    IS DATA RECORDED IN A PERMANENT MANNER?	  ARE DATA SHEETS COMPLETE?
    AVERAGE TIME TO REACH ISOKINETIC RATE AT EACH POINT 	
    IS NOMOGRAPH SETTING CHANGED WHEN STACK TEMPERATURE CHANGES SIGNIFICANTLY? _
    ARE VELOCITY PRESSURES Up) READ AND RECORDED ACCURATELY?  	
   LEAK TEST PERFORMED AT COMPLETION OF RUN  	cfm @ 	 IN  Hg.
PROBE, FILTER HOLDER, IMPINGERS SEALED ADEQUATELY AFTER TEST?	
GENERAL COMMENT ON SAMPLING TECHNIQUES	
IF ORSAT ANALYSIS IS DONE, WAS IT:  FROM STACK 	  FROM INTEGRATED  BAG
WAS BAG SYSTEM LEAK TESTED?	  WAS ORSAT LEAK TESTED? 	  CHECK AGAINST AIR?
IF DATA SHEETS CANNOT BE COPIED, RECORD:  APPROXIMATE STACK TEMPERATURE   	° F
    NOZZLE DIA. 	IN.   VOLUME METERED	 ACF
    FIRST 8 Ap READINGS .	  		 	  	

-------
                                                                  PAGE	OF

SAMPLE RECOVERY

GENERAL ENVIRONMENT-CLEAN UP AREA 	
WASH BOTTLES CLEAN? 	  BRUSHES CLEAN?     	  BRUSHES RUSTY?
JARS CLEAN?	  ACETONE GRADE	  RESIDUE ON EVAP. SPEC. 	%
FILTER HANDLED OK? _____  PROBE HANDLED OK?	  IMPINGERS HANDLED OK? __
AFTER CLEANUP: FILTER HOLDER CLEAN? 	 PROBE LINER CLEAN? 	
    NOZZLE CLEAN?	  IMPINGERS CLEAN?	  BLANKS TAKEN?	
DESCRIPTION OF COLLECTED PARTICULATE
SILICA GEL ALL PINK?  RUN 1 	  RUN 2	_,. RUN 3
JARS ADEQUATELY LABELED?	   JARS SEALED TIGHTLY?,
LIQUID LEVEL MARKED ON JARS?	   JARS LOCKED UP?
GENERAL COMMENTS ON ENTIRE SAMPLING PROJECT:
WAS THE TEST TEAM SUPERVISOR GIVEN THE OPPORTUNITY TO READ OVER THIS CHECKLIST?
DID HE DO SO?
OBSERVER'S NAME                                     TITLE
AFFILIATION                                         SIGNATURE

-------
                   PROCESS AND CONTROL SYSTEM EVALUATION FORM
Company Name
Address
Company Official:_
                                        Plant Identification_
                                        Location:
I. Process Data
   Rated Capacity of Dryer
Maximum Production Rate

Actual Production Rate
   Batch Size
   Process Weight Rate
   Cold Aggregate Feed Rate
                                   Atons\  at 	
                                  "V  ** I
                                   f tons\ Normal Production Rate
                                  1  hrj
         % aggregate moisture content.

                              / tons
                       (Ibs)
                              I tons \
                                 hr j
                               / tons\
                               \hr/
                               / tons \
                               •(jhr-J
                                              Type Mixture
                                           Mixture Composition
                                           Aggregate Sizes
                                                                                   -)
                                               %Asphalt
   Aggregate Feeds  percent moisture
     sieve analysis, % material retained on:
   No. 8        %  No. 32       %   No. 100
                                              %   No.  200
   percentage fines - material passing No.  200-mesh sieve
Burner Rating
                                 (Btu/hr)
Fuel Consumption
                                (gal/hr)
Type of fuel_
(ft3/hr)
                                (ftton)
                                                             (gal/ton)
Hot Aggregate Temperature
Excess Air at Dryer Exit
Damper Position, %open 	
                                         °F.   Exhaust Gas Temperature
                                                                            >F.

-------
II.  Control System Data:
     schematic diagram (exhaust system)
Baghouse:  Static pressure drop, Ap	(in. HO)
           cleaning cycle timer setting 	
           cleaning cycle pressure setting
Effective Filter Area__	Type of cloth
Inspection of Baghouse Interior-comments
Wet  collection devices:
     Venturi Scrubber- s
     throat opening dimensions
Venturi Scrubber- static pressure drop,Ap	(in. HO)
                                                           2
     throat opening area 	(ft )
Low Energy Scrubber-   oriface opening	
                       water level
Water Flow Rate:                                  Weir Formula
   Type of meter	      cross-sectional area of flow
                                                  horizontal distance x         (ft)
   Water Pump, horsepower	, rated capacity	rpm	
   Water-flow rate 	(gal/min)
   Water Pressure:  main scrubber supply line 	(psig)
                    spray system supply lines	(psig)

-------
Dilution Measurements - (note location on system diagram)
                                                   %co
     location                  time                  . 2
        1                    	             	
        2	             	
        3                    	             	
        4
System Air Flow:
         Cyclone- static pressure drop- Ap 	(in. HO)
         Fan Rating: horsepower	, capacity	at 	rpm
         Measured Fan Speed	rpm
         Fan-static pressure rise, Ap_	(in. HO)
Determined Opacity

-------
Date
Observer
Checked by

Start Time
                      Opacity Observation Record
                     __________      Source Location.
                                i      Address ———
Observation Point
Stack-distance from      Ht.
Wind-speed   •     Direct..
Sky Condition
Type of Installation
Fuel
Observ. Ended
    Smoke Density Tabulation
     Units No.  0
     Units No.  5
Units  No* 10
Units  No. 15
Units  No. 20
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
Units  No
                25_
                30_
                35_
                40_
                45_
                50_
                55
                60
                65
                70_
                75_
                80
                85
                90
                95
	Units No.  100
      Total  Units
2quiv. Opacity-	~
                         REMARKS:
                                              -*-
M^X
0
i
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
0






























15









^




















30






























45






























^
30
31
• 32
33
34
35
36
37
38
39
40
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              Appendix D

   ISOK1NETIC PARTICIPATE SAMPLING IN
NON-PARALLEL FLOW SYSTEMS - CYCLONIC FLOW
           JAMES W, PEELER
   ENTROPY ENVIRONMENTALISTS, INC,

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      ISOKINETIC PARTICULATE SAMPLING IN NON-PARALLEL
                FLOW SYSTEMS- CYCLONIC FLOW
     In most stationary sources, the direction of gas flow is
essentially parallel to the stack axis.  Examples of non-parallel
flow systems are flow  immediately  following a bend or turn in the
ductwork, flow in a convergent or divergent section, and cyclonic
(tangential) flow.  Cyclonic flow most often occurs after inertial
demisters following wet scrubbers, in stacks with tangential in-
lets, and after axial fans.  Method 1—Sample and Velocity Traverses,
and Method 2—Determination of Stack Gas Velocity and Volumetric
Flow Rate, are not applicable to stacks; with cyclonic flow.  Method
1 (2.4), gives explicit instructions for determining when unac-
ceptable flow .conditions exist.  In short, the angle (between the
pitot orientation and the plane perpendicular to the stack axis)
required to produce a null reading  is measured for each sampling
point.  If the average of the absolute.values of the angles is
greater than.10°, unacceptable flow conditions exist.
     In many cases, particulate sampling is required even though
the appropriate reference methods are not applicable due to non-
parallel flow.  This situation occurs more frequently at existing
sources than at new sources, since sources subject to NSPS are
required to provide sampling locations which permit sampling
according to the appropriate reference methods.  There are
three possible alternatives when unacceptable flow conditions
exist:
(1)  modify the sampling methodology to obtain accurate results

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(2)  use standard or alternate methodology which gives results
biased high (in the agency's favor), or (3) modify the source
to permit standard sampling procedures to be used.  This paper
discusses three sampling procedures which have been commonly
proposed.  Also, source modifications which can be employed are
described.  Current studies on tangential flow may provide better
solutions in the future.


BACKGROUND INFORMATION
     In order to determine the biases of various sampling tech-
niques in non-parallel flow systems, it is necessary to under-
stand the requirements of proportional sampling and the errors
associated with pitdt tube measurements.

     Proportional  Sampling  -   Source sampling  is  conducted  to
determine  the concentration of a particular pollutant  in  an
effluent  stream.   The concentration of component  Z which  is re-
presentative of  the effluent  is,                                  (1)
;  _   volume-of component  Z   _ CZ * V^/sec) x A(ft2)  x  9(sec)
  Z  total volume  of effluent   V(£t/sec) x A(£t2) x  e(sec)

                 C_ = I,  if  component  Z  is  a gas .
                 C7 = Ibs/ft  , if component Z  is particulate
                  i-t
For a  steady  state source with spatial  variations  in  concen-
tration  and velocity, Equation (1)  can  be  expressed as,

            C   -   4 CZVdA                                     (2)
                   \ VdA

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Evaluation of Equation (2) requires knowledge of concentration
and velocity as functions of location across the stack cross
section.   In practice, the integrals in Equation (2) are
approximated by sampling at a finite number of points,

             ?Ci ViAJ9i
       CZ~~  zVi Ai ei                              C3)

In the application of standard EPA methods, equal areas are
sampled for equal times.  Equation (3) becomes,

             *CiVi
       cz =  STT-                                  (4)
        z     EVT-

It is hot feasible to determine the concentration (C-) .,at 'each
sampling point.  However, the quantity  ['£C.V.']> can be .evaluated
                                        i x 1
by collecting a single integrated sample where the sampling rate
is weighed-proportionally to the stack velocity at each sampling
point.  This procedure of sampling at a rate which is related-to
the stack velocity by a constant is referred to as proportional
sampling.  In the preceding discussion it has been assumed that
the velocity of the effluent stream is parallel to the stack
axis.  In non-parallel flow systems, the sampling rate should
be weighted proportionally to the component of the velocity
parallel to the stack axis.
     When sampling for particulates it is necessary to sample
isokinetically to obtain a representative sample.  For sources
where the velocity is parallel to the stack axis, isokinetic
sampling is a special case of proportional sampling where the con-
stant relating the sampling velocity ±x> the stack velocity is 1.

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Thus, in parallel flow systems,  isokinetic  sampling auto-
matically satisfied proportional sampling requirements.   For
non-parallel flow systems,  isokinetic  sampling conditions must
be based on the velocity vector, however, proportional sampling
conditions must be based on the  component of velocity parallel
to the stack axis.  This creates considerable difficulty in
sampling non-parallel flow  systems. .
     Pitot Tube Errors - Pitot  tube  errors arise when the pitot
tube is not oreinted correctly  with  respect to the gas stream
velocity vector.  Two types of  pitot  tube misalignment are shown
in Figure.4-4. Figures 4-5 8  4-6 show the % error in the velocity
vector measurement as a function of  yaw and pitch angles for
a S-Type pitoti  When the  S-Type pitot is part of a probe
assembly, the  % error has  even  greater dependence on pitch and
yaw  angles.
             A
       Yaw Angle Misalignment       Pitch Angle Misalignment
                Figure 4-4•.  Types of Pitot "Tube Misalignment

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 Figure 4-5 Velocity Errors from Yaw Angle Misalignment
Figure 4-6 Velocity Errors  from Pitch Angle Misalignment

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SAMPLING TECHNIQUES FOR NON-PARALLEL FLOW SYSTEMS
     When attempting to sample a source with non-parallel flow,
several problems are encountered;  (1) velocity measurements
are subject to pitot tube errors, (2)  volumetric flow rate
determinations are difficult, (3) problems arise relating to
the alignment between the sample nozzle and flow stream, (4)
proportional sampling conditions are difficult to maintain; and
(5)  the inertial properties of the dust particles introduce
biases of unknown magnitude.  These problems are discussed as
they effect three sampling techniques.
     Before discussing individual sampling techniques, a bias
which is common to all sampling methods for non-parallel flow
systems should be considered.  All of the approaches which will
be described assume that a sample which is collected isokineti-
cally and weighted proportionally to the axial velocity will
accurately reflect the particulate concentration in the effluent
stream.  The methods for determining isokinetic and proportional
sampling conditions are based on measurements of gas velocity.
It should be noted that non-parallel flow systems are created by
inertial forces acting on the gas stream as the effluent moves
through the stack or ductwork system.  Since dust particles are
subject to much greater inertial affects than are gas molecules,
the actual velocities of the particles and the gas stream will
not be the same under cyclonic or other non-parallel flow con-
ditions.  In almost all cases, the greater inertial affects on
particles will create larger angles between the particle velocities
and the stack axis than between the gas velocity and the stack

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axis.  This introduces a low bias of unknown magnitude in the
measured concentration due to misalignment of the sampling
nozzle with respect to the particle velocities.  This bias in-
creases as the particle size increases.
     Criteria for determining the minimum number of sampling
points and for locating the sampling points in non-parallel
flow systems must be developed since Method 1 is not applicable
in these cases.  It is recommended that 48 sampling points (the
maximum specified by Method 1) be used until applicable criteria
can be developed.  All of the sampling techniques which will be
presented ass.ume that sampling -is conducted at points repre-
senting equal are.as .of the stack, cross-sec.tional area.  The pro-
cedures in Method (!•-for locating sampling points should be em-
ployed.

Blind Man's Approach--The blind man's approach is so named since
the standard test methods are applied and the non-parallel flow
situation is simply ignored.  This procedure is subject to
multiple biasing affects.
     Since the nozzle is not aligned with the direction of the
flow, the apparent or effective area of the nozzle opening is
reduced.  If the angle between the flow direction and the per-
pendicular to the nozzle opening is <)> , then the area of the
nozzle opening perpendicular to the flow stream is reduced by
cos  .  (Figure 4-7).

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                                                 J  O
                              actual area A  =TT[  •=• 3
                         effective  area  =  A cos
Figure 4-7.  Reduction  of  effective area of nozzle not aligned
            with direction  of  flow.

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In this approach, the sampler has no knowledge of the angle 4>
and therefore the sampling rate will be overisokinetic by an
amount directly proportional to cos ..   .
     Figures 4-5 and 4-5 show that the pitot tube gives incorrect
readings when not aligned with the flow.  For all yaw angles
where  -40°  < 0  < 40° and for all positive pitch angles the
pitot gives higher than real readings.   Thus for three out of
four cases of misalignment the pitot gives high readings which
creates overisokinetic sampling conditions.  It should be noted
that the pitot readings will be further influenced when the an-
gle of the flow is such that the pitot is effectively on the down-
stream side of the sampling nozzle.  In this situation the noz-
zle disturbs the flow stream and introduces additional velocity
measurement errors.
     The effects of the reduced effective nozzle opening, and,
in most cases, the effects of the pitot error, contribute to
overisokinetic sampling.  Overisokinetic sampling biases the
concentration measurement low.  The degree of the bias increases
as the particle size increases.
     In the blind man's approach, the sampling rate is weighted
proportionally to the magnitude of the velocity vector.  In
order to meet the constraint of proportional sampling, the
sampling rate should be weighted proportionally to the component
of the velocity vector parallel to the stack axis.  Therefore, if
the angle between the velocity vector and the stack axis varies
across the cross section of the.stack, then proportional sampling
conditions are not maintained.  The bias which results from

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non-proportional sampling increases as the variations in velocity
and concentration across the stack increase.  The direction of the
bias is not easily determined.
     If sampling is conducted to determine compliance with a mass
emission rate standard, (Ibs/hr), the total volumetric flow rate
must be determined.  Misalignment to the pitot with the flow re-
sults in errors in determining the magnitude of the velocity vec-
tor.  A second error in determining the volumetric flow rate arises
because the velocity vector is not parallel to the axis of the
stack.  The axial velocity vector component is equal to the velocity
vector times the cos  ^ , (where  is the angle between the velocity
vector and the stack axis).  The errors in determining the axial
velocity component due to pitot misalignment error, and due to ve-
locity direction error can be combined, and are shown in Figures
4-8 and 4-9. From these figures it is apparent that the axial velocity
and thus the volumetric flow rate are overestimated.  The degree
of the bias cannot be estimated since, in the blind man's approach,
the sampler has no knowledge of the angle between the velocity
and the stack axis.
     The mass emission rate is the product of the concentration
measur-ed by the sampling train and the total volumetric flow rate.
The concentration is biased low and the volumetric flow rate
is biased high.  The two errors tend to offset each other; however,
it is not possible to  determine the net affect due to the unknown
extent of the biases.  In addition, the magnitude and direction of
the bias due to non-proportional sampling is unknown.
     In some stacks, negative velocities are encountered at
particular sampling points.  When negative velocities are

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   Figure 4-8. Axial Velocity Component  Error due to Yaw Angle Misalignment
Figure 4-9. Axial Velocity Component Error due to Pitch Angle Misalignment

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encountered, no sampling should be conducted.   This biases the



concentration determination high if the negative flow region



contains any particulate material.  When determining the vol-



umetric flow rate for use in calculating a mass emission rate,



the negative pitot reading(s) should be used to calculate the



quantity of negative volumetric flow which should then be sub-



tracted from the positive volumetric flow.  It should be remem-



bered that negative velocity measurements are subject to similar



errors as positive velocity measurements.  Neglecting the pitot



errors, the mass emission rate will be biased high due to the



high bias in the concentration measurement created by negative



flow.





Alignment Approach--The alignment approach invloves determina-



tion of the direction of flow at each sampling point (by means



of three dimensional pitot sensor or similar device).  The



sampling nozzle and pitot are then aligned with the flow direction



at each sampling point.



     For standard Method 5 particulate sampling equipment, it



is easy to rotate the sampling probe for different yaw angles.



However, it is not possible to align the sampling nozzle and



pitot for different pitch angles.  Therefore,  the alignment



method is not applicable to sources where pitch angle misalign-



ment exists.  Figures 4-10 and 4-11 show pitch and yaw angles for



a typical stack with cyclonic flow.



     In the alignment method, the sampling rate must be based on



the magnitude of the velocity vector at each sampling point to



maintain isokinetic sampling conditions.  If the yaw angle varies

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Stack Wall

 10°-
 10° .
 20°_
 30° -
                Center of Stack
                                                      Stack Wall
   Figure 4-10. Typical Pitch Angle Profile in Stack with Cyclonic Flow.  Current
                Data near Walls and at Center is Unreliable.
Stack Wall
 40e
 50° .
 60C
 70°
 80° -
 90°
                                  Center of Stack
                                                                        Stack Wall
   Figure 4-11.
Typical Yaw Angle Profile,in ;Stack with Cyclonic Flow.  Current
Data near Walls and at Center' is Unreliable.

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across the stack cross section, then the sampling velocity is
not weighted proportionally to the axial component of the
velocity vector.  In this situation, proportional sampling
requirements can be satisfied by adjusting the sampling time
for each sampling point such that the volume of sample collected
is related by a constant to the axial velocity component at each
sampling point.  This can be accomplished by weighting the
sampling time at each point by cos<|>  (where   is the angle between
the velocity vector and the stack axis):

             92 = el cos*                                (S)
                    6, = nominal sampling  time per point
                    62 = actual sampling  time at a point
                      = misalignment angle  at  a point

The sampling team should be careful  in  selecting the nominal
sampling time per point to ensure collection of the minimum
required  sample volume  since  application of Equation 5  will  re-
duce  the  actual sampling  time.
      In sampling  to  determine compliance with a mass emission
rate standard  the  volumetric flow rate  must  be determined.   Since
the angle of  the  velocity vector (with respect to the stack
axis)  must be determined  to apply the  alignment approach,  the
axial volumetric  flow rate can be calculated as:
                           N      ._
               j:z  (\£P~  coscj^)
                           '—	               (6)

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       where:    Q  = stack volumetric flow rate (ft /sec)
                      actual conditions
                 K  = 85.48
                 C  = pitot tube coefficient
                                                    2
                 A  = stack cross-sectional area (ft )
                 T_ = average stack temperature (°R)
                 P  = absolute stack pressure (in.  Hg)
                 M  = molecular weight of stack gas, wet
                  s   (Ib/lb-mole)
                 A  = pitot reading' (in H^O)
                 <|>  = angle between velocity vector and stack axis
                 N  = number of sampling points
No additional biases are introduced-when calculating the volu-
metric flow rate if the angles . are accurately known.
     No sampling should be conducted at sampling points where
negative velocities are observed.  There "'is no way to assign
a negative value to the quantity C.V. when the velocity Is
negative since the sampling train obtains an integrated sample,
[E C-V-].  The fact that negative flows are not sampled biases
thie concentration measurement high if the negative flows contain
any particulate matter.  When determining a mass emission rate,
the negative volumetric flow rate should be calculated based on
the negative axial velocity component.-  The net volumetric  •
flow rate, (positive volumetric flow rate minus negative volu-
metric flow rate), must be used to calculate the mass emission
rate.  Where negative velocities are encountered, the mass
emission rate will be biased high due to the bias in the
concentration measurement.

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     Compensation Approach - The compensation approach requires



determination of the direction of flow at each sampling point,



(by means of a three dimensional pitot sensor or similar device),



and measurement of the velocity vector at each sampling point.



In the compensation approach, the sampling nozzle is aligned with



the stack axis as in the blind man's approach.  This method is



applicable to sources with both pitch and yaw angle misalignment



if a separate pitot and sampling probe are used.



     The nozzle is not aligned with the flow direction; therefore



the effective nozzle area is reduced by cos*  , Figure 4-12. In



the compensation approach, the angle $ is known and the sampling



rate is reduced by cos to maintain isokinetic sampling conditions.



The use of the nozzle area correction requires that the isokinetic



sampling rate is proportional to both the velocity vector V and



cos<|> .  Since the axial velocity component V  is Vcos<|>  , the
                                            ct


nozzle area correction also weights the sampling rate proportion-



ally to the axial velocity.  Therefore the requirements of



proportional sampling are satisfied.



     The compensation approach is subject to  biases when the



angle between the nozzle and the flow  stream becomes sufficient-



ly large.  For very large angles of misalignment, the flow



around the nozzle will create aerodynamic interferences with  the



isokinetic sampling.  In general, these interferences will bias



the concentration measurement low.  The degree of the bias will



increase as the velocity increases and as the angle of misalign-



ment increases.  Further study  is required to determine at what



angle these affects become  significant and the extent of the



biases on  the sampling results.

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                                    actual nozzle opening
                                    area,  A
                           effective area, EA
                           EA  =  A cos
Figure  4-12. Compensation  Approach

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     When sampling to determine a mass emission rate, the



volumetric flow rate should be determined as:
                          N



as in the alignment approach.  No additional biases are intro-



duced in calculating the volumetric flow rate if the angles



are determined accurately.



     As in the alignment approach, no sampling should be con-



ducted at sampling points where negative velocities are ob-



served.  Again, this biases the concentration high if the



negative flow contains particulate matter.  To calculate the



net volumetric flow rate where negative flows are encountered,



Equation 6 can be used by adding a negative sign to cos



where  is negative, or the negative volumetric flow can be



subtracted from the positive volumetric flow.  Where negative



flows are encountered the mass emission rate will be biased



high due to the high bias in  the measured concentration.







SOURCE MODIFICATIONS



     In some non-parallel  flow situations, modifications  to



the source can be made which  permit application of the  stan-



dard sampling methodology.  The simplest  source modification  is



to move the sampling site to  an alternative location and there-



by avoid the problem altogether.  This option is generally not



available since anticipated non-parallel flow conditions should



have been a major consideration in the selection of the origi-

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nal sampling site.  A second modification is to employ
straightening vanes to eliminate the non-parallel flow.
Straightening vanes can be fabricated of almost any material
(depending on the temperature encountered).  In most cases, a
single vane or a pair of vanes at- 90°, extending across the
stack are"sufficient to eliminate the flow problem.  The
straightening vanes should be at least 1/2 stack diameter in
length, (parallel to axis of stack).
     At some sources, particularly at asphalt plants, a stack
with cyclonic flow functions as part of the inertial demister
system for wet scrubbers.  Straightening vanes' employed in
this situation would eliminate the stack' s' 'function as-^"'Con-
trol device and thereby greatly increase emissions.  In'most
cases, a stack extension equippped with straightening vanes
can be employed  (Figure  4-13). Straightening vanes are used
to create a flow disturbance which improves the flow condi-
tions downstream at the sampling site.  The flow disturbance
from straightening vanes also propagates upstream to an un-
known extent.  It should also be noted that straightening vanes
exert work on the effluent stream which is evidenced by a
pressure drop across the vanes.  In most cases, the straighten-
ing vanes will have little affect on the volumetric flow rate
through the system since the pressure drop across the vanes
is small compared to other pressure drops  in the effluent
handling system.  Ideally, any modifications which are  employed
should not affect the flow pattern in stacks which function
as part of the control system.  Any affects on the flow pat-
tern in the existing stack will generally  reduce the cyclonic

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flow and increase the emission rate.  Adherence to the follow-
ing criteria will minimize the affects of a stack extension
and straightening vanes.
     1. the stack extension should be the same diameter
        as the existing stack
     2. the straightening vanes should be at least 1/2
        stack diameter .downstream from the exit of the
        existing stack
     3. the extension must be at least 2 1/2 diameters in
        length after the straightening vanes.
A second type modification which can be used for stacks with
cyclonic flow is essentially the addition of a tangential
outlet duct  (Figure 4-14). Although this type of extension is
more difficult to construct, there:is less affect on the flow
pattern in the existing stack and straightening vanes in the
extension may not be necessary.  In some cases, the diameter
of the extension may be smaller than the existing stack which
reduces the actual  length of the extension.  In any case, the
extension must be at least 2 1/2 diameters in length to
satisfy the minimum requirements of Method 1.

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CONCLUSIONS



     When particulate sampling is required and where non-



parallel flow conditions are encountered, a decision must



be made to either modify the source to eliminate the un-



acceptable flow situation or apply one of the special



sampling procedures which have been discussed.  Source modi-



fications should be employed when feasible since they will



reduce the complexity and difficulty in obtaining a repre-



sentative sample.  Modifications to sources where stacks with



cyclonic flow function as part of the control system should



be carefully planned.



     Where source modifications can not be employed and  special



sampling procedures are to be used,  either the alignment



approach or the compensation approach should be used.  The



blind man's approach should not be used due to the many



problems which are encountered which result in unknown biases



in the sampling results.  The alignment approach is limited



to non-parrallel flow situation where only yaw angle misalign-



ment exists.  The compensation method can be used in any non-



parallel flow situation, however a low bias in the  sampling



results may occur for large angles of misalignment.  Both the



alignment appeoach and the compensation approach allow a



particulate sample to be obtained isokinetically and both



approaches satisfy the requirements of proportionally weighting



the sampling relative to the  stack axial volumetric flow rate.



Application of either the alignment or compensation approach



will require considerably more time and effort to obtain valid



sampling results than is encountered in  the application  of



standard particulate  sampling procedures.

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                  >l/2d
                  >2d
                  >l/2d
                  >l/2d
                                                       TOP VIEW
              \
Figure 4-13.   Stack
Extension With Straightening
Vanes
Figure 4-14.
Temporary Tangential
Outlet

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