EPA-600/2-76-023
February 1976
Environmental Protection Technology Series
TENTATIVE PROCEDURES FOR
PARTICLE SIZING IN PROCESS STREAMS
Cascade Impactors
Industrial Environmental Research Laboratory
Office of Research anrj Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
EPA REVIEW NOTICE
This report has been reviewed by. the U.S. Environmental
Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policy of the Agency, nor does mention of trade
names or commercial products constitute endorsement or
recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
EPA-600/2-76-023
February 1976
TENTATIVE PROCEDURES FOR PARTICLE SIZING
IN PROCESS STREAMS—CASCADE IMPACTORS
by
D. Bruce Harris
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
ROAP No. 21ADM-012
Program Element No. 1AB012
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
-------
CONTENTS
Page
List of Figures iv
List of Tables iv
Acknowledgments v
Sections
1.0 Introduction . . . . . 1
2.0 The Presurvey . 2
3.0 Equipment Selection and Preparation 7
4.0 Collection Substrates and Adhesives . 13
5.0 Sampling 16
6.0 Post-sampling Procedure 17
7.0 Commercial Impactors 19
8.0 Data Analysis . 27
9.0 Bibliography 39
Appendix A -- Brink Orifice Calibration ..... 41
Appendix B— Design Drawings, Brink In-line Cyclone and
Impactor 43
Appendix C -- Cost Estimating Data Sheet 46
Appendix D -- Preliminary Survey . 48
Appendix E -- Stack Data Sheet 52
Appendix F -- Safety Checklist 54
Appendix G -- Metric System Conversion Factors . 56
in
-------
LIST OF FIGURES
Number Page
1 Presurvey sampling using Brink impactor •• • 3
2 Nomograph for selecting nozzles for isokinetic
sampling 10
3 Nomograph for sampling time selection
(25 mg sample) 12
4 Original Brink sampling train, BMS II design .... 20
5 Brink impactor sampling train using a
calibrated orifice flowmeter ... ... 21
6 Andersen or Pilat sampling train with recirculation . 24
7 Typical Andersen or Pilat train using calibrated
orifice and dry gas meter 25
8 Stage collection efficiency for a modified
Brink impactor 28
9 Simulation of a continuous particle size
distribution 36
10 Comparison of D™ and Picknett methods 37
LIST OF TABLES
Number Page
1 Impactor Decision Making 5
2 Sampling Information Required . ........... 18
IV
-------
ACKNOWLEDGMENTS
The author gratefully acknowledges the help of the members of the
working group who provided much useful information from their knowledge
of and experience in the field of particle sizing: Dr. Seymour Calvert
(APT, Inc.), Dr. Neal Hill (2000, Inc.), Gene Kennedy (Monsanto Enviro-
Chem), Joe McCain (Southern Research Institute), and Dr. Michael Pilat
(University of Washington).
A special thanks to Ken; Gushing and Joe McCain of Southern Research
Institute for their work on the computation section and Douglas VanOsdell
of Research Triangle Institute for general editorial assistance.
-------
1.0 INTRODUCTION
Inertial impactors are commonly used to determine the particle size
distributions from industrial particulate sources. These impactors have
several advantages over competing techniques: they are compact, can be
inserted directly into the duct (avoiding the sample loss problems of a
probe), and are fairly accurate. The Process Measurements Branch (PMB)
of EPA's Industrial Environmental Research Laboratory, Research Triangle
Park, N. C., has been using inertial impactors to determine fractional
efficiency for several years, as have a number of IERL-RTP contractors.
The PMB has also sponsored an evaluation of impactors to select devices
that could be used under normal field conditions. During the course of
these programs it became evident that no uniform approach to the field
use of impactors was available.
To develop uniform procedures, a working group of IERL-RTP personnel,
contractors, and independent experts met at Research Triangle Park, N.C.
This guideline is an outgrowth of the working group discussions, and is
intended to promote individual tests of similar quality so that valid
comparisons may be made.
It is emphasized that this document is for guidance only, and is
not a set of rules. Techniques for measuring particle size in stationary
sources are too new, and too few testing situations are the same. There
is unanimous concurrence that the present state of knowledge does not
permit a routine procedure to be set forth. Therefore, professional
judgment is still the most important element in successfully determining
fractional efficiency.
The scope of this report includes the preliminary survey, the
sampling apparatus, testing procedures, and data analysis. The information
is applicable to cascade impactors in general. Specific commercial
impactors are discussed in the section titled "Commercial Impactors."
-------
2.0 THE PRESURVEY
The key to performing a successful fractional efficiency evaluation
is thorough planning based on a complete pretest site survey. During
this survey, anything which could affect the testing program must be
noted. The accessibility and suitability of sampling ports, platforms,
and electrical power should be assessed. Requirements and provisions
for any special adaptors or processes should be determined. A good
guide is the presurvey form used by the Emissions Standards and Engineering
Division (ESED) of EPA's Office of Air Quality Planning and Standards.
A copy of this presurvey form has been included as Appendix D.
Other information which should be obtained during the presurvey
includes preliminary data on flue gas temperatures, velocities, gas
composition (COo, CO, ^0, 0^, toxic and/or non-toxic vapors, etc.), and
stack pressures. If possible, this data should be measured rather than
obtained from plant records or personnel.
A good presurvey should also include estimates of particulate
loading and size distributions. A few guide samples utilizing the Brink
impactor as a screening device will provide this information. The
sampling system shown in Figure 1 has been developed for presurvey
sampling. A collapsible pitot probe with an attached thermocouple is
used to determine stack gas velocity. Using the velocity information, a
nozzle is selected for the Brink impactor which will produce approximately
isokinetic conditions for the Brink sampling rate of 0.04 to 0.07 acfm*.
The sample should be taken within ±20 percent of isokinetic conditions.
If preweighed substrates are used in the Brink, a fairly accurate
picture of size distribution and mass loading can be developed. Very
rough estimates can be obtained from visual inspection of the substrates
if a balance is not available. Obtaining a particulate sample during
the presurvey provides ah opportunity for detection of possible trouble
such as acid condensation, physical obstructions at sample stations, and
process variability.
*Although it is EPA policy to use metric units in all documents it
produces, this report includes certain non-metric units for convenience.
Readers more familiar with the metric system may use the factors in
Appendix G for conversion.
-------
MAGNEHELIC%IFFERENTIAL PRESSURE
INDICATORS
0-2 in. H20 0-10 in. Hg
<^r^~^Nb
( HC JJ H
\\"/L- ,
0-0.5 in. H20
'/^\
(Oil
x,.^^
^~~ -'-
(A
J\
M"
\VyS
3- WAY
VALVE ^
7
1/4 INCH
NEEDLE
J7
J-
VALVE
r^t^i
l^fJ—
MOISTURE
TRAP
COOLING /Y
K
-iXjQ — l COIL I N )
3- WAY
VALVE
STATIC -IMPACT STACK ATMOSPHERIC
1 ' STATE PRESSURE
RTOT-TUBE PRESSURE
J^
IT
1^
METAL
BELLOWS
PUJMP
Dt» — 1 — 1
..-D
TEMPERATURE
*5fcoNTROLLER
0-500 °F
C «
!" '«
1
?
S • • s •
* s
J ^
IN OUT TEMPERATURE S^TSil.Mr
1 SOISOR I?^7"*6
eiAM*i TAPt
IMPACTOR SAMPLE WtoHflL
COLLAPSIBLE
PITOT-TU8E
Figure 1. Presurvey sampling using Brink impactor.
-------
In summary, the presurvey should provide the information necessary
to design an adequate test program. The decisions which must be made
are summarized in Table 1.
-------
Table 1. IMPACTOR DECISION MAKING
Item
Information Required
Criteria
Impactor
Loading and size estimate
Sampling rate
Nozzle
Pre-cutter
Sampling time
Collection
substrates
Number of sample
points
Loading and gas velocity
Gas velocity
Size and loading
Loading and flow rate
Temperature and gas
composition
Velocity distribution
and duct configuration
a. If less than 0.2 grain of
particles/acf is smaller than
5.0 ym, use high flow rate impactor
b. If greater than 0.2 grain of
particles/acf is smaller than
5.0 ym, use low flow rate impactor
a. Fixed, near isokinetic
b. Limit so last jet velocity does
not exceed:
-60 m/sec greased
-35 m/sec without grease
a. Near isokinetic
b. Sharp edged; min 2.0 mm
If pre-cutter loading is comparable to
first stage loading—use pre-cutter
a. Per Figure 3
b. No stage loading greater than 10 mg
a. Use metallic foil or fiber substrates
whenever possible
b. Use adhesive coatings whenever
possible
a. At least two points per station
b. At least two samples per point
-------
Table 1 (cont'd). IMPACTOR DECISION MAKING
Item
Information Required
Criteria
Orientation
of impactor
Heating
Probe
Duct size, port
configuration, and size
Temperature and condensible
vapors
Port not accessible using
normal techniques
Vertical impactor axis wherever
possible
a. If flue is above 350°F, sample
at process temperature
b. If flue is below 350°F, sample at
20°F above process temperature at
impactor exit using external heaters.
a. Only if absolutely necessary
b. Pre-cutter on end
c. Minimum length and bends possible
-------
3.0 EQUIPMENT SELECTION AND PREPARATION
3.1 IMPACTOR SELECTION
The selection of the proper impactor for a participate test situation
is primarily dependent upon the mass loading of the gas stream and its
effect on sampling time. There are three major criteria to be met to
match an impactor to a particulate stream:
1) The sampling period must be long enough to provide a
reasonable averaging of any short term transients in the
stack.
2) The maximum allowable loading on a given impactor stage is
about 10 mg.
3) The sampling rate through the impactor must be low
enough to prevent scouring of impacted particles by high
gas velocities.
For these reasons, an impactor with a comparatively low sample rate
must be used in a gas stream with a high mass loading. The low sample
rate allows a longer sampling time, although in some situations it will
still be undesirably short. The Brink impactor is an example of a low
flow rate impactor.
Conversely, in a low mass loading situation such as a control
device outlet, a high sample rate device must be used if a significant
amount of sample is to be gathered in a reasonable amount of time. The
Andersen Mark III and the Pilat (University of Washington) Mark III
impactors are examples of high sample rate devices.
A cascade impactor can normally yield useful information over a
range of sample rates differing by a factor of 2 or 3. As high efficiency
control devices cause the outlet mass loading to differ from the inlet
by a factor of ten, the same impactor cannot be used on both inlet and
outlet. Both high and low flow rate impactors are required to determine
the efficiency of most particulate control devices.
3.2 NUMBER OF SAMPLE POINTS
As the velocity and particulate distributions in industrial ductwork
are unlikely to be ideal, a large number of samples are required for
accurate particulate measurements. At least two points within a duct
should be sampled in each measurement plane, and at least two samples
taken at each of these points. These are minimum sampling efforts and
-------
are appropriate only for locations with well developed flow profiles and
consistent mass loadings. If the flow profile at the station is un-
certain due to duct configuration and/or the mass loading is not uniform,
the number of samples must be increased for reliable results.
3.3 IMPACTOR ORIENTATION
Whenever possible, the impactor should be oriented vertically to
minimize gravitational effects such as flow of grease or fall-off of
collected particles. Sampling situations requiring horizontal placement
will occur and extra care must be taken on such occasions not to bump
the impactor against the port during removal.
3.4 HEATING IMPACTOR
All condensible vapors must be in a gaseous state until they exit
from the impactor, unless a condensate is the prime aerosol being
measured. In gas streams above 350°F, auxiliary heating should not be
required. Below 350°F the exit temperature of the impactor should be
maintained at least 20°F above the process temperature. (A thermocouple
feedback temperature controller has proven useful.)
Whether the impactor is being heated in the duct or externally with
heater tape, an allowance of 30 minutes warm-up time is recommended as a
minimum to ensure that the impactor has been heated to duct or operating
temperature. High mass units such as the Brink may require 45 minutes.
Thermocouple monitoring of the impactor temperature and impactor exit
gas temperature is recommended.
3.5 PROBES
Sampling probes leading to an impactor outside of the duct should
be used only if there is no other way. They should be as short as
possible and contain the fewest possible bends. It is recommended that
a pre-cutter be mounted at the duct end of the probe to remove the large
particles and thus reduce line losses.
3.6 NOZZLE AND SAMPLING RATE SELECTION
It is preferable to use as large a nozzle diameter as possible to
minimize sampling errors resulting from nozzle inlet geometry. When
very small nozzles have been used with the Brink impactor, there have
been some cases in which large amounts of material were retained in the
nozzle or the nozzle was completely blocked. It is recommended that
-------
the nozzle not be smaller than 2.0 mm. In some instances bent nozzles
are necessary due to port location and gas direction, but these should
be avoided. Problems occur in cleaning bent nozzles, and it is difficult
to determine the size interval in which the deposited material originated.
If they cannot be avoided, bends should be as smooth as possible and of
large radius in order to minimize the losses in the fine particulate
region.
The sampling rate must be such that the last stage velocity does
not exceed 60 m/sec for greased collection surfaces or 35 m/sec for
ungreased plates if no suitable substrate can be found to limit particle
bounce. The flow rates above should not be considered the final word on
nozzle velocity, as particle bounce has been observed at nozzle velocities
as low as 10 m/sec. The exposed substrate should be visually examined
for evidence of re-entrainment and the rates adjusted accordingly.
It is apparent that sample rate and nozzle size are closely coupled.
The requirements for isokinetic or near-isokinetic nozzle flow sometimes
impose a compromise on nozzle selection. The general order of priorities
when choosing the sample rate is nozzle diameter (at least 2 mm), last
stage jet velocity, and flow rate required for isokinetic sampling.
Selection of nozzle diameter and impactor flow rate combinations for
achieving near-isokinetic sampling conditions can be made from Figure 2.
Note that the upper flow limits for some impactors have been indicated
by horizontal lines at the appropriate flow rate.
3.7 PRE-CUTTER USE
In many instances the percentage (by weight) of material with sizes
larger than the first impaction stage cut point is quite high. In such
cases a precollector cyclone is necessary to prevent the upper impactor
stages from overloading. A pre-cutter should always be used for the
first test. If the weight of material obtained by the pre-cutter is
comparable to that on the first stage, the precollector should be used
in all subsequent runs. Cyclones can be obtained from the impactor
manufacturer or can be shop made. A set of drawings of a cyclone for
the Brink is included in Appendix B. The basic design can be adapted
for attachment to other impactors. The use of two first stages in
series has also been suggested and appears to be a valid approach;
however, no data are available.
-------
NOTE: HEAVY HORIZONTAL LINES INDICATE MAXIMUM FLOW RATES
WITHOUT RE-ENTRAINMENT FOR VARIOUS IMPACTORS,
ANDERSEN-WITH FILTER
PILAT-WITHOUT GREASE
BRINK-WITHOUT GREASE
0.01
2 3 45678 910 2 3 456789 100
GAS VELOCITY, ft/sec
Figure 2. Nomograph for selecting nozzles for isokinetic
sampling.
10
-------
3.8 SAMPLING TIME
The length of the sampling time is dictated by mass loading and
i '
size distribution. An estimate for initial tests can be obtained from
Figure 3. The duration of the following tests should be adjusted so that
no single stage (excluding a pre-cutter if one is used) has more than 10
mg of sample.
11
-------
FLUE GAS MASS LOADING, gr/acf
OQ01
1000
0.01
0.1
1.0
10
100
100
READ DOWN FROM MASS LOADING TO IMPACTOR
SAMPLE RATE, READ LEFT TO TIME REQUIRED
TO COLLECT A 25 MG SAMPLE AT THAT SAMPLE
RATE,
to
I I I
1.0 0.50.40.30.2 0.1 0.05 0.03
IMPACTOR SAMPLE RATE, acfm
Figure 3. Nomograph for sampling time selection (25 mg sample).r
0.01
-------
4.0 COLLECTION SUBSTRATES AND ADHESIVES
4.1 COLLECTION SUBSTRATES
Due to the necessity of high weighing accuracy, large stage tare
weights, and low tare capacity of most field useable precision balances,
metal foil or glass fiber collection substrates should be used with all
impactors. The Brink has generally been used with aluminum foil or, in
some cases, glass fiber or Teflon substrates. The Andersen Mark III
utilizes special glass fiber inserts supplied by the manufacturer, and
the Pilat Mark III has been used with aluminum or stainless steel foil
substrates.
Glass Fiber Substrates -- The use of the glass fiber substrates
available for the Andersen is recommended. They are as resistant to
particle loss as are greased substrates. Care must be taken when using
glass fiber substrates in streams containing sulfur dioxide, however.
Recent experimentation has shown that glass fiber materials sometimes
show weight gains due to sulfate uptake on the substrates. Apparently,
sulfur dioxide in a gas stream can react with basic sites on some glass
fiber materials and form sulfates. Normal Andersen substrates have
shown significant weight gains at times due to this reaction.
There are two approaches to this problem. Substrates which will
gain weight from sulfate uptake can be preconditioned in the flue gas
before weighing. From two to six hours of exposure to the flue gas is
sufficient to use up all of the active sites and prevent weight gains.
Another approach is to use a fibrous substrate which shows little
weight gain in a sulfur dioxide stream. Some substances which have been
tested and exhibit only slight weight gains are Teflon, Whatman GF/A and
GF/D, and Reeve Angel 934 AH. It is not known whether these materials
have the same particulate retention characteristics as do the more
common substrates. The calibration of impactors used with these sub-
strates might be changed some.
Greased Substrates -- Grease must often be used on the collection
substrates of the Brink and Pilat impactors to aid in particle retention.
The use of grease allows higher flow rates than are possible without
grease. Flow rates as high as 60-65 m/sec have been used with greased
substrates and acceptable results obtained.
13
-------
A 20 percent solution of grease in benzene has been found suitable
for placing the grease on the substrates. The solution is dropped onto
the substrate with an eye dropper. A Pilat stage requires 7 or 8 drops
while the last stages of a Brink only require one drop. Even less
grease may be used if light stage loading is anticipated. After the
proper amount of solution has been placed on the substrate, the greased
substrates are baked at 400°F for 1 to 2 hours and then desiccated for
12 to 24 hours prior to weighing. Depending on the temperature in the
sampling duct, a silicone or other high viscosity type of grease may be
used on the substrates. Gas chromatographic material such as poly-
ethylene glycol 600 has exhibited more consistent characteristics than
materials such as stopcock grease. There have been cases of greased
substrate losing weight in hot, dry gases and this possibility should be
considered.
Horizontal operation of the impactors with greased substrates is
not recommended due to possible flow of the grease. Care must also be
taken to ensure that grease is not blown off the substrates (which tends
to occur at jet velocities greater than 60 m/sec).
4.2 BACK-UP FILTERS
Back-up filters are used on all impactors to collect the material
that passes the last impaction stage. Binderless glass fiber filter
material (such as Gelman type A Glass Fiber Filter Web) is used for this
purpose in all of the impactors, although the exact configuration
varies.
4.3 BALANCE REQUIREMENTS
For accurate weighing of collected material a balance with a
sensitivity of at least 0.01 mg is required. This is especially true
for the lower stages of the high loading impactors where collection of
0.3 mg or less is not uncommon. The balance must also be insensitive to
vibration if it is to be used in the field. These capabilities are
available in several electrobalances marketed in the U.S. It is also
desirable to have a balance with a large enough weighing chamber to
accommodate the Pilat foi.ls without having to fold them.
14
-------
4.4 SAMPLING TRAINS
The sampling trains for both the high and low flow impactors are
very similar. They basically consist of a vacuum pump and flow measure-
ment and control equipment. For long sampling times, or where there is
high water content, a series of condensers in an ice bath are useful
for removing the moisture. A drying column and cooling coil are recommended
to follow the condensers. Examples of sampling trains for the various
impactors are included in the appropriate impactor sections.
15
-------
5.0 SAMPLING
5.1 READYING THE IMPACTOR
The impactor should be carefully loaded with the preweighed stage
substrates and assembled. Antiseize compound should be applied to the
threads especially when high temperatures (>400°F) are encountered. The
appropriate nozzle is then attached.
If supplemental heating is required, the heating tapes, insulation,
and temperature monitors need to be added. A thermocouple mounted in
the gas flow immediately after the impactor is best for controlling
heating. This also yields the temperature needed for calculating
impactor cut points. A heating tape of sufficient wattage is wrapped
around the impactor. Glass fiber tape works well for holding the heating
tape. Insulation such as asbestos tape is then wound around the impactor.
Glass fiber tape again is used to hold the asbestos in place and also
acts as additional insulation. The impactor can now be mounted on the
appropriate probe, taken to the sampling position, and installed in the
sampling system.
5.2 TAKING THE SAMPLE
The impactor should be preheated for at least 45 minutes before
sampling. If supplemental heat is being used, the impactor should be
brought up to temperature outside the duct and then allowed some time to
equilibrate after insertion. The nozzle should not point into the flow
field during this phase. Without supplemental heat, the whole warm up .
is conducted within the duct, again with the nozzle pointed away from
the flow field.
A predetermined flow rate must be maintained to ensure stable cut
points. Any attempt to modulate flow to provide isokinetic sampling
will destroy the utility of the data by changing the cut points of the
individual stages. Rapid establishment of the correct flow rate is
especially important for the short sampling times typically found at the
inlets to control devices.
16
-------
6.0 POST-SAMPLING PROCEDURE
6.1 IMPACTOR CLEAN-UP
The post-test procedure is very important in obtaining useful
results. The crucial part is to make sure the collected material stays
where it originally impacted. After the test, the impactor should be
carefully removed from the duct without jarring, removed from the probe,
and allowed to cool. Disassembly is a delicate task in some cases. It
is necessary to have a pair of fine tweezers and a balance brush: a
Dumont INOX 3C tweezer and a No.7 Portrain brush are suggested. Specific
disassembly instructions are included in the impactor sections.
6.2 DRYING AND WEIGHING
All collected materials should be dried in a convection oven at
212°F, desiccated until cooled to room temperature, and weighed to 0.01
mg. The weighing chamber of the balance should also be kept desiccated.
The samples should be redesiccated for 2 hours and reweighed to establish
constant weight.
NOTE: The above drying and weighing procedure determines the stage
weights for use in final calculations. Normally, all samples should be
weighed before the next scheduled test to ensure that impactor conditions
are appropriate. Samples can be weighed immediately after clean-up for
this purpose.
6.3 DATA LOGGING
Records should be kept in notebooks for all phases of the sampling
program. It is generally easiest to keep three notebooks: one for
recording weights which remains in the lab with the balance, and one
each for recording the details on inlet and outlet sampling runs. A
form incorporating the items in Table 2 is useful for recording the
necessary information while sampling.
17
-------
Table 2. SAMPLING INFORMATION REQUIRED
Date
Sampling Location
Operator
Impactor Identification
Run Code No.
Port No.
Probe Depth
Ambient Pressure
Stack Temperature
Stack Pressure
Impactor Temperature
Impactor Location
in-stack/out-of-stack
Scalping Cyclone(s)
Pi.tot AP
Gas Velocity
Impactor Flow Rate
Nozzle Diameter
Impactor AP
Start Time
Gas Meter End Time
Total Sampling TimeV
Gas Meter Start Time
Meter Orifice Temperature
Meter Orifice AP
Pressure at Meter Orifice
18
-------
7.0 COMMERCIAL IMPACTORS
7.1 BRINK IMPACTOR
The Brink impactor is a low sample rate cascade impactor, suitable
for measurements in high mass loading situations. A drawing with
appropriate dimensions is shown as Appendix B. The information below
supplements the more general discussion in the body of this manual.
Sampling Rate -- The usual sampling rates for the Brink are in the
range of 0.04 to 0.07 acfm. The sampling rate must be low enough to
prevent re-entrainment of particles from the lower stages. Normally,
the last stage nozzle velocity must be less than 30-35 m/sec with un-
greased substrates, and less than 65 m/sec with greased substrates.
Collection Substrates and Adhesives -- The Brink impactor collection
stage is too heavy to use without a substrate. Foil cups are commonly
preformed and fit into the collection cups of the Brink stages. If
grease is to be used, the top stages require 5 or 6 drops of solution
while the bottom stages normally require only one drop in the center of
the cup.
Back-up Filter -- The Brink back-up filter is normally made of
binderless glass fiber filter material. Two 1-inch diameter disks of
filter material are placed under the spring in the last stage of the
impactor. The filter is protected by a Teflon 0-ring and the second
filter disk acts as a support.
Brink Sampling. Train -- Several Brink sampling train arrangements
are available depending on the impactor used, flow rate, sampling time,
etc. The original Brink design called for a system similar to that
shown in Figure 4. The flow rate was determined by the pressure drop
across the impactor. With the low flow rates found to be required for
high particle concentration, it was very difficult to accurately measure
the pressure drop across the Brink. Very low rates also precluded
the use of a dry gas meter for sample volume measurement.
A better method of flow control and volume determination is to use
a system built around a calibrated orifice as shown in Figure 5. To
ensure proper measurement by the orifice and to protect the vacuum pump
from damage resulting from condensation vapors, it is necessary to
19
-------
BACK
FRONT
TO DUCT
CYCLONE
IMPACTOR
CATCH
KJTTLE
<
o
»•?
f
f
-
—
,_
-?
w
1.0
'RE
-------
PROBE
PORT
CONDENSERS
ICE BATH
ANDERSEN OR PILAT
AIR
Hg MANOMETER
DRYING
COLUMN
COOLING COIL
MANOMETER
TO
VENT
Figure 5. Brink impactor samnling train using a calibrated orifice flowmeter.
-------
cool and dry the sampled gases after the impactor. For long sampling
times, or where there is high water content, a series of condensers in
an ice bath is useful for removing the water. A drying column and
cooling coil are recommended to follow the condensers. Different size
orifices (such as 0.03, 0.06, and 0.09 inches) allow for a wide range of
flow rates with reasonable pressure drops using a water manometer. A Hg
manometer is placed upstream of the orifice to determine the pressure at
the inlet to the orifice. Orifice calibration calculations are included
in Appendix A.
Brink Clean-up -- Careful disassembly of a Brink impactor is
necessary for obtaining good stage weights. If a precollector cyclone
has been used, all material from the nozzle to the outlet of the cyclone
is included with the cyclone catch. All of this material should be
brushed onto a small, tared, 1x1 inch aluminum foil square to be saved
for weighing. Cleaning the nozzle is also important, especially if it
is a small bore nozzle. All material between the cyclone outlet and the
second stage nozzle is included with material collected on the first
collection substrate. All appropriate walls should be brushed off, as
well as around the underside of the nozzle, where as much as 30 percent
of the sample has been found.
7.2 ANDERSEN IMPACTOR
The Andersen impactor is a relatively high sample rate impactor.
Normal samples rates are about 0.5 acfm. The information below is
specific to the operation of the Andersen impactor.
Sampling Rate -- The Andersen sampling rate is about 0.5 acfm. As
with other cascade impactors, the flow rate must be low enough to prevent
re-entrainment of impacted dust.
Collection Substrates and Adhesives -- Andersen substrates are
obtained precut from the manufacturer. The substrates are glass fiber
and of two types—one cut for the odd numbered stages, one for the even.
As discussed earlier, normal Andersen substrates have a tendency to
absorb S02 on basic sites in the substrate and therefore gain weight.
The manufacturer has recently made substrates from a less reactive fiber
material, and an effort should be made to obtain these if an S02 stream
is to be sampled.
22
-------
Back-up Filter -- The Andersen uses a 2-1/2 inch diameter disk
placed above the final F-stage. The filter should be cut from binder-
less glass fiber filter material such as Gelman Type A Glass Fiber
Filter Web or a material similar but resistant to SCL weight gain.
Andersen Sampling Train -- The Andersen sampling train is similar
to the Brink system except for higher flow capacity in the pumping and
flow measurement devices. Figures 6 and 7 are examples of high sampling
rate trains. The pumping and metering systems of the commercial Method
5, EPA mass sampling train can also be used with the Andersen.
Care should be exercised never to allow a gas flow reversal to
occur through the impactor. Material could be blown off the collection
substrate onto the underside of the jet plate or the collection substrates
could be disturbed. A check valve or maintenance of a very low form
while removing the impactor from the duct avoids this problem.
Andersen Clean-up -- Cleaning an Andersen impactor is difficult.
Foils should be cut to hold the substrates, and each foil and substrate
weighed together before and after the run. For disassembly, the foil to
hold the stage 1 substrate should be laid out. Next the nozzle and
entrance cone should be brushed out and onto the foil. Then the material
on stage 0 should be brushed onto the foil. The stage 1 filter substrate
material should then be placed on the foil and, lastly, the top of the
stage 1 plate 0-ring and cross piece should be brushed off. Depending
on how tight the impactor was screwed shut, some filter material may
stick to the 0-ring edge contacting the substrate. This should be
carefully brushed onto the appropriate foil. This process is continued
through the lower stages. Finally, the filter is carefully removed.
7.3 UNIVERSITY OF WASHINGTON MARK III (PILAT) IMPACTOR
The Pilat impactor is a high flow rate device with generally the
same characteristics as the Andersen. The information below supplements
that in the text.
Sampling Rate -- The Pilat sampling rate is on the order of 0.5
acfm. The flow rate must be low enough to keep scouring of impacted
particles to a minimum.
Collection Substrates and Adhesives -- The Pilat Mark III has often
been used with supplementary foil (aluminum or stainless steel) substrates.
23
-------
CONDENSERS
rss
DRYING
COLUMN
ANDERSEN OR PILAT
FLOW •
Figure 6. Andersen or Pilat sampling train with recirculation.
-------
ro
en
PROBE
IMPACTOR
AIR
FUOW
f-
PORT
DRYING
COLUMN
TEE
7
Hg MANOMETER
METERING
ORIFICE
XZt
COOLING COIL
PUMP
VENT
H20 MANOMETER
Figure 7. Typical Andersen or Pilat train using calibrated orifice and dry gas meter
-------
These substrates require the use of grease for most cases. Enough of
the grease solution is placed evenly on the substrate to adequately
cover the area under the jets (30 mg of grease). The normal cautions
for the use of greased substrates apply as discussed in the text.
. Pi!at Sampling Train -- As the Pilat is a high flow rate device,
its sampling train is similar to that of the Andersen. Figures 6 and
7 show examples.
Pilat Clean-up -- Pilat impactor clean-up is similar to that for
the Brink. Some problems have been noted with 0-rings sticking rather
tenaciously and care must be exercised not to dislodge the sample while
trying to separate the stages. .
26
-------
8.0 DATA ANALYSIS
8.1 CASCADE IMPACTOR DATA'ANALYSIS
The information directly available from a cascade impactor is
weight of particles on a stage. There are several ways to analyze and
present this data as particle size distributions and fractional
efficiencies. The increasing interest in participate information has
made it important that the data be analyzed using a standard method.
Two methods are discussed below: the D5Q method and the Picknett method.
8.2 D50 METHOD
The D50 method is presently used for the majority of cascade im-
pactor data reduction. The method is fairly straight forward and can be
hand-calculated, but it is a considerably simplified picture of the real
distribution and can cause a loss of information.
The Dcg of a stage is the particle diameter at which the stage
achieves 50 percent,efficiency; one half of the particles of that
diameter are captured and one half are not. Figure 8 shows a complete
set of theoretical capture efficiency curves for a modified Brink
impactor. The D^g of stage 4, for example, is about 1.2 ym. The cal-
culation of theoretical stage DCQ'S is discussed below.
The DCQ analysis method simplifies the capture efficiency dis-
tribution by assuming that a given stage captures all of the particles
with a diameter equal to or greater than the D™ of that stage and less
than the DSQ of the preceding stage. With this simplification, the mass
collected on a given stage can be assigned to a particular diameter;
often the geometric mean of the stage DrQ and the preceding stage D™ is
used.
Particle-size distributions may be presented on a differential or a
cumulative basis. When using the D™ method, either type of presentation
may be easily employed.
The size parameter reported can be either aerodynamic diameter
(that is, diameter based on the behavior of unit density particles) or
approximate physical diameter, which is based on an estimate of the true
particle density. In either case, the particles are assumed to be
spherical. The method of reporting diameters depends to a large extent
upon the ultimate use of the size distribution information. For this
reason it is suggested that the data be reported in two parallel sets:
27
-------
0.01 0.1 0.5 I 2 5 10 20
80 90 95 98 99 99.9 99.99
COLLECTION EFFICIENCY, percent
Figure 8. Stage collection efficiency for a modified Brink impactor
(T=72°F, P=29.60 in. Hg. P=1.35 g/cm3, flow = 0.03 acfm).
28
-------
one set based on aerodynamic diameters; the other based on approximate
physical diameters.
8.3 CALCULATION OF STAGE D5Q'S - D5Q METHOD
The reduction of field data obtained with a cascade impactor can
sometimes be troublesome and time consuming because of the computations
involved. The basic equation that defines the theoretical D5Q of a
given stage of a cascade impactor is:
(1)
= i -AV * in '..•.-'-• i ^ '
1.43 10
where:
(-0.44 D5Q x 10"4
1.23 + 0.41 exp (— —r ) 1 (2)
D50 x 10 '
DCQ = stage cut point, ym
iam = viscosity of air at conditions immediately downstream
of impactor jet(s), poise
DC = diameter of impactor jet(s), cm
PS = absolute pressure just upstream of 'jet(s'), in. Hg
PQ = absolute pressure in stack, in. Hg
X(I) = number of holes in stage
p_ = density of particle, g/cm
Qr = flow rate through impactor, acfm
C = Cunningham Correction Factor
L = mean free path of air molecule i cm
While these equations can in principle be solved rigorously when
necessary, it is usually easier to solve them by trial and error.
29
-------
One approach that can be used to further simplify the computations
is to develop curves for the impactor stage cut points at one set of
conditions; e.g., air at standard conditions and a particle density of
1.0. Then a suitable correction factor can be applied to these curves
for the actual sampling conditions. Unfortunately, further .simplifi-
cations are involved in making the correction factor simple enough to be
of value. Therefore, the use of this type of approach suffers from some
restrictions. Figure 8, presented earlier, shows a calibration for dry
air at laboratory conditions with an assumed particle density of 1.35
gram/cm .
All of the assumptions and calculations involved in going from
equations (1) and (2) to the calibration curve can be quite awkward,
particularly in cases where different types of sources are being sampled.
Perhaps the best approach is to write or obtain a computer program based
on the rigorous equations given initially. The program can not only
calculate impactor stage cut points but can also compute concentrations
of particles in each size range, as well as differential and cumulative
size distributions. It permits more sophisticated data reduction
methods to be used than would be possible by hand. Manual calculation
of cut points typically takes several hours. Using a computer program,
several sets of data can be calculated in a few minutes. Not only is
the computer faster but the possibility of computational errors is
greatly reduced.
In summary, there are basically two ways that the computational
difficulties associated with using the cascade impactor can be overcome.
Where basically the same types of sources are being sampled, the calibration
curve approach will work very well; however, in the general case where a
wide variety of different types of sources are being sampled, the
simplest approach is to use a computer program based on a rigorous
solution of the cascade impactor equations.
8.4 DIFFERENTIAL PARTICLE SIZE DISTRIBUTIONS - D5Q METHOD
It is assumed for the purpose of analysis that all of the mass
caught upon an impaction stage consists of material having aerodynamic
diameters equal to, or greater than, the D5Q for that stage, and less
30
-------
than the D5Q for the next higher stage. For the first stage (or cyclone),
it is assumed that all of the material caught has aerodynamic diameters
greater than, or equal to, the D™ for that stage (or cyclone), but less
than the maximum particle size. If the maximum particle size is not
known, some arbitrary large value, say 100 ym, is used.
If the true particle-size distribution constituted a continuum, the
amount of material having diameters between D and D+dD could be repre-
sented by dM. Then the integral
^ dD
dD dD
would yield ther total mass having diameters between D-, and D2>
Because the intervals between the stage D50's are logarithmically
related, and to minimize graphical scaling problems, the differential
particle size distributions are plotted on log-log or semi-log paper
with dM/d (log D) as the ordinate and log D as the abscissa. The mass
on stage "n" is designated by AM and is, in approximation, the mass of
particulate with diameter between (D5Q) and (D50)n+i. The A(log D)
associated with AMn is log (DsgL+i - log (D™) . Using these
approximations, the derivative term associated with stage "n" is:
AM '
,„,,/,„ nN I Mass on Stage "n"
dM/d"°9D)ln ' A(logD)| - log(D) -9,og(D5(,)n
Plotting this approximation of dM/d (log D) versus log D results in
a histogram. From such a histogram, the total mass of particles with
diameters between (D50)i and (D50h can be calculated as the sum:
where "a" takes on values corresponding to the discrete increments of the
histogram.
31
-------
If an impactor with an infinite number of stages were available,
the histogram would approach a continuous function, the A(log D50) terms
would approach d(log D), and the mass between Dm and Dp could be cal-
culated as:
D>
Such an impactor does not exist, but the histogram can be plotted as a
smooth' curve by assigning some average of (D50)n+-| and (D5Q)n to the
AM/Alog DgJ term. The geometric mean of the D5Q's is often used. This
curve is then a continuous function approximating the actual particle
size distribution. Such a curve is needed to calculate fractional
efficiencies of control devices if the D50's differ for inlet and outlet
measurements. The accuracy of the approximation is limited by the
number of points, and by the basic inaccuracy of neglecting the non-
ideal behavior of the impactors, especially overlapping collection
efficiencies for adjacent stages.
8.5 CUMULATIVE PARTICLE SIZE DISTRIBUTIONS
The data may be presented on a cumulative basis by summing the mar.s
on all the collection stages and back-up filter, and plotting the
fraction of the mass below a given size versus size. This is frequently
done on special log-probability paper. This paper may be preferable for
interpretation, especially if the distribution is not log-normal.
Cumulative distributions suffer from a couple of disadvantages when
compared to differential distributions. An error in stage weight will
be propagated throughout a cumulative analysis, but will be isolated by
the differential approach. Differential analyses made of data taken
over different size ranges can be compared, while cumulative plots of
the same data may not be comparable because of differences in starting
points.
When cumulative plots are used, the abscissa is the logarithm of
the particle diameter and the ordinate is the percentage smaller than
this size. The value of the ordinate at a given (D50)n would be
32
-------
Percent less than stated size = — x 100%
AM
£
£=0
where
£ = o corresponds to the filter,
i =-n corresponds to the stage under study, and
£ = N corresponds to the coarsest jet or cyclone
An analytical curve can be fitted to the cumulative distribution
obtained above, and values of dM/d(log D) obtained by differentiation of
the analytical expression. In general this requires some a priori
assumptions in determining the form of the expression to be used in the
curve fitting process, but several independent groups have used this
technique to good advantage.
In spite of the shortcomings of the D™ method, it is attaining
widespread use, partly because of the difficulty in establishing a
better procedure. It is recommended that the D™ method be used,
temporarily, and that the results be reported uniformly as dM/d(log D)
versus D in micrometers. For convenience, this data is usually plotted
on log-log paper in units of milligrams per dry standard cubic meter
3 • ' ' ' ' '
(mg/dsm ). Both aerodynamic and physical diameters should be presented
in each case.
8.6 PICKNETT METHOD
The Picknett Method is an alternate approach to particulate data
analysis which approximates an actual particulate stream as a combination
of monodispersed aerosols. The amount of each monodispersed aerosol is
weighted so that the aggregate, if passed through an impactor, would be
collected with the same mass fraction per stage as is the actual particu-
late stream. The capture efficiency with respect to diameter of each
stage of the impactor must be known to use this approach. The discussion
33
-------
presented below is introductory, and the reader should refer to the
literature for a detailed discussion of the method (see Bibliography).
A given disperse aerosol, when directed toward the stage of an
impactor, is partially retained. The fraction captured depends on the
size distribution of the aerosol and the statistical capture efficiency
of the stage; few of the smallest particles will be retained while most of
the largest will be. As can be seen from Figure 8, a monodisperse
aerosol which strikes the stage of an impactor is also only partially
retained. For instance, only 50 percent of a 1.2 ym particulate stream
would be retained by the Brink stage 4. If 50 percent of an arbitrary
disperse aerosol was also retained by stage 4, a rough estimate of the
dispersed aerosol particle size would thus be 1.2 ym. This principle
can be extended by considering two monodisperse aerosols whose diameters
bracket the diameter of the single monodispersed aerosol. Continuing
the example above, the two monodisperse aerosols (with diameters "d<"
and "d>") can be arbitrarily chosen as 1.0 ym and 1.5 ym in diameter.
From Figure 8, the capture efficiencies at these diameters are, respectively,
0.25 ("E<") and 0.87 ("E>"). The relative mass frequencies of the two
aerosols, which must add to 1.0, are "f<" and "f>". The total combination
of the two monodisperse aerosols is assumed to be retained in the same
fraction as the dispersed aerosol; in this example, one half of the
aerosol must be captured.
(f<)(E<) + (f>)(E>) =0.5.
As stated above:
(f<) + (f>) = 1.0
Solving these two equations, we find that the fictitious combination of
1.0 ym and 1.5 ym monodispersed aerosols must contain about 40 percent
of the 1.5 ym aerosol and about 60 percent of the 1.0 ym aerosol in
order to model the dispersed aerosol.
Picknett has extended this principle to cascade impactors. An
aerosol's behavior in an impactor with n stages is modeled with n+1
34
-------
fictitious monodisperse aerosols. As part of the given aerosol is left
on each stage in a cascade impactor, only that aerosol which reaches the
next stage is considered in calculating the collection efficiency.
The Picknett method provides the mass frequencies of a group of
fictitious monodisperse aerosols equivalent to the actual disperse
sample. This information can then easily be converted to cumulative
mass data. If desired, the continuous cumulative mass function can then
be differentiated to achieve a differential distribution.
8.7 COMPARISON OF THE D5Q AND PICKNETT DATA REDUCTION TECHNIQUES USING
REAL AND SIMULATED STAGE LOADINGS
In investigating data reduction techniques it is difficult to
separate inaccuracies in the theory and errors introduced by re-entrain-
ment, bounce, scouring, and poor calibration of the impactors. This
problem can be eliminated by simulating the capture of a fictitious
aerosol using the efficiency curve shown in Figure 8. Once the stage
loadings are calculated, this data is used to recalculate a particle-
size distribution, using either the DSQ or Picknett method, which should
ideally be identical to the fictitious input distribution.
Figure 9 is a test of both the D™ and Picknett techniques, using a
fictitious aerosol. The zero through 6 stages of the Brink impactor
were used, and cyclone Co, as shown in Figure 8.
It can be seen that both methods give very nearly correct values
for the mass median diameter. The Picknett method is much better at
the large particle end, because the D™ method does not account for the
fact that the cyclone collects some particles which would otherwise
reach the upper stages. The Picknett method does take this overlap in
collection efficiencies into account, and gives a good "average" of the
distribution, smoothing out the abrupt steps.
Figure 10 shows true and calculated particle-size distributions
using actual experimentation stage loadings. An 8.3 ym diameter
ammonium fluorescein aerosol was generated using a vibrating orifice
aerosol generator. About 4 percent of the particles were found to be
doublets (8 percent of mass). This time, we see that neither method
approximates the real distribution accurately, although the Picknett
method gives a good mass median diameter and better approximates the
true size distribution than does the D™ method.
35
-------
OJ
3 10
PARTICLE DIAMETER, um
100
Figure 9. Simulation of a continuous particle size distribution.
-------
1.0 . 10.0
PARTICLE DIAMETER, v™
Figure 10. Comparison of D™ and Picknett methods,
37
-------
In summary, the Picknett method has some advantages over the
DCQ method. It tends to give a more accurate model of the test
aerosol. However, the D50 method is easier to use and can handle
data which is somewhat scattered. The D™ method is also widely used
and understood. If the Picknett method proves superior, then it, or a
similar technique, should ultimately become the standard. The D™ method
will probably continue to be useful as a quick way to get approximate
results in the field.
38
-------
9.0 BIBLIOGRAPHY
1. Picknett, R.G., "A New Method for Determining Aerosol Size Distributions
from Multistage Sampler Data," Aerosol Science, 1972, Vol.3, pp.185-
198.
2. Smith, W.B., K.M. Gushing, and J.D. McCain, "Particulate Sizing
Techniques for Control Device Evaluation," Environmental Protection
Technology Series, EPA-650/2-74-102, October 1974.
3. Smith, W.B., K.M. Cushing, and G.E. Lacey, "Andersen Filter
Substrate Weight Loss," Environmental Protection Technology Series,
EPA-650/2-75-022, February 1975.
4. Smith, W.B., K.M. Cushing, G.E. Lacey, and J.D. McCain, "Particulate
Sizing Techniques for Control Device Evaluation," Environmental
Protection Technology Series, EPA-650/2-74-102-a, August 1975.
39
-------
40
-------
APPENDIX A
BRINK ORIFICE CALIBRATION
The use of a calibrated orifice to monitor the impactor flow rate
involves the following equation, giving the pressure drop across the
orifice water manometer:
/ \ 9 D^ T T
I 01 I , • -.2 s ° f , MM x
Ap = Ap0 I VL I (i . p y^ § —_I— ( "rc )
\ c / 2 ° c TS
AP .= calibrated orifice pressure drop, in. H^O
AP0 = pressure drop at which orifice calibrated, in. H20
QI = impactor flow rate chosen for isokinetic sampling,
Q = calibration flow rate for orifice
FU n = volume fraction of water in the stack gas
H2u
P_ = ambient stack pressure ?„ = P, + [AP,.], in. Hg.
s s a s
PO = pressure upstream of orifice referred to ambient, in. Hg
PC = ambient pressure when orifice calibrated, in. Hg
TO = temperature of orifice, °R
Tf = temperature of the orifice when calibrated, °R
T = stack gas temperature, °R
MM = mean molecular weight of flue gas
MA = mean molecular weight of air
To monitor impactor flow rate with a dry gas meter either individually
or in conjunction with a calibrated orifice, the following equation pertains:
T- -r- " - FH?O>
s a L.
41
-------
Q = flow rate indicated by the dry gas meter, acfm
Q = flow rate through the impactor at stack conditions, acfm
Ta =? temperature of metered air, °R
T = stack gas temperature, °R
P3 = ambient pressure upstream of the meter, in. Hg
a
P = ambient stack pressure, in. Hg
. -I '
FM Q - volume fraction of water in stack gas
42
-------
.280 BOffE-^ CLASS
T/Sffr PIT ' S.S. , /-i
, 30, 3.5.
/ z O/AW£ TEf? X 1. t 1C?
TUBE , J/i 5.-J". „ ,2«-S? 0//9/*t. X
AP.
O
m
to
FIHIfH
3L fllOKOIUCH
TO
S ~TO
RHS F~tfJHfl
to
co
73
7* -O
•-< m
:z z
i o
r- i—i
>-< x
m oo
o
o
i—
o
.??«
Of AM.
TOLERAHCQ UMLE5S
omEmnsE NOTED
SOUTHERN RESEARCH INSTITUTE
BIRMINGHAM, ALABAMA 35203
fJE- FGR
-------
J4-7A/C^
H-7 A/cJ
/4-2 P/A/H.
I-IOL£ -
"Zffp" STA&e-
f/O ?• 2 <- £-•
cycte> */£•--.
"if-Go" STH6S
<—*
57JKSff ^ -2^
^^^^ ^2,
STtKiE-Jj
fT&t* +-j
$T*G^ 5~
~2-*
5y»ff*-6_
MOOiFie'D
O'jne-T.
I I
«
«
*
t
•
•
I
'
Ifl-
/4SSeM6Ly
101
103
Syr-
ia.
SIXTH
t. r E'A
-rtZS- 3' •* 5. S.
i'l x J-3'2 I
/, 75-
z.r
3
/f4T//v&
-31. filter
-C-1
TOLERAMCQUHUS
OTHEmraE HOTEO
into
SOUTHEM RESEARCH MSnTUTE
tlBMINGHAM, ALA«AMA 332O5
DATE 7--
2123-d -
-------
2.
4 FIA.L. THREADS
D/AI.
STO'L.
C o i-(_ecT 100 COP
01*. onu.
C5(?iu. f rnP FOU.
r1-
I.Sf-
•*•• li: L
•«
.$00
ouri.tr
ft
DRILL. < C.'i>K Poo4-4O Sc«»w 4 PL AC CO
THRKAD
I. Ploui*M MJL.
lureaioe S
2. MAT'C. - 3lt» STUL.
Cy c L.o)oe
45
-------
COST ESTIMATING DATA SHEET
Quote No._
Job No.
_Client_
Date
Location
Purpose of Test_
Type of Test - Particulate_
Gases
Particulate Sizing_
Auxiliary Analysis
PERSONNEL
COST ESTIMATING - PROFESSIONAL SERVICES
Chemist/Engineers
Meteorologist
Project Director
Superv. Engr.
$
/Hr.
$
/Hf.
Hrs.
Cost
Hrs.
Cost
Total Cost
1. 0 Pre-Survey
1. 1 Travel Time
No. of Men
2. 0 Consulting
3. 0 Preparation of
Test Protocol
4.0 Preparation, Pack-
ing & Clean-up
4. 1 Construction
Special Test Equip.
5. 0 Project Planning
6. 0 Field Test
6.1 Travel Time
No. of Men
7. 0 Lab Analysis
8. 0 Calculations &
Report Writing
9. 0 Consulting &
Design
10.0
11. 0 Total
-
'""''" n - - \
H •£ r u
Out-of-Pocket Cost
(See next page)
TOTAL COST
Form M-014-8/73
46
-------
Appendix C (Cont.)
Quote No._
Job No.
Client
Date
Location
COST ESTIMATING OUT-OF-POCKET EXPENSES
2.
3.
5,
6.
7.
8.
9.
10.
11.
12i
Air Fare
Air Fare_
Air Fare
Round Trips
men
Round Trips i> $
men
_R
-------
APPENDIX D
PRELIMINARY SURVEY
Name of Company
Address
Plant Telephone Number
Description of Process
Date of Survey
Contacts
City
Title
State
Title
Title
FTS Number
Operating Schedule of Process
Batch or Continuous Process __
Feed Composition and Rates
Type of Fuel
Production Rate
Description of Air Pollution Control Equipment and Operation
Safety Hazards
48
-------
Appendix D (Cont'd) Page 2 - Preliminary Survey
Assumed Constituents of Stack Gas for Each Sampling Site
Possible Testing Sites (1)
(2) __________
(3)
(4)
Can Samples be collected of:
a. Raw Materials
b. Control equipment
effluent
c. Ash
d. Scrubber water
Signature Required on Passes
Best Time to Test
e.
f.
g.
Product
Fuel
Other
Waivers
Are the
a
b.
c.
d.
e.
f.
g.
Following Available at the Plant?
Parking Facilities
Electric Extension
Cords
Electrician
Safety Equipment
Ice
Acetone
Distilled water
i.
j.
k;
1.
. m.
n.
0.
Clean-up Area
Laboratory
Facilities
Sampling Ports
Scaffolding
Rest room
Vending Machines
Rope
h. Weighing Balance
49
-------
Appendix D (Cont'd) Page 3 - Preliminary Survey
1) Electricity Source
a. Amperage per circuit
b. Location of fuse box _
c. Extension cord lengths
d. Adapters Needed:'-
4)
5)
2) Safety Equipment Needed
a.
Hard hats
b. Safety glasses
c.
3) Ice
a.
b.
Goggles
Vendor
6)
Location ______
Acetone
a. Vendor •
b. Location '
c. Telephone "
Sampling Ports
a. Who will provide
b. Size opening
Scaffolding
a. Height
b. Length
c. Vendor
Address
Telephone
Quantity
d. Safety shoes
e. Alarms
f. Other
Welder:
50
-------
Appendix D (Cont'd) Page 4 - Preliminary Survey
7) Motels:
a. ' Phone
b. Phone
c. Phone
8) Restaurants:
a. Near Plant
Rate
Rate
Rate
b. Near Motel
9) Airport Convenient to Plant
Comments:
Distance
Survey By:
51
-------
APPENDIX E
STACK DATA SHEET
Properties of -
Sampling Locations
Purpose of stack
Height, ft.
Width, ft.
Length, ft.
Diameter, ft. I.D.
Wall thickness, in.
Material of construction
Ports: a. Existing
b. Size opening
c. Size of
platform
Straight stack run
before port, ft.
Type of restriction
Straight stack run
after port, ft.
Type of restriction
Environment
Work space
Ambient temp. , °F
Avg. pitot reading
in. H00
Stack velocity, ft/min
SCFM
Moisture % by volume
Stack temp. °F
Particulate loading
gr/SCF
Particle size
Stack pressure
in. Hg
Water sprays
Dilution air
Elevator
Stack #1
"
Stack #2
Stack #3
Stack #4
52
-------
Appendix E (Cont'd) Page 2
Sketch of Stack to be Sampled Showing Locations of Port Openings, Water
Sprayers, Flow Interferences, Dilution Air Inlets, and Scaffolding or
Platform Erection Dimensions.
53
-------
APPENDIX F
SAFETY CHECKLIST
Date-
Company
Location
A. MEDICAL:
1) Plant first aid available (yes/no)
If available give location of unit and telephone number
2) Phone number for ambulance
3) Phone number for hospital
4) Comments:
B. TEST SITE CHECKLIST: Check if OK.
1) Ladders:
General conditions ', rest stops _, cage
Comments:
2) Scaffolds/Platforms:
General conditions , guardrails
toeboards . , screening
Comments:
C. PERSONNEL PROTECTION EQUIPMENT: Check if needed.
1) Safety glasses • __, side shields
face shields , goggles ' , hard hat
safety shoes • . . , electrical hazard shoes _
life belt arid safety block ,
hearing protective devices , ladder climbing devices
2) Respiratory equipment:
Air purifying . air supplied .
self-contained ___>
Other
54
-------
Appendix F (Cont'd) Page 2 - Safety Checklist
3) Body protection:
Chemical protection garments
Heat protective garments
Chemical gloves
Heat resistant gloves
Other
D. ARE FIRE EXTINGUISHERS AVAILABLE AT SITE
E. SPECIAL OR UNUSUAL TEST PROCEDURES AND SAFETY PRECAUTIONS NECESSARY:
55
-------
APPENDIX G -•.-..••:
METRIC SYSTEM CONVERSION FACTORS
Non-metric
acfm
°F
in.
gr/acf
Multiplied by
28.317
5/9 (°F-32)
2.54
0.0023
•Yields Metric
liters/min
°C
cm
g/liter
56
-------
TECHNICAL REPORT DATA
(Please read Iiiitnictions on the reverse before completing)
1 REPORT NO.
EPA-600/2-76-023
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Tentative Procedures for Particle Sizing in Process
Streams--Cascade Impactors
5. REPORT DATE
February 1976
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8, PERFORMING ORGANIZATION REPORT NO.
D. Bruce Harris
9. PERFORMING ORGANIZATION NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, North Carolina 27711
10. PROGRAM ELEMENT NO.
1AB012; ROAP 21ADM-012
11. CONTRACT/GRANT NO.
NA (In-house Report)
12. SPONSORING AGENCY NAME AND ADDRESS
Same as Block 9, above.
13. TYPE OF REPORT AND PERIOD COVERED
Final; 12/73-11/75
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
report , in guideline form, is an outgrowth of discussions by members
of a working group of EPA/IERL-RTP personnel, contractors, and independent
experts who met to develop uniform procedures for the field use of inertial impactors
to determine particle size distributions from industrial particulate sources. It is
intended to promote individual tests of similar quality so that valid comparisons may
be made. It is emphasized that this document is for guidance only, and is not a set
of rules. Techniques for measuring particle size in stationary sources are too new,
and too few testing situations are the same. Professional judgment is still the most
important element in successfully determining fractional efficiency. The report
discusses the preliminary survey ,. the sampling apparatus, testing procedures, and
data analysis. The information applies to cascade impactors in general. Specific
commercial impactors are discussed.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Particle Size Distribution
Measurement
Impactors Data Processing
Field Tests
Sampling
b.IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Process Streams
Inertial Impactors
Cascade Impactors
Fractional Efficiency
c. COSATl Field/Group
13B
14B
09B
8. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
62
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
57
------- |