OURCE TESTING REPORT
ESSEX BITUMINOUS CONCRETE
CORPORATION
DRACUT, MASSACHUSETTS
ROV F. WESTOIM, IMC.
ENVIRONMENTAL SCIENTISTS AND ENGINEERS
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Source Testing Report
Essex Bituminous Concrete Corporation
Dracut, Massachusetts
EPA Report No. 75-STN-2
Hants
Project Manager
_£
i-^
James W. Davison
r Sampling Supervisor
2? December
Contract No. 68-02-0240
Task Order No. 10
Prepared by
Roy F. Weston, Inc.
Envi ronmental Consultants-Designers
Weston Way
West Chester, Pennsylvania
W.O. 300-57
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PREFACE
The Emission Source Sampling Program detailed in this report
was conducted by Roy F. Weston, Inc., pursuant to a task
order issued by the United States Environmental Protection
Agency, conforming to the terms of EPA Contract No. 68-02-
02^0. Mr. James W. Davison, Air Sampling Supervisor,
directed the Weston field team staffed by the following
personnel.
Mohammad A. Ansari Jeffrey D. O'Neill
Michael C. Carey Bruce Schultz
Barry L. Jackson
Approved for Roy F. Weston, Inc.
Petel<5L MVrks
Project Manager
Date
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TABLE OF CONTENTS
Page
PROJECT PARTICIPANTS
LIST OF TABLES
LIST OF FIGURES
INTRODUCTION 1
General Background 1
Operation and Equipment 1
Objectives of Study 2
TEST RESULTS 3
General Methodology 3
Preliminary Tests 3
Particulates 5
North Baghouse Outlet 5
South Baghouse Outlet 5
Visible Emissions 10
Moisture Content of Stone Samples 10
Particle Size Analysis of Dust Samples 10
PROCESS DESCRIPTION AND OPERATION 14
Process Description \k
Emission Control System 16
Process Operation 18
LOCATION OF SAMPLING POINTS 19
North Baghouse Outlet 19
South Baghouse Outlet 19
TEST PROCEDURES 2k
Preliminary Velocity Traverse 2k
Particulate Sampling 2k
North Baghouse Outlet 2k
South Baghouse Outlet 27
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Visible Emissions
Moisture Content of Stone Samples
Dust Samples
ANALYTICAL PROCEDURES
Sample Recovery
Particulate Analysis
Stone Moisture Content Analysis
TABLE OF CONTENTS
Page
27
28
28
29
29
30
30
APPENDIX A -
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
Particulate Sampling Test Results;
Sample Calculations
Visible Emissions Test Results
Field Data Sheets
Standard Test Procedures
Laboratory Reports
Particle Size Analysis Data
Equ i pment Ca1ib rat ion
Test Log
Sample Identification Log
Sample Handling Log
Process Operation Log
Related Reports
Summary of Project Costs
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PROJECT PARTICIPANTS
The following members of the staff of Roy F. Weston, Inc.
have participated in the planning and execution of this
project and the preparation of this report.
Peter J. Marks Pollution Control
Project Manager Concept Division
James W. Davison Pollution Control
Air Sampling Supervisor Concept Division
Kathryn K. Wahl Pollution Control
Laboratory Supervisor Concept Division
Barry L. Jackson Pollution Control
Assistant Project Scientist Concept Division
Michael C. Carey Pollution Control
Assistant Project Engineer Concept Division
Mohammed A. Ansari Pollution Control
Assistant Project Engineer Concept Division
Jeffrey D. O'Neill Pollution Control
Laboratory Technician Concept Division
Bruce Schultz Pollution Control
Laboratory Technician Concept Division
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Table No.
1
8
9
A-l
A-2
A-3
Title
Preliminary Velocity Traverse
North and South Baghouses
Summary of Particulate Emissions
North and South Baghouses
English Units of Measurement
Summary of Particulate Emissions
North and South Baghouses
Metric Units of Measurement
Summary of Test Results
North Baghouse Outlet
Particulates
Summary of Test Results
South Baghouse Outlet
Part i culates
Summary of Test Results
North Baghouse Outlet
Visible Emissions
Summary of Test Results
South Baghouse Outlet
Visible Emissions
Summary of Test Results
Moisture Content of Stone
Baghouse Dust Collected
Preliminary Velocity Traverse
North Baghouse Outlet
Preliminary Velocity Traverse
South Baghouse Outlet
Particulate Emission Data
North Baghouse Outlet
LIST OF TABLES
PAGE
k
11
13
17
Appendix A
Appendix A
Appendix A
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LIST OF TABLES
(continued)
Table No. Title Page
A-4 Particulate Emission Data Appendix A
South Baghouse Outlet
A-5 Visible Emissions Data Appendix A
North Baghouse Outlet
A-6 Visible Emissions Data Appendix A
South Baghouse Outlet
E-1 Stone Moisture Content Appendix E
Test Data
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LIST OF FIGURES
Figure No. Title Page
1 Stone Crushing and Classifying Operation 15
2 Emissions Control System 20
North Baghouse
3 Emissions Control System 21
South Baghouse
k Sampling Points Location 22
North Baghouse
5 Sampling Points Location 23
South Baghouse
6 Particulate Sampling Train 26
EPA Method 5
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Source Testing Report
Essex Bituminous Concrete Corporation
Dracut, Massachusetts
INTRODUCTION
General Background
In accordance with Section I I I of the Clean Air Act of 1970,
the United States Environmental Protection Agency is charged
with the establishment of performance standards for new in-
stallations or modifications of existing installations in
stationary source categories which may contribute signifi-
cantly to air pollution. A performance standard is a standard
for emissions of air pollutants which reflects the best
emission reduction systems that have been adequately demon-
strated, taking into account economic considerations.
The development of realistic performance standards requires
accurate data on pollutant emissions applicable to the various
source categories. In the stone-crushing industry the emissions
control system (baghouses) of the Essex Bituminous Concrete
Corporation, Dracut, Massachusetts, was designated by the
Environmental Protection Agency as representative of a well-
controlled operation of a stone-crushing process and was,
therefore, selected for the emissions testing program. This
report presents the results of the testing which was performed
at the Essex stone-crushing facilities and a discussion of the
sampling equipment and test procedures.
Operation and Equipment
The Essex stone-crushing operation involves traprock quarried
on-site and processed in a crushing plant rated at 300 tons
per hour. The end products consist primarily of road-base
stone and various grades of bituminous aggregate.
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The north and south baghouses, with associated hoods and duct-
work, comprise the stone dust-emission collection system. The
emission sources controlled by the north collectors include
the secondary and tertiary crushers and the primary and
secondary classifier screens. The two north baghouse collectors
are exhausted through the same fan and are rated at a combined
capacity of 26,000 ACFM. The south baghouse collects emissions
from the final sizing screen and from various associated dis-
charge and transfer points. The south side unit is rated as
23,000 ACFM.
Objective of Study
The primary objective of the testing program was the measure-
ment of the particulate matter concentration in the emissions
fromthe outlets of the north and south baghouses. The study
included comprehensive observations of visible emissions from
both baghouse outlets and from the crusher and classifier
screen hood and ductwork dust collection points. Samples of
the accumulated dust resulting from the baghouse collection
were obtained for size analysis. Crushed stone samples were
obtained for the determination of stone moisture content.
-2-
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TEST RESULTS
General Methodology
The Weston Test Team arrived at the plant on September 16,
197^ and proceeded to set up the testing equipment. The
preliminary tests accomplished that day included an initial
velocity traverse and gas moisture determination on each of
the north and south baghouse outlets. Sufficient preliminary
tests and measurements were completed in order to establish
nomograph values and to determine the proper sizes for the
sample collection nozzles. Formal test runs were conducted
on September 17, 18, and 19.
Three ^i-hour test runs were performed (a single test each
day) at each of the north and south baghouse outlets to
determine the concentration of particulate matter in the
exit gas stream. The sampling train and test procedures con-
formed to EPA Method 5 procedures. The measurement of gas
velocity and volumetric flow rates adhered to EPA Methods
1 and 2, as specified in the Federal Register, December 23,
1971.
The observations of visible emissions were recorded according
to EPA Method 9. Two certified observers simultaneously moni-
tored a single baghouse outlet during each of the first two
test periods and jointly observed emissions from the crushers
and classifier screens on the third day.
All samples for particulate analysis were returned to the
Weston Laboratories in West Chester, Pennsylvania. The dust
samples were shipped to EPA, Research Triangle Park, North
Carolina for size analysis and the moisture content of the
stone was measured on-site.
Preliminary Tests
Table 1 is a summary of the gas velocity and volumetric flow
rates as measured by a preliminary velocity traverse at the
outlet stacks of the north and south baghouses. The initial
velocity traverse was conducted immediately before the bag
cleaning operation and therefore reflects the reduced flow
through the dirty bags. The second velocity traverse on
each stack was accomplished within one hour after bag-shaking
and baghouse-cleaning procedures were completed. The gas flow
-3-
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Table 1
Preliminary Velocity Traverse
Date
Time
Gas Velocity FPM1
Gas Volume SCFM2
Gas Volume ACFM3
Temperature, F
Gas Moisture, %
Pressure Drop in,H20
North Baghouse Outlet
Before Cleaning After Cleaning'
South Baghouse Outlet
Before Cleaning After Cleaning
1345
3,810
27,760
28,1*50
70
1.3
8.0
9-16-74
1540
4,330
31,570
32,330
70
1.3
4.7
1345
2,965
21,560
22,140
70
1.5
7.8
9-16-74
15^5
3,771
27,430
28,150
70
1.5
4.6
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through the north baghouse increased from 27,760 SCFM initially
to 31,570 SCFM after cleaning and at the south baghouse from
21,560 SCFM to 27,if30 SCFM. Detailed preliminary velocity
traverse data are presented in Tables A-1 and A-2.
Particulates
A summary of the test results relative to the concentration of
particulate matter in the emissions from the north and south
baghouse outlets and the particulate emission rates is presented
in Table 2 and Table 3. Particulate concentrations are ex-
pressed in grains per dry standard cubic foot and grains per
actual cubic foot. The particulate emission rates are indicated
in pounds per hour. In Table 3 the test results are expressed
in metric units of measurement.
North Baghouse Outlet
The results of the particulate analysis of the samples col-
lected at the north baghouse outlet for each of the three test
runs are presented in Table k. Included are pertinent data
concerning sample volume and test conditions. Averaging the
results of the three runs indicates an average concentration
of particulate matter in the outlet gas stream of 0.0090 grains
per dry standard cubic foot as measured by the total catch.
The corresponding average emission rate was measured as 2.^1
pounds per hour. The average concentration and emission rate
based on just the particulate measured by the probe and filter
were 0.0085 grains per dry standard cubic foot and 2.27 pounds
per hour. Detailed results of the particulate testing at the
north baghouse outlet are presented in Table A-3,
South Baghouse Outlet
Table 5 summarizes the results of the particulate sampling of
the emissions of the south baghouse outlet. The average parti-
culate concentration for the three test runs (based on total
catch) was 0.0039 grains per dry standard cubic foot, and the
average emission rate was measured as 0.8^ pounds per hour.
Corresponding concentration and emission rates based on probe
and filter catch only are 0.0029 grains per dry standard cubic
foot and 0.63 pounds per hour. Detailed results of particu-
late testing at the south baghouse outlet are presented in
Table A-4.
-5-
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Table 2
Summary of Particulate Emissions
English Units of Measurement
Test Run Number
Date
North Baghouse
1 2 3 Average 1
9-17-7** 9-18-74 9-19-7^ 9-17-74
South Baghouse
2 3 Average
9-18-74 9-19-74
Gas Flow
Standard Cubic Feet/Minute, Dry
Actual Cubic Feet/Minute, Wet
31,370 30,650 31,230 31,083
31,830 31,810 31,950 31,863
26,200 25,230 24,170 25,200
26,790 26,260 24,830 25,960
Particulates (Probe and Filter)
Grains/SCF, Dry1
Grains/ACF, Stack Conditions^
Pounds/Hour
Pounds/Ton
Particulates (Total Catch)
Grains/SCF, Dry
Grains/ACF, Stack Conditions
Pounds/Hour
Pounds/Ton
0.0095 0.0081 0.0080
0.0094 0.0078 0.0078
2.55 2.13 2.13
0.01130 0.00926 0.00968
0.0100 0.0085 0.0086
0.0099 0.0082 0.0084
2.® 2.23 2.30
0.01196 0.00970 0.0105
0.0085
0.0083
2.27
0.01010
0.0027
0.0027
0.61
0.00271
0.0038
0.0036
0.82
0.00357
0.0023
0.0022
0.47
0.00214
0.0029
0.0028
0.63
0.0028
0.0090 0.0041 0.0045 0.0031
0.0088 0.0040 0.0043 0.0030
2.^1 0.91 0.98 0.64
0.01070 0.00404 0.00426 0.00291
0.0039
0.0038
0.84
0.00374
1Grains per Dry Standard Cubic Foot, Standard Conditions of 70°F, 29.92 in. Hg.
^Grains per Actual Cubic Foot, Stack Conditions
Based on Raw Material Entering Primary Crusher
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Table 3
Summary of Particulate Emissions
Metric Units of Measurement
Test Run Number
Date
Gas Flow
Normal Cubic Meters/Minute, Dry
Actual Cubic Meters/Minute, Wet
Particulates (Probe and Filter)
Milligrams/Normal Cubic Meter
Milligrams/Actual Cubic Meter^
Kilograms/Hour _
Ki lo.grams/MTon
Particulates (Total Catch)
Milligrams/Normal Cubic Meter
Milligrams/Actual Cubic Meter
Kilograms/Hour
Ki lograms/ MTon
North Baghouse
1 2 3
9-17.74 9-18-74 9-19-74
888.
901.
882.
915.
885.
905.
Average
885.
907.
21.70 18.56 18.19
21.36 17.88 17.77
1.16 0.98 0.97
0.00565 0.00463 0.00484
19.49
19.00
1.03
0.00505
22
22
1
0
.86
.49
.22
.00599
19
18
1
0
.46
.74
.03
. 00485
19
19
1
0
.68
.22
.04
.00525
20.
20.
1.
0.
67
15
10
00535
South Baghouse
1 2 3
9-17-74 9-18-74 9-19-74
742. 714. 685.
760. 744. 704.
6.21
6.06
0.28
0.00136
9.29
9.07
0.41
0.00202
8.67
8.31
0.37
0.00179
10.35
9.92
0.44
0.00213
5.20
5.05
0.21
0.00107
7.04
6.84
0.29
0.00146
Average
736.
6.69
6.47
0.29
0.00141
8.89
8.61
0.38
0.00187
1
3
Standard Conditions
Stack Conditions
Based on Raw Material Entering Primary Crusher
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Table 4
Summary of Test Results
North Baghouse Outlet
Particulates
Run Number
Date
Volume of Dry Gas Sampled, SCF1
Gas Flow Rate, SCFM2, Dry
Gas Flow Rate, ACFM3, Wet
Percent Moisture by Volume
Stack Gas Temperature, °F
Isokinetic Sampling, %
Feed Rate, Tons/Hr
Parti culates
Probe and Filter Catch, mg
Grains/SCF, Dry
Grains/ACF, Wet
Pounds/Hour
Pounds/Ton
Total Catch, mg
Grains/SFC, Dry
Grains/ACF, Wet
Pounds/Hour
Pounds/Ton
Impinger Catch, %
1
9-17-74
9-18-74
9-19-74
189.35
31,370.
31,830.
1.2
66.
97.1
225.
187.38
30,650.
31,810.
1.7
71.
98.4
230.
192.15
31,230.
31,950.
1.6
68.
99.0
ajo-r
116.6
122.8
5.05
Standard Cubic Feet at 70°F, 29.92 in. Hg.
2
Standard Cubic Feet per Minute at Standard Conditions.
^Actual Cubic Feet per Minute at Stack Conditions.
98.7
103.5
4.64
99.2
0.0095
0.0094
2.55
0.01130
0.0081
0.0078
2.13
0.00926
0.0080
0^0078
2.13
0.0096
107.3
0.0100
0.0099
2.69
0.0120
0.0085
0.0082
2.23
0.00970
0.0086
0.0084
2.30
0.01050
7.55
-8-
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Table 5
Summary of Test Results
South Baghouse Outlet
Particulates
Run Number
Date
Volume of Dry Gas Sampled,
Gas Flow Rate, SCFM2, Dry
Gas Flow Rate, ACFM3, Wet
Percent Moisture by Volume
Stack Gas Temperature, °F
Isokinetic Sampling, %
Feed Rate, Tons/Hr
Particulates
Probe and Filter Catch, mg
Grains/SCF, Dry
Grains/ACF, Wet
Pounds/Hour
Pounds/Ton
Total Catch, mg
Grains/SCF, Dry
Grains/ACF, Wet
Pounds/Hour
Pounds/Ton
1
9-17-74
156.73
26,200.
26,790.
1.3
69.
96.3
225.
2
9-18-74
153.27
25,230.
26,260.
1.6
74.
97.8
230.
3
9-19-74
147.17
24,170.
24,830.
1.3
72.
98.0
220.
27.6
0.0027
0.0027
0.61
0.00271
41.3
1
Impinger Catch, %
Standard Cubic Feet at 70°F, 29.92 in. Hg.
Standard Cubic Feet per Minute at Standard
^Actual Cubic Feet per Minute at Stack Condi
33.17
Conditions.
tions.
37.7
0.0038
0.0036
0.82
0.00357
45.0
16.22
21.7
0.0023
0.0022
0.47
0.00214
29.4
0.0041
0.0040
0.91
0.0040
0.0045
0.0043
0.98
0.00426
0.0031
0.0030
0.64
0.00291
26.19
-Q-
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Visible Emissions
The summary of test results for the two 4-hour periods of
observation for visible emissions from the outlets of the
north and south baghouses are provided in Tables 6 and 7-
At no time did either of the two observers note any visible
emissions (all runs had zero capacity) from either outlet.
Test Run 3 included observations of all possible locations on
the secondary crushers and classifier screens where dust
emissions could occur. No visible emissions were observed
from the controlled locations on either the crushers or the
classifier screens during the 4-hour period of observation.
All visible emissions observations were conducted simulta-
neously with particulate testing. Additional information
concerning visible emissions may be found in the test pro-
cedures section of this report. The record of visible
emissions field data sheets are found in Appendix B.
Moisture Content of Stone Samples
A summary of stone moisture content test results is outlined
in Table 8. The average moisture found in stone from the
primary crusher conveyor belt was 0.81%. The moisture con-
tent of the stone from the secondary crusher conveyor belt
averaged 0.32% and from the two tertiary crusher conveyor
0.30%.
Particle Size Analysis of Dust Samples
Six representative dust samples of the captured baghouse dust
were collected. A centrifugal classifier was used by EPA
laboratory personnel to determine the terminal velocity
distribution of the samples. Graphical presentations of the
data showing the percent (by weight) of those particles in
the dust samples with terminal velocities less than various
indicated values can be found in Appendix F.
-10-
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Table 6
Summary of Test Results
North Baghouse Outlet
Visible Emissions
Run No.
Date
Interval of Observations
Start
End
1
9-17-74
1
Duration of Observations (min)2
Total No. of Readings^
No. of Readings Unobservable
No. of Readings @ 0% Opacity
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
Percent Readings Unobservable
Percent Readings (5> 0% Opacity
5%
10%
15%
20%
Percent Readings Exceeding 20%
Observer 1
0900
1300
240
960
0
960
0
0
0
0
0
0
0
0
0
0
100
0
0
0
0
Observer
0900
1300
240
960
0
960
0
0
0
0
0
0
0
0
0
0
0
100
0
0
0
0
24-hour clock start and end times.
Excluding the time that readings were not recorded for period of observation,
^Readings recorded at 15-second intervals unless otherwise noted.
^Observer 1 - James W. Davison
Observer 2 - Jeffery D. O'Neill
-11-
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Table 7
Summary of Test Results
South Baghouse Outlet
Visible Emissions
Run No.
Date
Interval of Observations1
Start
End
Duration of Observation (min)^
Total No. of Readings3
No. of Readings Unobservable
No. of Readings & 0% Opacity
5%
10%
15%
20%
25%
30%
35%
40%
9-18-74
50%
Percent Readings Unobservable
Percent Readings & 0% Opacity
5%
10%
15%
20%
Percent Readings Exceeding 20%
Observer 1
0830
1230
240
960
0
960
0
0
0
0
0
0
0
0
0
0
0
100
0
0
0
0
Observer 2
0830
1230
240
960
960
0
0
0
0
0
0
0
0
0
0
0
100
0
0
0
0
1
24-hour clock start and end times.
2
Excluding the time that readings were not recorded for period of observation.
Readings recorded at 15-second intervals unless otherwise noted.
-'•-Observer 1 - James W. Davison
Observer 2 - Jeffrey D. O'Neil
-12-
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Table 8
Summary of Test Results
Moisture Content of Stone
Test Run No.
Test Date
Stone Sample
Sample No.
1
2 -A
2-B
3 -A
3-B
Location
Sample
Primary Conveyor Belt
Secondary Conveyor Belt
Secondary Conveyor Belt
Tertiary Conveyor Belt
Tertiary Conveyor Belt
1
9-17-74
1.00
0.24
0.41
0.26
0.39
2
9-18-7^
Percent Moisture
0.42
0.24
0.28
0.28
--
3
9-19-74
1.00
0.41
0.33
0.31
0.28
Average
0.81
0.30
0.34
0.28
0.34
-13-
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PROCESS DESCRIPTION
AND OPERATION
The Essex Bituminous Concrete Corporation, Dracut, Massachu-
setts stone-crushing plant is a relatively new installation,
constructed in 1968 at a capital expenditure of about
$500,000. The type of rock quarried and processed is a
traprock with a high quartzite content. End products consist
primarily of road-base stone and various grades of bituminous
aggregate. All end products are used captively by the company.
The stone-crushing plant is rated at approximately 300 tons
per hour.
Process Description
Stone is blasted from quarry deposits about every ten days;
shots range from eighteen to twenty thousand tons. A drop-
ball crane is used for secondary breakage. The broken stone
is loaded by shovel into two 25-ton quarry trucks for trans-
port via an unpaved road to the crushing plant, a distance
of about one mile.
At the plant (See Figure 1) trucks dump their loads into a
hoppered grizzly, which feeds the scalpings to the primary
crusher (a 42 x 36 inch Farrel1-Bacon jaw crusher). The 7"
(or smaller) crusher discharge and grizzly throughs are then
conveyed to a Hewitt-Robins 5 x 14 foot two-deck screen for
scalping. The oversize (2" and larger) goes to a 4' Traylor
standard cone for secondary crushing. When the stone is dirty,
the throughs (minus 1/2 inch to dust) are stockpiled as dense-
graded road-base stone; otherwise, this material plus the 2"
and smaller discharge from the cone and the 0.5"-2" fraction
from the second deck of the primary scalper are conveyed and
split to two Seco 6' x 16', three-deck screens. The over-
size (2" and larger) from both screens, along with the 3/4"-
2" material from one screen size are transported to two Tele-
smith 4' Gyrasphere cone crushers for further reduction in
size. The product from these two units is then shuttled
back to the two screens, thus forming a closed circuit with
a 3/4" maximum size. The 2" (and smaller) fraction from
the other Seco screen is stockpiled as product. The throughs
(3/4" and smaller) from both screens are conveyed to a 81 x
20' Hewitt-Robins three-deck screen for final sizing. Over-
size 1/2" and larger) material is shuttled back to the two
Telesmith Gyraspheres and re-crushed, forming a closed
-14-
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DUMP
FIGURE 1
ESSEX BITUMINOUS CONCRETE CORPORATION
DRACUT, MASSACHUSETTS
STONE CRUSHING AND CLASSIFYING OPERATION
\n
A. HOPPERED GRIZZLY FEEDER
B. FARRELL-BACON 42" x 36" JAW CRUSHER
C. HEWITT-ROBINS 5' x 14' (2-DECK) SCREEN
D. TRAYLOR 4' STANDARD CONE CRUSHER
E. SECO 6' x 16' (3-DECK) SCREEN
F. SECO 6'x 16'(3-DECK) SCREEN
G. HEWITT-ROBINS 8' x 20' (3-DECK) SCREEN
H. TELESMITH GYRO-DISC CONE
I. TELESMITH 4'GYROSPHERE CONE
J. TELESMITH 4' GYROSPHERE CONE
ROY F. WESTON. INC.
W.0.30057
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circuit with a 1/2" maximum size. End products including
1/2",3/8", and minue 3/8" aggregate are discharged from
the final screen and stockpiled. They are subsequently
reclaimed for asphalt manufacturing.
The plant operating hours are from 6:00 a.m. to 4:00 p.m.
Monday through Friday.
Emissions Control System
The Essex stone crushing plant is very well controlled. The
emission control system was designed by Dr. Melvin First of
Harvard, and constructed and installed by the New England
Roads and Machinery Company. All screens, crushers, and
conveyor transfer points, except the primary crushers, are
totally enclosed, and the emissions are vented to three
mechanical, shaker-type baghouses for collection. Two units
are used for the north side of the plant, and one for the
south side. The primary crusher uses wet control.
The two north-side collectors are exhausted through the same
fan, and have a combined rated capacity of 26,000 cubic feet
per minute at an air-to-cloth ratio of 2.3 to 1. The units
are equipped with 426 and 4-33 cotton sateen bags, respectively,
with a combined filtering area of 11,266 square feet. Emission
sources controlled by the north collectors include the top of
the primary scalping screen, the scalping screen discharge
points, the feed and discharge of the secondary cone crusher,
the feed and discharge of the two tertiors Gyrasphere
crushers, the top of both Seco screens, the throughs dis-
charge from both screens, and three conveyor transfer points.
The south side unit is equipped with 700 bags totaling 9,170
square feet of cloth area, and has a capacity of 23,000 cubic
feet per minute at a 2.5 to 1 filtering ratio. The south
baghouse collects emissions from the top of the final sizing
screen, the screen discharge points, and various reclaim
tunnel and conveyor transfer points.
The north and south baghouse units are shut down for brief
periods each day at 11:30 a.m. and at 3:30 p.m., during the
shaking and cleaning cycles. Collected fines are discharged
daily from the baghouse hoppers to trucks, and are used for
in-plant landfill. As shown in Table 9, approximately four
tons of stone dust are collected daily from the baghouses.
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Table 9
Baghouse Dust Collected
Test Dust Weight (Pounds)
Date No. North South Total
Ibs Ibs Ibs
9-17-74 1 3920 4820 8740
9-18-7^ 2 3160 4200 7360
9-19-74 3 4580 5040 9620
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Process Operation
Tests were conducted to determine participate emission levels
from control equipment during normal plant operation. Pro-
cess conditions were carefully observed, and testing was done
only when the facilities tested appeared to be operating
normally. Data relevant to the operation of the process
equipment and control units tested appear in Appendix J.
Although rated at 300 tph, the actual normal operating range
for this plant is 200 to 250 tph. Consequently, a through-
put of about 200 tph was considered the minimum for initi-
ation of a test run. Throughput was determined by the
number of truck dumps during each hour. Each truck is
assumed to carry 23 tons/load, and the accuracy of this
assumption should be within + 5 percent. The average through-
put during each of the three test runs was 225, 230, and 220
tph, respectively. The moisture content of the stone pro-
cessed did not exceed one percent at any time during the test
program.
The pressure drop across each baghouse was monitored during
each test run to assure proper operation. The pressure
drops across the baghouses nominally ranged from 5 to 6
inches of water over a four-hour test run. Also, visual
observations were made at collection points throughout the
test period. No visible emissions were observed, except
from belt wipes and conveyor idlers.
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LOCATION OF SAMPLING POINTS
North Baghouse Outlet
The two sampling ports in the north baghouse outlet were
located 10'8" downstream from the flange at the jointure of
the fan and stack, and 22" upstream from the stack outlet.
Two 4"-|.D. sampling ports were welded to the 37"-diameter
metal stack at right angles to each other and capped. The
port locations did not meet the "eight diameters" criterion
as outlined in EPA Method One1; consequently, 24 sampling
points were designated for each traverse axis, for a total
of 48 sampling points. Figure 2 shows the sampling port
locations and the dimensions of the outlet stack. Figure 3
indicates the exact distances of the sample points along
each traverse axis.
South Baghouse Outlet
The south baghouse outlet stack was fitted with two 4"-I.D.
sampling ports in a manner similar to the north unit. The
downstream distance of 10'8" and the upstream distance of
22" again dictated the use of 48 sampling points for proper
sampling. Figure 4 shows stack dimensions and port locations.
Sample point distances are outlined in Figure 5.
1EPA Standards of Performance for New Stationary Sources,
Federal Register, Volume 36, No. 247, December 23, 1971.
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FIGURE 2
ESSEX BITUMINOUS CONCRETE CORPORATION
DRACUT, MASSACHUSETTS
EMISSIONS CONTROL SYSTEM
NORTH BAGHOUSE
SAMPLING PORTS
PLATFORM
If
FRONT VIEW
OUTLET DUCT
Y
a
xrf' \- 1
Tl*-l— 1
INLET DUCTS
TOP VIEW
ROY f WESTON. INC.
-20-
ENVKWMENTM. V J CONSULTWT&OESIGNERS
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FIGURES
ESSEX BITUMINOUS CONCRETE CORPORATION
DRACUT, MASSACHUSETTS
EMISSIONS CONTROL SYSTEM
SOUTH BAGHOUSE
22"
00
FAN
OUTLET
DUCT-
;AMPLING
PORTS
PLATFORM
'STACK
'INLET
DUCTS
FRONT VIEW
OUTLET DUCT
TOP VIEW
W.O.30057
ROY F WESTON, INC
-21-
ENVWONMENTAL
COMSULTAMTSOeStQNERS
-------
FIGURE4
ESSEX BITUMINOUS CONCRETE CORPORATION
DRACUT, MASSACHUSETTS
SAMPLING POINTS LOCATION
NORTH BAGHOUSE
TRAVERSE
POINT
NUMBER
1
2
3
4
5
6
7
8
9
10
11
12
DISTANCE
IN FROM
OUTSIDE PORT
inches
4
41/4
5
6
67/8
77/8
9
101/8
11 1/2
13
15
173/4
TRAVERSE
POINT
NUMBER
13
14
15
16
17
18
19
20
21
22
23
24
DISTANCE
IN FROM
OUTSIDE PORT
inches
251/4
28
30
31 1/2
323/4
34
351/8
361/8
37
38
383/4
39
W.O.30057
-22-
ROY F. WESTON. INC.
ENWRONMENTM.
CONSULTW15OESIGNERS
-------
FIGURES
ESSEX BITUMINOUS CONCRETE CORPORATION
DRACUT, MASSACHUSETTS
SAMPLING POINTS LOCATION
SOUTH BAGHOUSE
X
TOP VIEW
TRAVERSE
POINT
NUMBER
1
2
3
4
5
6
7
8
g
10
11
12
DISTANCE
IN FROM
OUTSIDE PORT
inches
4
41/4
5
6
67/8
77/8
9
101/8
11 1/2
13
15
173/4
TRAVERSE
POINT
NUMBER
13
14
15
16
17
18
19
20
21
22
23
24
DISTANCE
IN FROM
OUTSIDE PORT
inches
251/4
28
30
31 1/2
323/4
34
351/8
361/8
37
38
383/4
39
W.O.30057
-23-
ROY F. WESTON, INC.
ENVnONMENTAL
OONSULTAN1&DESIGNERS
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TEST PROCEDURES
Preliminary Velocity Traverse
Gas stream velocities in each of the north and south baghouse
outlet stacks were measured at two different operating condi-
tions on September 16. Gas velocities were determined by
velocity traverse on each unit immediately before the bag-
cleaning cycle, and again after the bags were shaken and the
dust removed from the hoppers.
The gas velocity pressure differential was measured by a
calibrated "S" type pitot tube and inclined manometer. The
pitot tube was positioned in each stack at each of 48 traverse
points for 30 seconds to obtain a constant reading on the
manometer. A static pressure in the stack was obtained, and
stack gas temperature confirmed by utilizing a 24"-stem metal
dial thermometer. Stack gas moisture content was measured by
wet and dry bulb thermometers and determined from standard
psychometric tables. U-tube manometers were used to measure
the pressure drop across each baghouse unit. These data
were recorded hourly during the test periods and also before
and after each cleaning cycle.
The summary of the results of these tests can be found in
Table 1. Detailed test data is presented in Tables A-1 and
A-2 of Appendix A.
Particulate Sampling
North Baqhouse Outlet
The sampling train designed to perform the particulate sampling
of the emissions from the north baghouse outlet was a modified
EPA Method 51 train. The modifications consisted of the re-
moval of the cyclone from the train and the omission of heating
the sampling probe and filter holder compartment.
A 0.188"-I.D. stainless steel nozzle was attached to the 5/8"-
diameter pyrex probe. The probe was connected directly to the
pyrex filter holder containing a pre-weighed 9-cm diameter
Reeve Angel glass fiber filter (Type 900 AF). The glass cy-
clone was replaced with a glass connection, to provide the
Federal Register, Volume 36, No. 247, December 23, 1971.
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link between the filter holder and the probe. A small glass
90° elbow was used between the filter holder and the first
of four Greenburg Smith impingers.
The first impinger was modified by replacing the orifice with
a 1/2" tube opening. The second impinger was a standard type
Greenburg Smith, and the remaining two were modified. Each
of the first two impingers contained 100 ml of distilled water,
the third was dry, and the final impinger contained 200 grams
of pre-weighed dry indicator-type silica gel. To complete
the train, a Research Appliance control console provided a
leakless vacuum pump, a dry test meter, and a calibrated
orifice connected to an inclined manometer. Stack gas velocity
measurements were accomplished by means of a calibrated "S"
type pi tot tube attached to the sampling probe, and positioned
so that the measurements were made at the nozzle tip. The
sampling train is illustrated in Figure 6.
Before the start of each test, leak checks were made on the
assembled sampling train (excluding the probe). All checks
indicated leakage of 0.02 CFM of less at a vacuum of 15
inches Hg before the train was put into service.
Samples were continuously withdrawn from the gas stream for
five minutes at each of the ^8 sampling points, providing a
total test run time of four hours. The gas velocity was
observed immediately after positioning the probe at each
sampling point, and sampling rates were adjusted to maintain
isokinetlc sampling conditions. Temperature measurements
were obtained of the stack gas, and at the inlet and outlet
of the dry test meter. Test data were recorded every five
minutes throughout the sampling period.
The test procedures for sampling particulates conform to
Method 5 of the EPA Standards of Performance for New Stationary
Sources^. (See Appendix D)
The procedures for performing velocity traverses and volumetric
flow rates were in conformance with EPA Methods 1 and 2. The
composition of the gas stream was assumed to be air.
Federal Register, Volume 36, No. 2kj, December 23, 1971
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NJ
ON
s
T
A
C
K
rv.
FIGURE 6
ESSEX BITUMINOUS CONCRETE CORPORATION
DRACUT, MASSACHUSETTS
PARTICULATE SAMPLING TRAIN
EPA METHOD 5
PITOTTUBE
AND
MANOMETER
PYREX
PROBE
DISTILLED WATER
MODIFIED TYPE IMPINGER
GREENBURG-SMITH TYPE IMPINGER
MODIFIED TYPE IMPINGERS
VACUUM GAUGE
rJo—i
THERMOMETERS
I
VACUUM
PUMP
SILICA GEL
IMPINGERS IN ICE BATH
DRY TEST METER
ORIFCE
AND
MANOMETER
THERMOMETER
W.O.30057
ROY f. WESTON, INC.
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South Baqhouse Outlet
The sampling train utilized for particulate sampling of the
emissions from the south baghouse outlet was identical to
the train used for the north unit. The test procedures also
conformed to EPA Methods 1, 2, and 5. All field data sheets
can be found in Appendix C.
Visible Emissions
The visible emissions observations were scheduled to coincide
with the Jf-hour particulate sampling test runs. Two certified
observers were stationed on the roof of the south baghouse to
obtain simultaneous observations of the north baghouse emis-
sions. This location provided a clear view of the outlet
against a background of trees, and with a minimum of inter-
ference from ground-level fugitive dust blowing across the
line of view. The procedure adhered to EPA Method 9.
Observations were recorded every fifteen seconds for four
hours, and continued throughout periods of shutdowns of
particulate testing. The observations of the south baghouse
outlet were obtained with the two observers positioned on the
roof of the north baghouse. The procedure was identical to
the previous observation period.
This stone-crushing operation did not produce any emissions
from either baghouse outlet that could be rated above 0
opacity, except for a very brief period (10 seconds) during
the cleaning cycle when the emissions were observed to have
an opacity of 20 percent at the north side unit and 10 per-
cent at the south unit. Tables 6 and 7 provide the summaries
of test results. The detailed visible emissions test data
is located in Appendix B, Tables B-1 and B-2.
The two visible emissions observers also participated in four
hours of observations of dust emissions produced at controlled
areas at the crushers and classifier screens. The objective
of this test was to identify any locations where the emissions
control system allowed dust to escape during the 4-hour
particulate testing periods.
One observer had the responsibility for the secondary crushing
operations controlled by the north baghouse, and the second
observer monitored the classifier screens and transfer points
-27-
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serviced by the south unit. The observers moved to several
positions around their respective units during the test, to
permit observation of all possible emission points. With
the exception of several uncontrolled points at the idlers
on the transfer belts, no fugitive emissions were observed
at controlled locations throughout the 4-hour period of
observation. Data sheets with recorded observations are
provided in Appendix B.
Moisture Content of Stone Samples
Approximately one hour into the particulate test period,
samples of stone at various stages of the crushing operation
were collected for analysis on-site to determine the moisture
content of the stone. The sampling locations were as follows:
1 Conveyor Belt after Primary Crusher
2 Conveyor Belt after Secondary Crusher 1
2-A Conveyor Belt after Secondary Crusher 2
3 Conveyor Belt after Tertiary Crusher 1
3-A Conveyor Belt after Tertiary Crusher 2
The samples were grab samples from the moving belts. The
summary of test results is presented in Table 8. Table E-1
in Appendix E provides detailed test data.
Dust Samples
A sample of the dust collected by each baghouse was obtained
immediately after cleaning and hopper dumping. A dust sample
was taken from each baghouse for each test run. These samples
were shipped to the EPA Laboratories for centrifugal classifier
(Particle size) analysis. These results can be related to
the impinger catch portion measured during the particulate
testing.
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ANALYTICAL PROCEDURES
Sample Recovery
A consistent procedure was employed for sample recovery. One
person was assigned the task of cleaning an entire sampling
train, recovering the sample, and charging the train for the
next run. This individual had this responsibility for each
of the three test runs. The sample recovery proceeded in the
following manner:
1. The total liquid in Impingers One, Two, and Three
was measured and placed in a glass container fitted
with a teflon liner (Sample 1).
2. The impingers, connectors, and back half of the
filter holder were rinsed with distilled water once,
and then added to Sample 1.
3. The impingers, connectors, and back half of the
filter holder were rinsed once with acetone into a
separate glass container (Sample 2).
k. The glass fiber filter was removed from the holder
with tweezers and replaced in the original container
(petri dish), along with any loose particulate and
filter fragments. (Sample 3).
5. The silica gel was removed from the last impinger
and immediately weighed.
6. The probe brush was pre-rinsed with acetone, which
was discarded. The probe and nozzle were separated
and rinsed into a glass container with acetone while
brushing a minimum of three times. The brush was
again rinsed with acetone into the same glass con-
tainer (Sample k).
7. The front half of the filter holder was also rinsed
once with acetone into Sample 4.
8. Blanks of acetone and distilled water were retained
for analysis.
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Participate Analysis
The distilled water samples from the impingers and impinger
wash (Sample 1) were extracted with three 25-ml individual
portions of ether and chloroform to remove any organics in
the water sample. The ether-chloroform extraction was evap-
orated at ambient pressure and temperature in tared beakers
to a constant residue weight; a blank of the ether-chloroform
mixture was carried through the evaporation procedure.
The water samples were then evaporated to dryness in tared
beakers by means of a steam bath. A sample of the distilled
water was also treated as a blank.
The acetone impinger wash sample (Sample 2) was evaporated at
ambient temperature and pressure to a constant residue weight.
The glass fiber filters (Sample 3) were desiccated for 2k hours
and weighed to a constant weight. The acetone probe washings
samples and an acetone blank were transferred to tared beakers
and evaporated to dryness at ambient temperature. The beakers
were desiccated and dried to a constant weight.
All weight differences are reported to the nearest 0.5 milligram.
All final weights are adjusted by the corresponding values of
the appropriate blanks.
The weight of the material collected on the filter, plus the
probe washings sample residue weight represents the particulate
collected by the front half of the train. The total weight
of particulate collected includes the remaining residue weights
of the impinger water sample, ether-chloroform extract residue,
and acetone impinger wash residue, in addition to the front half
weight of particulates. Detailed analytical procedures and
calculations are included in EPA Method 5 (Appendix D). Appendix
contains the laboratory report.
Stone Moisture Content Analysis
The stone samples were collected in tared aluminum pans, and
weighed to the nearest 0.1 gram. The samples were placed in an
oven and maintained at 103°C for 24 hours. The samples were
then reweighed, and percent moisture calculated from the weight
loss. The summary of test results is found in Table 8.
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