United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 86-CEP-2
June 1986
Air
Chromium
Electroplaters
Test Report
Steel Meddle, Inc.
Greenville,
South Carolina
-------
EMISSION TEST REPORT
METHOD DEVELOPMENT AND
TESTING FOR CHROMIUM
CHROMIUM ELECTROPLATING INDUSTRY
STEEL HEDDLE CO.
GREENVILLE, SOUTH CAROLINA
ESED Project No. 85/2a
(86-CEP-2)
by
PEI Associates Inc.
11499 Chester Road
P.O. Box 46100
Cincinnati, Ohio 45246-0100
Contract No. 68-02-3849
Work Assignment No. 22
PN 3615-22
Task Manager
Mr. Frank Clay
Emission Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
EMISSION MEASUREMENT BRANCH
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
August 1986
-------
DISCLAIMER
This report was furnished to the U.S. Environmental Protection Agency,
Emission Measurement Branch, by PEI Associates, Inc., Cincinnati, Ohio, in
fulfillment of Contract No. 68-02-3849, Work Assignment No. 22. Its contents
are reproduced herein as received from PEI. The opinions, findings, and
conclusions are those of the authors and not necessarily those of the EPA.
Mention of company or product names does not constitute endorsement or
recommendations for use.
n
-------
CONTENTS
Page
Acknowledgment iv
1. Introduction 1-1
2. Summary of Test Results 2-1
2.1 Test protocol 2-1
2.2 Hexavalent and total chromium emission results 2-4
2.3 Process sample analysis 2-8
2.4 Particle size distribution test results 2-8
3. Project Quality Assurance 3-1
4. Sample Locations and Test Methods Used 4-1
5. Process Description and Operation 5-1
5.1 Process Description 5-1
5.2 Air Pollution Control 5-1
5.3 Process Conditions During Testing 5-5
Appendices
A. Computer Printouts A-l
B. ' Field Data Sheets b-1
C. Laboratory Data C-l
D. Sampling and Analytical Procedures D-l
E. Calibration Procedures and Results E-l
F. Project Participants and Field Log F-l
G. Draft Test Method for Hexavalent Chromium Emissions
From Stationary Sources G-l
H. Process Data Monitored During Tests H-l
-------
FIGURES
Number Page
2-1 Particle Size Distribution Test SIPS-1 (Scrubber Inlet) 2-12
2-2 Particle Size Distribution Test SIPS-2 (Scrubber Inlet) 2-12
2-3 Particle Size Distribution Test SIPS-3 (Scrubber Inlet) 2-13
2-4 Particle Size Distribution Test SOPS-1 (Scrubber Outlet) 2-13
2-5 Particle Size Distribution Test SOPS-2 (Scrubber Outlet) 2-14
2-6 Particle Size Distribution Test SOPS-3 (Scrubber Outlet) 2-14
4-1 Process Flow Diagram, Steel Heddle Co. 4-2
4-2 Scrubber Inlet Test Location, Steel Heddle Co. 4-3
4-3 Scrubber Outlet Test Location, Steel Heddle Co. 4-4
5-1 Schematic of Steel Heddle Chromium Plating Operation 5-2
IV
-------
TABLES
Number Page
2-1 Sample/Analytical Matrix for the Steel Heddle Company 2-2
2-2 Summary of Sample and Flue Gas Conditions 2-5
2-3 Summary of Cr and Total Cr Emission Data 2-6
2-4 Summary of Process Sample Analytical Results 2-9
2-5 Particle Size Characterization of Cr and Total Cr 2-16
3-1 Field Equipment Calibration 3-3
3-2 On-Site Field Equipment Calibration Verification 3-5
3-3 Filter and Reagent Blank Analysis Data 3-6
3-4 Linear Regression Data for Spectrophotometer 3-7
Calibration
3-5 QC Check Sample Data for ICP 3-7
3-6 Summary of Blank Data 3-8
3-7 Results of Spike and Duplicate Analysis 3-9
5-1 Dimensions and Operating Parameters of Hard Chromium 5-3
Plating Tanks 1, 2, and 4 at Steel Heddle,
Greenville., South Carolina
5-2 Average Operating Parameters Recorded During Each 5-6
Mass Emission Source Test Run
5-3 Total Current Supplied to Tanks 1, 2, and 4 During 5-7
Each Mass Emission Source Test Run
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ACKNOWLEDGMENT
This test program was conducted for the Emission Standards and Engineering
Division of the U.S. Environmental Protection Agency's Office of Air Quality
Planning and Standards.
Mr. Frank Clay, Emission Measurements Branch Task Manager, provided
overall project coordination and guidance and observed the test program. Mr.
Randy Strait and Ms. Robin Barker, representing Midwest Research Institute
(MRI), monitored process and control equipment operation throughout the test
period. Mr. Charles Bruffey was the PEI Project Manager. Principal authors
were Messrs. Charles Bruffey and Thomas Wagner.
-------
SECTION 1
INTRODUCTION
The U.S. Environmental Protection Agency (EPA) is currently evaluating
chromium and several other potentially toxic metals and their compounds.
Chromium emissions are not included in New Source Performance Standards
(NSPS) for stationary sources or National Emissions Standards for Hazardous
Air Pollutants (NESHAP).
As part of this study, EPA is evaluating atmospheric emissions of chro-
mium from hard chromium plating operations. The purpose of these tests is to
characterize uncontrolled and controlled emissions and size distribution of
hexavalent chromium (Cr ) and total chromium (Cr) from a representative
industrial operation.
The Emission Measurement Branch (EMB) of EPA's Environmental Standards
and Engineering Division (ESED) requires contractor assistance in obtaining
chromium emissions data from a representative source so that an accurate
assessment of the potential problems can be made and appropriate regulatory
action developed.
PEI Associates, Inc., under contract to EMB, conducted a testing program
at the Steel Heddle manufacturing facility in Greenville, South Carolina, on
June 24 and 25, 1986. Triplicate tests to determine Cr and total Cr emis-
sions were performed at the inlet and outlet of a double packed-bed scrubber
controlling chromic acid emissions from three hard chromium plating tanks.
1-1
-------
In addition, particle size distribution measurements were taken at-.sampling
points before and after the scrubber in an effort to characterize Cr and
total Cr emissions by size fraction. Samples of the plating tank solution
and scrubber water were also collected during each test and analyzed for Cr
and total Cr.
The objectives of this project were met, and no major problems were
encountered during the test project. Section 2 of this report presents a
summary and discussion of test results; Section 3 addresses quality assurance;
Section 4 describes the sampling locations and test procedures; and Section 5
describes source operation. Appendix A presents sample calculations and
computer printouts; Appendices B and C contain the field data sheets and
laboratory analytical results, respectively; Appendix D details sampling and
analytical procedures; Appendix E summarizes equipment calibration procedures
and results; Appendix F contains a list of project participants and a
sampling log; and Appendix G describes the draft test method for determining
hexavalent chromium emissions from stationary sources.
1-2
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SECTION 2
SUMMARY OF TEST RESULTS
This section details the results of the sampling program. Subsections
are used to identify results from each test type (i.e., Cr , total Cr
particle size distribution, etc.); results are expressed in both metric and
English units where applicable.
2.1 TEST PROTOCOL
Table 2-1 presents the sampling and analytical protocol followed through-
out this project, the test identification, and the sampling times for each
specific test type.
In summary, triplicate tests were conducted simultaneously at the scrubber
inlet and outlet to characterize uncontrolled and controlled Cr and total
Cr emissions from this type of source. Procedures detailed in EPA Test
*
Methods 1 through 4 were used to measure flue gas flow rate, temperature,
moisture content, and gas composition.
A Method 13 sampling train modified by eliminating the filter and
**
placing 0.1 N NaOH in the impinger section was used to extract samples.
This methodology was developed by EPA during previous studies on similar
plating operations. Cross-sectional, isokinetic sampling techniques were
used in each case.
40 CFR 60, Appendix A, EPA Reference Methods 1 through 4, July 1985,
40 CFR, Appendix A, Reference Method 13, July 1985.
2-1
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TABLE 2-1. SAMPLE/ANALYTICAL MATRIX FOR THE STEEL HEDDLE COMPANY
Run
No.
SIC-1
SOC-1
SIC-2
SOC-2
SIC-3
SOC-3
SIPS-1
SOPS-1
SIPS-2
SIPS-3
SOPS-2
SOPS-3
All
Date (1986)
and time (24)
6/24
6/24
6/25
6/25
6/25
6/25
6/24
6/24
6/24
6/24
6/25
6/25
6/24
(0827-1145)
(0833-1148)
(0808-1132)
(0811-1134)
(1245-1633)
(1247-1635)
(1209-1340)
(1055-1503)
(1430-1548)
(1643-1803)
(0746-1202)
(1217-1655)
_9K
t-*S
Sample parameters
Modified
Method, 13 Particle
for Cr 6 and size
Location total Cr distribution
Inlet X
Outlet X
Inlet X
Outlet X
Inlet X
Outlet X
Inlet - X
Outlet - X
Inlet - X
Inlet - X
Outlet - X
Outlet - X
Process
samples
0 Tank Soln.
0 Scrubbed
water
Analytical parameters
Cr*6
diphenyl-
carbazide
colorimeiric Total Cr
method by ICAP
X
X
X
X
X
X
-
-
-
X
X
X
X
X
X
X
X
-
-
-
X
X
Particle size
distribution
(gravimetric)
total Cr
by ICAP
-
-
-
X
X
X
X
X
X
-
-
Method 13 sampling train modified by eliminating the sample filter and charging the impingers with
0.1 N NaOH. Cross-sectional, isokinetic sampling techniques were used.
bTest Methods for Evaluating Solid Waste. U.S. EPA SW-846, 2nd ed., July 1982.
clnductively coupled argon plasmography (ICAP).
-------
Hexavalent chromium content was determined by procedures recently devel-
oped by EPA for determining Cr content in source emission samples. These
latter procedures entail extraction of the sample fractions with an alkaline
*
solution, followed by the diphenylcarbazide colorimetric method.
Each emission sample was also analyzed for total chromium by use of
Inductively Coupled Argon Plasmography (ICP) analytical techniques. A Per-
kin-Elmer Plasma II instrument was used for this analysis, which followed the
*
general procedures outlined in EPA Method 3050 of EPA SW-846.
Samples were collected for particle size distribution measurements at
the scrubber inlet and outlet by the use of in-stack cascade impactors. The
Andersen Mark III multistage impactor was used at both locations
Three particle size samples were collected at each location. Initially,
the acetone rinse and filter fraction were subjected to gravimetric analysis
using EPA Method 5 analytical procedures. At the completion of the gravi-
metric analysis, individual rinse and filter fractions were combined by stage
cutpoint and location so that one composite sample was available for analysis
of Cr and total Cr. The filters were digested and analyzed for Cr by use
of procedures detailed in Appendix .D of this report. Total Cr was determined
from the digestion procedure filtrate using ICP analytical techniques.
During each emission test, scrubber water and operational plating tank
solutions were collected. Grab samples were obtained approximately every 30
minutes during the Modified Method 13 tests. These grab samples were placed
Test Methods for Evaluating Solid Waste. U.S. EPA SW-846, 2nd ed., July
1982.
2-3
-------
in a 1-gallon polyethylene container so that one composite sample of each
type was available for analysis.
All collected samples were analyzed for Cr and total Cr by use of
procedures similar to those used in the analysis of the Modified Method 13B
samples. The following subsections detail the results of the sampling pro-
gram.
i
2.2 HEXAVALENT AND TOTAL CHROMIUM EMISSION RESULTS
Table 2-2 summarizes pertinent sample and flue gas; data for the chromium
tests, and Table 2-3 presents the Cr+ and total Cr emission results.
o
Sample volumes are expressed in dry normal cubic meters (dNm ) and dry
standard cubic feet (dscf). Volumetric flow rates are corrected to standard
conditions [20°C and 760 mm Hg (68°F and 29.92 in.Hg) and zero percent mois-
ture] and are expressed as dry normal cubic meters per minute (dNm /min) and
dry standard cubic feet per minute (dscfm). Actual flow rates at stack
conditions may be found in the computer printouts in Appendix A of this
report.
Concentrations of Cr and total Cr are expressed in milligrams per dry
2
normal cubic meter (mg/dNm ) and grains per dry standard cubic feet
(gr/dscf). Mass emission rates are expressed in kilograms per hour (kg/h)
and pounds per hour (Ib/h). Note that the Cr concentrations were calculated
using the total content of Cr and total Cr in the sample. Each recovered
sample consisted of the nozzle and probe rinse as well as the impinger
solutions and rinse of all connecting glassware.
As reported in Table 2-2, sample volumes were consistent and ranged from
4.85 to 4.93 dNm3 for the inlet trains and from 5.22 to 5.38 dNm3 for the
outlet trains. Isokinetic sampling rates ranged between 94.5 and 97.7
percent, which is within the acceptable range of 90 to 110 percent.
2-4
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TABLE 2-2. SUMMARY OF SAMPLE AND FLUE GAS CONDITIONS
(Steel Heddle Co.)
ro
i
en
Flue gas condition
Sample parameter
Run No.
SIC-1
SOC-1
SIC-2
SOC-2
SIC-3
SOC-3
Date
(1986)
6/24
6/24
6/25
6/25
6/25
6/25
Sample
location
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Sample
dNm3
4.93
5.22
4.88
5.36
4.85
5.38
volume
dscf
174.15
184.299
172.326
189.325
171.186
190.118
Volumetric
flow rate
Percent
isokinetic
96.6
97.7
94.3
97.3
94.5
97.4
dNm3/min
462
476
467
490
464
490
dscf/min
16,300
16,800
16,500
17,300
16,400
17,300
Temper-
ature
°C
36
27
32
24
36
23
°F
96
80
90
75
97
74
Moisture
content, %
2.6
2.9
2.2
2.5
2.2
2.3
Static
pressure,
in. H20
-3.3
-0.35
-3.55
-0.36
-3.5
-0.26
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TABLE 2-3. SUMMARY OF CR+6 AND TOTAL CR EMISSION DATA
(Steel Meddle Co.)
Concentration
Cr+6
ro
i
en
Run
No.
SIC-1
SOC-1
SIC-2
SOC-2
SIC-3
SOC-3
Date
(1986)
6/24
6/24
6/25
6/25
6/25
6/25
Sample
location
Scrubber
inlet
Outlet
Inlet
Outlet
Inlet
Outlet
mg/dNm3
2.7
0.05
1.2
0.05
1.1
0.05
gr/dscf
0.001
0.00002
0.0005
0.00002
0.0005
0.00002
Total Cr
mg/dNm3
2.55
0.05
1.1
0.05
1.1
0.06
gr/dscf
0.001
0.00002
0.0005
0.00002
0.0005
0.00002
Mass emission rate
Cr+6
kg/h
0.07
0.001
0.03
0.001
0.03
0.002
Ib/h
0.16
0.003
0.07
0.003
0.07
0.0035
Total
kg/h
0.07
0.001
0.03
0.001
0.03
0.002
Cr
e
Ib/h
0.16
0.003
0.07
0.003
0.07
0.004
Total Cr
collection
fficiency
%
98.1
OK 7
94 3
Total Cr collection efficiency calculated on mass rate basis.
Ib/h (in) -Ib/h (out) x 1nn
Ib/h (in)x 1UU
-------
At the scrubber inlet, the average volumetric flow a.t standard condi-
tions was 464 dNm /min (16,400 dscfm). Flue gas temperatures ranged from 32°
to 36°C (90° to 97°F) and averaged 35°C (94°F). The moisture content of the
gas stream averaged 2.3 percent. The static pressure was continuously
recorded using a 0- to 36-in. H^O water manometer during each test. These
pressures ranged between -3.3 and -3.6 in. FLO. Prior to sampling, flue gas
from the inlet was collected in a Tedlar bag and analyzed for oxygen (0?) and
carbon dioxide ((XL) content using an Orsat gas analyzer.. This analysis
(20.9 percent 0^ and 0.0 percent CO^) confirmed the basic ambient composition
of the gas stream, and no further attempts were made to measure gas
composition. The 0^ and C02 values determined from this sample were used to
find the molecular weight in both the inlet and outlet sample runs.
The Cr content of the inlet flue gas ranged between 1.1 and 2.7
3 3
mg/dNm (0.0005 and 0.001 gr/dscf) and averaged 1.7 mg/dNm (0.0007 gr/dscf)
for the three tests. The average mass emission rate was 0.04 kg/h (0.1
•5
Ib/h). Total Cr concentration ranged between 1.1 and 2.55 mg/dNm (0.0005
and 0.001 gr/dscf) with mass rates similar to those of Cr .
The total amount of Cr captured in the inlet trains ranged from a
maximum of 13.3 mg (Test SIC-1) to a minimum of 5.48 mg (Test SIC-3). Total
Cr content for these runs was 12.6 mg and 5.28 mg, respectively. Considering
that Cr and total Cr content of the samples was determined by two different
analytical techniques, the data are comparable and indicate that the majority
of Cr in these samples is in the form of Cr .
At the scrubber outlet, the average gas flow rate at standard conditions
was 485 dNm /min (17,133 dscfm), which is within 5 percent of the average
inlet flow rate. Flue gas temperatures ranged from 23°C to 27°C (74°F to
2-7
-------
80°F) and averaged 25°C (76°F). The moisture content of the gas stream
averaged 2.6 percent. Outlet static pressure was consistent and ranged
between -0.27 and -0.37 for the test series. The outlet Cr concentrations
averaged 0.05 mg/dNm (0.00002 gr/dscf) with a corresponding average mass
rate of 0.001 kg/h (0.003 Ib/h). Total Cr concentrations averaged 0.053
mg/dNm'
Ib/h).
mg/dNm3 (0.00002 gr/dscf) with an average mass rate of 0.0013 kg/h (0.0033
The Cr content of the outlet samples ranged between 0.265 and 0.293
mg, and the total Cr content ranged between 0.261 and 0.299 mg. Based on the
mass rate data, the scrubber removed between 94 and 98 percent of the Cr
and total Cr entering the control device.
2.3 PROCESS SAMPLE ANALYSIS
i r
Table 2-4 summarizes results for Cr and total Cr from plating tank
solutions and scrubber water collected during each test period. Plating tank
solutions from operational tanks 1, 2, and 4 were collected separately during
the first inlet particle size test (SIPS-1) and during each of the Cr /total
Cr emission tests. Scrubber water effluent was collected during the same
basic periods. Results for both Cr and total Cr are expressed in milli-
grams per liter (mg/liter). Analytical procedures were similar to those used
for the actual emission samples with Cr determined by the diphenylcarbazide
colorimetric method and total Cr by ICAP.
2.4 PARTICLE SIZE DISTRIBUTION TEST RESULTS
A total of three particle-size measurements were made at the inlet and
outlet test locations during the course of this study. These tests were
designed to characterize Cr and total Cr emissions by size fraction.
2-8
-------
TABLE 2-4. SUMMARY OF PROCESS SAMPLE ANALYTICAL RESULTS
Laboratory Run No./
No. description
FT433
FT434
FT435
FT436
FT437
FT438
FT439
FT440
FT441
FT442
FT443
FT444
FT445
FT446
FT447
FT448
SIPS-1
Tank No. 1
SIC-1
Tank No. 1
SIC-2
Tank No. 1
SIC-3
Tank No. 1
SIPS-1
Tank No. 2
SIC-1
Tank No. 2
SIC-2
Tank No. 2
SIC-3
Tank No. 2
SIPS-1
Tank No. 4
SIC-1
Tank No. 4
SIC-2
Tank No. 4
SIC-3
Tank No. 4
SIPS-1
Scrubber
SIC/SOC-1
Scrubber
SIC/SOC-2
Scrubber
SIC/SOC-3
Scrubber
Fraction
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Chromium (VI) ,
nig/liter
92,000
97,400
88,900
90,300
101,900
95,400
97,400
99,100
83,800
82,700
78,700
81,700
16.3
6.63
5.33
7.45
Total chromium,
mg/liter
97,200
98,600
96,200
98,600
106,800
103,600
103,400
104,400
92,900
91,100
87,300
90,300
11.1
7.99
6.74
7.53
2-9
-------
Initially, each individual sample was subjected to a gravimetric analysis as
delineated in EPA Method 5.* At the completion of this; analysis, filter
media were combined by location and stage cutpoint and analyzed for Cr and
Total Cr. Andersen Mark III in-stack impactors were used to measure particle
size at each location. The impactor consists of eight impaction stages
followed by a backup filter. In these tests, glass-fiber filter media were
used. All samples were collected at single points in the duct representing
the average velocity and temperature as measured during the Cr /total Cr
tests.
Each test was conducted according to the procedures described in the
Mark III operations manual supplied by the manufacturer. Isokinetic sampling
rates were set initially, and constant cutpoint characteristics were main-
tained throughout the sampling period. Test times ranged from 75 'to 90
minutes for the inlet, and were 240 minutes at the outlet.
Cumulative size distribution curves representing the total weight of
particulate matter smaller than the indicated aerodynamic particle diameter
[in micrometers (ym)] were established for each individual test. The cut-
points for each test were calculated by computer programs contained in "A
Computer-Based Cascade Impactor Data Reduction System"** (CIDRS) developed
for U.S. EPA by Southern Research Institute (SRI). All particle size results
are based on a particle density of 1 g/cm . Data reduction for the particle
size tests was performed by computer programming; data on flue gas moisture
and molecular weight were obtained from the Method 13B tests.
40 CFR 60, Appendix A, Reference Method 5, July 1986.
**
Southern Research Institute. A Computer-Based Impactor Data Reduction
System. Prepared for U.S. EPA under Contract No. 68-022-131. March
1980.
2-10
-------
The average isokinetic sampling rates were all within the acceptable
range of the IP Protocol* (80 to 120 percent), and the impactor sampling
rates were all within the manufacturer's suggested operating limits (0.3 to
0.75 acfm).
Figures 2-1 through 2-6 present the size distribution curves for each
individual test. These curves were developed using the net weight gain (or
loss) of each filter as determined from the Method 5 gravimetric analysis.
Actual impactor stage data points are depicted as solid dots, and the open
dots represent an extrapolated best fit curve.
Although individual impactor stages looked evenly and (in some cases)
heavily loaded upon recovery, the gravimetric data for each location show
that the samples did not contain enough material on the various stages to
yield reliable data (no more than 0.5 mg was collected on any stage, compared
with a desired amount of between 1 and 10 mg).
For the three inlet tests (designated SIPS), the total material catch
ranged between 9.3 and 15.9 mg; the majority of the material was found in the
acetone rinse of the impactor nozzle and inlet chamber. These data show that
between 3 and 8 percent of the particles (by weight) had diameters of 10 ym
or less; between 2 and 4 percent had diameters of 2.5 um or less. Since most
of the collected material was found in the nozzle and impactor casing acetone
rinse, the majority of the material would appear to be larger than 10 pm.
This may or may not actually be the case. If particles smaller than 10 ym
were collected in the nozzle or impactor casing, the cumulative percent less
*
Southern Research Institute. Procedures Manual for Inhalable Particulate
Sampler Operation. Prepared for U.S. EPA under Contract No. 68-02-3118,
November 1979.
2-11
-------
m yj-!-
fL SOr
i_< i-
- _ i
I
iu"
DIAMETER.- MICROHS
iu
Figure 2-1. Particle size distribution test SIPS-1 (scrubber inlet)
UJ "'
"± lu-
T2RSTPS--2. IT
i
1 !""!'•'
DlHtlETER.. MICROiiS
LIT
Figure 2-2. Particle size distribution test SIPS-2 (scrubber inlet),
2-12
-------
h-
-
•a --
L' .ih
L.
L _ l_ i • i j I i ! I ! .!.._ I ! i i
iu 10 l
DIAMETEF:.- MICRONS
10"
Figure 2-3. Particle size distribution test SIPS-3 (scrubber inlet).
*
0 id1
1E1EF:- MICRONS
10'
Figure 2-4. Particle size distribution test SOPS-1 (scrubber outlet),
2-13
-------
t: ...I
•:1 in}.
J p-
10
I ! I I ! !_i
10"' lo' i o
n ; c'UIFTEF:.- f-j T f:p0N':•
Figure 2-5. Particle size distribution test SOPS-2 (scrubber outlet),
i
L
t L
_^_. u'_; |_
Hi """'!
o L
Lu
-------
than 10 ym would be biased low; the magnitude of which is unknown. This
would be possible if the material collected was in the form of a mist which,
from visual observation, appeared to be the case.
The outlet particle-size measurements are depicted in Figures 2-4
through 2-6. A similar pattern was observed for these samples as with the
inlet samples; not enough material was collected on the various stages to
yield reliable test data. The total catch for these runs ranged between 5.8
and 10.2 mg; the majority of the material was found in the impactor nozzle
and inlet casing. The plotted data show that between 5 and 21 percent of the
particles had nominal diameters of 10 ym or less, and between 3 and 21 per-
cent had diameters of 2.5 ym or less. As with the inlet samples, the cumula-
tive percent less than 10 ym may be biased low.
In an attempt to characterize Cr and total Cr emissions by size frac-
tion, inlet and outlet samples were composited by stage cutpoint into a
single sample for each site.
The filters were cut into small pieces and digested using the alkaline
digestion procedure. Analysis for Cr followed the basic colorimetric
procedures used for the Method 13 emission tests. The total Cr content was
determined by digesting the filters and residue from the alkaline extract
with analysis by ICP. Table 2-5 summarizes the results of this anlaysis.
The size cutpoints were obtained from computer printouts for each individual
test, and the range of cutpoints are presented for each stage. The blank
corrected content of Cr and total Cr (in micrograms [yg]) is also presented.
For the inlet samples, the total content of Cr and total Cr was found in
the acetone rinse residue (>10 ym) and on stages 3 through 5 (1 to 3 ym).
For the outlet samples, the Cr and total Cr contents were 151 and 291 yg,
2-15
-------
TABLE 2-5. PARTICLE SIZE CHARACTERIZATION OF
Cr 6 AND TOTAL Cr
Run No.
Inlet
SIPS-1-3
Outlet
SOPS 1-3
i
Stage No.
0
1
2
3
4
5
6
7
Backup filter
Acetone rinse
0
1
2
3
4
5
6
7
Backup filter
Acetone rinse
Size
cutpoint,
urn
9.9 - 10.1
8.7 - 8.9
5.8 - 5.9
3.8 - 3.9
2.1 - 2.2
1.04 - 1.06
0.64 - 0.65
0.34
<0.34
>10
Total
10.1 - 10.6
8.8 - 9.4
5.9 - 6.3
3.9 - 4.0
2.2 - 2.3
1.1
0.65 - 0.70
0.35 - 0.37
0.36
>10
Total
b
Cr 6,
vg
0.875
1.3
4.2
13.5
55.7
32.4
1.0
0.3
0.875
840
950.2
1.3
1.5
6.8
26.1
85.9
25.1
1.4
0.8
0.2
1.4
150.5
i
Total Cr,
vg
8.75
10.9
16.5
26.8
81.1
51.4
9.8
8.3
0
1810
2023.6
10.4
8.8
17.1
41.7
114.3
48.2
14.3
9.2
0
27.1
291.1
aObtained from computer program calculations (see Appendix A).
Cr+6 and total Cr content in micrograms (vg). Values have been blank-
corrected.
2-16
-------
respectively, the majority..of which was found in stages 3 through 5 (1.1 to
4.0 pm). Note that the contents of Cr and total Cr do not compare as well
as the Method 13 test results. In these tests, the contents of each element
were essentially identical, which indicated that most of the chromium in the
samples is in the Cr form. The particle size data indicate that a chemical
reduction of Cr is taking place on the filter media,, in which case the
total Cr results would be expected to be higher.
2-17
-------
SECTION 3
PROJECT QUALITY ASSURANCE
The application of quality assurance procedures to source emission
measurements ensures accurate emission-testing results. Quality assurance
guidelines provide the detailed procedures and actions necessary for defining
and producing acceptable data. In this project, four documents were used in
the preparation of a source-specific test plan that would ensure the collec-
tion of acceptable data: 1) EPA Quality Assurance Handbook, Volume II,
EPA-600/4-77-0271; 2) PEI Emission Test Quality Assurance Plan; 3) PEI Labora-
tory Quality Assurance Plan; and 4) Determination of Hexavalent Chromium
Emissions From Stationary Sources, December 13, 1984. Two of these are PEI's
general guideline manuals that define the standard operating procedures
followed by the company's emission testing and laboratory groups.
In this specific test program, which was reviewed by EPA's Emission
Measurement Branch, the following steps were taken to ensure that the testing
and analytical procedures produced quality data:
0 Onsite quality assurance checks, such as leak checks of the sampling
train, pitot tube, and Orsat line. Onsite quality assurance checks
of all test equipment prior to its use.
0 Use of designated analytical equipment and sampling reagents.
0 Internal and external audits to ensure accuracy in sampling and
analysis.
0 Calibration of all field sampling equipment.
0 Checks of train configuration and calculations.
3-1
-------
Table 3-1 lists the specific sampling equipment used to perform the
Cr , total Cr, and particle size distribution tests as well as the calibra-
tion guidelines and limits. In addition to the pre- and post-test calibra-
tions, a field audit was performed on the metering systems and temperature-
measurement devices used during sampling. These data are summarized in Table
3-2, and copies of the field audit data sheets are presented in Appendix B of
this report.
The PEI project manager and EPA Task Manager performed the onsite sample
calculations, and computer programming was used to validate the data upon
return to PEI's Cincinnati laboratory. Minor discrepancies between the hand
calculations and computer printouts are due primarily to rounding off of
values. Computerized example calculations are presented in Appendix A.
The following subsections summarize the quality assurance activities
performed during the analytical phase of this project.. As a check of the
gravimetric analytical procedure for particle sizing, a blank set of filters
and a reagent (acetone) were analyzed in a fashion similar to that used for
the actual field samples. Table 3-3 summarizes the blank analysis data,
which indicate good gravimetric analytical technique.
Emission and process samples were analyzed in two separate batches.
Table 3-4 summarizes the linear regression data of the spectrophotometer
calibration for these samples. Standards containing 0, 5, 10, 15, 20, and 25
\ig of chromium(VI) per 50 ml were analyzed with each batch of samples. The
detection limits listed in Table 3-3 are based on an absorbance value of
0.005.
3-2
-------
TABLE 3-1. FIELD EQUIPMENT CALIBRATION
CO
I
CO
Equipment
Meter box
Pi tot tube
Digital
indicator
Thermocouple
and stack
thermometers
Orsat
analyzer
Impinger
thermocouple
Trip balance
Barometer
ID
No.
FB-3
FB-9
FB-11
FT-1
242
504
015
FT-1
219
101
412
409
422
1-15
1-1
Mett-
ler 1
406
Calibrated
against
Wet test meter
Standard pitot
tube
Millivolt signals
ASTM-2F or 3F
Standard gas
ASTM-2F or 3F
Type S weight
NBS traceable
barometer
Allowable
error
AH(<> ± 0.15
(Y ± 0.05 Y
post-test)
Cp ± 0.01
0.5%
1.5%
(±2% saturated)
± 0.5% CO:
± 2°F
± 0.5 g
± 0.10 in.Hg
(0.20 post-test)
Actual
error
0.05; 2.25%
0.11; 0.91%
0.05; -0.204%
0.05; -1.2%
+0.22%
-+0.20%
0.22%
0.3%
0.15%
0.2% 02: 0.0
C02: 0.2%
+1°F
+2°F
0.0
+0.01
Within
allowable
limits Comments
/
/
/
/
/ Visually inspected
/ onsite. Cp = 0.84
/ per Method 2.
/ Maximum deviation.
/
/ Maximum deviation.
/
/
/ See Table 3-1.
/
/
/ See Table 3-1.
/
(continued)
-------
TABLt 3-1 (continued)
Equipment
Dry gas
thermometer
Probe nozzle
ID Calibrated
No. against
FB-3 ASTM-2F or 3F
FB-9
FB-11
FT-1
4-112 Caliper
4-119
3-110
3-104
Allowable Actual
error error
± 0.5°F In: +2°F;
Out: +1°F
In: +3°F;
Out: +2°F
In: +2°F;
Out: +2°F
In: +2°F;
Out: +2°F
Dn ± 0.004 in. 0.002
0.004
0.00
0.001
Within
allowable
limits Comments
/ Maximum deviation
/
/
/
/ See Table 3-1.
/
/
/
-------
TABLE 3-2. ON-SITE FIELD EQUIPMENT CALIBRATION VERIFICATION
Equipment
Meter box
Pitot tube
Digital
indicator
Thermocouple
and stack
thermometers
Orsat
analyzer
Impinger
thermocouple
Trip balance
Dry gas
ID
No.
FB-3
FB-11
FT-1
FB-9
FT-1
219
101
412
422
1-1
1-15
Calibrated
against
Critical orifice
(Geometrical specs)
(Cylinder pitot tube)
Millivolt signals
ASTM-3F
Ambient air 00
2
ASTM-3F
Type S weight
ASTM-3F
Al lowable
deviation
Y ± 0.05 Y
AH@ ± 0.15
Cp ± 0.01
1.0%
± 7°F
(±2°F saturated)
± 0.7%
± 2°F
± 0.5 g
± 5°F
Within
Actual allowable
deviation limits
-2.03; - 0.01 / .
+2.7; -0.08 /
-1.55; -0.03 /
-2.1; - 0.04 /
/
<0.2% /
<0.25% /
-4°F /
-2°F /
NA /
-2°F /
-1°F /
NA /
-3°F; ±2°F /
Comments
PEI constructed
critical orifices used
for this audit.
Visually inspected
on site.
See Table 3-1.
See Table 3-1.
See Table 3-1.
Maximum deviation
thermometer
Probe nozzle
Caliper
Dn ± 0.004 in.
See Table 3-1.
-------
TABLE 3-3. FILTER AND REAGENT BLANK ANALYSIS DATA
Sample type
PEI lab
No.
Tare
weight,
mg
Average
gross
weight,
mg
Net
difference,
mg
Acetone
FT337 98,791.3 98,799.2 7.9 mg
(0.0410 mg/g)
Andersen
Stage
Stage
Stage
Stage
Stage
Stage
Stage
Stage
Backup
filter set
0
1
2
3
4
5
6
7
>
, No
, No
, No
, No
, No
, No
, No
, No
No.
. AS-37
. AP-37
. AS-19
. AS-49
. AM-32
. AP-90
. AP-88
. AO-06
A-294
FT328
FT329
FT330
FT331
FT332
FT333
FT334
FT335
FT336
159
164
162
163
144
142
142
149
220
.6
.2
.4
.0
.1
.3
.5
.3
.2
159
164
161
162
143
142
142
149
219
.7
.2
.9
.6
.7
.5
.5
.3
.6
0
0
0
0
0
-0
0
0
0
.1
.1
.5
.4
.4
.2
.6
If a blank residue value greater than 0.01 mg/g or 0.001 percent of the
blank weight was obtained, a maximum value of 0.01 mg/g was subtracted
from the sample weight.
3-6
-------
TABLE 3-4. LINEAR REGRESSION DATA FOR SPECTROPHOTOMETER CALIBRATION
Date
(1986)
7/20
8/12
Y-Intercept
-0.0045
-0.0000
Slope
0.0293
0.0265
Correlation
coefficient
0.9998
0.9999
Duplicate
curves
No
Yes
Detection
limit,
yg/ml
<0.4
<0.2
The TCP was also calibrated for each of the two batches. The initial calibra-
tion consists of a blank and a 5-ppm standard, both containing 50 ppm of
scandium as an internal standard. The internal standard is also added to all
samples at the same concentration. Table 3-5 summarizes the results of the
ICP QC check sample (1.00 ppm) analyzed after approximately every tenth
sample.
TABLE 3-5. QC CHECK SAMPLE DATA FOR ICP
Date Value determined,
(1986) ppm
7/23 1.00
1.02
1.06
1.05
8/15 0.93
0.92
0.97
0.93
0.92
0.94
3-7
-------
Table 3-6 summarizes all blank data for chromium(VI) and total chromium
analyses.
TABLE 3-6. SUMMARY OF BLANK DATA
Description
Reagent blank for particulate
Acetone blank
Filter stages 0, 2, 4, 6
Filter stages 1, 3, 5, 7
Backup filter
Method 5 sample blank
a
Based on largest volume of sampl
Chromium(VI), yg
<0.4
0.6
0.9
0.8
15
<6
e received.
Total chromium, yg
<2
<2
11.0
11.6
19,8
<20a
Two fractions were analyzed for the modified Method 5 samples and the
process: the liquid and the digested solids. The amount of solids were
small, and the amount of chromium(VI) and total chromium in the solids were
insignificant compared with that in the liquid.
Table 3-7 summarizes the results of the spike sample and duplicate
sample analysis for chromium(VI) and total chromium.
3-8
-------
TABLE 3-7. RESULTS OF SPIKE AND DUPLICATE ANALYSES0
Run No.
Spike recovery, %
Duplicate results, ing/liter
SIC-3
SOC-2
SIPS 1-3, acetone
SIPS 1-3, backup
SOPS 1-3, acetone
SIPS-1, Tank No. 1
SIC-3, Tank No. 2
SIPS-1,
Scrubber water
SIC-1,
Scrubber water
SIC-2,
Scrubber water
100.3, Cr(VI)
92.3, total Cr
105.8, Cr(VI)
85.5, total Cr
89.4, total Cr
96.2, Cr(VI)
92.8, total Cr
11.1, 10.2, total Cr
16.3, 11.9, Cr(VI)
7.99, 7.80, total Cr
6.63, 8.48, Cr(VI)
6.74, 6.38, Total Cr
5.33, 6.97, Cr(VI)
Spike recoveries on solid samples were within the same range.
3-9
-------
SECTION 4
SAMPLE LOCATIONS AND TEST METHODS USED
4.1 SAMPLE LOCATIONS
Samples were simultaneously extracted from the inlet and outlet ducts of
the scrubber. Figure 4-1 depicts a simplified process flow diagram and
Figures 4-2 and 4-3 show the inlet and outlet sample locations.
At the inlet, two sampling ports were located 90 degrees off-center,
approximately 2.6 duct diameters (dd) downstream and 0.53 dd upstream from
the nearest flow disturbance in the 32-inch i.d. round duct. A total of 24
traverse points (12 per port) were used to traverse the nonsectional area of
the duct. Each point was isokinetically sampled for 7.5 minutes to yield a
total test time of 180 minutes.
At the outlet, two sampling ports were located 90 degrees off-center,
approximately 1.5 dd downstream and 0.45 dd upstream from the nearest flow
disturbances in the 32-inch i.d. round duct. A total of 24 sample points
were used to traverse the cross-sectional area of the stack. Sample times
were identical to those used at the inlet. The minimum port location criteria
.*
specified in EPA Method 1 could not be met at the scrubber outlet location;
however, this was the only feasible location to extract samples. As detailed
in Section 2 of this report, the quality of inlet and outlet flow rate data
indicates that this problem did not adversely affect test results.
40 CFR 60, Appendix A, Reference Method 1, July 1985,
4-1
-------
A
•H-
STACK
KCH
SCRUBBER
•-B
FAN
ROOF
TANK
46
I I
RECIRCULATION
TANK
1
i i
TANK
3 F
1
1
TANK
2 E
> I
\
TANK
ID
LEGEND
A - SCRUBBER INLET
B - SCRUBBER OUTLET
C - SCRUBBER WATER
2-G - PLATING TANK SOLUTIONS
Figure 4-1. Process flow diagram, Steel Heddle Co.
4-2
-------
SAMPLE PORTS
SCRUBBER
0
•H7 in^
(0.53 dd)'
in.
(2.6 dd)
ROOF
-^
i
CROSS SECTION (LOOKING TOWARDS SCRUBBER)
TOP
SIDE (>•••
32 in. I.D.
I
EXHAUST '
FLOW FROM
PLATING TANKS
Figure 4-2. Scrubber inlet test location, Steel Meddle Co.
-------
RAIN CAP
14.5 in. (0.45 dd)
48 in. (1.5 dd)
FLOW
SAMPLE
PORT LOCATION
I.D. FAN
(MOTOR)
SCRUBBER
CROSS SECTION
,1 1
32 in. I.D.
Figure 4-3. Scrubber outlet test location, Steel Heddle Co.
4-4
-------
4.2 HEXAVALENT AND TOTAL CHROMIUM SAMPLE EXTRACTION AND ANALYSIS
As shown previously in Table 2-1, three tests were conducted at points
located before and after the scrubber in order to determine the Cr and
total Cr content.
Prior to sampling, velocity, static pressure, molecular weight, moisture
content, and temperature were measured to define sampling rates and nozzle
•if
sizes as described in EPA Reference Methods 1 through 4. In addition, the
degree of turbulent flow at each location was assessed based on procedures
described in EPA Reference Method 2. In this method, the face openings of
the Type-S pitot tube are aligned perpendicularly to the duct cross-sectional
plane, designated "0-degree reference." Null (zero) pitot readings obtained
at 0-degree reference indicate an acceptable flow condition at a given point.
If the pitot reading is not zero at 0-degree reference, the pitot is
rotated (up to 90 degrees ± yaw angle) until a null reading is obtained. The
value of the rotation angle (yaw) is recorded for each point and averaged
across the duct. Method 2 criteria stipulate that average angular rotations
greater than ±10 degrees indicate turbulent (nonaxial) flow conditions in the
duct(s). Angular rotations of less than 10 degrees were observed at each
location, which indicated acceptable flow patterns and enabled the extraction
of representative samples from this source.
An EPA Method 13B sampling train was used to extract samples. The train
was modified by eliminating the sample filter and placing 300 ml of 0.1 N
NaOH in the impinger section. Each train consisted of a heated, glass-lined
probe followed by a series of four Greenburg-Smith impingers, a calibrated
40 CFR 60, Appendix A, Reference Methods 1 through 5, July 1985,
4-5
-------
orifice, a dry gas meter, and associated equipment to measure gas flow and
temperature and maintain isokinetic sampling conditions.
The impingers were weighed before and after each test to determine the
moisture content of the flue gas stream. The contents of the impingers were
placed in a polyethylene container, and all glassware including the sampling
nozzle and probe were rinsed with 0.1 N NaOH; this rinse was added to the
same container. Appropriate blank solutions (0.1 N NaOH} were also taken for
analysis. Upon return to the laboratory, each sample (including blanks) was
analyzed for Cr+ using analytical methodology recently developed by EPA. A
copy of the draft method entitled "Determination of Hexavalent Chromium
Emissions From Stationary Sources" is contained in Appendix G of this report.
In summary, this method entails the extraction of the sample with an alkaline
*
solution, followed by the diphenylcarbazide colorimetric method.
At the completion of the Cr analysis, a separate portion of each
sample was digested and analyzed for total Cr by use of ICP analytical tech-
**
niques. Appendix D of this report contains the detailed analytical method-
ology used for these analyses.
4.3 PARTICLE SIZE DISTRIBUTION
Three samples were collected at each test location to determine particle
size distribution. These tests were designed to characterize Cr and total
Cr emissions by size fraction. All size distribution tests were performed in
accordance with procedures detailed in the equipment manufacturer's operations
Test Methods for Evaluating Solid Waste. U.S. EPA SW-846, 2nd ed., July
1982. Method 3060.
Test Methods for Evaluating Solid Waste. U.S. EPA SVI-846, 2nd ed., July
1982. Method 3050.
4-6
-------
manual. Guidelines established in the IP Protocol were used to evaluate
collected data.
Samples for particle-size distribution measurements were collected using
an Andersen Mark III impactor with glass-fiber filters as the substrated
media. This in-stack impactor consists of eight cut-point stages and a
backup filter. The sampled gas stream enters the system through the pre-
cutter. Particles with sufficient inertia are impacted against the sides of
the precutter. Smaller particles flow with the gas stream, exit the pre-
cutter, and enter the main impactor. Then, particles with sufficient inertia
are impacted on the front of the zero stage plate (no filter), smaller
particles pass through the holes in the zero stage plate, and the portion of
these particles with sufficient inertia impacts on the zero stage filter.
The remainder of the particles pass through the holes in the first stage
plate and similarly on to each succeeding stage. Finally, a glass-fiber
>•
backup filter removes all particles remaining in the gas stream downstream of
the final, seventh stage plate.
A single impactor was used to collect samples at each location. Two
points of average velocity were selected at the outlet location and a single
point of average velocity was selected at the inlet. Sampling times were 240
minutes at the outlet and between 75 and 90 minutes for the inlet samples.
Isokinetic sampling rates were set initially based on the expected
-J» V
average gas velocity at the selected sample points, and constant cutpoint
characteristics were maintained throughout the sampling period. The average
*
Procedures Manual for Inhalable Particulate Sampler Operation. Prepared by
Southern Research Institute for EPA, Contract No. 68-02-3118, November
1979.
4-7
-------
isokinetic sampling rate for each run was based on the actual flue gas
velocity pressures and temperatures measured at each of the test points. At
the completion of each test, the impactor samples were recovered according to
procedures described in the mark III operations manual.
Each recovered fraction was subjected to a gravimetric analysis using
procedures similar to those in EPA Method 5, except that the "constant weight"
i
criteria for the filters was ±0.2 mg instead of ±0.5 mg. At the completion
of the gravimetric analysis, samples were combined by location and stage
cutpoint for analyses of Cr and total Cr. Analytical procedures followed
those previously described.
Cut-points for the eight Mark III impactor stages were calculated by
computer programs contained in "A Computer-Based Cascade Impactor Data
Reduction System" (CIDRS) developed by Southern Research Institute (SRI).
All particle size results are based on a particle density of 1 g/cm . Data
reduction and intermediate results calculations were performed by the CIDRS
program, and moisture contents and gas molecular weights were obtained from
the Cr /total Cr tests. Size distribution curves were established to repre-
sent the total weight percent of particulate matter smaller than the
indicated aerodynamic particle diameter in micrometers..
4.4 PROCESS SAMPLES
Process samples (scrubber water and plating tank solutions) were collected
by PEI personnel during each test period. Each sample was collected at least
*
Southern Research Institute. A Computer-Based Cascade Impactor Data
Reduction System. Prepared for U.S. Environmental Protection Agency under
Contract No. 68-022-131, Revised March 1980.
4-8
-------
four times during the 3-hour test period and placed in polyethylene con-
tainers. These samples were analyzed for Cr and total Cr according to
procedures similar to those used for the actual emission samples.
4-9
-------
SECTION 5
PROCESS DESCRIPTION AND OPERATION
5.1 PROCESS DESCRIPTION
The Steel Meddle plant in Greenville, South Carolina, is an original
equipment manufacturer of steel heddles for textile looms. The plating
facility is operated both on a captive and a job shop basis. Metal
finishing operations at the plant include chromium, zinc, copper, nickel,
and copper/sulfate plating; chemical polishing; and sulfuric acid
anodizing. Reeds and combs for textile looms and miscellaneous parts from
outside customers undergo hard chromium plating. The plating facility is
operated 16 hours per day, 5 days per week.
The chromium plating facility consists of four tanks, arranged as
shown in Figure 5-1. Based on size; operating parameters such as current,
voltage, and plating time; and chromic acid concentration, all four tanks
are typical of other hard chromium plating tanks used in the
electroplating industry. During this source test program, tanks 1, 2, and
4 were operated. The dimensions and operating parameters for these tanks
are presented in Table 5-1. The plating solution used in the tanks is a
conventional hard chromium plating solution containing about 250 grams per
liter (g/i) (33 ounces per gallon [oz/gal]) of chromic acid and about
2.5 g/i (0.33 oz/gal) of sulfuric acid.
5.2 AIR POLLUTION CONTROL
Tanks 1 and 4 are equipped with push-pull emission capture systems.
The push side of the capture system consists of a 5.0-centimeter (cm)
[2-inch (in.)] diameter pipe along the entire length of each tank. The
pipe on tank 1 contains 54 holes spaced about 6.4 cm (2.5 in.) apart and
the pipe on tank 4 contains 36 holes spaced about 5.0 cm (2 in.) apart.
Each hole is 0.32 cm (0.125 in.) in diameter. The pull or exhaust side of
the capture system consists of a side draft hood. The hood on tank 1 is
3.8 meters (m) [12.5 feet (ft)] long and the hood on tank 4 is 2.1 m
(6.8 ft) long. Each hood has two rows of slots with four slots per row.
The slot dimensions for tank 1 are 45.7 cm (18 in.) long by 2.54 cm
(1 in.) wide and for tank 4 are 50.8 cm (20 in.) long by 2.54 cm (1 in.)
wide.
5-1
-------
STACK
KCH
SCRUBBER
\
X
FAN
ROOF
TANK
3
RECIRCULATION
TANK
TANK
2
TANK
1
LEGEND
AIRFLOW
HATER FLOW
Figure 5-1. Schematic of Steel Heddle chromium plating operation.
5-2
-------
en
GO
TABLE 5-1. DIMENSIONS AND OPERATING PARAMETERS OF HARD CHROMIUM PLATING
TANKS 1, 2, AND 4 AT STEEL HEDDLE, GREENVILLE, SOUTH CAROLINA
Tank
No.
1
2
4
Dimensions,
l.w.d
m (ft)
3.8,0.9,0.9
(12.5,3.0,3.0)
3.0,0.5,0.9
(10.0,1.8,3.0)
2.1,0.8,0.9
(6.8,2.5,3.0)
Capacity,
i (gal)
3,180
(840)
1,476
(390)
1,438
(380)
Voltage,
volts3
15
15
30
Current.
amperes
10,000
6,000
5,000
Method
of
cooling
Water
Water
Water
Constituents,
g/a (oz/gal)
Cr03
250
(33)
250
(33)
250
(33)
H2S04
2 5
(0.33)
2.5
(0.33)
2. 5
(0.33)
Maximum operating values.
-------
Tank 2 is equipped with a single-sided draft hood that is 3.0 m
(10.0 ft) long. The hood is located on the back of the tank and has
two rows of slots with eight slots per row. The slots are 38.1 cm
(15 in.) long and 2.54 cm (1 in.) wide.
Emissions from all three tanks are ducted to a fume scrubber system
that is located on the roof of the plating shop. The scrubber is a
horizontal-flow double-packed-bed unit manufactured by KCH Services, Inc.
(Model No. H-200D). The scrubber was installed in 1981. It has a design
gas flow rate of 538 cubic meters per minute (19,000 cubic feet per
minute) and a water flow rate of 439 liters per minute (116 gallons per
minute). The pressure drop is rated at 0.75 kilopascals (kPa) (3 inches
of water column [in. w.c.]). Removal of chromium mist from the gas stream
is accomplished by first reducing the velocity of the gas stream to less
than 152 meters per minute (500 feet per minute) at the scrubber inlet.
Then water is sprayed from six spray nozzles located in front of each
packed bed countercurrent to the flow of the gas stream and chromium mist
impinges on the packing material and is washed to the bottom of the
scrubber. The packed beds are 30.5 cm (12 in.) deep and are filled with
polypropelene spherical-type mass packing that is continuously washed with
water from the spray nozzles. The scrubber also contains a two-stage mist
elimination section located downstream of the second packed bed. The
first stage allows larger droplets to settle by gravity to the bottom of
the scrubber. The second stage contains a series of vertically mounted
chevron blades made of polyvinyl chloride that change the direction of the
gas flow four times at 30° angles which forces chromium mist to impinge on
the blades. The scrubber water flows by gravity from the scrubber to a
910-liter (240-gallon) recirculation tank located inside the plating
shop. Clean water is used to make up evaporation losses from the
system. The ductwork is washed down once per month with water that
subsequently drains into the plating tanks.
5-4
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5.3 PROCESS CONDITIONS DURING TESTING
Mass emission and particle size distribution testing was conducted at
the inlet and outlet of the scrubber to characterize the uncontrolled
emissions from all three hard chromium plating tanks and the performance
of the scrubber. The process was operating normally during the tests.
Process operating parameters such as the voltage, current, and plating
solution temperature were monitored and recorded during each mass emission
test run. Also recorded were descriptions (dimensions and surface area)
and plating requirements (current and plating time) of each individual job
or item being plated during each test run. Data sheets documenting the
process parameters recorded during each mass emission test run (Nos. SIC-1
through 3 and SOC-1 through 3) are presented in Appendix H. Data on the
average operating parameters recorded are presented in Table 5-2. In
addition, the pressure drop across the scrubber was also monitored. The
pressure drop averaged 0.7 kPa (2.9 in. w.c.) during run 1 and 0.8 kPa
(3.2 in. w.c.) during runs 2 and 3.
Grab samples were taken from each tank tested and from the scrubber
recirculation tank to determine the chromic acid concentration of the
plating solution and recirculation water during each mass emission test
run. The chromic acid concentration of the grab samples is reported in
Section 2.3 of this report.
Sampling interruptions during the test runs were very limited. All
three test runs were interrupted for 15 to 20 minutes for port changes.
Runs 2 and 3 were interrupted one additional time for 30 and 45 minutes,
respectively, during shift changes.
The total amount of current supplied to the tank during each test run
is calculated in terms of ampere-hours and included in Appendix E. A
summary of the total current values is presented in Table 5-3.
5-5
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TABLE 5-2. AVERAGE OPERATING PARAMETERS RECORDED DURING EACH
MASS EMISSION SOURCE TEST RUN
Test No.
Inlet/outlet
Temperature
Operating Operating of plating
Tank voltage, current, solution,
No. volts amperes °C (°F)
SIC-l/SOC-1
SIC-2/SOC-2
SIC-3/SOC-3
1
2
4
1
2
4
1
2
4
5.7
6.0
6.3
5.3
5.8
6.8
6.0
6.2
7.0
2,234
1,363
864
400
1,200
609
1,518
1,500
654
52 (125)
52 (125)
43 (110)
52 (125)
52 (125)
43 (110)
52 (125)
52 (125)
43 (110)
5-6
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TABLE 5-3. TOTAL CURRENT SUPPLIED TO TANKS 1, 2, AND 4
DURING EACH MASS EMISSION SOURCE TEST RUN
Test Run No. Total current, ampere-hours
Inlet/Outlet Tank No. Inlet Outlet
SIC-l/SOC-1 1 5,408 5,398
2 3,409 3,394
4 2.5J75 2,575
TOTAL 11,392 11,367
SIC-2/SOC-2 1 1,014 979
2 3,435 3,427
4 1^524 1,821
TOTAL 6,273 6,227
SIC-3/SOC-3 1 3,203 3,163
2 3,546 3,486
4 1^355 1,959
TOTAL 8,704 8,608
5-7
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