United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 86-CEP-3
June 1986
Air
Chromium
Electroplaters
Test Report

Able Machine Co.
Taylors,
South Carolina

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            EMISSION TEST REPORT
           METHOD DEVELOPMENT  AND
            TESTING FOR CHROMIUM

      CHROMIUM ELECTROPLATING  INDUSTRY
            ABLE MACHINE COMPANY
           TAYLORS, SOUTH CAROLINA
           ESED Project No.  85/2a
                 (86-CEP-3)
                     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  Z7711
               September 1986

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                                 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.
                                     11

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                                  CONTENTS

                                                                      Page

Acknowledgment                                                        vi

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  Particle size distribution test results                     2-8

3.   Project Quality Assurance                                        3-1

4.   Sample Locations and Test Methods Used                           4-1

     4.1  Sample locations                                            4-2
     4.2  Hexavalent and total chromium sample extraction and
            analysis                                                  4-4
     4.3  Particle size distribution                                  4-5
     4.4  Process samples                                             4-7


5.   Process Description and Operation                                5-1

     5.1  Process Description                                         5-1
     5.2  Air Pollution Control                                       5-3
     5.3  Process Conditions During Testing                           5-4


Appendices

    A.    Computer Printouts                                          A-l
    B.    Field Data Sheets                                           B-l
    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

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                                   FIGURES
Number                                                                Page

 2-1      Particle Size Distribution for Mist Eliminator  Inlet
            Run PSI-1                                                 2-10

 2-2      Particle Size Distribution for Mist Eliminator  Inlet
            Run PSI-2         |                                        2-10

 2-3      Particle Size Distribution for Mist Eliminator  Inlet
            Run PSI-3                                                 2-11

 2-4      Particle Size Distribution for Mist Eliminator  Outlet
            Run PSO-1                                                 2-11

 2-5      Particle Size Distribution for Mist Eliminator  Outlet
            Run PSO-2                                                 2-12

 2-6      Particle Size Distribution for Mist Eliminator  Outlet
            Run PSO-3                                                 2-12

 4-1      Tank No. 1 Inlet Sample Location,  Able Machine  Co.           4-2

 4-2      Tank No..l Outlet Sample Location, Able Machine Co.          4-3

 5-1      Schematic of New Hard  Chromium Plating Tank at
            Able Machine Company                                      5-2
                                     iv

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                                   TABLES

Number                                                                Page
 2-1      Sample/Analytical Matrix for the Able Machine Company       2-2
 2-2      Summary of Sample and Flue Gas Conditions (Able Machine
            Company)                                                  2-5
 2-3      Summary of Cr   and Total Cr Emission Data                  2-6
 2-4      Summary of Cr   and Total Cr Size Distribution Data         2-14
 2-5      Process Sample Analytical Results                           2-15
 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 Calibration    3-7
 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 Analyses                     3-9
 5-1      Average Operating Parameters for Three Mass Emission
            Source Test Runs                                          5-5
 5-2      Total Current Supplied to the Tank During Three
            Mass Emission Source Test Runs                            5-6

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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.  Mr. Michael Hamlin of EMB observed
the test program.  Mr. Randy Strait and Ms. Robin Barker, representing Mid-
west Research Institute (MRI), monitored process and control equipment opera-
tion throughout the test period.  Mr. Charles Bruffey was the PEI Project
Manager.  Principal authors were Messrs. Charles Bruffey and Thomas Wagner.

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                                  SECTION 1
                                INTRODUCTION

     The U.S. Envirgnmental 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 Able Machine Co. in Taylors, South Carolina, on June 30 and July 1 and
2, 1986.  Triplicate tests to determine Cr   and total Cr emissions were
performed at the inlet and outlet of a Duall mist eliminator controlling
chromic acid emissions from one hard chromium plating tank.
                                     1-1

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In addition, particle size distribution measurements were taken at sampling
points before and after the mist eliminator in an effort to characterize Cr
and total  Cr emissions by size fraction.  Samples of the plating tank solu-
tion and mist eliminator wash water were also collected during testing 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 analyzing 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 mist
eliminator 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, tempera-
ture, moisture content, and gas composition.
     A Method 13B 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 13B, July 1985.
                                     2-1

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                          TABLE 2-1.  SAMPLE/ANALYTICAL MATRIX FOR THE ABLE MACHINE COMPANY
I
ro
Sample parameters

Run
No.
MEI-1
MEO-1
MEI-2
MEO-2
ME I -3
MEO-3
PSI-1
PSO-1
PSI-2
PSO-2
PSI-3
PSO-3
All






Date (1986)
and time (24 h)
6/30 (1207-1609)
6/30 (1208-1606)
7/1 (0816-1143)
7/1 (0815-1127)
7/1 (1200-1500)
7/1 (1209-1507)
6/30 (1440-1540)
6/30 (1209-1610)
7/1 (0817-0932)
7/1 (0817-1226)
7/1 (1400-1515)
7/2 (0836-1202)
6/30-7/1 and 2






Modified
Method. 13b
for Cr 6 and
Location total Cra
Inlet X
Outlet X
Inlet X
Outlet X
Inlet X
Outlet X
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Process
samples
0 Tank
solution
0 Mist
elimina-
tor wash
water

Particle
size
distribution
_
_
_
X
X
X
X
X
X

-



—
Analytical parameters
Cr+*
diphenyl-
carbazide
colorimetric
method
X
X
X
X
X
X
-
-
-

X



X
Particle size
distribution
(gravimetric)
Total Cr Cr e and total Cr
by ICAP by size fraction
X
X
X
X
X
X
X
X
X
X
X
X

X



X
      aMethod 13B 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.
      p
       Inductively coupled argon spectroscopy (ICAP).

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     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 Spectroscopy (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 SW846.*
     Samples were collected for particle size distribution measurements at
the mist eliminator 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 v/ere 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, plating tank solutions were collected.  Grab
samples were obtained approximately every 30 to 40 minutes during the Modified
Method 13B tests.  These grab samples were placed in a 1-gallon polyethylene
container so that one composite sample of each type was available for analy-
sis.  Mist eliminator wash water was collected by MRI personnel at the end of
each test day.
* Test Methods for Evaluating Solid Waste.  U.S. EPA SVI-846, 2nd ed., July
  1982.
                                     2-3

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     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.

2.2  HEXAVALENT AND TOTAL CHROMIUM EMISSION RESULTS
     Table 2-2 summarizes pertinent sample and flue gas data, and Table 2-3
presents the results of the Modified Method 13B testing.
     Sample volumes corrected to standard conditions [20°C and 760 mm Hg
(68°F and 29.92 in.Hg) and zero percent moisture] are expressed in dry normal
                 3
cubic meters (dNm ) and dry standard cubic feet (dscf).  Volumetric flow
rates corrected to standard conditions are expressed as dry normal cubic
                      3
meters per minute (dNm /min) and dry standard cubic feet per minute (dscf/
min).  Hexavalent and total chromium emission concentrations are expressed as
milligrams per normal cubic meter (mg/dNm ).  Mass emission rates are ex-
pressed as kilograms per hour (kg/h) and pounds per hour (Ib/h).
     As reported in Table 2-2, sample volumes ranged between 3.16 and 4.66
dNm  for the inlet tests and between 2.21 and 3.48 dNm;i for the outlet tests.
Note that the first set of tests (MEI and MEO-1) were conducted for 180
minutes, while the remaining two tests were conducted for 120 minutes.
Isokinetic sample rates ranged between 93.4 and 100.1 percent for all tests,
which is within the applicable range of 90 to 110 percent.
     At the mist eliminator inlet, volumetric gas flow rates ranged between
               3                         3
156 and 167 dNm /min and averaged 161 dNm /min (5680 dscf/min) for the three
tests.  Gas temperature and moisture content averaged 33°C (92°F) and 2.8
                                     2-4

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                                    TABLE  2-2.   SUMMARY  OF  SAMPLE AND  FLUE GAS CONDITIONS
                                                      (Able  Machine Co.)
ro
en
Flue gas condition
Sample parameter
Sample volume
Run No.
MEI-1
MEO-1
MEI-2
MEO-2
MEI-3
MEO-3
Date
(1986)
6/30
6/30
7/1
7/1
7/1
7/1
Sample
location
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
dNm3
4.66
3.48
3.30
2.38
3.16
2.21
dscf
164.603
122.753
116.365
84.093
111.707
78.135
Volumetric
flow rate
Percent
isokinetic
98.3
98.8
97.8
100.1
98.3
93.4
dNm3/min
156
163
167
163
159
162
dscf /mi n
5,524
5,743
5,890
5,742
5,628
5,715
Temper-
ature
°C
34
37
30
35
36
39
°F
94
99
86
95
97
102
Moisture
content, %
2.9
3.8
2.7
3.8
2.7
2.4
Static
pressure,
in. H20
-1.9
+ 1.5
-1.7
+1.5
-1.65
+1.5

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                             TABLE 2-3.  SUMMARY OF Cr+6 AND TOTAL Cr EMISSION  DATA
                                               (Able Machine Co.)
                          	Concentration	       Mass  emission  rate
                                                                                             Total  Cr
                          	Cr 6              Total  Cr         Cr 6       Total  Cr       collection
Run     Date    Sample                                                                     efficiency  ,
No.    (1986)  location   mg/dNm3  gr/dscf   mg/dNm3   gr/dscf   kg/h   Ib/h    kg/h   Ib/h        %


MEI-1   6/30  Mist elim-   10.2    0.004     10.0    0.004     0.095   0.21   0.095   0.21
               inator                                                                           98.6
               inlet
MEO-1   6/30  Outlet        0.13   0.00006    0.14   0.00006    0.0014   0.003  0.0014  0.003


MEI-2   7/1   Inlet         6.85   0.003      6.76   0.003     0.068   0.15   0.068   0.15
                                                                                                98.0
MEO-2   7/1   Outlet        0.14   0.00006    0.15   0.00006    0.0014   0.003  0.0014  0.003


MEI-3   7/1   Inlet         6.84   0.003      6.90   0.003     0.064   0.14   0.064   0.14
                                                                                                98.6
MEO-3   7/1   Outlet        0.10   0.000045   0.11   0.00005    0.0009   0.002  0.0009  0.002


a Total Cr collection efficiency calculated on mass rate  basis.
                                Ib/h (in) - Ib/h (out)    10Q
                                        Ib/h (in)       x  1UU

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percent, respectively.  The static pressure of the inlet flue gas was con-
tinuously monitored using a 0- to 36-in. water manometer.  Static pressures
ranged between -1.65 and -1.90 in.HLO.
     At the mist eliminator outlet, volumetric gas flow rates averaged 163
   o
dNm /min (5733 dscf/min) for the three tests, which compares to within 5
percent of the average inlet flow rate.  Average temperature and moisture
contents were 37°C (99°F) and 3.3 percent, respectively..  The average static
pressure measured during each outlet test was +1.5 in.H,,0.
     The concentration of Cr   measured at the inlet to the mist eliminator
ranged between 6.84 and 10.2 mg/dNm  (0.003 and 0.004 gr/dscf) and averaged
7.96 mg/dNm3 (0.0033 gr/dscf) for the three tests.  Mass rates for Cr+6
ranged between 0.064 and 0.095 kg/h (0.14 and 0.21 Ib/h).  Total Cr concentra-
tions ranged between 6.76 and 10.0 mg/dNm  (0.003 and 0.004 gr/dscf) and
averaged 7.89 mg/dNm  (0.0033 gr/dscf) for the three tests.  Total Cr mass
rates were essentially the same as the Cr   mass rates.
     The content of Cr   in the inlet sample ranged between 21.6 and 47.4 mg,
compared with values of 21.8 and 46.5 mg of total Cr.  The overall compara-
bility of the data suggests that the majority of Cr in the samples is in the
form of Cr  .
     Concentrations of Cr   measured at the mist eliminator outlet ranged be-
tween 0.10 and 0.14 mg/dNm  (0.000045 and 0.00006 gr/dscf).  Mass rates for
Cr+6 averaged 0.0012 kg/h (0.0027 Ib/h).  Total Cr concentrations ranged
between 0.11 and 0.15 mg/dNm3 (0.00005 and 0.00006 gr/dscf) with an average
mass rate similar to that of Cr  .  The content of Cr   in the outlet samples
ranged between 0.226 and 0.451 mg and the content of total Cr ranged between
0.248 and 0.484 mg.  On a mass rate basis, the overall Cr collection effici-
ency of the mist eliminator was 98 percent or greater for the three tests
conducted.
                                     2-7

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2.3  PARTICLE SIZE DISTRIBUTION TEST RESULTS
     Andersen Mark III in-stack impactors were used to measure particle size
at each location.  Each impactor consists of eight impaction stages followed
by a backup filter.  In these tests, glass-fiber filter media were used.  A
total of three samples were collected at each location at points in the
duct(s) representing the average velocity and temperature.
     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 cut-point characteristics were main-
tained throughout the sampling period.  Test times were 180 minutes at the
outlet location and between 60 and 75 minutes for the inlet samples.
     At the completion of each test, the impactor samples were recovered
according to procedures descriged in the Mark III operations manual.
     Each individual impactor stage and acetone rinse of the sample nozzle
and impactor casing  was  subjected to a gravimetric analysis using procedures
similar to those in EPA Method 5.  Cumulative size distribution data points
representing the total weight of particulate matter smaller than the indi-
cated aerodynamic particle diameter [in micrometers (urn)] 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 Reduc-
tion System"* (CIDRS) developed for U.S. EPA by Southern Research Institute
                                                                            3
(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 program-
ming; data on flue gas moisture and molecular weight were obtained from the
Method 13B tests.
  Southern Research Institute.  A Computer-Based Impactor Data Reduction
  System.  Prepared for U.S. EPA under Contract No. 68-022-131, Revised March
  1980.
                                      2-8

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      Figures 2-1 through 2-6 depict individual size distributor! curves by
• test location.  These curves were plotted using size cutpoint and cumulative
 percent weight data from CIDRS computer programs.  Actual impactor stage data
 points are depicted by the solid dots, and the open dots represent an extrapo-
 lated best-fit curve.  (See Appendix A.)
      For the inlet impactor runs (Figures 2-1 through 2-3), individual impac-
 tor stages did not contain enough particulate matter to yield reliable data
 (no more than 0.4 mg was collected on any one stage, compared with a desired
 amount of between 1 and 10 mg).  Although the total catch for these runs
 ranged between 15.9 and 42.4 mg, the majority of material was collected in
 the sample nozzle and impactor casing prior to the filter media.  Since the
 collected material was observed to be a liquid mist, particles that normally
 would be collected on the various stages may have been collected in the
 nozzle and casing, which would tend to bias the cumulative percent less than
 10 to 15 pm on the low side.  The cumulative size distribution curves for
 these runs show that the percent less than 10 pm ranged from about 2 to 5
 percent with about 2 to 3 percent less than 2.5 urn.  The validity of this
 data is questionable.
      For the outlet impactor runs (Figures 2-4 through 2-6), individual
 impactor stage loadings ranged between zero and 0.4 mg., which is less than
 the desired loadings of between 1 and 10 mg per stage.
      Once again, the majority of the total catch for these runs was found in
 the sample nozzle and impactor casing prior to the filter media.  The total
 catch ranged between 0.9 and 6.0 mg.  It should be noted that 0.1 N NaOH was
 inadvertently used to rinse the nozzle and impactor casing for Test PSO-1;
 therefore, only the filter weights are reported, which (for all practical
 purposes) are considered void.  For Tests PSO-2 and 3, the cumulative percent
                                      2-9

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                              i o            i o *
                            DIAMETER,  MICRON?
.LLL..L

 10
Figure 2-1.   Particle  size  distribution for mist eliminator inlet Run PSI-1,
             r-

             'f-. ':/ y -
             t i _• • !
             LLJ
                10

                             !ii!i	!  i  ! ! j I I jj	i
                               10"           10A
                             DIAMETER,  MICRONS
     Figure 2-2.   Particle  size  distribution for mist eliminator inlet
                                Run PSI-2.
                                  2-10

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                                          €-'
                                             iO1
                             DJttMETER,  HITROMF
iu
        Figure 2-3.   Particle size  distribution for mist eliminator
                              inlet Run  PSI-3.
              L-i-l
                                           ,7* '*» *
Figure 2-4.   Particle  size distribution for mist eliminator outlet Run  PSO-1
                                  2-11

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             1-

                        m. MHFTFP..  MICROUS
Figure 2-5.   Particle size distribution for mist eliminator  outlet
                           Run PSO-2.
        LiJ
            10
                        DlnHLTEF:,  MICRON:"
Figure 2-6.   Particle  size distribution for mist eliminator outlet
                           Run PSO-3.
                             2-12

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less than 10 ym ranged between 26 and 35 percent, while the percent less than

2.5 ym ranged between 13 and 20 percent.                           <«•»

     The average isokinetic sample 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).
                                     i r
     In an attempt to characterize Cr   and total Cr by size fraction, inlet

and outlet samples were combined by stage cutpoint into a single composite

sample from each location and analyzed for Cr   and total Cr.  Combined

filters were digested following procedures described in Method 3060 of EPA

SW-846 (alkaline digestion method) and analyzed for Cr   using the diphenol-

carbazide colorimetric method.  The alkaline extract residue was then diges-

ted using Method 3050 of EPA SW-846 and analyzed for total Cr using ICP

analytical techniques.  Table 2-4 summarizes the analytical results.  The
                                  • C
inlet data show the majority of Cr   and total Cr in the acetone rinse as

greater than 10 ym in diameter.  These data correspond to the gravimetric

data presented in this section.  The remainder of Cr   and total Cr is con-

centrated on stages 2 through 6 with cutpoints ranging from 3.8 to less than

1.0 ym.

     For the outlet sample, the majority of Cr   and total Cr (exclusive of

the acetone rinse) is concentrated on stages 4 through 7 with cutpoints

ranging from 2.6 to less than 0.5 ym.  Note that the total amount of Cr   and

total Cr on each stage do not compare favorably as did the results of the
*
  Southern Research Institute.  Procedures Manual for Inhalable Particulate
  Sampler Operation.  Prepared for U.S. EPA under Contract No. 68-02-3118,
  November 1979.
                                      2-13

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     TABLE 2-4.   SUMMARY OF Cr 6 AND TOTAL Cr SIZE DISTRIBUTION DATA

Run No. Stage No.
PSI 1-3 0
1
2
3
4
5
6
7
Backup
Acetone
PSO 1-3 0
1
2
3
4
5
6
7
Backup
Acetone
Range of
size
cutpoints,
vim
9.7 - 9.8
8.6 - 8.7
5.8
3.8 - 3.9
2.1
1.03 - 1.04
0.64
0.34
<0.34
>10 urn
11.8 - 12.1
10.4 - 10.6
6.9 - 7.1
4.6 - 4.7
2.6
1.3
0.8
0.43
<0.43
>12 vim
Cr+6,
pg
(blank
corrected)
4.6
6.5
27.8
64.8
78.4
35.9
22.4
13.8
1.3
13,800
4.3
2.2
3.1
3.8
20.1
68.9
30.6
25.9
5.2
121
Total Cr,
vg
(blank
corrected)
18.25
18.0
51.45
101.1
125.25
61.4
42.75
30.9
0
24,800
15.85
10.8
14.1
15.8
40.1
102.1
50.5
45.8
15.6
164
Range of size cutpoints as determined from the CIDRS computer program.
(See Appendix A.)
                                   2-14

-------
modified Method 13B samples.  This probably results frorr, a reduction of Cr

to a lower valence state on the glass-fiber filter media.


2.4  PROCESS SAMPLE ANALYTICAL RESULTS

     Samples of plating tank solution were collected during each modified

Method 13B emission test and analyzed for Cr   and total Cr using procedures

similar to those used for the emission samples.  Mist eliminator washwater

was collected at the end of each day (6/30 and 7/1) on which the Method 13B

tests were conducted.  Table 2-5 summarizes the analytical results.


               TABLE 2-5.  PROCESSS SAMPLE ANALYTICAL RESULTS
Laboratory
No.
FT499
FT450
FT451
FT452
FT453
Run No./
description
ME wash
water, 6/30
ME wash
water, 7/1
MEI (MEO) -1
tank
MEI (MEO) -2
tank.
MEI (MEO) -3
tank
Fraction
Liquid
Liquid
Liquid
Liquid
Liquid
Chromium(VI) ,
mg/liter
2,790
3,470a
79,000
81,000
82,700
Total chromium,
mg/liter
3,490
4,220
84,500
85,800
85,100
  Spike recovery was 105.8 percent for Cr(VI) and 70.5 percent for total Cr.
  In the total chromium spike, 2 yg was added to the 40 wg present in the
  sample.  This spike level was too low for the amount already in the sample
  and probably explains the lower recovery determined for this sample.
                                     2-15

-------
                                  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
yg of chromium(VI) per 50 ml were analyzed with each batch of samples.  The
detection limits listed in Table 3-4 are based on an absorbance value of
0.005.
                                     3-2

-------
                                             TABLE 3-1.  FIELD EQUIPMENT CALIBRATION
OJ
I
to
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
016
FT-1
219
411
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 3


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%

± 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%
0.40%
0.22%
0.3%
0.15%
CO: 0.2% 02: 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.
/
/
0 -/

/
/
/

/

        (continued)

-------
TABLE 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

MEO Caliper
MEI Caliper
3-110
3-104
Within
Allowable Actual allowable
error error limits
± 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. 0.001 /
0.003 /
0.004 /
0.000 /


Comments
Maximum deviation












-------
                         TABLE 3-2.   ON-SITE FIELD EQUIPMENT  CALIBRATION VERIFICATION
Equipment
Meter box



Pitot tube

Digital
V indicator
en
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

411
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
Allowable
deviation
Y ± 0.05 Y
AH@ ± 0.15


Cp ± 0.01

1.0%



± 7°F
(±2°F saturated)
± 0.7%

i 2°F

± 0.5 g
± 5°F
Actual
deviation
-3.10; + 0.06
-0.81; -0.05
-0.01; +0.03
-2.7; - 0.01


NA
-0.45

NA
NA
NA
NA

-2°F
-1°F
NA
NA
Within
allowable
limits Comments
/ PEI constructed
/ critical orifices used
/ for this audit.
^
/ Visually inspected
on site.
/
/


/ See Table 3-1.
^
/ See Table 3-1.

/
/
/
/
 thermometer
Probe nozzle
Caliper
On ± 0.004 in.
See Table 3-1.

-------
             TABLE 3-3.  FILTER AND REAGENT BLANK ANALYSIS DATA


PEI lab
Sample type No.

Tare
weight,
mg
Average
gross
weight,
mg

Net
difference,
mg
Acetone1
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 ICP 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
Chromium(VI), yg
<0.4
0.6
0.9
0.8
1a5
<6a
Total chromium, yg
<2
<2
11.0
11.6
19,8
<20a
  Based on largest volume of sample received.

     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 ANALYSES'
     Run No.
Spike recovery, %
Duplicate results, mg/liter
PSI 1-3
Stage 5

PSI 1-3
acetone

MEI-3

MEO-1

MEI wash
water 7/1
MEI wash
water 6/30
  87.4 total  Cr

  88.4 Cr(VI)


 101.0 Cr(VI)

  92.5 total  Cr

 105.8 Cr(VI)  ,
  70.5 total  CrL
 3,470, 4070 mg/liter Cr(VI)
 4,220, 3,950 mg/liter total
  Cr

 2,790, 3,270 mg/liter Cr(VI)
 3,490, 3,320 mg/liter total
  Cr
  Spike recoveries on solid samples were within the same range.

  Spike level was inappropriate for accurate recovery determination (2 vg were
  spiked in 40 yg).
                                     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 mist eliminator.  Figures 4-1 and 4-2 show the inlet and outlet sample
locations.
     At the inlet, two sampling ports were located 90 degrees off-center,
approximately 2.4 duct diameters (dd) downstream and 0.62 dd upstream from
the nearest flow disturbance in the 19i-inch i.d. round duct.  A total of 24
traverse points (12 per port) were used to traverse the cross-sectional area
of the duct.  Sample times were 180 minutes (7.5 minutes per point) for the
first test (MEI-1) and 120 minutes (5 minutes per point) for the remaining
two tests (MEI-2 and -3).
     At the outlet, two sampling ports were located 90 degrees off-center,
approximately 1.33 dd downstream and 0.58 dd upstream from the nearest flow
disturbances in the 24-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 cri-
                               *
teria specified in EPA Method 1  could not be met at the mist eliminator
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
  40 CFR 60, Appendix A, Reference Method 1, July 1985.
                                     4-1

-------
i rmuuor
AND TO
X*
V
WHLL 	 »•
ROOF
1
^

TANK NO. 1
^




FAN
1
1



MIST _ "
ELIMINATOR "^


j I
^.
*— 47
y
,'->-
'»-•*
^i
in' • M2in!.
59 in. >|
CROSS
^
y
\
PORT
LOCATION
SECTION
"^?2N
127
.°LX
                                               19 I/!! in.  i.d.
                             PLAN VIEW
             /^  N             /   \
             I     )             II
             V   /             V   /
               TANK NO.  1
            FLOOR
                                                TO MIST
                                               ELIMINATOR
              19 1/2  in. i.d.
                ROUND DUCT
48 in.
                   .ELEVATION AND CROSS-SECTION
Figure 4-1.   Tank No.  1  Inlet Sample Location,  Able Machine Co.
                               4-2

-------
                   ,«,„>
            SAMPLE
        PORT LOCATION
                       32 in.
                         1
                                       MOISTURE EXTRACTOR
*J=
                                               PLATING SHOP
     FLOW
CROSS-SECTION
         24 In.  I.D.
                            = 16  ft
                                        FROM MIST
                                        ELIMINATOR
                              ELEVATION
    Figure 4-2.  Tank No. 1 Outlet Sample Location, Able  Machine Co.
                                4-3

-------
outlet flow rate data indicates that this problem did not adversely affect
test results.  Note also that samples were extracted after the mist elimina-
tor but before a fixed vane moisture extractor designed to remove mist which
may pass through the mist eliminator.

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 mist eliminator 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
                                                        *
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.
*
  40 CFR 60, Appendix A, Reference Methods 1 through 5, July 1985.
                                     4-4

-------
     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
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
 * 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 SW-846, 2nd ed., July
   1982.  Method 3050.
                                     4-5

-------
Cr emissions by size fraction.  All size distribution tests were performed in
accordance with procedure's detailed in the equipment manufacturer's operations
                                                  *
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 180
minutes at the outlet and between 60 and 75 minutes for the inlet samples.
     Isokinetic sampling rates were set initially based on the expected
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.
                                     4-6

-------
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"
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 (plating tank solution) were collected by PEI personnel
during each test period.  Each sample was collected at least four times
*
  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.
                                     4-7

-------
during the test period and placed in polyethylene containers.  A sample of
mist eliminator wash water was collected at the end of each test day and
placed in a polyethlyene container.  These samples were analyzed for Cr   and
total Cr according to procedures similar to those used for the actual  emission
samples.
                                     4-8

-------
                                 SECTION 5
                     PROCESS DESCRIPTION AND OPERATION

5.1  PROCESS DESCRIPTION
     Able Machine Company is a small-sized job shop that performs hard
chromium electroplating of industrial rolls.  Hard chromium plating of
industrial rolls provides a wear-resistant surface and protection from
corrosion.  The plating facility consists of two tanks, a new tank and an
old tank.  The old tank, however, is used only when the new tank is down
for repairs or otherwise unavailable.  The emission measurements
documented in this report were performed on the new tank (see Figure 5-1)
                                                 \
and 'its associated control device.
     The new tank was installed in July 1985.  Based on size; operating
parameters such as current, voltage, plating time; and chromic acid
concentration, the tank is typical of other hard chromium plating tanks
used in the electroplating industry.  The tank is 4.3 meters (m)
(14.0 feet [ft]) long, 1.2 m (4.0 ft) wide, and 3.0 m (10.0 ft) deep, and
holds about 15,820 liters (i) (4,180 gallons [gal]) of plating solution.
The plating bath used is a conventional hard chromium plating solution
containing about 210 grams per liter (g/s.) (28 ounces per gallon [oz/gal])
of chromic acid and 1.3 g/i (0.18 oz/gal) of sulfuric acid.  The normal
operating temperature of the plating bath ranges from 43 to 60°C (110° to
140°F).  The tank is cooled with circulating water.  The tank is equipped
with a transformer rectifier rated at 12 volts and 12,000 amperes.
     The plating tank is operated 8-hours (h) per day, 5 days per week.
However, the tank is sometimes operated overnight to plate rolls that
require a thick metal deposit.  Typically, the tank is operated at full
capacity (12 rolls).  An overhead hoist is used to transport rolls to and
from the plating tank.  After plating, the rolls are rinsed with water
from a hose over the top of the plating tank.  This rinsing allows excess
plating solution on the rolls to drain into the plating tank, thus
reducing drag-out.  It takes a total of about 40 minutes to unload and
load the plating tank.
                                   5-1

-------
tn
ro
                               STACK

                                t
m
                                      MOISTURE
                                      EXTRACTOR
                                        LEGEND
                                          AIRFLOW
                                       <	•+-
                                          WATER  FLOW
                         WALL
                                                    MIST
                                                 ELIMINATOR
                                MEZZANINE
                                                                                    HOLDING
                                                                                      TANK
                                                                 J
                Figure  5-1.  Schematic  of new hard chromium plating  tank  at Able Machine  Company.

-------
5.2  AIR POLLUTION CONTROL
     The plating tank is equipped with a push-pull capture system and a
chevron-blade mist eliminator that were manufactured and-installed in July
1985 by Duall Industries, Incorporated.  The push side of the capture
system consists of a 5.1-cm (2-in.) diameter pipe along the entire length
of the tank.  The pipe contains 72 holes that are each 0.32 cm (0.125 in.)
in diameter.  The holes are spaced 5.1 cm (2 in.) apart.  The pull side of
the capture system consists of an exhaust hood installed on the back of
the tank.  The hood measures 3.6 m (12 ft) in length and 1.8 m (6 ft) in
height and contains 3 rows of slots with 15 slots per row.  The slots are
25.4 centimeters (cm) (10 in.) in length and 2.54 cm (1 in.) in width.
Both sides of the tank are equipped with baffles 1.2 m  (4 ft) in length
and 1.8 m (6 ft) in height.  Removable panels are placed over the top of
the tank during plating to enclose the surface of the plating solution to
maximize capture efficiency.
     Chromium emissions from the tank are vented to a chevron-blade mist
eliminator located on a mezzanine structure behind the  tank.  The mist
eliminator contains two sets of chevron blades.  Each set changes the
direction of gas flow four times at thirty degree angles.  The gas flow
rate of the system is 170 cubic meters per minute (6,000 actual cubic feet
per minute).  The pressure drop of the mist eliminator  is rated at
0.5 kilopascals (2 in. of water column).  A moisture extractor is
installed in the stack downstream of the mist eliminator.  The moisture
extractor consists of a stationary set of blades that centrifugally forces
acid mist or droplets entrained in exhaust gas to impinge against the
sides of the extractor wall.  The droplets drain down the sides of the
extractor into collection areas.  The moisture extractor was installed at
the company's request to control chromium emissions that might be drawn
through the mist eliminator.  The mist eliminator and moisture extractor
are washed down with about 284 liters («,) (75 gallons [gal]) of water at
the end of each work day, and at the beginning of the work day if the tank
was operated overnight.  Washdown water is drained into a 606-t (160-gal)
holding tank inside the plating shop.  The plating tank is equipped with a
float that regulates the flow of makeup water from the  holding tank to the
plating tank.

                                    5-3

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5.3  PROCESS CONDITIONS DURING TESTING
     Mass emission a*nd particle size -distribution tests were conducted at
the inlet and outlet of the mist eliminator on the new tank to
characterize the uncontrolled emissions from the hard chromium plating
tank and the performance of the mist eliminator.  The first and second
mass emission and particle size distribution runs were conducted
concurrently.  The third particle size distribution run was conducted
after the third mass emission run was completed.  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.  Descriptions (dimensions and surface areas) and
plating requirements (current and plating time) of each individual part
plated also were recorded for each test run.  Process data sheets
documenting the process and control device operating parameters during
mass emission testing (test run Nos. MEI-1 through 3 and MEO-1 through 3)
are presented in Appendix H.  Data on the average operating parameters
recorded during the mass emission test runs are presented in Table 5-1.
The pressure drop across the mist eliminator was not monitored; however,
there were no indications of any malfunctions in the mist eliminator or
capture system during testing.
     Grab samples were taken from the tank to determine the chromic acid
concentration of the plating solution during each mass emission run.  Grab
samples of the mist eliminator and moisture extractor washdown water also
were taken at the end of the day.  The mist eliminator and moisture
extractor were washed down with about 318 i (84 gal) of water after the
first mass emission test run and with about 254 i (67 gal) of water after
the third mass emission test run.  The chromic acid concentration of the
grab samples is reported in Section 2.4 of this report.
     Test run Nos. 1, 2, and 3 were each interrupted for approximately
45 minutes to unload and reload the tank.
     The total amount of current supplied to the tank during each test run
is calculated in terms of ampere-hours and included in Appendix H.  A
tabular summary of the total current values is presented in Table 5-2.
                                    5-4

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          TABLE  5-1.   AVERAGE  OPERATING  PARAMETERS  FOR THREE  MASS
                         EMISSION  SOURCE TEST  RUNS
Test Run No.
Inlet/Outlet
                               Temperature
Operating      Operating        of  plating
 voltage,        current,         solution,
  volts         amperes          °C (°F)
MEI-l/MEO-1


MEI-2/MEO-2


MEI-3/MEO-3
    7.5
    7.1
    7.5
8,579
9,527
7,054
  52
(125)

  52
(125)

  52
(126)
                                    5-5

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        TABLE  5-2.  TOTAL CURRENT SUPPLIED TO THE  TANK DURING THREE
                      MASS EMISSION SOURCE TEST RUNS

Test Run No.                                   Total current, ampere-hours
Inlet/Outlet                                     Inlet              Outlet


MEI-l/MEO-1                                      25,790             24,367

MEI-2/MEO-2                                      18,717             18,773

MEI-3/MEO-3                                      16,868             13,771
                                    5-6

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