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OAR Box 1313 

Prepped by LaTeia Shed 

Document Number: 

68) ll-B-42 

Docket Number: 

A-88-02 

Printed 6/12/2008 9:03:30 AM Sheet 68 of 99 
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MRI® 

A-88-02 

MIDWEST RESEARCH INSTITUTE 

H-P>-<--.'2- Suite 35 

-01 Hamson Oaks Bouievatc 

Carv. NC 2751 

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Date: May 20, 1988 

(Finalized June 30, 1988) 

Subject: Site Visit—Vermont American Corporation 

Chromium Electroplating NESHAP 

EPA Contract 68-02-3817; ESED Project 85/02a 

MRI Project 7717-K 

From: Robin Barker 

To: Andrew Smith 

ESD/ISB/SSS (MD-13) 

U. S. Environmental Protection Agency 

Research Triangle Park, N.C. 27711 

I. Purpose 

The purpose of this site visit was to determine the suitability of 

this plant for performance testing of a chevron-blade mist eliminator with 

a double set of blades. 

II. Place and Date 

Vermont American Corporation 

Post Office Box 787 

Toccoa, Georgia 30577 

(404) 779-3391 

February 10, 1988 

III. Attendees 

Vermont American Corporation 

Tommy Carlton, Plating Supervisor 

Midwest Research Institute (MRI) 

Robin Barker 

IV. Discussion 

A meeting was held with Mr. Carlton of Vermont American Corporation 

to discuss the hard chromium plating operation and possible emission 

testing at the plant. The discussion was followed by a tour of the 

plating facility. 

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A. General 

Vermont American Corporation is a captive shop primarily engaged in 

hard chromium plating of circular saw blades. The plating shop typically 

operates 24 hours/day, 5 days/week, 52 weeks/year, but may operate 

7 days/week if demand is high. 

B. Process Description 

There are three hard chromium plating lines at this plant (Nos. 1, 

2, and 3). Each line is identical in process configuration and size. All 

three lines are automated and are used to plate circular saw blades. The 

automated lines consist of a series of tanks for cleaning and plating the 

part. The process seguence is as follows: (1) alkaline soak; (2) spray 

rinse; (3) acid pickle using muriatic acid; (4) spray rinse; (5) electroclean; (6) two dip rinses; (7) drip tanks; (8) hard chromium plating; 

(9) four cold water rinses; and (10) hot water rinse. 

The three hard chromium plating tanks are each 4.0 meters (m) 

(13.0 feet [ft]) long, 0.8 m (2.5 ft) wide, and 0.8 (2.7 ft) deep. Each 

tank holds approximately 2,010 liters (530 gallons) of plating solution. 

Ten racks of parts are in the chromium plating tank at a time with a 

retention time of 2 to 3 minutes for each rack. Each rack holds one 

25.4-centimeter (cm) (10-inch [in.]) blade or two smaller blades. The 

plating thickness is approximately 0.0008 cm (0.0003 in.). Each tank is 

equipped with a rectifier and operates at approximately the same process 

loading. The typical operating voltage is 6 volts, and the amperage 

ranges from 2,000 to 4,000 amperes of direct current. 

The chromium plating solutions contain chromic acid at a 

concentration range of 225 to 240 grams per liter (30 to 32 ounces per 

gallon) of water. The plating solutions also contain a small amount of 

sulfuric acid catalyst. The sulfate ratios for the baths are maintained 

at approximately 200:1. The operating temperature of the plating solution 

is 54°C (130°F). 

C. Emission Control 

All three chromium plating tanks are equipped with single-sided 

draft hoods. Each tank is ducted through the roof to a chevron-blade mist 

eliminator with a double set of blades. The two mist eliminators on lines 

Nos. 1 and 3 were manufactured and installed by Duall Industries, Inc. 

The mist eliminator on line No. 2 was manufactured and installed by KCH, 

Services, Inc. Line No. 1 is also equipped with an evaporator prior to 

the mist eliminator. Line No. 1 is vented to the atmosphere following the 

mist eliminator. A mesh-pad mist eliminator manufactured by Kimre, Inc., 

and installed by KCH Services, is located downstream of the chevron-blade 

mist eliminator on line No. 2. Both mist eliminators on line No. 2 were 

installed in December 1987. A moisture extractor, which was installed by 

Duall Industries, Inc., is located downstream of the chevron-blade mist 

eliminator on line No. 3. The ventilation rate for each system is 

2,260 actual cubic meters per minute (8,000 actual cubic feet per minute). 

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The chevron-blade mist eliminators are equipped with spray washdown 

systems for periodic rinsing of the chevron blades. Each mist eliminator 

is washed for 10 to 15 minutes at the end of each 8-hour shift. The 

washdown water is drained to each plating tank to make up for evaporation 

losses. The pressure drop across each mist eliminator is 0.5 kiloPascal 

(2.0 inches of water column). 

The capture systems on the plating tanks appeared to be operating 

effectively during the plant visit. No misting was observed escaping the 

hoods on line Nos. 1 and 3. The plating tank on line No. 2 was not 

operating at the time of the visit. The control devices used on the tanks 

appeared to be effective at controlling chromic acid mist because no 

visible spots of chromium were observed on the roof and ductwork around 

the stacks. 

The acid pickle and electroclean tanks on each process line are 

equipped with single-sided draft hoods. The two process tanks for each 

line are then ducted together and vented to a single packed-bed 

scrubber. The scrubbers are vertical-flow units and were manufactured and 

installed by Duall, Industries. The three scrubbers are located on the 

roof adjacent to the mist eliminators. 

0. Conclusions 

Vermont American Corporation is a captive shop performing hard 

chromium plating of circular saw blades. Emissions from the hard chromium 

plating tank on Line No. 2 are controlled by a chevron-blade mist 

eliminator with a double set of blades as well as a mesh-pad mist 

eliminator. The capture system on Tank No. 2 would be expected to operate 

as effectively as those on Tank Nos. 1 and 3. Therefore, the hard 

chromium plating tank in line No. 2 is a good candidate for testing the 

performance of a chevron-blade mist eliminator with a double set of blades 

as well as performance testing of two control devices used in series. The 

plant has agreed to cooperate in a source test at this facility. 

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