OAR Box 1313 

Prepped by LaTeia Shed 

Document Number: 

29) ll-B-3 

Docket Number: 

A-88-02 

Printed 6/12/2008 9:03:28 AM Sheet 29 of 99 

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A-88-02 

MIDWEST RESEARCH INSTITUTE 

4505 Creedmoor Road 

Raleigh, N.C. 27612 

Telephone (919) 781-5750 

FINAL 

Date: March 14, 1986 

(Finalized September 18, 1986) 

Subject: Site Visit—-Tri-Mer® Corporation 

Chromium Electroplating NESHAP 

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

MRI Project 7717-K 

From: Randy Strait 

To: Al Vervaert 

ESED/ISB/SSS (MD-13) 

U. S. Environmental Protection Agency 

Research Triangle Park, N.C. 27711 

I. Purpose 

The purpose of this visit was to gather background information about 

control devices manufactured by Tri-Mer® for controlling chromium 

electroplating emissions and to obtain names of plants that properly 

operate and maintain Tri-Mer® control devices that could serve as possible 

test candidates. 

II. Place and Date 

Tri-Mer® Corporation 

1400 Monroe 

Owosso, Michigan 48867 

(517) 723-7838 

January 8, 1986 

III. Attendees 

Tri-Mer® Corporation 

Kevin Banghart, Director of Engineering 

U. S. Environmental Protection Aqency 

Al Vervaert, ISB 

Midwest Research Institute 

Randy Strait 

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IV. Discussion 

We arrived at Tri-Mer® Corporation at 9:00 a.m. and were met by 

Mr. Banghart. The visit began with a discussion about the types of 

control equipment manufactured and marketed by Tri-Mer® to control 

chromium electroplating emissions. This was followed by a tour of the 

manufacturing facility. 

A. General 

Tri-Mer® Corporation manufactures industrial and municipal 

ventilation, air pollution, and odor control systems. The systems are 

typically made of polyvinyl chloride (PVC), polypropylene, or other 

corrosion resistant materials. Tri-Mer® was founded in 1961. Brochures 

describing the various types of control equipment were provided. 

Tri-Mer® manufactures two basic types of fume scrubbers: 

conventional packed-bed units and fan/separator units. Mr. Banghart 

estimated that up until 5 to 10 years ago, about 50 percent of Tri-Mer®'s 

business was with platers, but it is now less than that. About 80 percent 

of current business with platers is directed toward new plants and 

20 percent toward existing plants. A double packed fan/separator is the 

control device generally recommended by Tri-Mer® for controlling chromium 

emissions from chromium plating facilities. Fan/separators provide high 

control efficiencies with low operation and maintenance costs. 

B. Control Device Information 

1. Fan/separator scrubber. A schematic of the fan/separator scrubber 

is shown in Figure 1. The fan/separator unit was developed in 1965. The 

design of the unit is based on the concept of impingement rather than 

absorption as the principal mechanism for the control of chemical fumes of 

relatively high molecular weight and size. The fan/separator operates in 

two stages: a dynamic scrubbing stage and an impingement stage. In the 

first stage, ventilation air is ducted into the eye of a backward-blade 

centrifugal fan where it is sprayed with high pressure, low volume water 

or scrubbing liquid. Contaminant aerosols present are entrained and spun 

out centrifually onto the fan scroll. The centrifugal action created by 

the fan wheel eliminates approximately 50 percent of the chromium. 

In the second stage, the chemical fumes flow into an expansion 

chamber containing one or more packs of hydrophobic tubing made of 

polypropylene. The expansion chamber is designed to slow the gas flow 

rate to no more than 500 feet per minute for maximum impingement 

efficiency and to lower the humidity in the chamber to eliminate potential 

plume problems associated with wet scrubbing. The gases are sprayed 

withwater before the first pack. The second pack is dry and is used as a 

mist eliminator. Contaminated water is pumped from the unit through a 

venturi-type drain to a recirculation tank or a wastewater treatment 

system. 
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Figure 1. Fan/separator scrubber. 

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The packs cannot be back washed in the fan/separator; however, the 

units are designed so that the packs can be easily removed, cleaned, and 

reinserted. Platers can remove chromium deposits by placing the beds in a 

chromium plating cleaning solution. If the fan/separator is properly 

operated and maintained, the pressure drop across the unit should not 

exceed 3 inches of water column. Control efficiencies are estimated to 

range from 95 to 99 percent. 

The major advantages of the fan/separator scrubber over the 

conventional packed-bed scrubber are that the fan/separator scrubber uses 

about one-tenth as much water and costs less to operate and maintain 

because there are fewer moving parts. The fan is constructed of PVC to 

protect against corrosion, and its low horsepower requirements reduce 

energy costs. Waterflow rates to the scrubber range from 5 to 20 gallons 

per hour. 

2. Packed-bed scrubber. Tri-Mer® does not recommend that packed-bed 

scrubbers be installed to control chromium emissions from chromium plating 

operations because they cost more to operate and require more water than 

the fan/separator unit. Double packed-bed scrubbers are recommended if 

packed-bed scrubbers are to be used at all. 

3. Packing materials. Tri-Mer® markets a special type of packing 

material (Tri-Packs®) for vertical packed-bed scrubbers. Tri-Packs® are 

spherical in shape and are designed to provide maximum surface contact 

between the gas and the scrubbing liquid by continuously forming droplets 

throughout the packed bed. The Tri-Packs® also are designed to eliminate 

plugging and puddling, produce very low static pressure per unit volume, 

reduce the size of the packed bed required, and maximize impingement 

efficiency by reducing the amount of scrubbing liquid required. 

Tri-Packs® can be made of PVC, polypropylene, or other types of plastic 

depending on the application. 

4. Capture systems. Tri-Mer® designs capture systems based on the 

American Conference of Governmental Industrial Hygienists, "Practices for 

Ventilation and Operation of Open Surface Tanks." 

C. Test Data and Candidate Plants 

"Mr. Banghart said that they have had independent firms test their 

scrubbers. However, most of these tests were performed on units 

controlling exhaust gases containing hydrochloric acid (HCl). Exhaust gas 

streams containing HCl are used as the standard for documenting control 

efficiencies even though a unit may be used to control other chemical 

pollutants. One test was performed on a fan/separator scrubber used to 

control chromium emissions; however, the results of the test are 

confidential. 

Mr. Banghart said that he would contact chromium electroplating 

shops that use the fan/separator scrubber to control chromium emissions to 

see if any would be willing to allow EPA to test the scrubber. 

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