Letter 1005

Counterflow Rinsing Design

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NEED INFO ON COUNTERFLOW RINSING, PROCESS DESIGN OF TANKS ETC. WOULD LIKE TO RETROFIT TWO TANKS TO COUNTERFLOW.

Mark Muchoney

The Metal Finishing Guidebook has an article by yours truly on this subject.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Mark,

The May 1982 "Plating & Surface Finishing" magazine has an excellent tip on counterflowing 2 tanks without expensive plumbing or pumps.

Mike McDonald
mack products - Jefferson, Wisconsin

Dear Mark, The reason to counterflow is to both save money and keep your TDS to an allowable limit. If you had say a five stage washer without counterflowing, you would overflow the rinse stages to keep the TDS down. With counterflowing available, you would counterflow stage 4 rinse to stage 3 phosphate and to 2 rinse. Stage 2 would feed stage 1 cleaner. In this scenario, you do not put water down the drain unless you have a particularly heavy dragout fron stage 1 into stage 2 "1000 TDS or over". With todays push for water conservation this will go all long way and should also assist you on your SAC rate also.

Bob Utech Brooklyn Park, MN

Editor's note:  Mr. Utech is the author of -->

A Guide to High Performance Powder Coating [link is to Amazon]