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Agitation of pickling lines by using compressed air

Dear All:
Happy New Year,
Is it available to use a compressed air for HCl pickling agitation to accelerate the pickling process?
What are the advantages and what are the disadvantages?
Thank you, and best regards,

Salah Salman
- Cairo, Egypt
2007

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First of four simultaneous responses --

Salah,
The disadvantages outweigh the advantages here. HCl pickling obviously emits HCl vapors. The escape of HCl is measured by a vapor pressure, the higher the pressure the more HCl escapes. If you add compressed air to the scenario the safety of workers will be greatly affected, the equipment around the pickling process will suffer, not to mention the structure of the building. The push air, fume exhaust, and fume scrubber will be far less efficient with the accelerated escape of the vapors. Sorry, I can't give you any advantages.

Mark Baker
Process Engineer - Syracuse, New York
2007

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Second of four simultaneous responses --

Poor idea. You will rust out every iron and steel part within 50 feet.Use a pump or a mixer.

James Watts
- Navarre, Florida
2007

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Third of four simultaneous responses -- 2007

Salah
I would never recommend blowing air through an HCl bath. It will greatly increase the fumes for very little increase in speed.
If you must increase the agitation consider using eductors [on eBay or Amazon] (search the web)
The primary controllers of speed are temperature and concentration.
But first, I would ask why you need to increase the speed. The overall speed of a process line is the slowest step. If you have a 30 minute plating process and a 2 minute pickle, you just produce a build up of work on the line.
It is also worth considering if HCl is the best acid. Dilute sulfuric is effective without the fumes and is easier to treat the effluent. It usually needs some heat, but in Egypt probably not much.

Geoff Smith
Hampshire, England

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Fourth of four simultaneous responses --

I would strongly recommend using any form of air agitation with an HCl pickle, because of the considerable increase in fumes that would be generated from the process. HCl produces quite a lot of fumes already, and you don't want to make it any worse. Consider mechanical agitation instead.

John Reid
- Brisbane, Queensland, Australia
2007

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2007

Dear Salha
you can not use air agitation with any acids pickling tanks it is very dangers . you can use mechanical agitation for the work parts
best regards,

Ali Gomaa
- Cairo, Egypt

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