exhaust ventilation alkaline cleaner tank
exhaust ventilation alkaline cleaner tank
(OP)
I have a small black oxide line in my plant. The first (cleaner) tank is caustic soda heated to 140°F. There are vapors coming off the tank that cause an unpleasant odor. I had an air quality audit done a while back and the industrial hygienist recommended local exhaust ventilation on this tank. The vapors consist of sodium hydroxide, sodium metasilicate and /or glycol ether. He said I need 190 cfm/ft^2 of surface area or 956 cfm total (5.03 ft^2). There is an overhead crane above the tank, so I can't put a hood over the top. I will have to install ductwork on the sides of the tank and draw the vapors underneath and then somewhere. Now my question:
What do I do with the air and vapors? Can I filter it or condense it and then blow the air outside, or just blow it all outside? If I blow it outside do I need to allow for makeup air to keep the doors from being sealed shut? Unfortunately the guy that did the audit is no longer at my insurance company and I haven't been able to get in contact with anyone there that could help me. Any ideas?
What do I do with the air and vapors? Can I filter it or condense it and then blow the air outside, or just blow it all outside? If I blow it outside do I need to allow for makeup air to keep the doors from being sealed shut? Unfortunately the guy that did the audit is no longer at my insurance company and I haven't been able to get in contact with anyone there that could help me. Any ideas?





RE: exhaust ventilation alkaline cleaner tank
The most usual solution to your problem is a push-pull system consisting of forced air outlets across one side of your tank with inlets (exhaust) on the other. The system essentially functions as an air curtain over the tank to capture the fumes. Given the contaminants in your airstream, you might want to put in a plain water scrubber to remove the contaminants before exhausting the air outside. Depends on the concentrations, odor levels and your environmental permits. Filtration might work, depends on the level of aerosol in your exhaust. Aerosols tend to gum up dry filters, so you might want to avoid those. The thing to do first is to determine the level you might have. You can estimate these levels from algorithms for caustic baths found in literature from the EPA, AWMA and the American Association of Industrial Hygienists. From there, you can determine what is then needed in the way of control before exhausting the airstream.
RE: exhaust ventilation alkaline cleaner tank
RE: exhaust ventilation alkaline cleaner tank
The major atmospheric contaminant will be an alkaline mist and/or steam that can be treated with a mist eliminator. However, this equipment might not be necessary - you might be able to blow it outside, check with your local authorities.
RE: exhaust ventilation alkaline cleaner tank
RE: exhaust ventilation alkaline cleaner tank
RE: exhaust ventilation alkaline cleaner tank
RE: exhaust ventilation alkaline cleaner tank