2009 International Mechanical Code Section 510. Essentially you need to provide:
-- 1 CFM/square foot of exhaust air and cannot be recirculated
-- Makeup air equivalent to the exhaust air flow rate
-- The system needs to be designed for continuous operation
-- Materials of construction must be corrosion-resistant
-- The exhaust air inlets must be terminated within 12 inches AFF
-- The exhaust air outlet needs to terminated outside the building in accordance with the hazardous exhaust system requirements, including separation distances from other air inlets and the building's lot line
Use all coated parts in the airstream. Fiberglass/lined ductwork.
I'd use a centrifugal blower and an upblast stack that, in addition to IMC req'ts, extends well above the adjacent area (roof deck?) to avoid anyone getting a wiff.
Nasty stuff if you happen to breath some at very low concentrations; I can vouch for that. 98% is incredibly dangerous.
Real world knowledge doesn't fall out of the sky on a parachute, but rather is gained in small increments during moments of panic or curiosity.
I agree that the tanks will be best placed outdoors in a contained area, however the client wants to know what will be required if placed indoors. the building is a small, unoccupied, process station. I do not have experience in locating acid and caustic tanks and their requirements. What are some reasons I could list justifying locating the tanks outdoors? What would the outdoor requirements be for the tank storage? If you have some thoughts, I would appreciate it.
IMHO, These are some reasons why these tanks should be outside:
- Tank venting becomes a problem. Vents should be directed outdoors rather than in the room with the tank. A good HAZOP will identify this.
- Acid/caustic fumes during internal inspections. Where will these fumes go during times when the manways are open ?
- Caustic tanks can be a particular mess, especially if the caustic is 73% and must be maintained at ~110-140F. There are additional heat loads to the room and caustic crystalizes whenever there is maintenance done on the heater. If the tank is outdoors, a hose can clean things up quickly.
- Tank drainage. Sooner or later you must drain the tank. Where will you drain into can become a problem if the tanks are located in a lower floor of a building ?
