Process vessels that could contain uranium should vent to the process
off-gas system, which in turn should pass through pretreatment, if
needed, and HEPA filtration.
Three types of metallurgical processes require special ventilation
Processes that use volatile or easily entrained organic liquids should
have a ventilation system that provides sufficient air movement around
the process area to prevent exposure of personnel to the hazardous
liquid or vapor. The design should incorporate roughing filters and/or
other types of traps to remove entrained organic liquid droplets from the
process off-gas before the off-gas enters the main ventilation. As a
result, the ventilation ducts should not become coated with the organic
materials, which would create a fire hazard.
Processes that produce either finely divided particles of metal or small
metal chips should have the same kind of front-end ventilation
adaptations as for hazardous vapors and liquids to prevent metal
accumulations in the off-gas ducting or in the final filtration train(s).
Roughing filters or centrifugal separators may be sufficient to remove
metal particles from the off-gas.
Processes that use corrosive chemicals (e.g., acids, perchlorates) should
use off-gas scrubbers to preclude damage to the exhaust air cleaning
system (e.g., HEPA filtration train).
Metallurgical processing equipment should have dedicated ventilation systems
that exhaust to a common, final filtration train. If airborne particle capture is
required, a high linear velocity will be necessary to ventilate these process areas
due to the greater densities of metal particles.