Spray particles are removed in at least a 180.degree. surround of an article traversing an arcuate path in the interior of a spray booth. The booth includes a water wash extending vertically for a height greater than the work area and a spray area and preferably extends upwardly to the area of an overhead conveyor. Air flow is maintained at a substantially constant velocity to carry overspray particles into the water wash and away from the article and a water particle eliminator eliminates water particles from the cleaned air being discharged. The preferred booth comprises a plurality of adjacent units set at angles to each other to define a polygon of at least 180.degree. with a planar water wash means being provided in each unit. A conveyor protection device may be used which discharges positively pressure air from a housing about the conveyor with the air flow in the booth pulling this blown air away from the spray areas and booth portal and into and through the water wash.

A hood assembly for at least partially defining an enclosure in which two or more non-parallel rapidly moving air streams cooperate to entrain minute air borne particles in the enclosure to recover the latter and prevent the escape of the particles through an opening in the forward part of the enclosure. The air defining the air streams may in whole or in part be discharged to the ambient atmosphere substantially free of entrained air borne particles, or the air may be sequentially recycled through the enclosure. The hood assembly is particularly adapted for paint spray booths, but is equally useful and effective, when the air borne particles constitute smoke or fumes.

Exhaust system control apparatus operative to automatically close a damper in an exhaust duct leading from a spray booth when the spray booth is not in operation. A reversible damper motor is energized to rotate the damper to an open position when the spray booth is in operation. The damper motor is automatically reversed to close the damper in response to termination of spray booth operation. Energy is thus conserved by reducing the amount of heated air that would otherwise escape through the exhaust duct when the spray booth is not being used. In case of fire, the same damper is automatically rotated to a closed position in the exhaust duct by a spring loaded sprocket assembly on the damper shaft. This safety action takes place in response to the melting of a fusible link located in the exhaust duct and connected to a sprocket retention cable.

A system and process is disclosed for eliminating paint solvents released during paint spraying operations into the circulated air including a liquid spray solvent stripper over which the exhaust air is passed, and a heating and cooling arrangement for regenerating the solvent absorber liquid. A heat exchanger recovering heat from an incinerator vaporizes the solvent and the absorber is recovered by being passed over cooling coils in a condensing chamber. The exhaust air is treated with a water circulation system to remove paint solids, a proportion of the solvent vapors passing into solution with the treatment water. A solvent stripper is provided consisting of an arrangement for applying a vacuum to the water circulated from a paint solid removal unit, causing the solvent to be vaporized out of solution, with the vapors condensed by being passed over cooling coils in a condensing chamber. The air and water stripper condensing chambers are purged by a vacuum pump directing the uncondensed solvent vapors into the incinerator.

Described is a process for the purification of gaseous effluent of industrial processes by providing a gas containing at least a hydrocarbon solvent and/or an oxygenated solvent and passing said gas into a gas absorbing means comprised of a nonreactive liquid solvent for said gas, said liquid solvent being liquid and substantially nonvolatile at ambient temperatures and pressures. Preferably, the liquid absorbing solvent is reclaimed by separating the gaseous effluent therefrom. The gaseous effluent is preferably that resulting from the application of paint.