Recovery of perchloroethylene from exhaust of dry-cleaning machine - by cooling and washing, with a final filtration

摘要

The solvent-charged air from the dry-cleaning machine enters the recovery appts. at a low level and p asses upwards, (a) first through a cooler at 0 degree C, then (b) through two near-freezing water sprays separated by a grid and finally (c) through a filter before returned to the dry-cleaning machine. The perchlorethylene condenses into droplets, which fall into the water at the bottom of the appts. Here they meet a sloping plate down which the solvent runs to collect at one side of the appts. while the water gravitates towards the other, a partition separates the two regions. When enough solvent has collected, it is runn off though a cock, the water, still at 0 degree C, is returned to the spray nozzles.