Reducing the concentration of solvent vapors in drycleaning machines

Apparatus for reducing the concentration of solvent vapor in the drum of a drycleaning machine upon completion of a cleaning and drying operation, the drycleaning machine being of the type having a drum, and a solvent recovery system communicating with the drum, the solvent recovery system including a fan for circulating solvent-laden air through the solvent recovery system and the drum during a drying and solvent recovery cycle to remove solvent from the solvent-laden air, the apparatus comprising:

• filtering means for filtering solvent from solvent-laden air, the filtering means including adsorption means for adsorbing solvent from the solvent-laden air, and circulating means for circulating solvent-laden air from the drum through the adsorbing means;
• first valving means between the solvent recovery system and the drum;
• second valving means between the filtering means and the drum;
• control means for operating the first valving means and the second valving means to circulate solvent-laden air from the drum through the solvent recovery system during the drying and recovery cycle, and to close communication between the drum and the solvent recovery system, including the fan of the solvent recovery system, during a post-recovery cycle, to isolate the drum from the solvent recovery system, including the fan of the solvent recovery system, subsequent to the drying and recovery cycle, and circulate solvent-laden air from the drum through the filtering means during the post-recovery cycle, while the solvent recovery system, including the fan of the solvent recovery system, is maintained isolated from the drum and the filtering means, to reduce to a minimum the concentration of solvent vapor in the drum.