RECOVERY OF ORGANIC SOLVENT

PURPOSE:To desorb and recover an org. solvent by short-time heating without using steam or an inert gas, by a method wherein the adsorbent having the org. solvent adsorbed thereby in an adsorbing and desorbing tank from which air is expelled is irradiated with electromagnetic microwaves to utilize induction heating. CONSTITUTION:After an org. solvent-containing exhaust gas (a) is passed through a filter 10 and a dehumidifier 11 to remove dust and moisture therein, the treated gas is guided to an adsorbing tank 1 having an adsorbing layer 4 provided on a ceramic mesh tray therein. When an adsorbing process is finished, valves 41, 50 are opened to purge air in the adsorbing tank 1 by a vacuum pump 12. In the next step, the valve 50 is closed while a valve 60 is opened and a magnetron 2 is operated to subject the adsorbent layer 4 to induction heating by microwaves sent thereinto from a wave guide. The desorbed org. solvent is liquefied in a condenser 13 and a gas-liquid separator 14 to be recovered while the uncondensed gas is combined with the exhaust gas (a) to be treated through a duct (a) and a check valve 80 to be sent to an adsorbing tank 1'. After desorption is finished, the magnetron 2 is stopped, a check valve 70 is closed and a valve 31 is opened to guide the gas purified in the adsorbing tank 1' to cool the adsorbent layer 4.