摘要 |
<p>METHODS AND APPARATUS FOR RECOVERING SOLVENTS Methods and apparatus for recovering hydrocarbon solvents evaporated during the curing of solvent borne coatings in an oven include supplying an inert gas to the vicinity of the oven entrance and exit to substantially exclude oxygen therefrom while safely maintaining a solvent vapor partial pressure within the oven of at least 75% of the lower explosive limit of such vapor in air. The oven atmosphere is exhausted and passed to a condenser to enable recovery of at least 85% of the solvent vapor as a liquid. Preferably, condensation of the solvent vapor is effected by heat exchange with liquid nitrogen which is effective to vaporize the liquid nitrogen to produce nitrogen gas which may then be utilized to exclude oxygen from and to inert the oven.</p> |