Abstract Recovery of impregnant in a process in which tobacco is impregnated with a water-immiscible organic impregnant and then subjected to a stream of gas heated to a temperature substantially above the boiling point of the organic impregnant whereby the organic impregnant is volatilized and the tobacco is expanded, with the expanded tobacco being then separated from the resulting impregnant-containing gas stream. Recovery of the organic impregnant is accomplished by passing a portion of the gas stream into a lower section of a packed tower and introducing into the upper section of said tower water at a controlled temperature to effect removal of tobacco fines in the gas stream, to cool the stream and condense a substantial proportion of the water present therein and to strip organic impregnant from process waste water introduced into the upper section of said tower. The organic impregnant is then condensed and recovered by conventional procedures for subsequent reuse.
The process of claim 1 wherein the water which is introduced into the upper section of said packed tower is at a temperature approximately 5* to 20* F. above the boiling point of the organic impregnant.
Claim 2
Dependent Claim
26 words
The process of claim 1 wherein water introduced into the packed tower is collected in a liquid pool in said lower section of the packed tower.
Claim 3
Dependent Claim
20 words
The process of claim 3 wherein water from said liquid pool is recycled to the upper section of said tower.
Claim 4
Dependent Claim
40 words
The process of claim 1 wherein the packed tower is provided with a perforated plate in the lower section thereof through which said volatilized stream passes upwardly prior to passage through a bed of packing material in said packed tower.
Claim 5
Dependent Claim
26 words
The process of claim 5 wherein the bed of packing material occupies from about 60 to about 80 percent of the height of said packed tower.
Claim 6
Dependent Claim
251 words
In a process in which tobacco is impregnated with a water-immiscible organic impregnant and then is subjected to a stream of a gas heated to a temperature substantially above the boiling point of the organic impregnant whereby the organic impregnant is volatilized and the tobacco is expanded and wherein the expanded tobacco is subsequently separated from the resulting volatilized stream, the improvement which consists in passing a portion of said volatilized stream into a lower section of a packed tower having an upper section comprising vapor exit means and a plurality of nozzles for introducing water at a controlled temperature which is above that of the boiling point of the impregnant and below that of water, an intermediate section comprising packing material suspended above the lower section by means of a porous support and a lower section comprising means for maintaining a predetermined maximum level of liquid in said lower section together with means for withdrawing said liquid, a horizontally-disposed perforated plate located above said predetermined maximum level of liquid and means for introducing said volatilized stream into said lower section of the tower at a point intermediate between said perforated plate and said predetermined maximum level of liquid, introducing water through said nozzles for downward flow through said packing material to condense at least a portion of water vapor contained in said voltatilized stream which is moving upwardly through said packing material, withdrawing an organic impregnant-containing vapor through said vapor exit means and recovering the withdrawn impregnant vapors by condensation.
Claim 7
Dependent Claim
23 words
The process of claim 7 wherein a portion of the water introduced through said nozzles is derived from an organic vapor recovery system.