Abstract: A process is disclosed for the recovery and reuse of heat contained in the wet exhaust gases emanating from a solids dryer or liquor concentrator, particularly one in which drying or concentration is facilitated by purging the vapor with some noncondensable gas such as air or nitrogen. Water or solvent vapor in the moist exhaust mixture is separated from the noncondensable gas or gases by preferentially passing the vapor through a semipermeable membrane. The water or solvent vapor is then compressed and subsequently condensed in a heat exchanger, permitting recovery of its latent heat of vaporization for reuse in the evaporation process. In a drying process, this recovered energy is conveniently used to reheat the dry gases that exit from the membrane separator, permitting the hot, dry gases to be recirculated through the dryer. Alternatively, an indirect heat exchanger may be used to transfer this heat to the material being dried.

Abstract: Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption.

Abstract: A dispenser for active ingredients is disclosed which provides zero-order rate of release of essentially all of the active ingredients. The dispenser comprises a rate-controlling membrane and a solid microporous polymeric reservoir having interconnected or continuous pores capable of retaining the active ingredient by capillary forces, the reservoir being such that the active ingredient is essentially insoluble therein.

Abstract: A process is disclosed for the recovery and reuse of the heat contained in the gas/vapor overhead mixture from a stripping column in which a noncondensable gas is stripped from a liquid solution by contacting the solution with a hot vapor such as steam. The steam or other vapor in the overhead mixture is separated from the non-condensable gas or gases by preferentially passing the vapor through a semipermeable membrane. The water or other condensable vapor is then compressed and either reinjected at the bottom of the stripping column or condensed in the column reboiler, thus permitting its reuse in the stripping process. If the compressed vapor is reinjected into the stripping column, it serves as the stripping medium itself. If the compessed vapor is condensed in the column reboiler, its latent heat of vaporization is thereby recovered and used to generate the required stripping vapor by boiling the solution being stripped.

Abstract: An osmotic dispenser comprised of (1) a water permeable membrane forming part or all of the walls of an enclosure surrounding (2) an active agent, and in some cases (3) an additional compound known as an osmotic attractant which together exhibits an osmotic pressure against water. When placed in an aqueous environment water is osmotically drawn into the enclosure by the combined action of the agents (2) and (3) which distends and swells the enclosure until the membrane or some other part of the enclosure wall reaches the point of ultimate elongation and a portion of the wall yields and ruptures releasing the contents of the enclosure to the environment.