Countercurrent exchange

About: Countercurrent exchange is a research topic. Over the lifetime, 2255 publications have been published within this topic receiving 28687 citations. The topic is also known as: Countercurrent exchange.

Enhanced pressure swing adsorption processing

Abstract: A feed gas is passed to a pressure swing adsorption system, each bed of which undergoes a processing cycle that includes (1) pressurization (2) copurge at upper adsorption pressure, (3) countercurrent depressurization, including, in some embodiments, evacuation to a lower subatmospheric desorption pressure. By recycling effluent gas released upon copurge and countercurrent depressurization for use in the pressurization or the copurge step, the more readily adsorbable component of the feed gas is advantageously recovered at high purity and at high recovery levels. Enriched less readily adsorbable component is also recoverable as coproduct effluent at relatively high recovery levels. The process can be advantageously employed for the separation and recovery of product nitrogen from air.

Heat transfer method

Abstract: A heat transfer method using ternary compositions containing 2,3,3,3-tetrafluoropropene, 1,1-difluoroethane and difluoromethane, said compositions being especially interesting as a heat transfer fluid in compression refrigeration systems comprising exchangers operation in counterflow mode or in split flow mode with counterflow tendency. The use of a ternary composition of 2,3,3,3-tetrafluoropropene, 1,1-difluoroethane and difluoromethane as heat transfer fluid in compression-type refrigeration systems with exchangers operating in countercurrent mode or in crossed-current mode with countercurrent tendency.

Mass transfer in regular arrays of hollow fibers in countercurrent dialysis

Abstract: The concentration profiles in a countercurrent hollow fiber bundle mass exchanger dialyzer is derived, assuming a uniform distribution of fibers in the dialyzer shell. Mass transfer coefficients are obtained as a function of fiber packing density, membrane thickness, membrane material, and solute type.

An electrically driven multistage countercurrent solvent extraction device: the emulsion-phase contactor

Abstract: An electrically-driven, high-surface-area solvent extraction system has been conceived and tested. The system accomplishes droplet formation, coalescence, and phase separation utilizing a single electric field while operating under countercurrent flow conditions. The mass-transport capability of this system has been analyzed by observing the transfer of acetic acid from water (dispersed phase) into methyl isobutyl ketone. Results are reported in terms of the number of theoretical transfer stages per centimeter of column. The emulsion-phase contactor, which has 1.7 stages/cm, outperforms laboratory-scale versions of the York-Scheibel column by a factor of 17 and the Podbielniak centrifugal contactor by a factor of 10. The mass-transfer performance along with the minimal energy requirements of this conceptual device combine to make it an attractive possibility for greatly enhanced solvent extraction operations.