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.

Continuous countercurrent chromatography system

Abstract: A continuous countercurrent chromatography system has several rotating chambers arranged around a rotational axis. The chambers are provided for receiving a liquid or liquid mixture to be examined, and the individual chambers are interconnected via liquid carrying connections in such a way as to relay two liquids in countercurrent, wherein one liquid first passes through several chambers and is then returned to the chambers first traversed.

Macroscopic governing equations for bioheat transfer phenomena

Abstract: The volume averaging theory of porous media has been applied to obtain a general set of macroscopic governing equations for countercurrent bioheat transfer between terminal arteries and veins in the circulatory system. Capillaries providing a continuous connection between the countercurrent terminal arteries and veins are modeled introducing the perfusion bleed-off rate. Three distinctive energy equations are derived for the arterial blood phase, venous blood phase and tissue phase. It has been found that the resulting model reduces to Chato’s countercurrent heat transfer model for the case of closely aligned pairs of artery and vein. The effect of spatial distribution of perfusion bleed-off rate on total countercurrent heat transfer has been investigated in depth exploiting the present bioheat transfer model.

Countercurrent contact apparatus

Abstract: The present invention relates to countercurrent liquid contact apparatus and more particularly to mixing devices for promoting liquid contact. The liquid contact apparatus of the type described herein is of value, for example, in the solvent extraction of lubricating oils for separation of...

Countercurrent dual-flow spiral-wound dual-pipe membrane separation device

Abstract: The present invention relates to an improved design for a spiral-wound membrane separation device. The improved module (50) has one feed pipe (51A) separated into compartments (A, B) which are connected axially to a porous spacer (55) surrounded by a membrane envelope (54). A separate permeate pipe (51B) is immediately adjacent and generally in a parallel configuration to the fluid feed pipe (51A) and is in fluid communication with a different porous spacer sheet (58). When the porous feed membrane (54) are combined using appropriate complementary shaped spaced filling means (52A, 52B), a spiral-wound membrane separation device is obtained having two centrally located pipes. In one aspect, the membrane separation module (50) further includes means for the addition of a countercurrent or cocurrent sweep fluid (gas) permeate.

Foam layer structure on countercurrent contact elements with stabilization

Abstract: Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of foaming devices and opens up new opportunities for intensifying technological processes with the simultaneous for creation of lowwaste technologies. The article reveals the basic regularities of the hydrodynamics of the foam layer with the stabilizer on counteracting contact elements. The structural parameters of the phases of the foam layer as a whole medium are considered. Take into account the mutual influence of two phases. The laws of gas content and parameters of the contact area of phases have been studied. The functional dependences of the main parameters of the process are established. The conducted analysis of a number of studies has shown that a promising direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms made of porous materials. Consequently, it is necessary to carry out special investigations of the hydrodynamic modes of the apparatus with a foam layer, which stabilizes with the definition of parameters that affect the transition speed of the contact element from one mode to another. In today's conditions, a significant human-induced environmental impact on time is the search for the most effective and economical methods for the purification of industrial emissions. Methods of cleaning and equipment being developed should take into account the possibility of work in a wide range of working conditions. In order to reduce energy consumption in systems for catching harmful and toxic substances, it is necessary to provide a reduction of hydraulic resistance while maintaining the high efficiency of gas streams cleaning. Given the controversial requirements for equipment and despite the large number of existing machines for mass transfer processes, the development of new high-intensity and efficient equipment is of considerable interest for environmental technologies in many industries.