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.

Determination of the ozone volumetric mass transfer coefficient in bubble column with two-fluid nozzle gas distributor

Abstract: Experimental investigation of gas-liquid mass transfer of ozone in water, in bubble column with two-fluid nozzle gas distributor (BKDM), under different operating conditions, are presented in this work. The main objective was to determine the ozone volumetric mass transfer coefficient, kL a, in calm uniform section of the column, under different values of gas and liquid flow rates. Obtained values of these coefficients were compared with the values in countercurrent bubble column. The critical liquid flowrate, when gas hold up reaches its maximum, was experimentally determined. It was shown that the maximum value of the ozone volumetric mass transfer coefficient is obtained just when liquid flowrate is at its critical value. [Projekat Ministarstva nauke Republike Srbije, br. 172022]

Calculation of hydrodynamic parameters in tubed vessels with rising cocurrent flow

Abstract: The rising cocurrent flow mode is prefereably used in processes in which diffusional resistance in the gas phase plays a significant role, and in which the temperature conditions are regulated by external action. Since the change from countercurrent to rising cocurrent flow intensifies the exchange ]processes in the gas phase to a greater degree than in the liquid phase, this mode is best in the selective absorption of gases from a mixture. The short residence time of the reactants in the reaction zone and the possibility of regulating the residence time by changing the gas velocity with simultaneous supply or withdrawal of heat through the wall are incentives for using the rising cocurrent flow mode in processes for obtaining pure substances and in processing heat-labile products.

High-performance countercurrent chromatograph and analysis method using it

Abstract: PROBLEM TO BE SOLVED: To provide a high-performance countercurrent chromatograph that dispenses with complex work using a conventional separatory funnel and can show an improved performance also in safety, and to provide an analysis method using the high-performance countercurrent chromatograph. SOLUTION: The high-performance countercurrent chromatograph comprises a rotatable support; a drum that is mounted so that it can rotate on its own axis and move around along the support by a rotary synchronization mechanism; and a tube as a column wound around the periphery of the drum. In the high-performance countercurrent chromatograph, a sidewall inlet is punched at least at one location on the sidewall of the tube. The analysis method simultaneously and continuously performs a process for introducing an extraction phase from the sidewall inlet near a column tail into the tube for discharging from a column head, and a process for introducing a sample containing an extraction substance from the sidewall inlet near the column head for discharging from the column tail of the tube. COPYRIGHT: (C)2006,JPO&NCIPI

High temp. gas desulphurisation with lime - sliding downwards over gratings in shaft reactor in countercurrent to gas

Abstract: Desulphurisation of gases with any temp. up to 1000 deg.C is carried out by passing the (waste) gas in countercurrent to lump lime sliding downwards over gratings in a shaft reactor. Complete utilisation of the countercurrent principle is possible and the layer of material on the gratings has a relatively high air passage area, allowing optimum contact between gas and lime.

Modeling and Simulation of Liquid Membrane Separation for Carbon Dioxide from Natural Gas

Abstract: A numerical analysis of countercurrent separator unit fitted with a liquid membrane with facilitated transport is presented for the separation of carbon dioxide from natural gas with nitrogen as a sweep gas on the permeate side. Two kinds of liquid membranes are studied: symmetric and asymmetric. A mathematical formulation and calculation procedure using numerical methods to solve material and transport equations is presented for each membrane for predicting the membrane area required to purify a natural gas containing to a desired level of purity. It has been found that the asymmetric liquid membrane provides more membrane area than the symmetric liquid membrane for the same level of separation.