scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Patent
14 Mar 2010
TL;DR: This invention relates to a breakthrough in the art of chromatography allowing 1) larger scale of operation; 2) faster processing time; 3) disposability; 4) reduction of media/resin expenses; and 5) a reduction of capital equipment investment.
Abstract: This invention relates to a breakthrough in the art of chromatography allowing 1) larger scale of operation; 2) faster processing time; 3) disposability; 4) reduction of media/resin expenses; and 5) a reduction of capital equipment investment. In this invention, the chromatography column is replaced by a module that consists of two or more interconnected tangential flow filters and static mixers. The chromatography resin flows through this module in a single pass, while similar operations to a regular chromatographic process are performed on the resin (binding, washing, elution, regeneration, and equilibration). The buffers for these operations are pumped into the module in a countercurrent direction to the flow of resin, and permeate solutions from later stages are recycled back into previous stages. This creates concentration gradients in the permeate solutions of the tangential flow filters in the countercurrent direction to resin flow, thus saving buffer volume and increasing process efficiency.

3 citations

Journal ArticleDOI
TL;DR: In this paper, the mass transfer coefficients for cocurrent and countercurrent flow at the same flow rate were compared and shown that with flooding excluded in cocurrent flow, columns can be operated with higher liquid loads than in counter-current flow, and nitrogen released in the top part of the packing is better utilized as stripping gas.
Abstract: Conventional vacuum stripping to reduce the oxygen content of injection water for secondary recovery of oil is carried out in packed columns with the released gases and water flowing countercurrently; hence large column diameters (normal liquid load circa 100 m3/(m2h)) and foaming that requires the addition of defoaming agents. Measurements with cocurrent and countercurrent flow at the same flow rate produced practically identical mass transfer coefficients. With flooding excluded in cocurrent flow, columns can be operated with higher liquid loads than in countercurrent flow. In addition, nitrogen released in the top part of the packing is better utilized as stripping gas, and foam is withdrawn as soon as it increases the pressure drop.

3 citations

Patent
04 Feb 2015
TL;DR: In this paper, the authors presented a double-effect countercurrent ammonia concentration device with three evaporators and two condensers, which mainly consisted of a primary evaporator, a control evaporation, a secondary evaper, a primary condenser and a secondary condenser.
Abstract: The utility model discloses a double-effect countercurrent ammonia concentration device. The double-effect countercurrent ammonia concentration device mainly comprises three evaporators and two condensers, namely a primary evaporator, a control evaporator, a secondary evaporator, a primary condenser and a secondary condenser. The utility model provides a double-effect countercurrent evaporation method through optimization and innovation on the basis of the traditional double-effect evaporation device, namely the primary evaporator is heated by using steam of the secondary evaporator, use of ammonia-containing water vapor which is inconvenient to use is avoided, and secondary steam of which ammonia is clearly removed is used. Therefore, the energy-saving efficiency of the device is over 30 percent in the production process.

3 citations

Journal ArticleDOI
TL;DR: In this article, two dimensionless correlations were proposed for predicting average static holdup in the column as a function of average mother drop size, physical properties, rotor speed, phase flow rates, and number of stages in column for the two mentioned cases.
Abstract: Local and average static holdups in a rotary disc contactor were studied under various operating conditions. All experiments were performed by use of a swarm of dispersed phase drops and countercurrent continuous phase flow. Different parameters consisting of droplet size, static holdup, and continuous and dispersed phase flow rates were measured experimentally. Based on experimental data, two dimensionless correlations were proposed in the case of immovable rotor discs and also in the case of rotating rotor discs. Finally, two other correlations, in terms of dimensionless numbers, were proposed for predicting average static holdup in the column as a function of average mother drop size, physical properties, rotor speed, phase flow rates, and number of stages in the column for the two mentioned cases. The maximum absolute average relative error and standards deviation of the proposed correlations are 9.8% and 7.3%, respectively.

3 citations

Patent
17 Mar 2005
TL;DR: In this article, the authors proposed a solution to improve the radiation performance of a heat sink for a heating element by using a countercurrent vibration stream type heat transfer apparatus, which is distributed over the whole heat sink.
Abstract: PROBLEM TO BE SOLVED: To improve the radiation performance of a heat sink for a heating element. SOLUTION: The heat, which is produced from a heating element 3 in a countercurrent vibration stream type heat transfer apparatus 6 of a heat dissipation means, is distributed over the whole heat sink 5. Thereby, as the whole heat sink 5 becomes an almost same temperature, the temperature difference between the atmosphere in a portable phone base station 1 and the heat sink 5 becomes approximately uniform. Moreover, as the whole heat sink 5 can efficiently radiates heat, the radiation performance of the heat sink 5 can be enhanced. COPYRIGHT: (C)2005,JPO&NCIPI

3 citations


Network Information
Related Topics (5)
Heat transfer
181.7K papers, 2.9M citations
80% related
Laminar flow
56K papers, 1.2M citations
78% related
Reynolds number
68.4K papers, 1.6M citations
76% related
Particle size
69.8K papers, 1.7M citations
73% related
Adsorption
226.4K papers, 5.9M citations
72% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202358
2022115
202127
202041
201947
201849