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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
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Journal ArticleDOI
TL;DR: A reverse flow chromatographic reactor with side feed (RFCR) was used to improve the conversion and selectivity for irreversible and reversible reaction systems beyond the values obtained from conventional steady-state reactors in the case where the reactants are more strongly adsorbed than the products.
Abstract: A reverse flow chromatographic reactor with side feed (RFCR) can be used to improve the conversion and selectivity for irreversible and reversible reaction systems beyond the values obtained from conventional steady-state reactors in the case where the reactants are more strongly adsorbed than the products. It is also simpler than conventional chromatographic, moving, and simulated moving beds and other systems that combine reaction and adsorption separation. The results of the study show the robustness and stability of the system, as well as its capacity to significantly improve conversion and selectivity for several reaction systems, including consecutive reactions. Simulation results of this mathematical model for the hydrogenation of 1,3,5-trymethylbenzene (MES) compare well with previous studies, using countercurrent moving-bed reactors and simulated countercurrent bed reactors. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2266–2275, 2004

11 citations

Patent
24 Jul 1984
TL;DR: In this paper, an apparatus for the countercurrent treatment of liquids with adsorbents in an adsorption-filter is described, where the space of which is divided by trays which are permeable to liquids into at least two chambers, in which before and/or during the charging of the adsorbent in the upward flow, the regeneration of the charged adsorbant in the downward flow, and the backwasting in upward flow particular levels to which the industrial chambers are filled are established.
Abstract: An apparatus for the countercurrent treatment of liquids with adsorbents in an adsorption-filter the space of which is divided by trays which are permeable to liquids into at least 2 chambers, in which before and/or during the charging of the adsorbent in the upward flow, the regeneration of the charged adsorbent in the downward flow and the backwasting in the upward flow particular levels to which the industrial chambers are filled are established by transferring adsorbent from one chamber to the adjacent chamber.

11 citations

Journal ArticleDOI
TL;DR: In this article, the mechanism of countercurrent flow limitation (CCFL) was investigated analytically and quantitatively for the existing experimental results for vertical circular tubes, adopting a criterion that the CCFL condition is given by maximizing falling water mass velocity with respect to void fraction for the whole flow channel.
Abstract: The mechanism of countercurrent flow limitation (CCFL) was investigated analytically and quantitatively for the existing experimental results for vertical circular tubes, adopting a criterion that the CCFL condition is given by maximizing falling water mass velocity with respect to void fraction for the whole flow channel. Through the analysis, it was found that significant factors in the CCFL condition were the interfacial friction factor between liquid and gas based on the relative velocity, wall friction factors for laminar, transition and turbulent liquid flows and the effects of tube diameter and length. Analytical results gave very good predictions of the experimental results for vertical circular tubes of 19 to 140mm in diameter and 12.7 to 1520mm in length, under atmospheric pressure.

11 citations

Journal ArticleDOI
TL;DR: In this article, a new method of dynamic countercurrent cyclic extraction is proposed, where a mixture of components to be separated is injected with one of the phases during a certain time period, which does not exceed the time of this phase motion stage in the initial process cycle.
Abstract: This paper deals with a new method of dynamic countercurrent cyclic extraction. Each cycle consists of two lightand heavy-phase motion stages. The time of each phase is variable and must be specified for each process cycle. A mixture of components to be separated is injected with one of the phases during a certain time period, which does not exceed the time of this phase motion stage in the initial process cycle. A mathematical model of dynamic countercurrent cyclic extraction is developed. Some analytical relationships for calculating the separation of liquid mixtures by this method are derived. The proposed dynamic regime of extraction has been established to considerably (by several times) increase the operational efficiency of extraction units. A comparison of the experiment and theory demonstrates satisfactory agreement between them.

11 citations

Journal ArticleDOI
TL;DR: In this paper, a methodology for predicting the gas holdup for both the homogeneous and heterogeneous regimes and the transition gas velocity and holdup is developed by extending existing models for homogeneous, heterogeneous and non-homogeneous regime.

11 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202358
2022115
202127
202041
201947
201849