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.
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TL;DR: In this article, a model based on consideration of the function of movement of self-similar saturation profiles is proposed, which gives the imbibition volume, the saturation and imbibion-flux profiles, and the parameters at entry into the medium and on the saturation front.
Abstract: Consideration is given to the one-dimensional countercurrent capillary imbibition of a wetting phase (water) into a semiinfinite porous medium. A model based on consideration of the function of movement of self-similar saturation profiles is proposed. An equation is derived for it, and boundary conditions are determined. The solution of the equation gives the imbibition volume, the saturation and imbibition-flux profiles, and the parameters at entry into the medium and on the saturation front. Calculation of the imbibition indices for a sandstone sample is performed.
3 citations
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TL;DR: In this paper, the authors have carried out numerical simulations of a countercurrent flow in a vertical tube so as to investigate the CCFL characteristics and compare them with the previous experimental results.
3 citations
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25 Feb 2015
TL;DR: In this paper, an MVR evaporation and concentration and ultrasonic countercurrent extraction production line is presented, which is used for extracting active ingredients in medicinal materials and liquid medicine via reasonable structural arrangement.
Abstract: The invention provides an MVR evaporation and concentration and ultrasonic countercurrent extraction production line. According to the production line, an ultrasonic countercurrent extraction device used for extracting active ingredients in medicinal materials is effectively combined with an MVR evaporation and concentration device used for liquid medicine via reasonable structural arrangement, so that the MVR evaporation and concentration and ultrasonic countercurrent extraction production line disclosed by the invention has the advantages of energy conservation, effective extraction and concentration and solvent recovery and environment friendliness compared with the prior art, and the production cost of enterprises is further reduced.
2 citations
29 Jul 1960
TL;DR: In this paper, the removal of cesium, strontium, and rare earth cations from dilute aqueous solutions by adsorption on foam surfaces was studied.
Abstract: The removal of cesium, strontium, and rare earth cations from dilute aqueous solutions by adsorption on foam surfaces was studied. The primary objective in the study was to determine the technical feasibility of a foam separation process for the removal of specific nuclides from nuclear process streams. Foam separation takes advantage of the concentration difference existing between the surface layers and the bulk regions of solutions containing surface active solutes. Enrichment of non-surface active materials, such as cations and arions, at the air-water interface may be achieved by complexing these materials into a surface active form. Equilibrium surface adsorption coefficients, GAMMA /C, were determined for cesium, strontium, and samarium in 10/sup -5/M solutions combined with various surface active agents. Among those studied, the foaminB agents that showed best selectivity for strontium and samarium were the amino polycarboxylic acids. Promising cesium enrichments were obtained using a combination of an amino polycarboxylic acid and sodium tetraphenyl boron. The equilibrium surface adsorption was found to depend upon the type of foaming agent, the foaming agent concentration, the metal non concentration, pH, the inert salt (NaNO/sub 3/) concentration, and the temperature. Continuous separation of strontium and samarium from 10/sup -5/M aqueous solutions containing lMmore » sodium nitrate was studied in experimental countercurrent foam columns. Decontamination values of 400 to 7OO were demonstrated for strontium and samarium in a single pass through a three foot foam column, with corresponding volume reductions of 100 to 400 without evaporation. Decontamination values for strontium in the order of 10/sup 4/ to lO/sup 7/ were observed in a four column series set up. A study of the effect of the continuous column operating variables, such as liquid and gas flow rates, foam bubble size, column dimensions and temperature, on the separation efficiency was conducted. It was concluded that the degree of metal ion separation is primarily dependent on three factors: the equilibrium distribution coefficient, the ratio of the surface area generated to the liquid feed rate, and the height of the foam column. The experimental results indicate that the performance of a continuous countercurrent foam column can be quantitatively described by a Kremser or Colburn type of relationship, commonly employed in the design of conventional mass transfer unit operations. Relationships of this type were derived from a mathematical analysis of a foam column model. (auth)« less
2 citations
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2 citations