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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Patent•
01 Jul 2015
TL;DR: In this paper, a method for separating a polyphenol monomer from canavalia maritime by adopting high-speed countercurrent chromatography is presented. But the method is not suitable for the use of high performance liquid chromatography.
Abstract: The invention discloses a method for separating a polyphenol monomer from canavalia maritime by adopting high-speed countercurrent chromatography. The method comprises the following steps; (1) extracting canavalia maritime by using an accelerated solvent extraction method to obtain a coarse extract; (2) selecting a solvent system of the high-speed countercurrent chromatography; (3) concentrating the coarse extract to a paste, dissolving by using a bottom phase of the solvent system of the high-speed countercurrent chromatography to obtain a high-speed countercurrent chromatographic separation sample liquid; (4) separating sample liquid by the high-speed countercurrent chromatography and collecting fractions; and (5) analyzing the fractions by using high performance liquid chromatography, qualitatively determining the fractions according to retention time during the high performance liquid chromatography, and collecting the fraction which is consistent in retention time with main components of the coarse extract to obtain the polyphenol monomer. The method combines accelerated solvent extraction ASE and high speed countercurrent chromatography HSCCC to separate and purify the polyphenol monomer from canavalia maritime. Compared with the conventional separation and purification methods, the method has the advantage that the precision and reproducibility are improved. The method is simple to operate, small in time consumption, wide in application range, small in environmental pollution and easy to industrially promote.
Patent•
04 Feb 2020
TL;DR: The double tunnel-type countercurrent ultrasonic and homogeneous combination extraction system is composed of two parts of a primary tunnel and a secondary tunnel type countercurrent ultrasound and homogenous combination extraction systems as discussed by the authors.
Abstract: The invention discloses a double tunnel-type countercurrent ultrasonic and homogeneous combination extraction system The double tunnel-type countercurrent ultrasonic and homogeneous combination extraction system is composed of two parts of (1) a primary tunnel-type countercurrent ultrasonic extraction system and (2) a secondary tunnel-type countercurrent ultrasound and homogeneous combination extraction system, the primary tunnel countercurrent ultrasonic extraction system includes a solvent storage tank (1), a raw material box (2), a spiral transmission device (3a), tunnel-type countercurrent ultrasonic extraction equipment (4a), a horizontal centrifuge (9) and an extraction fluid storage tank (11) which are successively connected, and a primary extraction residue tank (5), a spiral transmission device (3b), a stirring tank (6), a homogenizer (7), a screw pump (8), tunnel-type countercurrent ultrasonic extraction equipment (4b), the horizontal centrifuge (9), a secondary residue storage box (10) and the extraction fluid storage tank (11) are connected successively According to the double tunnel-type countercurrent ultrasonic and homogeneous combination extraction system, the extraction temperature is room temperature, the double tunnel-type countercurrent ultrasonic and homogeneous combination extraction system is suitable for extraction of heat sensitive components, and after ultrasonic secondary countercurrent extraction, the extraction rate is greatly increased
Patent•
16 Oct 2020
TL;DR: In this article, a shell-and-tube heat exchanger is described, in which an electric heater is arranged into a plurality of sections in the length direction of a shell, each section is independently controlled, and the electric heater can be sequentially started in the direction opposite to the flowing direction of fluid in a shell pass along with the change of time in a period until all the sections are started, and then are sequentially closed from the flow direction of the fluid until all segments are closed.
Abstract: The invention provides a shell-and-tube heat exchanger. The shell-and-tube heat exchanger is characterized in that an electric heater is arranged into a plurality of sections in the length direction of a shell, each section is independently controlled, and the electric heater is sequentially started in the direction opposite to the flowing direction of fluid in a shell pass along with the change of time in a period until all the sections are started, and then are sequentially closed from the flowing direction of the fluid until all segments are closed. The heat exchanger is gradually started in the fluid flowing direction through the electric heater, so that the heating temperature of the rear end is high, a similar countercurrent effect is formed, fluid flowing is further promoted, and the elastic vibration effect is improved.
01 Jan 1990
TL;DR: In this article, the relative magnitude of kinetic coefficients can be calculated specifically from an absolute rate theory approach for the common case of countercurrent donor-acceptor movement subject to the complication of donoracceptor pair formation, which is incorporated into the kinetics using a linear expansion of the logarithm of the activity coefficient.
Abstract: The diffusion of substitutionally dissolved donors and acceptors has been described in terms of point defect movement and an irreversible thermodynamic treatment has been used to identify the interactions among the different diffusing species. The principal diffusive interactions for a donor species have been shown to be countercurrent donor-vacancy movement, countercurrent donor-solvent movement, countercurrent donor-acceptor movement and co-current donor-acceptor movement. The relative magnitude of kinetic coefficients can be calculated specifically from an absolute rate theory approach. This paper deals specifically with file common case of countercurrent donor-acceptor movement subject to the complication of donor-acceptor pair formation. This is incorporated into the kinetics using a linear expansion of the logarithm of the activity coefficient. A representative diffusion profile is given showing significant attractive segregation of the donor on a gradient of acceptor despite the extreme diluteness of the reactants.
Patent•
12 May 2020
TL;DR: In this article, the improved 3A molecular sieve raw powder has been obtained by subjecting the potassium-containing exchange liquid recovered by countercurrent exchange of a vacuum belt filter and a 4-Amolecular sieve to mixing and stirring in a pre-exchange tank for exchange.
Abstract: The invention discloses a preparation method of improved 3A molecular sieve raw powder. The preparation method comprises the following steps: subjecting potassium-containing exchange liquid recoveredby countercurrent exchange of a vacuum belt filter and a 4A molecular sieve to mixing and stirring in a pre-exchange tank for exchange, and pumping the potassium-containing exchange liquid and the 4Amolecular sieve to the vacuum belt filter for tertiary countercurrent exchange and secondary countercurrent washing after exchange is completed; and carrying out flash evaporation and drying to obtainthe improved 3A molecular sieve raw powder. The improved 3A molecular sieve raw powder prepared by the method is high in ion exchange rate and has better water adsorbability.