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.

An electrolytic countercurrent column for isotope separation: a simplified theoretical approximation

Abstract: IN this communication, the possibility is considered of multiplying a single, electrolytic isotopic separation effect in a continuous process occurring in an electrolyser with a countercurrent flow and conversion of two immiscible liquid phases. The latter consisted of an electrode and an electrolyte. Such a process may—among other applications—be used to the enrichment of lithium. The process is presented schematically in Fig. 1. A solution of the lithium salt chosen is electrolysed during the flow between the immovable anode 1, and the movable cathode 2, which is mercury flowing in countercurrent. During the flow the isotopically enriched lithium is accumulated in the mercury. The resulting amalgam is then decomposed in the converter 3. The solution of the lithium salt obtained and the pure mercury are turned back to the electrolyser. Part of the solution of the salt in the converter can be taken off as the enriched product P. The dilute and isotopically exhausted electrolyte is removed from the device, which, owing to the apparent analogy, may be called the electrolytic column.

The Separation of Isotopes by Countercurrent Gaseous Exchange Column. II. Experimental Tests of the Theory

Abstract: The separation of carbon isotope C14 by the countercurrent gaseous exchange method has been studied using a hot wire type thermal diffusion column. The isotopic exchange reaction employed for the experiments was a reaction between carbon dioxide and carbon monoxide. The separation column was constructed with a water-jacketed glass tube of 150 cm. long and 12.7 mm. in diameter. An electrically heated platinum wire was placed at the center of the tube, and its temperature was measured by thermal expansion of the wire. The column was filled with carbon dioxide. A converter was put at the bottom of the column in order to reduce carbon dioxide to carbon monoxide. The concentration of C14 at the bottom of the column was measured by a Lauritsen type electrometer. The over-all separations at the equilibrium states were observed for the various filament temperatures between 570 and 1170°C. The dependence of over-all separation on the filament temperature and initial isotopic transports were in reasonable agneement...

Heat Exchanger Control by Stream(s) By-Pass

Abstract: The e-Ntu methodology is used to present criteria for the successful implementation of by-pass control of two stream heat exchangers. The theory has been installed in an algorithm for investigation of particular heat exchangers. An example of a 1:1 countercurrent exchanger is used to investigate the use of by-pass for flow disturbances to both streams. For negative disturbances with respect to the design flowrates, the algorithm predicts the by-pass flows that achieve the desired outlet temperatures. By-pass will be ineffective for positive disturbances.

Dual shell side staggered flat tube heat exchanger

Abstract: The utility model belongs to chemical equipment manufacturing technical field and aims to overcome the low heat transmission rate problem of a traditional heat exchanger; the utility model discloses a dual shell side staggered flat tube heat exchanger which comprises a shell body, a fixed tube sheet, a U-shaped heat exchange tube, hoops and separators. The U-shaped heat exchanger adopts the staggered flat tube with both ends fixed on the tube sheet, the joint part of the flat tube and the tube sheet is provided with a round tube, the U-shaped part is a round tube, the adjacent heat exchange tubes are in point contact with each other along the maximum flat tube long axis, the adjacent heat exchange tubes are fixed by a hoop, no baffle plate is used and the flowing dead area is avoided and the tube bundles are separated by separators. The tube side fluid and shell side fluid generate complex flow with waved feature, form cross turbulent flow and obtain stronger agitation, the internal and external mediums of the heat exchange tube form simple countercurrent so as to enhance the heat transfer process to a greater degree. The tube wall can automatically clean the surface in the presence of shell side medium and is not easy to form fouling. Besides, the dual shell side structure is adopted to increase the flow path of the shell side fluid, thereby increasing the heat exchange area and improving the heat exchange efficiency.

Method and apparatus for the continuous heat treatment of food

Abstract: The invention relates to a method and apparatus for continuous heat treatment of foodstuffs. In contrast to known cooking apparatuses having a substantially homogeneous temperature profile of the heat carrier water, a multi-zone system consisting of pre-heat (6), cooking is proposed (14) and re-cooling zone (24) through which are passed foods to be treated successively. In this case, the heat transfer medium to the conveying direction is contrary flowing passed through the rear cooling zone (24) and from there fed bypassing the cooking zone (14) of the preheating zone (6), whereby due to the transferred to the heat carrier during the return cooling process thermal energy, a temperature increase of the latter takes place. The energy demand is met by supplying heat in the cooking zone, which also operates by means of recirculating the countercurrent principle.