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.

Desorption device for the absorption cold and/or hot pump process

Abstract: The invention relates to a device for introducing heat into a cyclic absorption process with simultaneous rectification of mixed vapours. The heat injection has to take place throughout the desorption process, including the subsequent rectification, it being possible to utilise the substantial temperature differences between head (lowest temperature) and bottom (highest temperature) of the column. The device according to the invention, which is shown by way of example in the drawing, enables the introduction of heat along the column during the rectification process, the solution to be rectified being distributed as a falling film on the inside walls of vertical pipes arranged in a bundle and flowing in countercurrent to the rising mixed vapour. On the outside of the tubes, that is to say in the enclosing space, the heating agent flows vertically upwards so that it is able to supply heat to the falling solution through the pipe wall up to the coldest point in the column head. When heating agents flowing upwards in the enclosing space of the column section cool down on giving off heat, which is the case for flue gases from directly heated desorbers, the trend of the temperature variation corresponds to that in the interior space of the tube. Lower waste-gas temperatures can consequently be achieved, which improves the firing efficiency.

Very low temperature rectification system for low-pressure operation

Abstract: PURPOSE: To lower a working pressure of a higher pressure column by making a lower pressure column bottom fluid pass as a countercurrent indirect contact flow with vapor generated by condensing higher pressure column shelf vapor in a once-through downflow reflux condenser to subject the flow to an additional rectification process. CONSTITUTION: Oxygen enriched liquid is partially evaporated by indirect heat exchange with nitrogen condensate vapor which is condensed while flowing through a downflow reflux condenser 41 to generate an oxygen enriched vapor, and a rectification is caused by a counter current direct contact between the oxygen enriched liquid and the oxygen enriched vapor so that nitrogen is transferred into the vapor from the liquid while the oxygen is transferred into the liquid from the vapor. The oxygen enriched vapor thus obtained flows out of an upper part of the downflow reflux condenser 41. Then, the oxygen enriched vapor is passed upward through a column 42 as vapor ascending flow for cryogenic rectification. This constitution enables the lowering of a required temperature and a corresponding pressure level necessary for the operation of a higher pressure column.

Thin-Layer Chromatography of Polar and Ionic Compounds Using Active Gas Flow Over the Silica Gel Adsorbent Layer

Abstract: Separation of polar and ionic substances in carbon dioxide and ammonia atmospheres on unmodified silica gel TLC plates with reduced moisture content has been studied by single and multiple development chromatography with countercurrent drying. Regulation of moisture content and of saturation of the layer with mobile phase vapor, creation of active atmospheres, and countercurrent drying of the mobile phase was achieved by flow of gas over the adsorbent layer. The possibility of simple gradient separation by passage of polar vapor is also shown.

Stirling engine with an even number of working gases

Abstract: In a thermal engine operating on the Stirling principle with an even number of working gases (two or a multiple of two), every two working gases are passed through a countercurrent heat exchanger such that in the countercurrent heat exchanger (1), prior to reaching the cooler, a hot working gas flowing from a working cylinder (2) gives off thermal energy to and thus preheats a cold working gas flowing in the opposite direction from a compression cylinder (5) to the working cylinder (9). The working gas coolers can be reduced in size. Regenerators can be dispensed with entirely when the countercurrent heat exchanger is suitably enlarged.