I have a few questions regarding the air separation field; thank you
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1. The operating pressure of the air separation unit is determined by the pressure of the cryogenic cycle system. May I ask which part is referred to as the “low-temperature circulation system”, and what components does the system consist of? 2. Classified by the type of heat exchanger, air separation units can be divided into tubular, shell-and-tube, and plate-type air separation units. How should a \"tube-and-plate\" heat exchanger be understood?
1. The resistance to the backflow of product or nitrogen-rich gas back into the upper column determines the pressure in that column; the temperature difference in the main cooler and the pressure in the upper column, in turn, determine the pressure in the lower column. The pressure in the lower column then determines the exhaust pressure of the air compressor, as the resistances along the path remain essentially constant. 2. Composition of the tube sheet heat exchanger The tube sheet heat exchanger is composed of components such as the tube box, shell, tube sheet, and tubes. It has a compact structure, a large number of tubes, a larger surface area for a given diameter, and is relatively simple to manufacture. The structural feature of a fixed-tube-sheet heat exchanger is that a tube bundle is installed within the shell; the tubes at both ends of the bundle are fixed to the tube sheet by welding or expansion bonding. The tube sheets at both ends are directly welded to the shell, while the inlet and outlet pipes on the shell side are directly welded to the shell as well. The outer circumference of the tube sheet and the head flanges are secured together with bolts. The inlet and outlet pipes on the shell side are also welded to the head. Inside the tube bundle, several baffle plates are placed according to the length of the heat exchange tubes. The tube side of this heat exchanger can be divided into any number of sections using partitions.
Reply to 2# zhengyanbin2011: Does the term \"low-temperature circulation system\" refer to a distillation system? What are the differences between shell-and-tube heat exchangers and tube heat exchangers?
Reply to 3# shuhuahuang: A low-temperature circulation system – since it is a circulation system, it certainly isn’t a distillation system; it should be a refrigeration system. Distillation systems are used for gas separation!