Shell and tube heat exchanger

　　Fixed tube sheet heat exchangers have a simple, compact structure and are inexpensive to build, but the outside of the tubes cannot be mechanically cleaned. In this type of heat exchanger, the tube bundle is connected to the tube sheet, and the tube sheets are welded to both ends of the shell. The top cover is connected to the tube sheets, and the top cover and shell are fitted with fluid inlet and outlet connections. A series of baffles perpendicular to the tube bundle are usually installed outside the tubes.

　　At the same time, the connection between the tubes and tube sheets and the shell is rigid, while the inside and outside of the tubes are fluids with different temperatures. Therefore, when the temperature difference between the tubes and the shell is large, due to the different thermal expansion of the two, a large temperature difference stress is generated, causing the tubes to twist or loosen from the tube sheet, or even damage the heat exchanger. To overcome the temperature difference stress, a temperature difference compensation device is required. Generally, when the temperature difference between the tube wall and the shell wall is more than 50℃, for safety reasons, the heat exchanger should have a temperature difference compensation device. However, the compensation device (expansion joint) can only be used when the temperature difference between the shell wall and the tube wall is below 60-70℃ and the shell-side fluid pressure is not high. Generally, when the shell-side pressure exceeds 0.6Mpa, because the compensation is too thick and difficult to expand and contract, the temperature difference compensation effect is lost, and other structures should be considered.

　　Floating head heat exchanger: One tube sheet of the heat exchanger is connected to the shell with a flange, and the other tube sheet is not connected to the shell, so that the tubes can expand and contract freely when heated or cooled. However, a top cover, called a "floating head", is connected to this tube sheet, so this type of heat exchanger is called a floating head heat exchanger. Its advantages are that the tube bundle can be pulled out for cleaning; the expansion of the tube bundle is not constrained by the shell, so when the temperature difference between the two heat exchanger media is large, temperature difference stress will not be generated due to the difference in thermal expansion between the tube bundle and the shell.

　　Stuffing box heat exchanger: The structural characteristics are similar to those of the floating head type, but a stuffing box sealing structure is used at the sliding contact surface between the floating head and the shell, so that the tube bundle can expand and contract freely without generating thermal stress caused by the difference in thermal deformation between the shell wall and the tube wall. It has a simple structure, is easy to manufacture, and is inexpensive. The tube bundle can be pulled out from the shell for easy cleaning and maintenance.

　　U-tube heat exchanger: In a U-tube heat exchanger, each tube is bent into a U-shape and both ends are fixed to the same tube sheet. Each tube can expand and contract freely, thus solving the problem of thermal compensation. The tube side has at least two passes, the tube bundle can be pulled out for cleaning, and the tubes can expand freely. It has a simple structure, light weight, and is suitable for high temperature and high pressure conditions.

　　KLM's shell and tube heat exchangers are reliable in quality and superior in performance, and have been sold domestically and internationally for many years. The heat exchangers usually produced are divided into three types according to material: carbon steel shell and tube condenser, stainless steel shell and tube condenser, and carbon steel and stainless steel mixed shell and tube condenser. According to the form, they are divided into fixed tube sheet type, floating head type, and U-tube type heat exchangers. According to the structure, they are divided into single-pass, double-pass, and multi-pass. The heat transfer area is 0.5-500m2. Customized according to user needs, please refer to the data table on the right page for specific parameters.