Shell & Tube Heat Exchanger
- JOSTON
- WENZHOU, CHINA
- 35 DAYS
- 20 SETS/MONTH
shell and tube heat exchnager is used for heating and cooling ,the medium and products will be separate pass path by the tube .
Tubular type Heat exchanger is mainly composed of shell, tube plate, heat exchange tube, baffle and so on. During heat transfer, one kind of liquid fluid enters from the connecting pipe of the head, flows in the pipe and flows out from the outlet pipe at the other end of the head, which is called the pipe process; the other kind of fluid enters from the nozzle of the shell and flows out from the other nozzle on the shell, which is called the shell process. These two kinds of liquid fluid have the heat exchange .
Tubular type Heat exchanger material can be used SS304 ,SS316L ,SS2205 ,SS201 ,Ti2 etc material as the working medium .
according to the inside tube welding structure ,it can be devided into differece model:
1).Fixed tube sheet type:
The structure of tubular heat exchanger is simple and compact, but mechanical cleaning is not allowed outside the tube. The tube bundle of the heat exchanger is connected on the tube plate, which is welded on both ends of the shell respectively, and is connected with a top cover, and the top cover and the shell are equipped with fluid inlet and outlet pipes. A series of baffles perpendicular to the tube bundle are usually arranged outside the tube. At the same time, the connection between the tube and the tube plate and the shell is rigid, while the inner tube and the outer tube are two different temperature fluids. Therefore, when the temperature difference between the tube wall and the shell wall is large, due to the different thermal expansion of the two, a large temperature difference stress is generated, so that the tube is twisted or loosened from the tube sheet, or even the heat exchanger is damaged.
In order to overcome the temperature difference stress, there must be a temperature difference compensation device. Generally, when the temperature difference between the pipe wall and the shell wall is more than 50 ℃, for the sake of safety, 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 lower than 60-70 ℃ and the fluid pressure in the shell side is not high. In general, when the shell side pressure exceeds 0.6MPa, due to the thickness of compensation ring, it is difficult to expand and expand, and the effect of temperature difference compensation is lost, other structures should be considered.
2).Floating head type:
One tube plate of the heat exchanger is connected with the shell by flange, and the other tube plate is not connected with the shell, so that the tube can expand freely when heated or cooled. However, a top cover is connected to this tube plate, which is called "floating head", so this kind of heat exchanger is called floating head heat exchanger. The utility model has the advantages that: the tube bundle can be pulled out for cleaning; the expansion of the tube bundle does not change the restriction of the shell, so when the temperature difference between the two kinds of heat exchanger media is large, the temperature difference stress will not be generated due to the difference of the thermal expansion between the tube bundle and the shell. Its disadvantages are complex structure and high cost.
3).U pipe type:
U-tube heat exchanger, each tube is bent into U-shape, both ends are fixed on the same tube plate, each tube can be freely retracted, so as to solve the problem of heat compensation. The tube side is at least two, the tube bundle can be drawn out for cleaning, and the tube can expand freely. Its disadvantage is that it is difficult to clean the inner wall of the pipe, to replace the pipe, and to arrange fewer pipes on the pipe plate. The utility model has the advantages of simple structure, light weight and suitable for high temperature and high pressure conditions.
