Overview of shell and tube heat exchangers

- Sep 18, 2019-


Shell-and-tube heat exchanger (also known as tube-and-tube heat exchanger), the shell-and-tube heat exchanger mainly consists of a shell, a tube bundle, a tube sheet and a head. The shell is mostly round and has a parallel tube bundle inside. Or a spiral tube, the ends of which are fixed to the tube sheet. Two kinds of fluids that exchange heat in a shell-and-tube heat exchanger, one flowing in the tube, the stroke is called the tube path; and the other is flowing outside the tube, and the stroke is called the shell side. The wall surface of the tube bundle is the heat transfer surface. The tube-and-tube heat exchanger tubes are of different models. The process is generally three models with diameters of 16mm, 20mm or 25mm. The wall thickness is generally 1mm, 1.5mm, 2mm and 2.5mm. The imported heat exchanger has a diameter of 8mm and a wall thickness of only 0.6mm. The heat exchange efficiency has been greatly improved, and it has been gradually promoted in the domestic market this year. The shell-and-tube heat exchanger and the spiral tube bundle design can increase the turbulence effect to a limit and increase the heat exchange efficiency. The asymmetrical design of the inner shell and tube layers can reach 4.6 times. This asymmetric design determines its wide application in the field of vapor-water heat transfer. The heat exchange efficiency can reach 14000w/m2.k, which greatly improves production efficiency and saves costs. At the same time, because the shell-and-tube heat exchangers are mostly metal structures, with the introduction of the new GMP in China, the stainless steel 316L is the main heat exchanger, which will become a must for the beverage, food, and pharmaceutical industries.


Shell and tube heat exchanger installation attention

 

1. The installation height of all kinds of valves and instruments should be easy to operate and observe.


2. The front end of the shell-and-tube heat exchanger should have space for pumping and unloading the tube bundle, that is, the distance between the head of the shell and the roof should not be less than the length of the heat exchanger, and the net width of the equipment operation and operation channel should not be less than 0.8m.


3. The vertical clearance of the upper part of the shell heat exchanger (generally referred to as the safety valve) to the low point of the building structure shall meet the requirements for installation and inspection, and shall not be less than 0.2m.


4. The heat exchanger shall be hydraulically tested at 1.5 times the working pressure. The steam portion shall not be lower than the steam supply pressure plus 0.3 MPa; the hot water portion shall not be lower than 0.4 MPa. Under the test pressure, the pressure shall not be maintained for 10 minutes. drop.


The shell-and-tube heat exchanger manufacturer Guangzhou has summarized the above, for the introduction of the shell-and-tube heat exchanger, including the tube, shell, model and application, the installation considerations of the shell-and-tube heat exchanger can not be ignored, pay attention to the installation attention. The matter is a good start for a fully rational use of the tube heat exchanger.