Several Causes of Shell and Tube Heat Exchanger Port Leakage

Shell and tube heat exchangers are currently the most widely used type of heat transfer equipment. Compared with several other inter-wall heat exchangers, the unit volume of equipment can provide a much larger heat transfer area, and the heat transfer effect is also better. Due to the compact structure of the equipment, the solid, and can choose a variety of materials to manufacture, it is more adaptable, especially in large devices, and high-temperature, high pressure is widely used.

Over the years, various failures in the heat exchanger, and tube leakage accounted for the largest proportion. Therefore, analyzing the causes of heat exchanger leaks to find countermeasures to minimize leakage is very important. Below we introduce several causes of tube port leakage.

Here is the content list:

• Excessive thermal stress

• Tube plate deformation

• Improper tube plugging process

Excessive thermal stress

Shell and tube heat exchanger in operation, due to the cold, hot fluid temperature differences, so that the shell and tube wall temperature differences between each other. This difference makes the shell and tube thermal expansion different, when the temperature difference between the two may twist and bend the tube, make the tube from the flower plate pulled loose, or even destroy the entire shell and tube heat exchanger. Heat exchanger in the process of starting and stopping the temperature rise rate, temperature drop rate exceeds the provisions, so that high plus the tube and tube plate are subject to greater thermal stress, so that the tube and tube plate connected to the weld or expansion joint damage occurs, causing port leakage.

Tube plate deformation

Mainly the processing deformation of the tube plate and the deformation generated during processing, the tube, and the tube plate are connected, the deformation of the tube plate will make the port of the tube leak. High plus the water side of the tube plate pressure is high, low temperature, the steam side is low pressure, high temperature, especially with built-in hydrophobic cooling section, the temperature difference is greater. If the shell and tube heat exchanger tube plate thickness is not enough, the tube plate will have a certain amount of deformation. The center of the tube plate will bulge toward the steam side where the pressure is low and the temperature is high. On the waterside, the tube plate undergoes a central depression. These changes can deform the tube plate resulting in tube port leakage or permanent deformation of the tube plate.

Improper tube plugging process

Generally, conical plugs are commonly used to weld the pipe plug. Hit into the conical plug with moderate force. The whacking force is too large, causing deformation of the tube hole, affecting the neighboring tubes and tube plate even, will cause damage, and making it appear new leaks. Welding processes, such as preheating, welding seam location, and size are not appropriate, and will cause damage to the neighboring tubes and tube plate connection. The use of other pipe plugging methods, such as pipe expansion plugging, explosion plugging, etc., such as improper processes, can also cause leakage in the neighboring orifice. Therefore, strict plugging procedures should be followed for the installation of shell and tube heat exchangers.

These are a few common causes of leaks in shell and tube heat exchanger tube ports. Only by knowing the cause of the problem can we better solve it. After reading this article, do you have a more in-depth understanding of shell and tube heat exchangers?