Heat Exchanger Tube Maintenance and Replacement

Composition

Shell-and-tube heat exchangers are a traditional, most widely used heat exchange device. Due to its sturdy construction and the ability to be manufactured from a variety of materials, it is highly adaptable. Shell-and-tube  heat exchangers are widely used in various industries. They are often  used as oil coolers for equipment oil stations in cement production  enterprises, and are used as vehicle engine oil coolers. For  a long time, steel shell-and-tube heat exchangers have always dominated  the production and use of heat exchangers due to their strong  structure, high reliability, adaptability and wide selection of  materials. With the development of technologies  such as heat transfer enhancement, shell-and-tube heat exchangers are  also constantly improving in manufacturing technology and heat transfer  performance. However, due to the complexity of the  structure and the variety of operating conditions, part failure or  even total scrap of the heat exchanger often occurs.

shell-and-tube heat exchanger composition

Shell-and-tube heat exchanger works

The main components of  the shell-and-tube heat exchanger include: cylinder, head, heat exchanger tube bundle,  tube sheet, baffle, nozzle, flange, etc., under various working  conditions and medium environments, various forms may occur. Invalid. From  the structural analysis, the part that is prone to failure is the joint  between the components, such as the joint between the pipe and the tube  sheet; from the perspective of the force analysis, the surface of the  structure is discontinuous, especially at the sudden change of stress,  due to the existence of additional stress. And cause  failure, such as the weld of the cylinder and the tube sheet; from the  use condition analysis, the thermal stress or the additional stress  caused by the high temperature and high pressure, the working medium is  corrosive, and the fluid is frequently started and stopped to cause the  fluid induction of the heat exchange tube. Vibration, etc., will cause the cylinder, heat exchange tube and even the whole machine to fail.

Causes and preventive measures

1. heat exchanger tube corrosion and abrasion failure

Most of the failure of heat exchangers is caused by corrosion. The  most common corrosion sites are heat exchange tubes, which in turn are  tube sheets, heat exchanger heads, and small diameter nozzles.

The main reasons for tube bundle corrosion and abrasion failure are:

1 dirt corrosion;
2 fluid is corrosive;
3 The inner wall of the tube has foreign matter accumulated and local corrosion occurs;
4 crevice corrosion occurs at the pipe end.

Preventive measures include:

1 regularly clean the heat exchanger tube ;
2 reasonable selection of materials for heat exchanger tube ;
3 adding a corrosion inhibitor to the fluid;
4 setting a filter device, a buffer structure, etc. at the fluid inlet;