Fixed tube plate heat exchanger

The fixed tube plate heat exchanger mainly consists of components such as the shell, tube plate, tube bundle, and head cover. The structural characteristics of a fixed tube plate heat exchanger are that two tube plates are welded to both ends of the shell, and the tube bundle is fixed to the tube plate at both ends by welding or expansion. The inlet and outlet tubes of the shell side are directly welded to the shell, and the outer circumference of the tube plate and the head flange are fastened with bolts. The inlet and outlet tubes of the tube side are directly welded to the head. Several baffle plates are set inside the tube bundle according to the length of the heat exchange tubes. The tube side of a fixed tube plate heat exchanger can be divided into any number of stages using baffles.

Advantages of Fixed Tube Plate Heat Exchanger

1. The structure is simple and compact, with a larger heat transfer area under the same heat exchanger diameter, and a heat transfer area that is 20% to 30% larger than that of a floating head heat exchanger;
2. Less use of forgings, with a cost reduction of over 20%
3. Fixed tube plate heat exchanger tubes for easy cleaning
4. The tube side can be divided into multiple stages, and the shell side can also be divided into two stages, with a wide range of specifications
5. The bypass leakage is small and there is no internal leakage.

Limitations of the application of fixed tube plate heat exchangers:

1. The shell side cannot be mechanically cleaned. It is best to use clean and non scaling materials for the shell side. Fixed tube plate heat exchangers should not be used for dirty or corrosive media
2. After corrosion of the pipe, it is scrapped along with the shell, and the lifespan of the shell components is determined by the lifespan of the pipe, which is relatively low
3. When the temperature difference between the shell and the heat exchange tube is large (greater than 50 ℃), the temperature difference stress (also known as thermal stress) generated is destructive.
   A compensation ring needs to be welded at an appropriate position on the shell. When the shell and tube bundle experience different thermal expansions, the compensation ring undergoes slow elastic deformation to compensate for the thermal expansion caused by temperature difference stress.
   Expansion joints can also be installed, but due to the strength limitations of the expansion joints, the shell side of the fixed tube plate heat exchanger cannot be too high.