Fixed tube plate heat exchanger
The fixed tube plate heat exchanger is a type of shell and tube heat exchanger. The tube sheets at both ends of the fixed tube plate heat exchanger are welded to the casing, and are mainly composed of a casing, a tube sheet, a tube bundle, a top cover (head) and the like.
The advantages of fixed tube plate heat exchangers are:
Within the same housing diameter, the number of tubes is the largest and the bypass is the least;
Each heat exchange tube can be replaced and the inside of the tube can be easily cleaned.
The disadvantages of fixed tube plate heat exchangers are:
The shell process cannot be mechanically cleaned;
When the temperature difference between the heat exchange tube and the casing is large (greater than 50 ° C), temperature difference stress is generated. The solution is to provide an expansion joint on the casing, so that the shell side pressure is not limited by the strength of the expansion joint;
It is only suitable for workplaces where the fluid is clean and not easy to scale, and the temperature difference between the two fluids is small or the temperature difference is large but the shell pressure is not high.
Floating head heat exchanger
The floating head heat exchanger is a type of shell-and-tube heat exchanger. It has a tube sheet at one end that is not connected to the outer casing and can float freely in the axial direction, also called a floating head. The floating head is composed of a floating tube plate, a hook ring and a floating end cover, and is detachably connected, and the tube bundle can be taken out from the casing.
The advantages of a floating head heat exchanger are:
If there is a temperature difference between the heat exchange tube and the casing, that is, when the casing or the heat exchange tube is expanded, no temperature difference stress is generated;
The tube bundle can be withdrawn from the housing to facilitate cleaning between the tubes and the tubes.
The disadvantages of floating head heat exchangers are:
The structure is more complicated, the amount of materials is large, and the cost is high;
If the seal between the floating head cover and the floating tube sheet is not tight, an internal leak will occur, causing mixing of the two media.