Applications of floating-head heat exchangers

Floating-head heat exchangers can withstand high pressures on both the inside and outside of their tubes, making them suitable for use in high-temperature and high-pressure environments. One of the tube sheets in such heat exchangers can expand and contract freely, which is what is referred to as a “floating head”. It is suitable for situations where there is a large temperature difference between the tube wall and the shell wall, and the tube bundle area needs to be cleaned frequently. However, its structure is complex, and the cost of processing and manufacturing it is high.

Please refer to the topic 02-2-12 (What are the advantages and disadvantages of floating-head heat exchangers?) posted earlier by the original poster; it will likely provide a clear and comprehensive understanding of floating-head heat exchangers.

In a floating-head heat exchanger, the tube sheets at both ends are not connected to the shell; the end that is not connected in this way is called the floating head. When the tubes are heated, the tube bundle together with the floating head can expand and contract freely along the axial direction, completely eliminating thermal stress. Suitable for heat exchange with a large temperature difference between two media. In a floating-head heat exchanger, one end plate of the tubes is fixed between the shell and the tube box, while the other end plate can move freely within the shell; this feature can be observed on site. The thermal expansion of this heat exchanger shell and tube bundle is free, and the tube bundle can be removed to facilitate cleaning between and inside the tubes. Its disadvantages are a complex structure and high cost (20% higher than that of fixed tube sheets), as well as leaks at the floating head during operation, which are difficult to detect and repair. Floating-head heat exchangers are suitable for conditions where there is a large temperature difference between the shell and the tube bundle, or where the fluid in the shell side tends to form scale.

Floating-head heat exchanger: The tube sheets at both ends of the heat exchanger are not connected to the shell; the end that is not connected is called the floating head. When the tubes are heated, the tube bundle together with the floating head can expand and contract freely along the axial direction, completely eliminating thermal stress. Features: complex structure, high cost, easy to clean and maintain, completely eliminates thermal stress, and is widely used.

The thread posted by the original poster relates to the topic discussed on the 3rd floor: http://bbs.hcbbs.com/viewthread.php?tid=387673&highlight=%B8%A1%CD%B7%CA%BD%BB%BB%C8%C8%C6%F7. There is also a summary regarding floating-head heat exchangers in the Final Fantasy section, which can be referred to. http://bbs.hcbbs.com/viewthread.php?tid=380043&highlight=%B8%A1%CD%B7%CA%BD%BB%BB%C8%C8%C6%F7

Floating-head heat exchangers are complex to manufacture and expensive； :)

For floating-head heat exchangers, I agree with what was said on the third floor: they are used in situations where there is a large temperature difference between the tube walls and the shell, and the shell needs to be cleaned frequently

First question: The floating-head heat exchanger combines the features of the fixed-tube-sheet type and the U-tube type. 1. The tube bundle can float freely in the shell medium, reducing thermal stress, and is suitable for applications with large temperature differences. 2. There are more tube bundles in this arrangement compared to the U-tube layout; due to the influence of the bend radius, too many U-tubes cannot be used, resulting in a lower utilization rate of the tube sheet compared to the floating head design. 3. The tube bundle can be removed, allowing both the tube side and shell side to be cleaned, whereas in the fixed tube sheet design, the shell side cannot be cleaned. Therefore, it can be used in applications where both the tubes and shells are prone to scaling. 4. Due to the use of a floating head, there is an additional seal, and leaks at the floating head end cannot be detected during normal operation. Therefore, high requirements are placed on sealing, as well as on the quality of maintenance work. Therefore, it cannot be used in situations where the pressure and temperature in the pipeline are too high. 5. Easy to block the pipe. A leak in one of the U-tube heat exchange tubes is equivalent to two broken tubes. Therefore, I believe that floating-head heat exchangers are suitable for situations where there is a large temperature difference, both the tube side and shell side are prone to scaling, but the pressure and temperature on the tube side are not very high. Second question: Based on the above, I believe it is not suitable for use in high-pressure gas exchange applications.