Single tube pass floating head heat exchanger design help
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This post was last edited by kareale88 on 2019-7-2 23:04 Hello colleagues, I have come across a single-tube floating head heat exchanger in the past few days. Please tell me how to calculate the strength of points 1 and 2 in the picture (it is best to explain the basis for the calculation), and how to determine the structural size. This is the first time I encountered this kind of heat exchanger, and it has been bothering me for a few days. I hope you can give me some advice. Kneel down and thank you
The structural design must meet the requirements of craftsmanship, strength, safety, operability, and economy!
In Hiyou's structure, the expansion of the pipe side is achieved by the expansion joint at the head. The expansion is very limited. The end can be considered to be a packing-sealed structure, which can expand freely.
This structure is not good. It is better to make a stuffing box seal at the bottom to allow the tube to move freely. The expansion and contraction of your tubes are completely absorbed by the expansion joints. Don't know how to calculate it?
I would like to ask why this does not meet the craftsmanship, strength, safety, operability and economy you mentioned? There are a lot of equipment with this structure now. This is a piece of equipment designed by the Sixth Academy. However, I have never known how to calculate this structure, so I would like to ask you here. If you know about the equipment with this structure, please give me some meaningful reply. Thank you~! Don’t just reply “Does it make sense?” ”, I really think your reply makes no sense at all.
The internal pressure blind force of the bellows is much smaller than the pressure of the container, so you can just calculate it as a flat cover. On the other hand, you need to calculate the strength and stability of the bellows and both ends of the bellows. If the shell side pressure is greater than the tube side, you need to calculate it carefully.
This post was last edited by chen11376 on 2019-7-4 18:31. I personally believe that 1 can be calculated as a reverse flange, with the additional axial force of the expansion joint. 2 It can be calculated as a flat flange cover, and the axial force of the expansion joint is added. Personally, I think the sealing surface of this structure has a self-compression effect, making the sealing more reliable. Looking at the picture, I always feel that the cylinder 12 and the head are not coordinated. If I were asked to design it, the cylinder might be designed in sections, or connected by increasing the arc, or connected by cutting edges. The size of the opening is estimated to be determined based on the outer diameter of the flange, so the outer diameter of the flange should be small, and the opening should also be small. The shell has two sets of bolt connections, so it needs to be pre-assembled and welded, and it must be marked and disassembled during maintenance.
Thank you for your answer! Please tell me how to convert the axial force of the expansion joint into equivalent pressure. Also, the structure is outside the diameter of the bolt hole, not within the diameter of the bolt hole. How should this be considered?
For equivalent pressure, please refer to Section 9 of HGT 20582-2011. For stress analysis, please refer to the article Structural Design and Stress Analysis of the End of the Inlet Gas Preheater Barrel. If you can calculate it manually, you will have a better understanding of the standard.