Is it necessary to install an expansion joint on the heating element of an aqueous solution?
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The heaters designed by the Fourth Research Institute for Raw Materials processing generally do not have expansion joints in their housings, and it seemed there were no problems with that at the time. However, in recent years, as the production scale has continued to expand, the heat exchange area has also increased, leading to an increasing number of leaks at the welds between the heat exchange tubes and the tube sheet. Therefore, it was suggested to install expansion joints at the junction with the housing. Please have the sea enthusiasts discuss this: Can installing expansion joints solve the leakage problems mentioned earlier?
Installing expansion joints at the one-inch plus shell is at least a method that can be tried. Our factory has also had to shut down for repairs several times due to leaks at the welds between the heat exchange tubes and the tube sheet. :handshake
An expansion joint must be installed when any one of the following three conditions is not met. 1. The axial stresses in the shell and tube bundle of the heat exchanger must meet the strength requirements, that is, the axial stress in the shell σs ≤ 3sτφ, and the axial stress in the tube bundle σb ≤ 3bτφ. 2. The axial compressive stresses in the shell and tube bundle must satisfy stability conditions: the compressive stress in the shell |Nσs + Tσs| ≤ B, and the compressive stress in the tube bundle |Nσb + Tσb| ≤ … 3. The pulling force between the tube sheet and the heat exchange tubes, q, must not exceed the allowable pulling force (for expansion joints) or 3 (for welding). In simple terms, if the secondary stresses are not within acceptable limits, or if the pulling force between the tubes and the tube sheet is too high, expansion joints are required. The poster can download a software called SW6 for automatic calculation; if the tube sheet is found to be unsatisfactory, a warning will be given once the results are generated.
A 1-inch heater can be equipped with an expansion joint; our 1-inch column heater has a heat exchange area of 685㎡, and it performs well when an expansion joint is used.
Our factory has a production capacity of 130,000 tons. Initially, there were no expansion joints, and leaks occurred several times; after installing expansion joints, there have been no leaks since then.
If the temperature difference is greater than 60, the thermal expansion and contraction of the material should be taken into consideration