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How to overcome Thermal Expansion in Heat Exchangers?

So many times industries come across problems associated with thermal expansion in Heat Exchanger, and they have to trade off between four aspects of Heat Exchanger Design..

 1. Allowance for Thermal Expansion

 2. Efficient Heat transfer

 3. Ease of Cleaning

 4. Mechanical Robustness 
As shown in the figure how floating head exchangers are work..
The tube side flow enters from the bottom of the tube head.  Generally we take cold fluid on Tube side and Hot fluid on Shell side. 

 Inside the exchanger we have pass partition plate which forces the total  flow only through bottom half of the tubes. 

 Now if you have noticed that one of the end of heat exhcanger is open. so the question is Why one of the end must be kept open to float?

 so the reason is Thermal expansion, more preciously the differential rate of thermal expansion between tube and shell.

 As higher the temp, and heat transfer takes place between shell and tube side fluid there must be chances for Thermal Expansion. so to avoid thermal expansion we have to place one of the end free so floating head heat exchangers are worked well in these conditions where there is grater chances of thermal expansion.
other way to avoid thermal expansion problem is individual U bands for each tubes, and that acts like mini floating head for each tube. 
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Comments

  1. Ajay16 October 2017 at 07:33

    Good work done..
    Keep sharing this things..

    ReplyDelete

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