Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Calculation of tube stresses when lifting a heat exchanger with a thin bellows
(OP)
Does anyone know of a method to check the stress in the tubes of a heat exchanger when lifting the unit from horizontal to vertical when there is a thin bellows expansion joint in the shell? I know the tubes will take the load but is there a method to determine the load on the tubes?
Thanks
Tomtation
Thanks
Tomtation





RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Regards,
Mike
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Thanks
Tomtation
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Someone smarter than I pointed out that my proposed method is invalid because the tubes do not act in unison to resist the shear flow due to the bending moment. So I'm back to square one.
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Regards,
Mike
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Thanks for your comments.
Regards
Tom
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
RE: Calculation of tube stresses when lifting a heat exchanger with a thin bellows
Sure, they are probably a little oversized. But those things are NOT intended to prevent the movement of the entire heat exchanger and both ends and both tubesheets (or one end and one tubesheet and all of the tubes in the bundle.)
the tube bundle, as pointed out above, will not act as a single "reinforced mass of tubes" but as a very large of loosely sliding individual tubes each contacting the loose hole in the tubesheet and spreader plates one at a time. So, the first tube hits the tube sheet hole, picks up all the weight stress (because it is the first to touch and begin resisting the bending force) and so deforms (kinks. The second touches, deforms, and kinks. The third, the fourth, etc. Eventually of course, enough tubes have kinked so the 331st is not kinked.