Shell and tube heat exchanger - for use in cooling uranium hexafluoride in gaseous diffusion isotope enrichment

摘要

In the mfr. of straight tube heat exchangers for the cooling of UF6 in gaseous diffusion plants for the isotopic enrichment of U-238 with U-235, (a) the tube bundle is fabricated by assembling the tubes on two end tube plates in a non-polluted environment while the shell is manufactured in an ordinary environment (b) the interior of the shell is protected and (c) each tube plate is joined by simple welding to the appropriate part of the shell. More especially a special flexible element is inserted in each joint between the tube plate and the shell to take up unbalanced stresses due to unequal thermal expansion etc. A better thermal efficiency can be achieved due to the higher permissible cooling water velocities and therefore the heat exchange surface can be reduced.