Recuperator with two concentric ceramic pipes - with annular passage between them for economical heat recovery in heating furnace combustion air

摘要

Recuperator has two concentric pipes. The ceramic outer pipe has a closed end, the inner pipe, may be ceramic or metallic and protrudes into the outer pipe and opens into it a short distance from its inner (closed) end. Fluid (e.g., air) to be heated goes first through the inner pipe and then turns to go in the opposite direction through the annular space between the two pipes, with the outer pipe immersed in the heat-emitting medium. The outer pipe is made of SiSiC or SSiC material, and an expression is given for the vol. flow, of the fluid being heated, through such a recuperator of specified dimensions under specified fluid-temp. conditions.