Heater for low pressure loss air flow - has two annular passages each containing coupled heat exchange surfaces, one passage having heated air other air to be heated

摘要

The heater for a flow of air having a low pressure loss has a cylindrical shell (11) containing a xoaxial sleeve (13) connected to one end of the shell by a bellows (28, 31) outside the shell. The sleeve increases in diameter near a first end of the sheel to a cylindrical portion near the shell. A convection input passage is formed between the shell and the cylindrical portion. A heat exchange surface (43) extends from the sleeve into the input passage. The second ends of the shell and sleeve are separated to form a radiant zone (15) containing a hot gas generator (37) which causes hot gas to flow from the radiant zone through the convection passage to an outlet. The cylindrical portion of the sleeve contains a cylindrical baffle (14) which forms a convection output passage between the baffle and sleeve. Air to be heated is supplied into the sleeve to pass through the output passage.