RECUPERATEUR METALLIQUE

摘要

1278548 Apparatus for recovering heat from waste gases W SCHNEEWIND 31 July 1970 [21 July 1970] 37147/70 Heading F4S A flue gas duct made of fire-resistant brick or other non-metallic refractory material is encircled by a metal tube coil in which fluid e.g. air is heated. As shown, the gas duct 2 has a wall reducing in thickness in stages in the direction of gas flow and the tube coil 3 is spaced from the duct wall so that heat transfer is mainly by radiation from said wall. The tube coil may have a tube cross-section with external fins such as shown in Fig. 4. A further tube coil or an extension of the coil 3 may be disposed in the hot gas stream, beyond the wall 2 and may include a conically coiled portion (9, Fig. 2) wherein the tube cross-section is of streamline form (Fig. 5). Either the same or different fluids may be heated in the various tube coils. In a further arrangement (Fig. 6) the flue gas stream may be diverted beyond the duct wall 2 by a transverse wall member (13) so as to flow downwardly over the outer surface of the coil 3 in a passage (12) defined by an outer shell (11).