GB630549A - Fluid heating - Google Patents

Abstract

630,549. Furnaces. BABCOCK & WILCOX CO. June 7, 1945, No. 14379. Convention date, July 4, 1944. [Class 51 (ii)] [Also in Group XIII] In a " pebble " heater unit (see Group XIII) in which gaseous fluid is heated e.g. to temperatures above 1650‹ C., by a fluent mass of refractory solid material which moves through superposed chambers 12, 13 in which it is heated by combustion gases and cooled by passing the fluid in contact with the fluent mass in the cooling zone, part of the heated fluid takes part in combustion with a further gaseous fluid, the combustion products passing through and heating the solid material in the heating zone, and the remainder of the heated fluid is taken off for external use. If air is heated in the lower chamber 13, part of it can be passed through ducts 69, 82, Fig. 6 to a furnace needing a high-temperature oxidising atmosphere, e.g. a continuous tunnel kiln 80 for the glazefiring of ceramic ware at 985‹ C. The heated air passes at one end of the kiln into longitudinal side chambers 83 and through the perforated walls 84, and is withdrawn at the other end through ducts 85 by a fan 87 which returns it through a pipe 89 to the chamber 13, where it is re-heated. The combustion gas is preheated in the preheater 88. If fuel gas is heated in the heater of Fig. 6, part of it may be used in a furnace needing a high-temperature reducing atmosphere, e.g. a furnace, Fig. 8, used for the bright annealing of copper sheets 104. The hot gas enters this furnace at the bottom at one end through a pipe 97, and after flowing over the-stack of copper sheets passes out at the sides through passages 108 and outlets 98 back to the lower chamber 13 of the gas heater. The returning gas may preheat the air for combustion in the heater, and part of it may be bled off. The upper part 95 of this annealing furnace is removable for charging, and has a sand or liquid seal 96 with the fixed base 94. After charging and before supplying the hot gas, cold fuel gas is supplied t o the furnace to drive out air through a vent pipe 106. Specification 628,321, [Group XIII], is referred to. The Specification as open to inspection under Sect. 91 comprises also the use of all or part of the air or gas, heated in the lower chamber of a pebble heater, in a high-temperature industrial process, and passing the combustion gases resulting from its combustion with complementary gas or air, either in a process furnace or a combustion chamber to the upper chamber of the pebble heater to heat the fluent mass. For example, air heated in the pebble heater is supplied to a gaseous or liquid fuel burner mounted in a melting pot, from which the hot gases pass to an annular chamber surrounding an opening into the lower part of the upper chamber of the pebble heater. This subject-matter does not appear in the Specification as accepted.