GB164914A - An improved method and apparatus for burning solid fuels - Google Patents

Abstract

164,914. Martin, J. April 14, 1920. Grates; refuse fuel, furnaces for burning; fuel, feeding.-Solid fuels, particularly those not readily ignitible, or which are mixed with or produce much slag, such as coke with residues from the coking process, or garbage, are burnt in a furnace in which the fuel is continuously separated on an ignition grate within the heating range of the main grate, the finer particles falling through on to the latter whilst the coarser particles are retained longer on the ignition grate before falling in an ignited state on to the main grate, which is of step form and has mechanical means for breaking up the fuel. In the furnace shown, fuel is fed from a hopper 1, e.g. by a feed-screw 3, Fig. 4, to the ignition grate 4, the bars 5 of which project over the main grate and are longitudinally adjustable so that the projection may be varied, by which means the coarse partides may be retained for a greater or less time on the ignition grate. The bars are rocked by a shaking device such as the eccentric 7. A second charging device 8 may supply solid or liquid fuel to the main fuel. The main grate consists of U-shaped members forming hollow and perforated steps 9 with hollow side portions 10, through which air is supplied from pipes 12, the supply to individual steps being controlled by valves 13, which may be connected for operation in groups. Between the steps are pusher grates 15, 16, which are alternately connected to bars 17, 18 by which they are given reciprocating motions over the steps, adjacent grates thus moving in opposite directions. The slag passes out beneath a curtain 24 forming an air-seal and consisting of a number of hanging plates or doors 25, Fig. 5, arranged side by side, each having side wings 26 and a plate 30 hinged at its bottom. The slag passes into a collector 22 and pre-heats air for combustion which is drawn through the collector by a fan 33. The slag may be automatically discharged from the collector 22 in accordance either with the quantity of slag or its temperature. Part of the air may also pass through a heater 35 and be supplied by a pipe 36 to beneath the ignition grate 4.