Patent GB-784745-A (GB)
IPC: C10J3/08
Abstract: 784,745. Rotary furnaces. POWER JETS (RESEARCH & DEVELOPMENT), Ltd. Feb. 11, 1955 [Feb. 25, 1954], No. 5607/54. Classes 51 (1) and 51 (2). The furnace shown comprises a vertical cylindrical body 1 with upper rim and flange 1a, 1b, and lower conical portion 1c terminating in a cylindrical skirt 17 mounted for rotation within a stationary cylindrical casing 2. The latter comprises an annular-shaped bottom plate 2b, an upwardly extending flange 2e and a conical portion 2a which is connected to a cylindrical skirt 18. Both skirts 17, 18 are arranged to dip into an ash disposal bath 19 the latter being mounted on a structure 20 which also supports, through vertical brackets 21, an electric motor 11 and the casing 2. The casing is covered by annularly shaped covers 3 and 4 the latter supporting an outlet tube 16 which depends into the body 1 and supports pulverized fuel injecting tubes 23, air swirl vanes 22 and an ignition tube 24. Air for combustion is introduced tangentially through a port 4b into the space between the tube 16 and the body flange 1b the fuel tubes being arranged to give a similar tangential flow. Cooling air is introduced into the casing via tube 3a and after passing through the space between body and casing is discharged through a port 2c. The body 1 is supported for rotation by brackets 5 resting, through a ring 6, bearings 7 and race 8, on an annular plate 9 mounted on brackets 10 in casing 2. The motor 11 through coupling 12, shaft 13, and pinion 15 effects rotation of the body 1 through a toothed ring 6a which is fastened around the body 1 and secured thereto through brackets 5. The lining S of molten and solidified fused slag takes the form shown in Fig. 1, surplus slag from the combustion process falling into the water bath 19 from whence it is removed. In a modified furnace the surplus slag is sprayed over the upper rim 1a by centrifugal action being collected on the top of the casing 2. The bottom of the body 1 may then be closed a slag lining forming thereon. In a further construction the body 1 is open at both ends air and fuel being introduced through inlets in a stationary bottom plate around which the lower end of the body rotates. Gases discharge through the upper end of the body and slag, surplus to the lining, may either fall through the bottom or be centrifugally sprayed over the top. Alternatively the air and fuel inlets may be at the top, the gases being discharged at the bottom. This latter construction may be modified such that body 1 is horizontal and rotates about a horizontal axis. In any of the above constructions the motor and pinion 11, 15 may be omitted, rotation being effected by the action of the incoming air-or the outgoing gason vanes &c. attached to the body. When fuel is used which does not produce slag the lining is formed by asn or refractory pebbles which is introduced into the body 1 where they will be fused by the heat. Alternatively the body may be lined with cement or other heat-resistant material which fuses at the combustion temperature. The invention may be applied to a high-temperature reaction process wherein a chemical process has one product at least which is heat insulating and molten, e.g. calcium carbide. The slag layer may be initially formed by pouring molten material into the combustion chamber or by lining it with cement or other heat-resistant material which is attacked and subsequently replaced by the molten slag formed during the operation of the furnace.