GB776932A - Improvements in or relating to combustion apparatus - Google Patents

Abstract

776,932. Cyclone furnaces; generating combustion, products under pressure. BABCOCK & WILCOX, Ltd. July 2, 1954 [July 2, 1953], No. 19459/54. Addition to 763,014. Class 51 (1). Combustion apparatus for fluent fuel comprises primary combustion chambers 1, 2, Fig. 2, each supplied with a stream of fuel, e.g. pulverized fuel entrained in a stream of air, and a stream of combustion air and means, upstream of the point at which the air and fuel streams mix, to effect pulsations in the streams, whereby resonance may be produced in the chambers which. discharge into a cyclone combustion chamber 4 associated with the combustion chamber of a water-tube boiler of the kind described in Specification 598,142. The pulsations produced in the chambers 1 and 2 are 180 degrees out of phase with each other so that the gases entering the cyclone chamber 4 are substantially free from vibration. In operation, combustion air under pressure passes from a duct 17 into an annular duct 16 having a nozzle ring 18 into which opens a ring 19 communicating with a distributer ring 20 to which air-borne fuel is fed through a duct 21. The frequency at which resonance occurs in the chamber 1 is controlled by adjustment of a piston 23 in an extension of the chamber. The combustion chambers are cooled by water tubes 25 embedded in refractory material. In a modification, the primary combustion chambers 1, 2, Fig. 3, discharge tangentially and independently into a vertical cyclone chamber 34 from which the combustion products pass to a radiation chamber 36, while molten slag discharges through an aperture 37. In this modification, the gases entering the chamber 34 from the chambers 1, 2 whirl in the same direction, but in another arrangement, the directions of whirl are opposite. The means for supplying the pulsating streams of fuel to the primary combustion chambers comprise a hopper 50, Fig. 7, containing pulverized fuel which is fed by a screw 51 to a mixing valve 52 supplied with entraining air by a fan 53 connected to a heater 55 heated by the waste gases from the watertube boiler with which the apparatus is associated, and from which air passes to the mixing valve. From the valve, the fuel stream flows through a duct 57 and branch ducts to the distributer rings 20 of the chambers 1, 2. The out-of-phase pulsations are impressed on the fuel streams by dampers 60, 61 in the branch ducts rotated through a coupling from a synchronous A.C. motor. The combustion air streams are supplied to the annular ducts 16 of the chambers 1, 2 by a fan 65 which supplies air to a heater 67 from which the air flows through branch ducts having rotary pulsationproducing dampers 70, 71. Specification 598,142 is referred to.