GB870472A - Improvements in stokers - Google Patents

Abstract

870,472. Scraper conveyers; hoppers for feeding fuel to furnaces. BABCOCK & WILCOX Ltd. Aug. 20, 1959 [Aug. 22, 1958], No. 27033/58. Class 78 (1). In a spreader stoker for a furnace the fuel is fed from a hopper 56 on to a conveyer comprising a pair of endless chains between which there are secured transverse members 10 which drag the fuel along a platform 34 from the end of which it falls to a plate 40, the return run of the transverse members then propelling it along the plate 40 over the forward edge of which the fuel falls on to a bladed rotary projector 68 for projection into the furnace. A steady discharge of fuel over the edge of plate 40 is ensured by constructing the transverse members 10, Fig. 2, of either cranked form, as shown, or of inclined or V-form. The position of the forward edge of plate 40 is adjustable by screw-and-nut mechanism 50 which can be operated to slide the plate 40 longitudinally over a nest plate 48. A grating comprising a plurality of vertically arranged side-by-side plates 80 extends between the forward edge of plate 40 and the projector to allow air to be blown into the furnace. The hopper 56 has a rotary valve 58 and a plate 65 is pivoted at 66 on its rear wall so that its lower end can be adjusted by links 67 to vary the size of the discharge opening. An adjustable trimming plate 62 is also provided. The conveyer and the projector are driven through separate variable-speed mechanisms from a motor 96. These mechanisms comprise pairs of driving bands 98, 100 and 109, 112 passing over respective common pulleys 102, 110 which are of reeves type and are adjustable through respective levers 107, 118 to vary the transmission ratios between the motor and the projector or conveyer respectively.