GB465854A - Improvements relating to furnaces - Google Patents

Abstract

465,854. Boiler &c. furnaces. STREICHENBERGER SOC. ANON. July 6, 1936, No. 18767. Convention date, July 6, 1935. [Class 51 (i)] A furnace for finely divided solid fuel comprises a rotary grate 4 having a centre conical part and an outer inverted trunco-conical part, a fuel hopper 1, a gravity feed tube 3, a plurality of fixed clinker bars 22 having their extremities located so as to stir the fuel bed 21 at different radial positions and fixed ash discharge baffles 42 co-operating with the outer portion of the grate. The furnace is intended to operate with a comparatively thin bed of fuel. The grate, of which the middle part 5 is formed by annular firebars 8 while the edge portion 6 is imperforate, is rotated by a motor 41 which also drives an air supply fan 13. Primary air is fed to a chamber 9 beneath the grate and secondary air through ducts 14 to a preheating chamber 17, formed between the conical bottom of the hopper 1 and a ribbed wall 18 substantially parallel thereto. The preheated air enters the combustion chamber through an annular outlet 20 around the feed tube. Air is also supplied through a pipe 32 to the top of the fuel hopper to prevent the emission of fumes. The clinker. bars 22 are formed with passages 23 and 24 and may be air cooled, in which case the heated air is discharged through outlets 25 as secondary air or, alternatively where the furnace serves to heat water, the bars may be water cooled and connected into the circulation system. The ash discharging baffles 42 feed the ash from the edge of the grate into an ashpit comprising two removable parts 50 of arcuate form. The outlet flue 28 of the furnace may be connected to a boiler.