Patent GB-189907418-A (GB)
Title: Improvements in or relating to Boiler and other Furnaces.
Inventor: BENNIS EDWARD
Filed: 1899-04-08
Granted: 1900-04-07
Abstract: 7418. Bennis, E. April 8. Mechanical stoking; firebars and grates.-Relates to steam-boiler and other furnaces. Fig. 4 shows in sectional elevation, and Fig. 2 shows in sectional plan, the essential parts of the fuel-feeding apparatus. Fuel from a hopper falls into a box B, with an inclined floor B<1> on which a feeder C reciprocates. Its movement is checked by the flap H, which is pressed against the stop B<2> by a spring or weight. Falling over the end of the plate B', the fuel is delivered into the furnace by a " striker" J pivoted at J<3>. The "striker" is V-shaped in plan, so as to scatter the fuel. The feeder C and the striker J are operated respectively (the former entirely, and the latter as regards its backward movement), by cams E and K on the shaft Y, the cam E being constructed to produce a variable motion in the direction of its axis, which is transmitted through the bell-crank lever D, and the cam K being a multiple wiper or tappet cam acting directly on the external arm of the striker. The projections of the cam K and the grooves of the cam E are correspondingly formed to give a recurrent series of strokes of varying extent, so that the fuel is delivered evenly to all parts of the furnace. The stroke of the cam E is varied by adjusting its outer portion by means of the lever F and screw G. The striker is impelled forward by a spring in a cylinder L, which also contains air to act as a cushion. The grate consists of a series of large reciprocating hollow bars or troughs with tubular trumpet-mouthed ends into which jets of steam are delivered to induce a blast of air. Fig. 6 shows in elevation the front end of one of such bars to be placed at the side of the grate, and Fig. 7 a similar view, partly in section, of one of the intermediate bars. Fig. 8 shows a cross-section through the trough-shaped portion of a bar. Covering the trough-shaped portions are a series of small firebars 0 with inclined ribs O<1> on each side ; or grids may be used. According to the Provisional Specification, bars or grids of zig-zag form leaving a serpentine space between them may be used, or the tops of the trough may be covered with longitudinal, oblique, or transverse gratings in place of the bars. Holes N<2> for the escape of ashes are formed in the bottom of the trough, such holes being only momentarily opened during the reciprocation of the trough as they pass corresponding holes in a fixed plate P with inclined upper surfaces. The troughs rest on rollers T supported on perforated bearers U ; they are reciprocated by cams on a shaft V, being brought forward one by one and pushed back all together. The cams Q<2>, Q<3>, Q<4>, Fig. 7, for bringing the intermediate troughs forward are set at different angles so as to act successively; but the troughs on each side are brought forward together by cams Q', Fig. 6, and pushed back together by cams Q acting on horns N<6>. Above the whole series runs a transverse bar S, which is held between lugs on the side troughs so as to move with them. During the inward motion of the side troughs, this bar acts on lugs N<3> on the intermediate troughs, and pushes them in together. W is a dead-plate over the tubular ends of the troughs. Superheated steam is delivered through a pipe X with nozzles opposite the mouths of the troughs.