GB191209555A - Improvements in Furnace Grates. - Google Patents

Abstract

9555. Fletcher, J. E. April 23. Fire-bars and grates; fire - bridges.-A grate comprises a series of rotating or oscillating hollow perforated bars with intermediate stationary or rocking bars and means for injecting steam into the open ends of the hollow bars for forcing air through them. The bars may be arranged in an horizontal plane, as shown in Figs. 1 and 2, or in an inclined plane as shown in Fig. 3. Each fire-bar consists of a perforated tube 3 closed at the back by a plug 4 constituting a journal for the bar and engaging with a recess in the bridge casting 6. The front end of the tube engages with a hollow journal 7 into which a steam nozzle 11 delivers. A number of cast metal rings 14 are fitted over the tube 3 and are provided with radial recesses which form tuyere - shaped openings for delivering air into the fuel and into the closed ash-pit. The air that is delivered to the ash-pit passes up through the bars as indicated by the arrows shown in Fig. 2. The stationary or rocking bars are shown at 2, Fig. 2, and, in addition, side stationary bars 23 mounted on perforated air-supply tubes 18 are arranged at the side of the grate. The tubes 3 may be carried beyond the bridge so that air may be delivered to the furnace gases; or the air may pass from the tubes into the hollow, bridge instead of passing direct from the ash-pit to the holes 22 in the bridge-plate 19. In the inclined grate shown in Fig. 3, the intermediate stationary or rocking bars are omitted and the rotary bars are mounted in a closed casing 40 having a door 41 opposite which fixed bars 42 are arranged. The air escapes from the bars and takes the directions indicated by the arrows. In each modification, ratchet gearing, as shown in Fig. 2, or other well-known means are provided for rotating or rocking the bars.