Patent GB-443372-A (GB)
Title: Improvements in coal stokers
IPC: F23K3/14
Filed: 1934-08-23
Abstract: 443,372. Screw conveyers. BROOKS, H. M., 120, Broadway, New York, GARDINER, W. T., 60, State Street, Boston, and HAWES, R. K., 57, North Main Street, Fall River, both in Massachusetts, both in U.S.A.-(Assignees of Schweickart, W. M. ; Ramsey, New Jersey, U.S.A.) Aug. 23, 1934, No. 24318. Convention date, June 26. [Class 78 (i)] [See also Group XII] A stoker installation for domestic furnaces burning coarse coal comprises a coal bin, conveyer means comprising a bin conveyer to convey coal from a bin to a point intermediate the bin and the furnace and a furnace conveyer to convey the coal from the intermediate point, and a blower, driving motor and speed reducing mechanism located at or near the intermediate point of the conveyer means. The bin conveyer, Figs. 1 and 3, comprises a conduit 11 with a screw 13 and the furnace conveyer a conduit 10 with a screw 12 which feeds the coal upwardly into a firepot 4. The two conduits are connected by an elbow member 14 so shaped as to allow the ends of the screws to be exposed for connection to their common driving means. An extension 18 on the screw 12 is hollowed out to receive the end 20 of the screw 13, and a driving sprocket 17 is pinned to both members 18 and 20. Collars having threads 23 and 24 are provided on the screws to prevent coal entering the bearings 19 formed on the elbow member. The member 14 forms a base supporting the driving motor 26, speed reducing gearing 27 and the blower 31 which is connected by a conduit 32 to an air chamber surrounding the firepot. In order to prevent a back flow of air from the firepot, through the conveyer to the bin, part of the thread is omitted from the conveyer screw 12 so as to form a coal plug at 40, the conduits 10 and 32 are connected together by a channel 42 on the furnace side of the plug, and the interior of the conveyer on the bin side of the plug is connected to the outside of the building or, as shown, the elbow 14 is provided with a port 36 leading into the blower intake conduit 37. At the end projecting into the coal bin 1, the screw 13 is made of a lower capacity as by making the thread of smaller pitch or increasing either the thickness of the threads or the diameter of the shaft portion. In a modified form, Fig. 6, which is adapted to take coal from one direction and feed it to another, the bin conveyer 68 is provided with an extension 68<a> connected by a ball-and-socket joint to the top of a base member 64 on which the driving gear and blower are mounted. The bin conveyer screw 69 is rotated by a pawl-and-ratchet mechanism 71 driven by a link 72 from the speed reducing gearing 66. In this form the apparatus is also provided with an ash conveyer running parallel with the furnace conveyer and leading to an elevator by which the ash is deposited into an ash bin. In a further modification, the adjacent ends of the two conveyer screws are arranged side by side within a connecting base member, the bin conveyer being at a slightly higher level, and the ends of the screws are exposed at opposite sides of the base member for gearing to the driving means.