Abstract: An individual key, a stoker incorporating a plurality of the keys, or a furnace incorporating the stoker which includes a key apparatus having a mounting surface dimensioned and configured for sliding engagement with an associated arm, the mounting surface is disposed on the bottom of the key, an upper face receives associated fuel to be burned, a first side having a first contour, and a second side having a second contour. The second contour is different than the first contour. In some forms of the invention the first contour and the second contour are dimensioned and configured for meshing engagement whereby a first side of a first key will mesh with a second side of a second key when a plurality of the identical keys are arrayed in side abutting relationship. The first contour may includes a first lip and the second contour may include a second lip and the the first lip may be disposed at a different elevation than the second lip.

Abstract: A refuse fuel burning boiler system incorporating a unique tuyere construction wherein the tuyere plates associated with the conveyor-like stoker grate are hingedly mounted to permit the passage of any hard deposits of metal or glass contaminates which form upon the grate during incineration of the refuse fuel. The tuyere plates and support structure are designed for relatively easy retrofit into an existing conventionally designed refuse burning boiler or be incorporated into a new boiler construction. Vertical pivoting of the tuyere plates is limited by hold-down members installed between adjacent plates. These members further function to fix the lateral position of each plate and form the top of an enclosure over the recess in the support wall in which the plates are pivotally mounted.

Abstract: In a submerged scraper conveyor (10), an automatic voltage control system controls the speed of variable speed drive (32), in turn the speed of follower sprocket (22) and in turn the speed of drag chain (16) as a function of the torque on the headshaft (21). The tension on endless roller chain (36) is monitored by load cell (40) as indicative of the torque on the headshaft (21) and a standard process control signal is generated therefrom. The speed of variable speed drive (32) is varied as a function of the measured torque between a lower speed drive limit and an upper speed drive limit.