Underfeed Stoker (Patent No: 393442)

Inventor: Hamilton, William J.

Location: Edmonton

Comments: patented and manufactured by the Ottewell family; W.G. Ottewell homesteaded Edmonton 1882; operated coal mine; developed way to burn coal more efficiently; see extant example H71.8.2 in PMA collection; brochure

Description: WHAT I CLAIM IS:-

1. Fuel burning apparatus comprising a stationary circular grate having an inverted conical central portion and a slightly conical flange projecting outwardly from the top of the central portion and integral therewith, a plurality of slots being provided in the grate adjacent the top thereof, an air chamber surrounding said grate, means for guiding fuel upwardly into said grate, an ash eliminator ring rotatably mounted adjacent the top of the outer margin of said grate, means for feeing fuel into said felt guiding means, gearing connecting said fuel feeding means and said ring to cause rotation of the ring with respect to said burner, and means for admitting air under pressure to said air chamber.
2. Fuel burning apparatus as claimed in Claim 1, wherein said slots are disposed in vertical, radial planes and extend from points adjacent the top of the central portion to points adjacent the periphery of the flange of the grate.
3. Fuel burning apparatus as claimed in Claim 1, wherein said air chamber is formed between said grate and a member having a centrally apertured lower portion on which the central part of the grate rests, and a vertical outer wall engaging at its upper end the periphery of the flange on the grate.
4. Fuel burning apparatus as claim in Claim 1, wherein said air chamber is formed between said grate and a member having a centrally apertured lower portion on which the central part of the grate rests, and a vertical outer wall engaging at its upper end the periphery of the flange on the grate, and wherein the ash eliminator ring is rotatably mounted on and extends outwardly from the top part of said vertical wall.
5. Fuel burning apparatus as claimed in Claim 1, wherein ridges or projections are formed on the top surface of said ash eliminator ring.
6. Fuel burning apparatus as claimed in Claim 1, wherein said fuel guiding means is in the form of an elbow having a horizontally disposed fuel inlet and a vertically disposed fuel outlet arranged in communication with the interior of said circular grate, and wherein a fuel feeding screw conveyor projects into the inlet of said elbow and the shaft of said conveyor projects through a bearing in said elbow, a gear being mounted on the outer end of said shaft and meshing with teeth on an ash eliminator ring rotatably mounted adjacent the top of the grate.
7. Fuel burning apparatus as claims in Claim 1, comprising, also a fuel supply hopper, a conduit connecting said hopper to the fuel guiding means, a screw conveyor extending through said hopper and said conduit, a fan, a pipe connecting said fan to the air chamber, a prime means for driving said fan and said screw conveyor and means interposed between the prime mover and the conveyor for converting the high speed continuous rotation of the prime mover into a relatively low speed intermittent rotation of the conveyor.
8. Fuel burning apparatus comprising an elbow adapted to guide fuel upwardly, a stationary fire pot having an annular air chamber arranged on and communicating with said elbow, said fire pot having slots at the top thereof, an ash eliminator ring mounted on the top of said fire pot and at the outer margin thereof, means for feeding fuel into said elbow, gearing between said fuel feeding means and said ring, and means for intermittently rotating said feeding means and ring.