Granular fuel burning with a hollow hood and timed ash discharge

摘要

An enclosed granular fuel burning boiler has a brazier 20 with an apertured grate-like base 21 movable by a servo-motor (15, fig 1) after a preset elapsed time from an operative position retaining fuel in the brazier 20 to a discharge position where ash falls through a hole (26, fig 4) in the base 21, with fragmentation occurring as crushing teeth (38, fig 5) on the base 21 move across the brazier 20, and a hollow hood 80 over the brazier 20 through which air is delivered. The air cools the hood 80. A spring (41, fig 5) transferring force from the servo-motor helps prevent damage. The tooth and a wall it engages can be inclined (fig 8). The fuel may be wood pellets.