Abstract: An air inlet valve subassembly for use on a particle fuel burning furnace includes a manifold tube and a hollow spout mounted to an outer end of the manifold tube. The spout has an outer rim defining a valve opening and the manifold tube is adapted to be mounted at its inner end to the furnace to provide a passageway for communicating air from the valve opening into the furnace. A valve flap is mounted adjacent to the spout for pivotal movement toward and away from the spout between closed and open positions in which the manifold tube passageway is closed and opened to the communication of air. For sealing the valve opening, a generally planar, resiliently flexible disk with an annular ring of gasket material adhered thereon is provided. The disk, preferably made of stainless steel material, is removably mounted to the valve flap at the respective centers thereof with its outer side facing toward the flap and its inner side facing toward the spout rim.

Abstract: A particle fuel burning furnace has an upper combustion chamber holding a pile of particle fuel and burning the same from the bottom. The furnace includes a lower combustion chamber for afterburning combustible gases off by burning solid fuel in the upper chamber and replaceable refractory bricks containing a series of spaced vertically-extending passageways interconnecting the bottom of the upper chamber and the top of the lower chambers for communicating combustible gases from the upper to the lower chamber. An improved particle fuel diversion structure in the furnace includes an elongated fuel diverter block having a recessed dome-shaped cavity therein and open at a bottom side and spacer blocks disposing the diverter block in the upper chamber in spaced relationship above the bottom of the upper chamber and with its recessed cavity overlying the bricks containing the passageways. Furthermore, the bricks extend above the bottom of the upper chamber and into the recessed cavity of the diverter block.

Abstract: A particle fuel burning furnace has an upper combustion chamber for holding a pile of particle fuel and burning the same from the bottom thereof. The furnace also includes a lower combustion chamber for afterburning combustible gases given off by the burning of solid fuel in the upper chamber and a series of spaced apart vertically-extending passageways arranged in a row and interconnecting the upper and lower chambers for communicating the combustible gases from the upper to the lower chamber. A first improved feature relates to a particle fuel delivery control device which operates an auger for filling the upper chamber with particle fuel to a desired level. A beam of light is transmitted and reflected between a photoelectric cell and reflector respectively of the device. When the particle fuel pile has grown in height during filling to the desired level the light beam is interrupted and filling is terminated.

Abstract: A particle fuel burning furnace has an upper combustion chamber for holding a pile of particle fuel and burning the same from the bottom thereof. The furnace also includes a lower combustion chamber for afterburning combustible gases given off by the burning of solid fuel in the upper chamber and a series of spaced apart vertically-extending passageways arranged in a row and interconnecting the upper and lower chambers for communicating the combustible gases from the upper to the lower chamber. A first improved feature relates to a particle fuel delivery control device which operates an auger for filling the upper chamber with particle fuel to a desired level. A beam of light is transmitted and reflected between a photoelectric cell and reflector respectively of the device. When the particle fuel pile has grown in height during filling to the desired level the light beam is interrupted and filling is terminated.