Pneumatic spreader stoker

Claim 2

A pneumatic spreader stoker for feeding a controlled, continuous supply of pulverent refuse fuel to a combustion chamber of a furnace at a uniform rate comprising; pneumatic means delivering a flow of gas under pressure through a conduit communicating with the combustion chamber of a furnace, the gas flow capable of discharging fuel delivered into the gas stream into the combustion chamber of the furnace, feeding means for delivering the fuel at a uniform rate into the flow of gas through the conduit, a pair of opposed rotary damper blades disposed in the path of gas flow ahead of the fuel discharge into the gas stream for alternately increasing and decreasing the quantity and pressure of gas delivered to the combustion chamber at a substantially linear rate; and means powering the rotary damper blades.

Claim 3

A pneumatic spreader stoker for feeding a controlled continuous supply of pulverent refuse fuel to the combustion chamber of a furnace at a uniform rate comprising; a rotary screw conveyor and housing therefor for delivering the fuel from an infeed end to a discharge end, the screw flights of the conveyor being of increased pitch at the discharge end; a discharge opening in the screw housing below the screw flights of increased pitch, the opening diverging outwardly toward the discharge end of the screw conveyor; pneumatic means positioned below the discharge opening in the screw housing delivering a flow of gas under pressure for discharging the fuel passing through the discharge opening into the combustion chamber of the furnace, a pair of opposed, rotary damper blades disposed in the path of gas flow ahead of the fuel discharge into tHe gas stream for alternately increasing and decreasing the quantity and pressure of gas available for delivering fuel into the combustion chamber of the furnace at a substantially linear rate, and means powering the rotary damper blades.

Claim 4

A pneumatic spreader stoker for feeding a controlled continuous supply of pulverent refuse fuel to the combustion chamber of a furnace at a uniform rate comprising; a rotary screw conveyor and housing therefor for delivering the fuel from an infeed end to a discharge end, the screw flights of the conveyor being of increased pitch at the discharge end; a discharge opening in the screw housing below the screw flights of increased pitch, the opening diverging outwardly toward the discharge end of the screw conveyor; pneumatic means positioned below the discharge opening in the screw housing delivering a flow of gas under pressure for discharging the fuel passing through the discharge opening into the combustion chamber of the furnace, a pair of opposed, rotary damper blades disposed in the path of gas flow ahead of the fuel discharge into tHe gas stream for alternately increasing and decreasing the quantity and pressure of gas available for delivering fuel into the combustion chamber of the furnace at a substantially linear rate, and means powering the rotary damper blades.

Claim 5

The pneumatic spreader stoker of claim 2 including a damper positioned in the path of gas flow ahead of the opposed rotary damper blades for controlling the maximum gas flow to the combustion chamber of the furnace.

Claim 6

The pneumatic spreader stoker of claim 3 including a gas conduit means by passing the opposed rotary damper blades and a damper positioned in the path of gas flow through the by-pass conduit, the damper adjustable for controlling the minimum gas flow to the combustion chamber.

Claim 7

The pneumatic spreader stoker of claim 1 wherein the rotary screw conveyor comprises a pair of rotary screw conveyors disposed in side-by-side relation for delivering fuel from an infeed end to a discharge end, the screw flights of each rotary screw being of increased pitch at the discharge end a screw housing for the pair of rotary screw conveyors, means for operating the rotary screw conveyors, discharge openings in the screw housing below the screw flights of increased pitch of each rotary screw, each of the openings diverging autwardly toward the discharge end of the rotary screws.

Claim 8

A pneumatic spreader stoker for feeding a controlled continuous supply of pulverent refuse fuel to the combustion chamber of a furnace at a uniform rate comprising; a pair of rotary screw conveyors disposed in side-by-side relation for delivering fuel from the infeed end to a discharge end, the screw flights of each of the conveyors being of increased pitch at the discharge end, a screw housing for the pair of rotary screw conveyors, discharge openings in the bottom of the screw housing below the screw flights of increased pitch of each rotary screw conveyor, each of the discharge openings diverging outwardly toward the discharge end of the rotary screw conveyors, means for operating the rotary screw conveyors, means to supply fuel to the infeed end of the pair of rotary screw conveyors, an air conduit positioned below the discharge openings in the screw housing, a gravity chute interconnecting the discharge openings in the screw housing with an opening in the conduit for conveying the fuel discharged through the discharge openings into the conduit, pneumatic means delivering a flow of air under pressure through the conduit for discharging the fuel delivered by gravity through the gravity chute uniformly over the grates in the combustion chamber of a furnace, a pair of opposed rotary damper blades disposed in the conduit ahead of the opening for fuel flow into the conduit, the dampers rotating from a vertically aligned position wherein air flow through the conduit is at a minimum to a horizontal position wherein the blades of the damper are substantially parallel with each other and wherein air flow therethrough is at a maximum, thereby alternately increasing and decreasing the quantity and pressure of air available for distributing the fuel into the combustion chamber of the furnace, a by-pass conduit by-passing the opposed rotary damper blades allowing air flow around the opposed blades, a damper positioned in the path of the air flow through the by-pass for controlling the air flow therethrough, the damper set to deliver a minimum of air flow to the combustion chamber at all times.

Claim 9

A pneumatic spreader stoker for feeding a controlled continuous supply of pulverent refuse fuel to the combustion chamber of a furnace at a uniform rate comprising; a pair of rotary screw conveyors disposed in side-by-side relation for delivering fuel from the infeed end to a discharge end, the screw flights of each of the conveyors being of increased pitch at the discharge end, a screw housing for the pair of rotary screw conveyors, discharge openings in the bottom of the screw housing below the screw flights of increased pitch of each rotary screw conveyor, each of the discharge openings diverging outwardly toward the discharge end of the rotary screw conveyors, means for operating the rotary screw conveyors, means to supply fuel to the infeed end of the pair of rotary screw conveyors, an air conduit positioned below the discharge openings in the screw housing, a gravity chute interconnecting the discharge openings in the screw housing with an opening in the conduit for conveying the fuel discharged through the discharge openings into the conduit, pneumatic means delivering a flow of air under pressure through the conduit for discharging the fuel delivered by gravity through the gravity chute uniformly over the grates in the combustion chamber of a furnace, a pair of opposed rotary damper blades disposed in the conduit ahead of the opening for fuel flow into the conduit, the dampers rotating from a vertically aligned position wherein air flow through the conduit is at a minimum to a horizontal position wherein the blades of the damper are substantially parallel with each other and wherein air flow therethrough is at a maximum, thereby alternately increasing and decreasing the quantity and pressure of air available for distributing the fuel into the combustion chamber of the furnace, a by-pass conduit by-passing the opposed rotary damper blades allowing air flow around the opposed blades, a damper positioned in the path of the air flow through the by-pass for controlling the air flow therethrough, the damper set to deliver a minimum of air flow to the combustion chamber at all times.

Claim 10

The pneumatic spreader stoker of claim 6 including a damper positioned in the path of air flow ahead of the opposed rotary damper blades for controlling the maximum air flow to the combustion chamber.

Claim 11

The pneumatic spreader stoker of claim 6 wherein the discharge openings in the screw housing are V-shaped slots.

Claim 12

The pneumatic spreader stoker of claim 6 wherein the rotary screw conveyors are operated 90* to 180* out of phase with each other.