Solid refuse furnace
AssigneeEnergy Alternatives, Inc.
InventorDavid B. Spaulding
Life of this patent
Estimating the term…
Abstract
A new furnace is provided which employs a forced draft to efficiently and cleanly burn a wide variety of fuels such as wood and refuse. The furnace is designed to internally and continuously pyrolyze (gasify) fuel prior to the burning phase which is conducted in a lower chamber of the furnace where air is admitted at a controlled rate. Combustion temperature is maintained at 1800.degree. F. or higher to completely burn gasified fuel by enclosing the burning zone with refractory material and by not extracting sensible heat from the combustion region until after exhaust gases exit the lower chamber. Ash is produced in a fine powder as a consequence of its being removed from the combustion effluent by gravity and cyclonic (i.e. turbulent) separation.
Claims21
A plural-chamber fire box comprising:
- first refractory means having surfaces defining an upper chamber in which solid fuel may be stored, dried, gasified and partially combusted, at least a portion of said upper chamber converging in a funnel-like fashion to an opening at the bottom of said upper chamber;
- second refractory means having surfaces defining a lower chamber which communicates with the upper chamber through said opening,
- additional refractory means forming a structure which surrounds and contains a lower portion of the upper chamber and said opening;
- means for introducing primary combustion air into the converging region of the upper chamber such that, in the presence of heat, various degrees of partial combustion may take place in said upper chamber;
- means for introducing secondary combustion air at the periphery of the opening so that complete combustion of gases may take place in said opening and the lower chamber;
- means located in the lower chamber below said opening for supporting (a) hot char at the bottom of the upper chamber so that the hot char serves as a gas igniter and (b) regulating the velocity and volume of total flow of air and combustion products through the firebox;
- means comprising at least part of said additional refractory means defining a passageway for exiting unreacted air and hot gaseous combustion products from the lower chamber so that the heat of said unreacted air and gaseous combustion products assists in maintaining the temperature above that required for complete combustion of smoke, creosote, and other noxious emissions;
- and
- insulation disposed about said first, second and additional refractory means for thermally isolating the outside surfaces of the upper and lower chambers from surrounding structures in a manner which does not restrict thermal communication between said upper and lower chambers.
A furnace for consuming solid carbonaceous fuels for the purpose of space and hot water heating comprising:
- a refractory firebox comprising first refractory means defining an upper chamber and second refractory means defining a lower chamber, said upper chamber having an opening at its lower end and at least a portion of said upper chamber converging in funnel-like fashion to said opening, said lower chamber connecting with said upper chamber through said opening;
- an air-tight door for allowing access to said upper chamber for the introduction of fuel;
- an access port for removal of ash and other solid residues from said lower chamber;
- means for introducing primary combustion air into said upper chamber at or proximate to said converging portion of said upper chamber so that, in the presence of heat, various degrees of partial combustion may occur in said upper chamber;
- means for introducing secondary combustion air to the periphery of said opening so that complete combustion can occur in said opening and in said lower chamber;
- an adjustable burning plate disposed in the lower chamber below and in line with said opening for supporting hot solid fuel at the bottom of the upper chamber and regulating the velocity and volume of flow of air and combustion products through said opening into said lower chamber;
- a heat exchanger for extracting heat from the hot furnace exhaust gases and transferring said heat to a working fluid such as air or water;
- means providing an exit passageway for conducting hot exhaust gases from said lower chamber through said heat exchanger;
- an extraction blower for sustaining the flow of primary and secondary combustion air into and through said firebox and for extracting hot unreacted air and gaseous combustion products from the firebox via said passageway;
- and
- valve means for regulating the proportion of primary and secondary combustion air delivered to said firebox so as to regulate the portion of combustion which occurs in the upper chamber relative to that in the lower chamber and for regulating the rate of solid fuel gasification and combustion in said firebox.
Dependencies are inferred from the claim text.