Method and apparatus for improved firing of biomass and other solid fuels for steam production and gasification
OwnerDaniel R. Higgins, Eugene Sullivaninventors
Life of this patent
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Abstract
A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.
Claims18
A floor of a solid fuel fired boiler comprising one or more cells in which most of the fuel firing said boiler falls into said cell or cells and burns therein, each of said cell or cells having sloping sides and including an outer supporting structure, an inner refractory layer, and an insulating layer between said outer supporting structure and said inner refractory lining, and wherein the bottoms of each of said cell or cells are truncated resulting in openings in the bottoms of each of said cell or cells, and a movable grate floor resides below each of said openings such that each of said movable grate floors may be opened periodically to discharge the contents of each of said cell or cells;
- further comprising a plenum from which combustion air, oxygen, or recirculated boiler flue gas, or any combination thereof, is injected from below each of said movable grate floors and then flows up through each of said movable grate floors;
- and
- in which each of said movable grate floors is supported by a rotatable shaft, and each of said floors opens by rotating each of said shafts.
A method of constructing a solid fuel fired boiler comprising:
- configuring a furnace in one or more cells, each comprising:
- an outer support structure;
- an insulator layer lining said support structure;
- and
- a refractory layer lining said insulator layer;
- wherein the bottoms of each of said cell or cells are truncated resulting in openings in the bottoms of each of said cell or cells, and a movable grate floor resides below each of said openings such that each of said movable grate floors may be opened periodically to discharge the contents of each of said cell or cells;
- in which each of said movable grate floors is supported by a rotatable shaft, and each of said floors opens by rotating each of said shafts
- positioning an array of chamber walls above said furnace for generation of steam, wherein each wall comprises a generally vertical array of approximately parallel steam-generating tubes;
- and
- locating at the top of said boiler a fuel bin, comprising a floor including one or more fuel-conveying screws.
A solid fuel boiler including a boiler floor comprising one or more cells in which most of the fuel firing said boiler falls into said cell or cells and burns therein, each of said cell or cells having sloping sides and including an outer supporting structure, an inner refractory layer, and an insulating layer between said outer supporting structure and said inner refractory lining, and wherein the bottoms of each of said cell or cells are truncated resulting in openings in the bottoms of each of said cell or cells, and a movable grate floor resides below each of said openings such that each of said movable grate floors may be opened periodically to discharge the contents of each of said cell or cells
- further comprising a plenum from which combustion air, oxygen, or recirculated boiler flue gas, or any combination thereof, is injected from below each of said movable grate floors and then flows up through each of said movable grate floors;
- and
- in which each of said movable grate floors is supported by a rotatable shaft, and each of said floors opens by rotating each of said shafts.
Dependencies are inferred from the claim text.