Method and apparatus for burning solid waste products using a plurality of multiple hearth furnaces
AssigneesGurries & Okamoto, Inc., Associated Mechanical Contractors, Inc.
InventorsRichard M. Gurries, Jay K. Johnson, Eric A. Nering
Life of this patent
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Abstract
Method and apparatus for incinerating low density organic materials using a pair of side by side multiple hearth furnaces are disclosed. The first furnace of the pair operates in a temperature-controlled reducing atmosphere to achieve complete volatilization of non-fixed carbon contained in the fuel feed stock. The second furnace operates in a temperature-controlled oxidizing atmosphere to achieve complete oxidation of all fixed-carbon contained in the char output of the first furnace. The gaseous products of both furnaces are combined and burned in a low - Btu gas burner, thus providing the heat input to a power boiler or other process suited to the heat quality produced.
Claims26
A process for continuously burning solids comprising the steps:
- a. partially burning said solid in a first multiple hearth furnace which is operated under reducing conditions and forming a carbon-containing char and a low Btu gas in said first multiple hearth furnace;
- b. recovering said char from said first multiple hearth furnace and conveying said char to a second multiple hearth furnace which is operated under oxidizing conditions;
- c. substantially completely burning the char recovered from said first multiple hearth furnace in said second multiple hearth furnace;
- d. transporting said low Btu gas from said first multiple hearth furnace to a burner where substantially complete burning of said low Btu gas takes place;
- and
- e. recovering oxygen containing gas from from said second multiple hearth furnace and utilizing said gas in said burner for burning said low Btu gas recovered from said first multiple hearth furnace.
Apparatus for continuously burning solids comprising:
- a. a first multiple hearth furnace including means for partially burning said solids under reducing conditions to form a carbon-containing char and for producing a low Btu gas from said solid being partially burned;
- b. a second multiple hearth furnace spaced from said first multiple hearth furnace including means for substantially completely burning said carbon-containing char under oxidizing conditions;
- c. means for transporting said low Btu gas from said first multiple hearth furnace to a burner where substantially complete burning of said low Btu gas takes place;
- and
- d. means for transporting oxygen-containing gas recovered from said second multiple hearth furnace and utilizing said gas in said burner for burning said low Btu gas recovered from said first multiple hearth furnace.
The apparatus according to claim il wherein said solids comprise agricultural waste products introduced into said first multiple hearth furnace and further including means for monitoring and controlling the NOx content of said gases in said low Btu gas burner.
Dependencies are inferred from the claim text.