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US 9,638,414 B2Granted
Systems and methods for processing municipal wastewater treatment sewage sludge
AssigneeWasteDry, LLC
InventorsBruce Johnson, Robert G. Graham, Tony A. Kuipers, T. Terry Tousey, Joseph C. Snodgrass, David E. Prouty
Life of this patent
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Abstract
The present invention relates generally to systems and methods for drying and gasifying substances using the calorific value contained in the substances, and it more specifically relates to apparatus and methods for processing wet, pasty, sticky substances, such as municipal wastewater treatment sewage sludge, into a workable, powdered product.
Claims18
A system for processing a sewage sludge, comprising:
- a dryer for partially drying the sewage sludge;
- a gasifier for substantially converting the partially dried sewage sludge into syngas, wherein the gasifier applies heat in an oxygen-starved environment, whereby carbon-containing materials in partially dried sewage sludge chemically react to produce the syngas without burning;
- a low NOx oxidizer for combusting substantially all of the syngas to substantially reduce NOx compounds and produce heat and hot flue gas, wherein the heat is used to directly or indirectly partially dry the sewage sludge in the dryer;
- a pathogen destruction furnace downstream from the low NOx oxidizer for substantially destroying volatile organic compounds and/or residual pathogens;
- and a lime injection system for substantially removing SOx in the pathogen destruction furnace.
2 more elements
A method for processing a sewage sludge composition comprising:
- drying a sewage sludge composition into a partially dried compound;
- using a gasifier to apply heat in an oxygen-starved environment to substantially convert a portion of the partially dried compound into syngas, wherein carbon-containing materials in the partially dried compound chemically react to produce the syngas without burning;
- combusting substantially all of the syngas in a low NOx oxidizer to substantially reduce NOx compounds and produce heat and hot flue gas;
- directing the hot flue gas to a pathogen destruction furnace;
- substantially destroying pathogens and volatile organic compounds in the flue gas in the pathogen destruction furnace;
- substantially removing SOx from the flue gas in the pathogen destruction furnace by injecting lime into the pathogen destruction furnace;
- and
- using the heat to dry the sewage sludge composition.
5 more elements
A method for processing a sewage sludge composition comprising:
- drying a sewage sludge composition into a partially dried compound;
- using a gasifier to apply heat in an oxygen-starved environment to substantially convert a portion of the partially dried compound into syngas, wherein carbon-containing materials in the partially dried compound chemically react to produce the syngas without burning;
- combusting substantially all of the syngas in a low NOx oxidizer to substantially reduce NOx compounds and produce a hot flue gas;
- directing the hot flue gas to a pathogen destruction furnace;
- substantially destroying pathogens and volatile organic compounds in the flue gas in the pathogen destruction furnace;
- substantially removing SOx from the flue gas in the pathogen destruction furnace by injecting lime into the pathogen destruction furnace;
- using the hot flue gas to heat air;
- and
- using the heated air to dry the sewage sludge composition.
6 more elements
Dependencies are inferred from the claim text.