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US 6,202,577 B1Granted
Method and apparatus for treating refuse
OwnerAnatoly Boguslavsky, Yuriy Rabinerinventors
Life of this patent
Estimating the term…
Abstract
A municipal or like refuse, from which large articles of metals have been removed, is mixed with an alkaline substance like limestone preferably in a triple screw mixer, and then advanced along the pyrolysis path in which the refuse mixture is subjected to heat from combustion gases from an incineration chamber therebelow. A portion of the pyrolyzed product is recycled to the upstream side of that path and the remainder of the pyrolyzed product is scrubbed with an aqueous medium, e.g. water and/or aqueous acetic acid and the washed pyrolyzed product is then incinerated to produce the combustion gas.
Claims13
A method of treating refuse comprising the steps of:
- (a) removing large articles of metals from refuse to form a pyrolyzable refuse product;
- (b) mixing said pyrolyzable refuse product with limestone in an amount sufficient to combine with chlorine contained in said pyrolyzable refuse product and optionally with a sewage sludge to form a pyrolyzable mixture;
- (c) passing said pyrolyzable mixture through and along a rotary drum of a rotary kiln in one direction while subjecting the pyrolyzable mixture to pyrolysis by heating with a combustion gas to produce pyrolysis gases discharged from said rotary kiln and a pyrolyzed product;
- (d) recycling a recycled portion of said pyrolyzed product in a hot state through a recycling tube extending axially through said drum to mix with said pyrolyzable refuse product at an upstream side of said rotary drum whereby said pyrolyzable refuse product is dehydrochlorinated by heat of the recycled portion of pyrolyzed product and simultaneous neutralization of discharged hydrogen chloride by the limestone at a temperature produced at least in part by mixing the recycled portion with said pyrolyzable refuse product;
- (e) washing a further portion of said pyrolyzed product with an aqueous washing liquid to remove inorganic salts from said further portion of said pyrolyzed product and produce a washed pyrolyzed product, mixing a hot slag with wet washed products to dry them and use evaporated water from the wet and washed products in the stage of washing;
- and
- (f) incinerating said washed pyrolyzed product to produce a slag residue including said hot slag and said combustion gas.
4 more elements
An apparatus for treating refuse comprising:
- a kiln for pyrolysis of organic compounds which are contained in a pyrolyzable mixture of a pyrolyzable refuse product from which large articles of metals have been removed, limestone in an amount sufficient to combine with chlorine contained in pyrolyzable waste product and optionally a sewage sludge, a device for moving said pyrolyzable mixture and a mixing device, where part of hot solid products of pyrolysis is mixed with said pyrolyzable mixture whereby the pyrolyzable refuse product is dehydrochlorinated and discharged hydrogen chloride is neutralized by limestone at a temperature produced at least in part by mixing a recycled portion of hot solid products with the pyrolyzable refuse product;
- said kiln for pyrolysis heated by combustion gas throughout a heat-exchange surface of the kiln;
- a fire chamber provided with a traveling grate below said kiln for incinerating washed pyrolyzed product;
- and
- a drying mixer for mixing part of said hot slag with the wet washed pyrolyzed product;
- and
- a washer between said kiln and said drying mixer for washing further portion of said pyrolyzed product with an aqueous washing liquid to remove inorganic salts from said further portion of said pyrolyzed product and produce said washed pyrolyzed product.
4 more elements
A method of treating refuse comprising the steps of:
- (a) removing large articles of metals from refuse to form a pyrolyzable refuse product;
- (b) mixing said pyrolyzable refuse product with an alkaline substance in an amount sufficient to combine with chlorine contained in said pyrolyzable refuse product and optionally with sewage sludge to form a pyrolyzable mixture;
- (c) passing said pyrolyzable mixture along a pyrolysis path in one direction while subjecting the pyrolyzable mixture to pyrolysis by heating with a combustion gas to produce pyrolysis gases discharged from said path and a pyrolyzed product;
- (d) recycling a portion of the pyrolyzed product in a hot state to said pyrolyzable refuse product at an upstream side of said path through a mixer whereby said pyrolyzable product is dehydrochlorinated by heat of recycled portion of pyrolyzed product at a temperature produced at least in part by mixing the recycled portion with said pyrolyzable refuse product, and simultaneous neutralization of discharged hydrogen chloride by said alkaline substance;
- (e) washing another portion of said pyrolyzed product with an aqueous washing liquid to remove inorganic salts from said other portion of said pyrolyzed product and produce a washed pyrolyzed product, mixing a hot slag and wet washed solids to dry said wet washed solids;
- and
- (f) incinerating said washed pyrolyzed product to produce a slag residue including said hot slag and said combustion gas.
4 more elements
Dependencies are inferred from the claim text.