Thermolysis of pentachlorophenol treated poles
AssigneeWorthing Industries, Inc.
InventorsPeter Fransham, John Rasmussen, Stan Ainslie
Life of this patent
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Abstract
This invention comprises a method and apparatus for removing oil and tar based wood preservatives from sawdust. A pole treated with oil or tar basee wood preservative is shaved to remove the treated outer wood layer, leaving the interior preservative free. The sawdust is subjected to rapid heating in a turbulent oxygen-free gas stream and the oil and tar are rapidly distilled from the sawdust. The sawdust and gas are separated in a mechanical separator and the hot gas is rapidly cooled, condensed and recovered.
Claims6
A method of removing pentachlorophenol and creosote from utility poles comprising the steps of:
- (1) removing an outer wood preservative impregnated surface of said poles by chipping or shaving particles of wood;
- (2) reducing the size of said wood preservative impregnated particles;
- (3) conveying the particles into a thermolysis reactor;
- (4) subjecting the particles to hot oxygen-free gases in said reactor until said wood preservative vaporizes;
- (5) subjecting said vaporized mixture to a cyclone at a temperature sufficiently high to keep said wood preservative in a vapour state;
- (6) removing solids from said cyclone for storage;
- (7) quenching said vaporized wood preservative and gases to a lower temperature and passing said wood preservative and gases through a venturi scrubber;
- (8) passing a resultant wood preservative condensate through a knockout drum and storing the same for recycling;
- (9) passing the remainder of said gases through a heat exchanger and removing any condensed water in a knockout drum;
- and
- (10) reheating and returning the remainder of said gases to said reactor.
A method of removing pentachlorophenol and creosote from utility poles comprising the steps of:
- (1) removing an outer wood preservative impregnated surface of said poles by chipping or shaving particles of wood;
- said wood preservative including a carrier oil;
- (2) reducing the size of said wood preserative impregnated particles;
- (3) conveying the particles into a thermolysis reactor;
- (4) subjecting the particles to hot oxygen-free gases in said reactor at a temperature of greater than 310 degrees celsius until said wood preservative vaporizes;
- (5) subjecting said vaporized mixture to a cyclone at a temperature sufficiently high to keep said wood preservative in a vapour state;
- (6) removing solids from said cyclone for storage;
- (7) quenching said vaporized wood preservative and gases to a lower temperature and passing said wood preservative and gases through a venturi scrubber;
- (8) passing a resultant wood preservative condensate through a knockout drum and storing the same for recycling;
- (9) passing the remainder of said gases through a heat exchanger and removing any condensed water in a knockout drum;
- and
- (10) reheating and returning the remainder of said gases to said reactor.
Dependencies are inferred from the claim text.