Solid refuse disposal process
AssigneeUnion Carbide Corporation
InventorsVictor E. Bergsten, Edward P. Eardley, Theodore F. Fisher
Life of this patent
Estimating the term…
Abstract
Process for solid refuse disposal in which a vertical shaft furnace is maintained at 30-250 psia, part of the recycle-condensate is filtered to form liquid waste a portion of which is incinerated with a minor part of the product gas to form hot exhaust gas used to heat feed water in steam boiler zone, and energy from the resulting steam is recovered as part of the process energy requirement.
Claims12
In a process for disposal of solid refuse feed by conversion to useful gaseous product and inert solid residue in a vertical column with an upper end for fresh solid refuse feed as a drying zone and a lower end providing a thermal decomposition zone for the refuse, and a hearth beneath said column as a combustion-melting zone, in which air is separated to produce at least 40% oxygen by volume and fed to said combustion-melting zone, molten residue is discharged from said combustion-melting zone, fine particulate-containing overhead gas is discharged from the column upper end, and said overhead gas is cleaned by cooling and scrubbing with recycle condensate from a scrubbing-separation zone to provide product gas and bottom condensate, the improvement comprising:
- (a) a maintaining said vertical column and said hearth at pressure between 30 and 250 psia;
- (b) dividing the bottom condensate from said scrubbing-separation zone into three parts;
- (c) mixing a first part of said bottom condensate as a portion of said recycle condensate with said overhead gas for cooling and partial scrubbing thereof in said scrubbing-separation zone to form partially scrubbed overhead gas;
- (d) cooling a second part of said bottom condensate externally supplied refrigerant and contacting the so-cooled second part with the partially scrubbed overhead gas from (c) in said scrubbing-separation zone as another portion of said recycle condensate;
- (e) filtering the third part of said bottom condensate in a first filter section to remove solid particulate material therefrom to form liquid waste having an organic portion;
- (f) flowing a minor portion of said liquid waste through a second filter section previously loaded with solid particulate from the bottom condensate third part and removing the solid particulate from said second filter section to form a slurry recycle;
- (g) mixing said slurry recycle with fresh solid refuse to form said refuse feed;
- (h) flowing the remaining major portion of said liquid waste to an incineration zone;
- (i) diverting a minor part of said product gas while discharging the product remainder from said process, and passing the so-diverted product gas to said incineration zone;
- (j) providing air and passing same to said incineration zone;
- (k) completely oxidizing the organic portion of the liquid waste remainder in said incineration zone and forming hot discharge gas therein;
- (l) flowing said hot discharge gas to a steam boiler zone along with feed water for heat exchanging therein, and generating steam from said feed water while partially cooling the incinerator discharge gas;
- and
- (m) discharging said steam from said steam boiler zone and recovering energy therefrom as part of the refuse disposal process energy requirement.
Dependencies are inferred from the claim text.