Spent activated carbon is received in DOT approved containers and slurry trailers. The regeneration process then starts with spent carbon inspection and acceptance, the carbon is transferred as a slurry into the spent carbon storage tanks. From the storage tanks the water-carbon slurry is pumped to a furnace feed tank. The water-carbon slurry is dewatered using an inclined dewatering screw and the remaining carbon is weighed before it is fed into the multiple hearth furnace. After the carbon has been introduced into the furnace, it is heated to progressively higher temperatures to remove moisture, volatile organics and the carbonized char from the carbon pores by a steam-carbon reaction.
Some of the organics are destroyable in the reactivation furnace. The remaining contaminants are thermally oxidized in an afterburner which has a minimum destruction efficiency of 99.9998%. In addition to the afterburner, a venturi scrubber removes particulate matter; a packed-bed caustic scrubber removes acid gases; and a wet electrostatic precipitator is provided for additional particulate removal.
After regeneration the carbon exits the bottom of the furnace where it is cooled using a water-jacketed conveyor. The cooled reactivated carbon is transported pneumatically to the carbon packaging facility where it is screened and packaged for reuse.