Electric furnace for continously heating and regenerating spent activated carbon

Claim 2

A furnace for heating particulate material cmprising: an air-tight shell defining an enclosure, a heat insulating lining within the shell, the inside of which defines a hollow shaft, electrical resistance heating elements spaced along the length of the hollow shaft adjacent the insulating lining, a baffle system supported within the shaft, comprising: side supports vertically positioned within the shaft; a plurality of inner trays each defining pairs of sloping surfaces joined at a ridge, said pairs of inner trays spaced vertically and secured by the side supports; a plurality of outer trays each defining a sloping surface, each of said outer trays arranged to receive material falling from the inner tray thereabove and to deliver material to the ridge of an inner tray therebelow; said inner and outer trays arranged such that said material forms a flowing bed gently conveyed by gravity down through the furnace from tray to tray in a sinuous path exposing the flowing bed of material first on one side and then on the other and such that flow from an upper to a lower tray stops when the lower tray is filled; and the side supports having a plurality of openings therein positioned under the inner trays and the space above the upper edges of the outer trays being open such that the surface of the flowing bed while conveyed over both inner and outer trays is exposed to radiation from the heating elements and to circulation of convection gases.

Claim 3

A furnace for heating particulate material comprising: an air-tight shell defining an enclosure, a heat insulating lining within the shell, the inside of which defines a hollow shaft, electrical resistance heating elements spaced along the length of the hollow shaft adjacent the insulating lining, a sealable inlet at the top of the shaft, a hopper at the bottom of the shaft with a sealable outlet near the bottom thereof, a discharge table mounted near the top of the hopper, a baffle system supported within the shaft, comprising: side supports vertically positioned within the shaft; a plurality of inner trays each defining pairs of sloping surfaces joined at a ridge, said pairs of inner trays spaced vertically and secured by the side supports; a plurality of outer trays each defining a sloping surface, each of said outer trays arranged to receive material falling from the inner tray thereabove and to deliver material to the ridge of an inner tray therebelow; said inner and outer trays arranged such that said material forms a flowing bed gently conveyed by gravity down through the furnace from tray to tray in a sinuous path exposing the flowing bed of material first on one side and then on the other and such that flow from an upper to a lower tray stops when the tray is filled; the said baffle system arranged to receive material from the inlet and to deliver material to the table, the side supports having a plurality of openings therein positioned under the inner trays and the space above the upper edges of the outer trays being open such that the surface of the flowing bed while conveyed over both inner and outer trays is exposed to radiation from the heating elements and to circulation of convection gases, means for pushing material off the discharge table for controlling the rate at which material moves downwardly through the baffle system.

Claim 4

A furnace for heating particulate material comprising: an air-tight shell defining an enclosure, a heat insulating lining within the shell, the inside of which defines a hollow shaft, electrical resistance heating elements spaced along the length of the hollow shaft adjacent the insulating lining, a sealable inlet at the top of the shaft, a hopper at the bottom of the shaft with a sealable outlet near the bottom thereof, a discharge table mounted near the top of the hopper, a baffle system supported within the shaft, comprising: side supports vertically positioned within the shaft; a plurality of inner trays each defining pairs of sloping surfaces joined at a ridge, said pairs of inner trays spaced vertically and secured by the side supports; a plurality of outer trays each defining a sloping surface, each of said outer trays arranged to receive material falling from the inner tray thereabove and to deliver material to the ridge of an inner tray therebelow; said inner and outer trays arranged such that said material forms a flowing bed gently conveyed by gravity down through the furnace from tray to tray in a sinuous path exposing the flowing bed of material first on one side and then on the other and such that flow from an upper to a lower tray stops when the tray is filled; the said baffle system arranged to receive material from the inlet and to deliver material to the table, the side supports having a plurality of openings therein positioned under the inner trays and the space above the upper edges of the outer trays being open such that the surface of the flowing bed while conveyed over both inner and outer trays is exposed to radiation from the heating elements and to circulation of convection gases, means for pushing material off the discharge table for controlling the rate at which material moves downwardly through the baffle system.

Claim 5

The furnace according to claim 1 or 2 having means for circulating gas through the shaft.