Abstract: A gas distribution system employing an array of parallel gas inlet pipes and a pair of transverse gas inlet pipes located below the first group of pipes to fluidize a particulate bed in a reaction vessel and to remove non-fluidizable particles that may be introduced into or form in the bed.

Abstract: An apparatus for improving mass transfer in a multiple hearth furnace has a plurality of risers adjacent the furnace center shaft which are in fluid communication with a source of treatment fluid. The risers have radially extending branch pipes, each pipe having a plurality of downcomers corresponding to the rabbles on an adjacent rabble arm. The downcomers have outlets or nozzles at their distal ends and they are preferably located adjacent a rear face of the rabble, near a trailing edge. In operation, as the rabbles plough over the material on the furnace hearth, the downcomers inject a treatment fluid, such as steam or reducing gas, into the material at the point of stirring. This ensures full exposure of the material to the treatment fluid. A second embodiment places the outlets beneath the top surface of the material to be treated. A method for mass transfer on a rotary hearth furnace is also disclosed.

Abstract: A method of oxidizing feed materials using a multiple hearth furnace comprises the steps of introducing the feed materials to be oxidized on at least the uppermost hearth, introducing fuel/air mixtures in the uppermost hearth to dry and ignite the feed materials, introducing air on at least one hearth to support combustion of the feed materials, allowing the feed materials to move downwardly from hearth to hearth and thereafter to exit the bottom of the furnace, and causing the combustion products formed by oxidation of the fuel and feed materials to be drawn down through the furnace and exhausted from a lower hearth.

Abstract: A furnace for heating particulate material comprises an air-tight shell and a heat insulating lining which define 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 promotes heating by radiation and convection. The baffle system has side supports vertically positioned within the shaft, a plurality of inner trays each defining pairs of sloping surfaces joined at a ridge, and a plurality of outer trays each defining a sloping surface. The outer trays are arranged to receive material falling from an inner tray thereabove and to deliver material to the ridge of an inner tray therebelow.

Abstract: A system and method of reactivating wet spent activated carbon comprising a batch operated solid-liquid separator, a continuous feed electrically heated furnace and surge bin therebetween. Heat exchangers recover sensible heat of the exhaust gases and/or hot carbon leaving the furnace to heat the air used by the solid-liquid separator. A portion of the furnace exhaust along with added air is recirculated through the furnace to provide the appropriate atmosphere for regeneration of the carbon.