Method of thermally bloating clay pellets using a fluidized bed

Abstract

Abstract Method for producing expanded lightweight aggregate by heattreating prepared predried clay pellets or the like in a fluidized bed maintained by hot gases, assisted by additional radiating heat directed downwardly upon the bed, with means for separately controlling the amount of radiating heat, and the bed temperature, whereby the bed temperature is maintained substantially below the surface sintering temperature of the pellets, but above the temperature required to expand the pellets. The upflow rate or velocity of gases in the fluid bed are controlled in such a manner that the pellets are constantly raised to the surface where the downwardly directed radiant heat forms a sintered or glassy outer skin on the expanded pellets. The turbulence caused by the controlled velocity of the gasses then causes these pellets to be circulated back down into the fluidized layer so that all of the expanded pellets are exposed to the radiant heat momentarily and repetitiously as they pass through the fluid bed furnace. The expanded pellets are cooled in the final section of the fluid bed furnace.

Inventors

• 👤 Henry Kepper

Bibliographic Details