System for withdrawing solids from a high temperature fluidized bed

Abstract From the Canadian patent

Particulate solids are continuously discharged from a high temperature fluidized bed through a descending solids withdrawal line into a fluidized bed cooling vessel while controlling the solids discharge rate indirectly by regulating the cooling vessel pressure preferably by means of a control, valve which is used to throttle gag taken off overhead from the vessel. Fluidized solids may be discharged from the cooling vessel into a second vessel in which they are slurried in water and removed from the system through one or more pressure letdown valves. Alternatively the particles, may be passed from the fluidized bed colling vessel into a lock hopper from which they are withdrawn periodically.