Patent ID: 7331299

Claim:
A fluidized-bed furnace system comprising: a fluidized-bed furnace to have a fluidized-bed formed therein by a fluidized medium so as to combust, gasify, or pyrolyze an object containing an incombustible, said fluidized-bed furnace having a pressure detector for measuring a pressure at a bottom of said fluidized-bed furnace; and an incombustible withdrawing system including (i) a mixture delivery path to deliver a mixture of the fluidized medium and the incombustible from the bottom of said fluidized-bed furnace, (ii) a fluidized-bed separating chamber disposed downstream of said mixture delivery path to separate the mixture into a first separated mixture having a high concentration of the fluidized medium and a second separated mixture having a high concentration of the incombustible, (iii) a fluidized medium ascent chamber as a return passage to return the first separated mixture to said fluidized-bed furnace, (iv) a pressure detector for measuring a pressure in said fluidized-bed separating chamber, (v) a differential pressure gauge for measuring a sealing differential pressure based on the pressure at the bottom of said fluidized-bed furnace and the pressure in said fluidized-bed separating chamber, and (vi) a control valve operable to be opened or closed based on the sealing differential pressure as measured by said differential pressure gauge for supplying a fluidizing gas to a side portion of said fluidized medium ascent chamber.