Fast fluidized bed reactor and method of operating the reactor

Claim 1

A fluidized bed reactor, comprising: (a) a substantially upright fluidized bed reaction chamber for containing a bed of granular material, said chamber having an upper region and a lower region, said upper region having a cylindrically shaped interior surface; (b) means for feeding matter to be reacted into said lower region of the reaction chamber; (c) means for supplying a first stream of pressurized air to said reaction chamber through a plurality of openings in said lower region at a sufficient velocity to fluidize said granular material in the circulating regime, whereby at least a portion of the granular material is continually entrained upward into said upper region; (d) means for tangentially supplying a second stream of pressurized air to said upper region of the reaction chamber through at least one opening in said cylindrically shaped interior surface, said second stream being supplied, and said reactor being constructed, in a manner adapted to provide a Swirl number of at least about 0.6 and a Reynolds number of at least about 18,000 in said upper region, thereby creating a cyclone of turbulence in the upper region which increases the rate of reaction in said chamber, wherein, at maximum operating capacity for the reactor, the second stream of air constitutes in excess of about 50% of the total pressurized air fed to the reaction chamber; (e) means for separating the granular material and the reaction gases exiting from said reaction chamber at a location adjacent to the upper boundary of said cyclone of turbulence, and returning the separated granular material to said lower region of the reaction chamber; (f) a second fluidized bed fluidized in the bubbling regime and situtated in said lower region of said reaction chamber adjacent a partition formed in said lower region for partitioning said circulating fluidized bed from said second fluidized bed, said second fluidized bed receiving and fluidizing at least a portion of the granular material separated from the reaction gases, said partition being situated so as to permit a portion of the granular material from said second fluidized bed to overflow said partition into said circulating bed; and (g) first heat exchange surface means immersed in said second fluidized bed for removing heat therefrom.