| 摘要 |
PURPOSE: To provide an operational method for controlling the fluidity of a granular layer in pneumatic feeder of a circulating fluidized bed in the good condition, at the time of reducing powdery ore in the circulating fluidized bed. CONSTITUTION: The fluidity of the granular layer in a pneumatic feeder is controlled in the good condition by supplying the powder containing coarse grain directly into the pneumatic feeder 9 or supplying into a secondary downcomer 8 or into the gas inlet of a secondary cyclone 7. Further, the pressure is measured from a pressure measuring hole 13 arranged at the secondary downcomer 8, and the timing for supplying the powder containing the coarse grain into the pneumatic feeder 9 is decided by observing the height of a grain packing layer in the secondary downcomer. The diameter of the supplied grain is made to be >=100μm and the ratio of the grain having >=100μm diameter of the powder in the pneumatic feeder 9 is adjusted to >=5wt.% to reduce the powdery ore.
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