关键词: 固体浓度, 气固流化床, 分布器, 静床高, 开孔率

Abstract: The experiments were conducted in a cold conventional fluidized bed using fiber optical probe as the detecting apparatus. The system compromises a replaceable gas distributor in a 0.284 m internal diameter acrylic column, a compressor, a series of knock-out drum, a freezer dryer, a rotameter, a fiber optic probe system and a series of cyclone. The experiments were carried out at ambient conditions and under different superficial gas velocities ranging from 0.3 to 0.5 m/s and different initial bed height ranging from 0.6 to 1.5 m using air as the fluidizing gas. A mixture of sands ranging from 154 to 180 mm diameter and average density of 2550 kg/m3 were used as the fluidizing particles. The effects of radial distance, axial distance, superficial gas velocity, initial bed height, porosity and shape of distributor on solid concentration in the bed were examined. The experimental results show that the time-averaged solid concentration increases in the dense phase area with the increase of superficial gas velocity. The shape of distributor does not exert much influence on the solid concentration while the smaller porosity of distributor gives rise to a lower and steeper solid concentration distribution. The initial bed height influences the solid concentration distribution contours significantly.

Key words: solid concentration, gas-solid fluidized bed, distributor, initial bed height, porosity