气固脉冲流化床的流体力学特性

HYDRODYNAMICS OF GAS SOLID PULSED FLUIDIZED BEDS

在直径７０ｍｍ的流化床中，采用ＦＣＣ、空心玻璃珠、细沙等Ａ类和Ｂ类颗粒，在０～１０Ｈｚ的频率范围内，测定了气固脉冲流化床的流体力学特性。采用时间继电器改变脉冲气流的频率和脉宽周期比，利用微压传感器记录床层压力变化，研究了瞬时床层压力、平均床层压力，最大床层压降、起始流化速度、床层高度等随操作条件的变化规律。并对脉冲流化床中的气泡现象进行了初步的观察和研究，发现在脉冲流化床中气泡的形成和发展受到了有效抑制，床层中的气固接触效率可大为提高。

The hydrodynamics of pulsed fluidized beds was studied with four kinds of particles of the category of A and B in a frequency range of 0 to 10 Hz. The effects of operating conditions on the pressure drop and bed height were discussed. The operating conditions studied include pulse frequency, duration ratio and U g,p /U g,s . Four kinds of pattens of pressure fluctuation can be obtained with different operating conditions. The bubbling phenomena in pulsed fluidized beds were also observed. The formation and development of bubbles are restricted in the pulsed fluidized bed and, hence, the gas solid contact can be enhenced.