高温鼓泡流化床的流化行为

Fluidization Behavior of a High-temperature Bubbling Fluidized Bed

床层温度在 2 0～ 10 0 0℃范围内 ,以 4种粒径的煤灰为实验物料 ,研究了不同表观气速下最小流化速度、床层平均空隙率、压力波动标准偏差和主频的变化规律 ,最小流化速度随床层温度升高而减小 ;相同床温下 ,平均空隙率随表观气速升高而增大 ;不同床温下 ,压力波动偏差随流化数增加而增大。相同流化数时 ,B类颗粒的压力波动标准偏差受床层温度变化影响较小 ,而D类粒子随床层温度升高压力波动标准偏差减小。随着流化数增加 。

With the bed temperature ranging from 20 - 1000℃ and coal ash of four kinds of particle diameter serving as experimental materials the variation relationship of the following parameters is investigated under various apparent gas speeds. The parameters include: the minimum fluidization speed, bed average voidage, pressure fluctuation standard deviation and main frequencies. The minimum fluidization speed will decrease with a rise in bed temperature. Under the same bed temperature the average voidage will increase with a rise in apparent gas speed. Under different temperatures the pressure fluctuation deviation will experience an increase with an increase in fluidization number. Under the same fluidization number the influence exerted by a change in bed temperature on pressure fluctuation standard deviation of B particles is insignificant, while for particles of D category the pressure fluctuation standard deviation will decrease with a rise in bed temperature. An increase in fluidization number will lead to a decrease in the main frequency of pressure fluctuations.