增压流化床最小流化速度的实验研究

Experiment Study on Minimum Fluidization Velocity in a Pressurized Fluidized Bed

在80mm的铸铁流化床实验台上,以窄筛分和宽筛分两类颗粒为实验物料,在压力(101kPa^6 000kPa)和温度(20℃~800℃)范围内,研究了两类颗粒的最小流化速度。实验结果表明:在相同的温度下,随压力的增大最小流化速度减小。然而,在压力不变的情况下,温度对最小流化速度的影响与床料的平均粒径有关。最后,根据上述实验结果和空气在不同压力和温度下的密度,研究了增压流化床在临界流化状态下,风机送风量随流化床压力和温度的变化规律。风机送风量在温度不变的情况下,随压力的增大而明显增加。然而,温度对其的影响随床料的平均粒径的不同而略有不同。

In order to study the minimum fluidization velocity of narrow and wide particle size distribution of quartz and ceramic sand, an experimental test has been carried out in a bubb- ling fluidized bed made of iron with inner diameter of 80 mm with pressure range of 101 kPa-6 000 kPa and temperature range of 20℃ -800℃. Results show that the minimum fluidized velocity reduce with the pressure at the same temperature. However, at a given pressure the influence of temperature on the minimum fluidized velocity is relied on average particle diameter of particle size distribution. Finally, based on the experiment results and air density at different pressure and temperature, the variation of air flow of forced draft fan with pressure and temperature was studied at critical status of pressurized fluidized bed. Air flow of forced draft fan increases with the increasing pressures significantly at the same temperature. But the influence of temperature on the air flow is almost the same among different average particle diameter of particle size distribution.