负压区的存在对刚性陶瓷过滤器脉冲反吹性能的影响

利用压电式压力传感器测定了陶瓷过滤器在脉冲反吹过程中滤管内动态压力的变化规律，表明在脉冲反吹快要结束和正常过滤尚未开始的过渡过程中，滤管内存在严重的负压区。利用单个颗粒轨道模型分析了部分已被吹离滤管表面的小颗粒在负压区的作用下会重新返回到滤管壁，从而证实了负压区是影响刚性陶瓷过滤器稳定运行的重要原因。

EFFECT OF NEGATIVE PRESSURE REGION ON PULSE-JET CLEANING PERFORMANCE OF RIGID CERAMIC FILTERS

In a ceramic filter experimental set-up with three filter candles, the dynamicpressures at the inner wall of one filter candle during pulse-jet cleaning are measured byusing resize-electric pressure transducer. The experimental results show that the dynamicpressure in whole pulse-jet cleaning process consists of two parts. One is the positive pressurein the filter candle greater than the pressure outside the filter candle which corresponds tothe outward radial fluid flow to break up and dislodge the dust cake on the surface of thefilter tube. The other is a negative pressure region which is responsible for inward radial flowwhile the pulse-jet is closed. The influences of reservoir pressure on the dynamic pressureare discussed. The calculation results of particle motion indicate that negative pressureregion cause a fraction of particles removed re-deposit on the candle surface. Especially finerparticles is more easterly re-deposited on the surface to form thin and dense layer on the filtercandle and to increase gradually the residual Pressure drop across the candle. It is concludedthat negative pressure region may have important effects on the long--term stable operationof the filter unit.