陶瓷过滤器脉冲反吹全过程的瞬变流场计算

NUMERICAL CALCULATION OF TRANSIENT FLOW FIELD OF CERAMIC CANDLE FILTER DURING PULSE CLEANING PROCESS

采用二维轴对称非稳态流动模型对陶瓷过滤器脉冲反吹全过程中滤管内外的瞬变流场进行了数值模拟 ,所计算的滤管外径向速度波形与实验测定结果基本吻合 ,给出了从正常过滤过程到脉冲反吹结束的全过程中引射区域和滤管内速度场及温度场的变化 ,分析了反吹气体温度对滤管内温度分布的影响 .模拟结果表明 ,过滤器的操作温度与反吹气体温度差提高 。

On the basis of experimental results, the flow in the pulse-jet space and inside ceramic candle filter is regarded as a two-dimensional, unsteady, compressible arid axisymmetric flow. The flow across the ceramic tube wall is considered as unsteady Darcy flow. The κ-Ε two-equation turbulence model and energy equations are used to account for the turbulence and heat-transfer effects. The flow procedure can be used to calculate the transient flow characteristics of rigid ceramic candle filter during the whole pulse cleaning process. The numerical predictions of flow field are in good agreement with the experimental measurements. The effects of pulse gas temperature and filter operating temperature on flow field are numerically investigated. The numerical calculations provide the theoretical basis for optimum design of pulse cleaning system and understanding of the filtration mechanism inside ceramic filter.