过渡角对脉冲气流干燥器干燥过程影响的研究

Influence of Transitional Angel on Drying Process in Pulsed Pneumatic Dryer

脉冲气流干燥器中的过渡角会对干燥器内流场产生影响,直接影响干燥器的干燥性能。设计7种不同大小过渡角的脉冲气流干燥器来进行对比研究,利用计算流体动力学对脉冲气流干燥器的干燥过程进行数值模拟。模拟结果表明过渡角过大时在过渡段产生了涡流,对干燥过程不利;随着过渡角增大,干燥器中的压降不断增大,湿含量逐渐降低;不同过渡角时颗粒在干燥器中的停留时间基本保持不变。通过对计算数据的分析,过渡角在60°左右时脉冲气流干燥器的综合效果最好。

In pulsed pneumatic dryer, the transitional angel will affect the flow field at the transitional section, and the flow field will affect the drying peorormance. A comparative study was conducted between 7 different transitional angels. By using the CFD technology, the numerical simulation was conducted. The result showed that eddy current was detected near the transitional section when the transitional angel is over 90°. With the transition angle increases, the pressure loss increases. The drying effect also has a certain improvement with the transition angle increases, which cause the final particles＇ moisture reduced gradually. The particles＇ residence time keep at the same level under different cases. By analyze all the data, the results shows that the comprehensive drying peoformance was best when the transitional angel is 60°.