滚筒筛式膜杂风选机筛孔清堵装置设计与试验

Design and Test of Screen Hole Clearing Device for Trommel Sieve Type Membrane Miscellaneous Wind Separator

为解决滚筒筛式膜杂风选机运行过程中易发生筛孔堵塞,导致筛分性能差、膜中含杂率高等问题,设计了一种通过喷头喷射气流扰动筛孔处流场、破坏堵塞物在筛孔处受力平衡的筛孔清堵装置。该装置包含对角安装在滚筒筛式膜杂风选机两侧的离心式鼓风机、稳压管、滚筒外缘的气流管道等。通过理论分析确定了筛孔清堵的临界气流速度为1.151 m/s,采用计算流体力学仿真与曲线拟合的方法探明了风机风速与喷头喷射气流速度呈正相关关系,最终确定风机风速为9.2 m/s。设计并搭建样机进行试验,结果表明:当风机风速为9.2 m/s时,筛孔堵塞率为8.28%,膜中含杂率为7.33%,较安装筛孔清堵装置前筛孔堵塞率、膜中含杂率分别降低16.27、4.64个百分点,其中各喷头喷射气流速度平均值为3.81 m/s,最小值为1.22 m/s,满足清堵要求,清堵装置持续工作过程中,筛孔堵塞率和膜中含杂率基本保持不变。

In order to solve the problem that the screen holes are prone to clogging during the operation of the drum screen type film and debris separator,resulting in poor screening performance and high debris content in the film,a screen hole clearing device was designed to disturb the flow field at the screen holes by spraying airflow from the nozzle and disrupt the balance of force of the clogged material at the screen holes.The device consisted of a centrifugal blower mounted diagonally on both sides of the drum screen type film separator,a pressure stabilizing pipe and an airflow duct on the outer edge of the drum.The critical air velocity for screen hole cleaning was determined to be 1.151 m/s by theoretical analysis,and a positive correlation between fan air velocity and nozzle jet air velocity was investigated by using computational fluid dynamics simulation and curve fitting to determine a final fan air velocity of 9.2 m/s.The prototype was designed and tested,and the results showed that 8.28%of the screen holes were clogged and the rate of debris in the film was 7.33%,which was 16.27 and 4.64 percentage points lower than before the installation of the screen hole clearing device.The average jet air velocity of each nozzle was 3.81 m/s and the minimum value was 1.22 m/s,which met the requirement of clearing the blockage,and the blockage rate of the screen pore and the rate of impurities in the film remained basically unchanged during the continuous operation of the clearing device.The research result can provide reference for the design of various forms of screen hole clearing devices.