上吸风环形风道碾米机设计与试验

Design and experiment of the top-suction rice mill with annular air duct

针对卧式碾米机收集到的米糠混有碎米的缺陷,设计一种具有环形风道的上吸风式碾米机,可直接对米糠和碎米进行分离收集。运用Fluent对该新型碾米机流场进行分析,采用多孔介质模型模拟碾白室内糙米对气流的阻碍作用,并搭建样机利用PIVlab软件进行观测,结果表明:当上吸风口与喷风机风速分别为6 m/s和10 m/s时,环形风道内形成环形绕流,流速分布均匀、流场稳定,平均风速为4.1~4.6 m/s,垂直方向分速度为2.0~6.5 m/s,介于米糠与碎米悬浮速度之间;气压隔板形成狭管效应,上升气流从1.4 m/s加速至3~4 m/s;喷风槽附近米筛网内外压差最大约5550 Pa;试验证明碎米与米糠的分离效果良好。

For the defect that the rice bran collected by the horizontal rice mill is mixed with broken rice,a top-suction rice mill with an annular duct was designed,which can directly separate and collect the rice bran and broken rice.Based on the Fluent,the flow field of the new rice mill was analyzed,and the porous media model was used to simulate the blocking effect of brown rice on airflow in the milling room,and a prototype was built and observed by PIVlab.Simulation results show that when the wind speeds of the upper suction port and the blower are 6 m/s and 10 m/s,respectively,an annular flow around the rice sieve was formed in the annular duct,and the flow velocity and direction was uniform.The average air velocity was 4.1~4.6 m/s,and the vertical velocity was 2~6.5 m/s,which is between the suspension velocity of rice bran and broken rice;The pressure partition can form the narrow tube effect,and the updraft was accelerated from 1.4 m/s to 3~4 m/s;The maximum pressure difference between the inside and outside of the rice sieve at the spout was 5550 Pa;Experiments prove that the separation of broken rice and rice bran was good.