基于Fluent的小麦辊式制粉流场模拟及试验验证

Fluid Field Simulation of Wheat Milling Based on Fluent and Experiment Verification

为了研究小麦辊式制粉过程中芯磨辊间研磨区的流场特性和压力分布规律,探讨各操作参数对小麦粉质量的影响规律,以试验磨粉机的光辊研磨机构为研究对象,应用计算流体力学软件Fluent对喂料量分别为40、50、60 g/min、轧距分别为0.10、0.15、0.20 mm以及快辊转速分别为16、26、36 rad/s等不同操作参数下的粉磨流场进行了数值模拟,并通过磨粉试验对模拟结果进行了验证。结果显示:随着喂料量、快辊转速的增大,以及轧距的减小,快辊与物料接触面最大动压力及粉料颗粒流沿着定直线段的动压力增加,试验结果显示小麦粉中灰分减小;在制粉有效压缩区内,喂料量为60 g/min、快辊转速为36 rad/s、轧距为0.10 mm时,辊面压力沿磨辊轴向最为均匀,且定直线压力曲线斜率最大,试验结果表明,该工况下小麦粉中灰分含量最小,具有较好的制粉效果。

In order to research the properties of flow field characteristics and press distribution rules in wheat milling zone between reduction rollers, and discuss the effects of various operating parameters on the quality of the wheat flour, in this paper we took the smooth roller mill of the experiment flour miller as a research subject, and made use of the computational fluid mechanics software Fluent to simulate values of flour fluid field under different operating parameters such as the feeding quantity of 40,50 and 60 g/rain, and roll clearance of 0.10, 0.15 and 0.20 mm, as well as the rotate speed of the fast roller of 6,26 and 36 rad/s and the simulation results were validated by milling experiments. The results showed that, with the increase of feeding quantity and rotate speed of the fast roller, as well as the decrease of the roll clearance, the maximum dynamic stress between surface of roller and material, and the dynamic pressure of powder particles flow along the straight line segment increased, and experimental results showed that the ash content of flour decreased ; in the pulverizing effective compression zone, when the feeding quan- tity is 60 g/rain , and rotate speed of the fast roller is 36 rad/s, and the roll clearance is 0.10 mm, the roller surface pressure along roller is most even, and constant linear pressure curve slope is the largest, the experiment results showed that the gray - level of flour in this working status is minimum with better flour processing effect.