核桃壳仁混合物风选机工作参数优化与试验

Optimization and experiments on working parameters of winnowing machine for walnut shell and kernel mixture

目的:提高核桃壳仁混合物清选效率,减少损失。方法:研制了一款小型负压式核桃壳仁风选机。基于清选率与损失率2个分离效果指标,采用单因素试验和响应曲面试验优化风选机的工作参数。结果:对于1/2壳仁、1/4壳仁、1/8壳仁、1/16壳仁物料的最优工作参数:喂料速度分别为4.0,3.5,3.0,2.5 kg/min;风机频率分别为40,35,30,30 Hz;进料口高度分别为400,400,300,300 mm。从不同等级的核桃壳仁物料分离效果可以看出,1/2壳仁物料,1/4壳仁物料的分离效果最佳,但对于1/8和1/16较小壳仁物料其悬浮速度重合区间大。结论:通过控制风选机的工作参数可以有效地实现壳仁分离,但较小颗粒的壳仁物料悬浮速度重合区间大,分离难度大。

Objectives:To meet the requirements of high cleaning rate and low loss rate.Methods:A small negative pressure winnowing machine for walnut shell and kernel mixtures was developed.Single factor test and response surface optimization method were used to analyze the working parameters of winnowing machine based on such two separation effect indicators as cleaning rate and loss rate.Results:For 1/2 shell kernel,1/4 shell kernel,1/8 shell kernel and 1/16 shell kernel materials,the optimal feeding rates were 4.0,3.5,3.0,2.5 kg/min,the fan frequencies were 40,35,30,30 Hz,the feeding inlet heights were 400,400,300,300 mm,respectively.It was seen from the separation effect of different grades of walnut shell materials that 1/2 and 1/4 shell kernel materials had the best separation effect.Conclusion:Shell and kernel separation can be effectively realized by controlling the working parameters of winnowing machine.It is difficult to separate 1/8 and 1/16 shell kernel materials for the overlapping range of suspension speed of shell and kernel materials.