Impurity Removal From Corn Mixture Based On Solid-solid Phase Separation

In practice,it is inevitable to adulterate impurity into corn stover in the process of corn collection and the impurity is mainly sand.The sand can cause great wear on process piping,impeller,volute and cover of pump,and stirring paddle,these increase equipment and operating costs and reduce production efficiency. Therefore,the impurity removal from corn mixture is necessary.Corn mixture are solid-solid phase system,and are studied to separation using gravity sedimentation.The determination of particle-size distribution is systematically studied by sieving analysis and wind winnowing.Based on the characteristics of sand’s and corn stover’s size,settling chamber is designed and produced,the internal flow should be analyzed and simulated,and separation efficiency will be tested. The result shows that particle-size distributions are basically the same using sieving analysis and winnowing.when the particle size is greater than0.045mm,the two methods are equivalent. Then the curves of particle-size distribution of sand and corn stover are measured and calculated,respectively is Fsan(dVsand)=1-e-34981dVsand1.94.1and Fcorn(dVcorn)=1-e-0.5590dVcom1.1312.In the designed settling chamber,internal flow is in line with assumptions that the drag coefficient of horizontal and vertical direction are constant,and this assumptions are also confirmed by FLUENT simulation.And when the corn yield of75.62%,the purity of94.5%;when the product purity of99.74%,the yield of merely15%,separation efficiency of settling chamber should be further improved.