EXPERIMENTAL RESEARCH ON THREE-LEVEL VIBRATING SCREENING OF BUCKWHEAT BASED ON DISCRETE ELEMENT METHOD

Abstract

To improve the operating effect of buckwheat classifying equipment and meanwhile reduce the dependence on tests in the process of operating parameter optimization of the equipment, this paper designed a three-level classifying screen for buckwheat, confirmed the structure and parameters of upper and lower sieves, established a three-level screening discrete element model for buckwheat with the EDEM software, and conducted the numerical simulation for the sieving processes at an amplitude of 24 mm, 28 mm and 32 mm, respectively. The results indicated that when the inclination angle of screen surface was 3°, the vibrational direction angle was 30° and the vibrational frequency was 4.5 HZ, as the amplitude increased, the conveying capacity of the classifying screen increased and at the same time the seed loss rate also increased, of which at 16 s, the loss rate was 0.03%, 0.37% and 1.42%, respectively; the proportion of medium particles in the collecting box of screen overflow was 2.88%, 8.65% and 17.65%, respectively; and the proportion of small particles in the collecting box of screen residue was 0.58%, 6.06% and 19.14%, respectively. Through comprehensive analysis of conveying capacity, screening loss and classifying effect, when the amplitude of the classifying screen was 28 mm, the classifying operating effect was good. This study can provide reference for the design and operating parameter optimization of buckwheat classifying equipment.