Design and Simulation of Buckwheat Clean Threshing Device

Aiming at traditional buckwheat threshing device，closed cut-flow threshing drum device with buckwheat，problems of residual grain，and high impurity content during threshing process，a clean system design study was carried out.The system included two wind-speed inlets.Each wind speed inlet was composed of a small pipe with a length of 820 mm and a diameter of 27 mm in the same direction as grain barrel threshing drum.Each small pipe had circular holes with a diameter of 12 mm and an interval of 6 mm，used to clean up remaining kernels in the threshing device.The ANSYS Fluid Flow（Fluent）fluid dynamics simulation technology was used to simulate wind field of bar-closed tangential threshing device.Results showed that，when two inlets worked at the same time and wind speeds of 12 and 15m/s were used，cleaning wind speed approximately equal to critical value of floating speed of buckwheat grains.Under this condition，increasing wind speed inlet area，flow velocity between threshing drum and grid concave plate was 3.8～8.3 m/s，which was greater than floating speed of buckwheat grains; velocity of flow field under the grid concave plate was 7～15 m/s，and negative pressure in the flow field was reduced，which was the best choice.