Parameters optimization of vertical axial flow thresher for soybean breeding

In order to find the optimal combination of the structure and working parameters of the vertical axial-flow soybean breeding thresher , and experiments were conducted to study the effect of the structure and working parameters for threshing, separating and cleaning. The structure and working principle were introduced. A central composite rotatable orthogonal experimental design of response surface methodology was employed for finding the optimum combination effecting on the working properties. The four parameters: linear velocity, concave clearance, feeding rate and moisture content were selected as input variables. Cracked grains, impurities, loss of entrapped grains, loss of unthreshed grains, spattered grains and residual grains were selected as response functions. Experimental results indicated that the most optimum combination region of the moisture content was 14-20%, the linear velocity was 6.5-8.3 m/s, the concave clearance was 15 mm, the feeding rate was 2.4 kg/min, the cracked grains were less than 1%, impurities were less than 0.5%, loss of unthreshed grains were less than 2% and loss of entrapped grains were less than 0.7%. Spattered grains and residual grains were zero.