In order to reduce the waste grain of the semi-spherical conic-column grain
a model was built with the UG NX software and the calculations were programmed with the MATLAB software
the relations between the waste grain rate and the design parameters were obtained. The calculated results showed that the larger radius of circular groove meant the smaller waste grain rate and the decrease of waste grain rate. There was a negative correlation between the waste grain rate and the radius of the inner hole
the larger value meant the smaller waste grain rate. There was an approximate parabola relation between the waste grain rate and the radius of the circular center of the circular groove. When the value became big
the waste grain rate increased first and then decreased. The waste grain rate is approximately linear with the length of the cylinder
the larger value meant the higher residual rate. The maximum relative error between the calculated result and the actual data was 0.084%.