| In order to solve the problem of high loss rate of Camellia oleifera seed shell toothed-smooth roller sorting machine, using the physical properties differences of the seeds and shells after hulling of Camellia oleifera green fruit, the spiral- propelled type Camellia oleifera seed shell low -loss sorting machine was designed, the key parameters such as screw roller diameter, length and speed, thread form, screw pitch and helix angle were designed to establish a force model for Camellia oleifera seed. Taking the sorting rate and the loss rate of Camellia oleifera seed as the evaluation indexes, single-factor test and response surface methodology were used to optimize the operating parameters such as feeding rate, screw roller speed and roller spacing.The results showed that the sorting machine designed had a screw roller with diameter of 50 mm, length of 1 000 mm，speed not exceeding 200 r/min and pitch of 50 mm, and the thread were arranged in the form of a double helix， the cross-section of the thread was in the form of a right-angled trapezoid, with a working inclination angle of 120°, and the height of the thread was 4 mm; the helix angle was 30°.The optimized operating parameters were the feeding rate 1.1 t/h, the screw roller speed 170 r/min, and the roller spacing 12 mm,in addition designing brushes on the upper plane of the sorting machine to increase the probability of adjusting the posture of the Camellia oleifera shells during the sorting process. Under the optimal conditions, the sorting rate and the loss rate of Camellia oleifera seed were 90.39% and 0.54%,respectively. In conclusion, the designed spiral-propelled type Camellia oleifera seed shell low-loss sorting machine reaches the expected design goal, which can better complete the sorting operation of Camellia oleifera seed shell mixture, and at the same time significantly reduce the loss rate of Camellia oleifera seed. |
