Abstract:Small-scale pellet mill has many advantages, such as small mass production, less energy and raw materials consumption and low costs. Recently many researches were focused on the pelleting experiments, but the lack of small-scale pellet feed machine had become a problem of the influence of different formulas and processing conditions on pellet feed quality. To solve the problem, a structure of small-scale pellet mill was designed, which consisted of ring die and its matching components, roller and its matching components, transmission mechanism, etc. The prototype was manufactured and the production experiment was conducted. The adjusting mechanism for the roller was located outside the chamber, so the gap between roller and ring die could be real-timely adjusted when the production was in process. The structure could ensure that the production of pellet feed would be non-stop. Based on elastic-plastic theory and continuum mechanics, the software Abaqus and its built-in Drucker-Prager Cap material model were used for the numerical simulation and analysis of the pelleting process. The simulation results showed that the gap between roller and ring die should be adjusted with the friction coefficient of raw materials;proper increase of raw materials’ friction coefficient could avoid internal sliding and energy consumption, which could help to improve the yield and quality of pellet feed. Some suckling pig feed formula was taken as raw material to be produced, and the performance indicators of the pelleting mill were determined. The experiment results showed that the moisture content was 13.53%, diameter of the pellet feed was 3mm, pellet durability index was 94.34%, hardness of pellet feed was 176.03N, and productivity of the pelleting mill was about 42kg/h. All the indexes met the design requirements, which could meet the production need of small-scale pellet mill. The design of the pelleting mill and experiment research provided reference for the pelleting technology and development of the similar equipments.
