Key Technology Research And Equipment Development Of Tomato Seeds Coating Granulation

China ranks first worldwide in tomato planting area and production, however, Chinese tomato industry and its mechanization is limited by absent seed processing equipment. Currently, the troubles for seed processing equipment, especially light-small seed coater, are imperfect technology, insufficient automation, poor quality pelleted seed and low operating efficiency. To shoot these, comprehensively employing both theoretical and experimental analysis, a prototype of tomato seed coating and drying integrated processing equipment was developed and evaluated.The main research content and conclusions are as follow:1. Based on analysis of operational principle and key technology of tomato seed coating pelletization, automation and precision controlled coating pelletization equipment was designed. Specifically, precision feeding device and coating agent and liquid precision supplying technology under different relative motion mode were studied. Multi parameters dynamic analysis was on-line optimized and the adaptively adjusted. Instead of traditional seed and coating agent supplying mode, the independent metering pump for precision measuring and controlling seeds and suspension liquid was developed, resulting mechanized feeding, liquid supplying, coating and pelleting.2. The relation model of heat energy utilization and drying efficiency of drying equipment was researched, developing Hollow Square drying equipment. The structure, parameters and transmission principle were studied based on the whole machine. By calculating each working parts parameters, each working parts parameters and transmission ratio based on mechanical transmission were concluded.3. To realize high-efficiency, precision and automation of tomato seed coating and pelleting machine, STEP 7-MICRO/WIN software was employed to design a control system with core of PLC controller, frequency converter and servo motor, which realizes fully automatic, highly efficient and stable running of coating machine, and greatly enhances working efficiency of the machine.4. The parameters of tomato seed coating and pelleting machine were optimized. Using orthogonal and regression test was taken with the 3 indicators of compressive strength, the containing seed rate and the germination percentage, and factors of roller speed, coating time, coating agent weight and suspension liquid volume. Then by using the DPS software, to statistical analyze the experiment data, the influence of the roller speed, coating time, coating agent quality and liquid suspension volume on the compressive strength, the containing seed rate and the germination percentage was obtained. The optimal parameters were the roller speed of 500 r/min, the coating time of 300 s, the coating weight 55 g, and the liquid suspension volume of 40 ml. Accordingly, the compressive strength was 316.8 g, the containing seed rate was 87%, and the germination percentage was 93%, which indicated that mechanism met the requirement of actual testing.The coating and drying integrated tomato seed processing equipment developed preliminarily solves the problem of tomato seed pelletization, and this enable enhances equipment automation enhancement, coating and drying process precision, and even theoretical reference to promote light-small seed coating technique.