Study On Shelling Method Of Castor Beans And Key Technology Of Rolling-rubbing Shelling Machine

Abstract:Castor-oil plant is a crop of high economic value, ecological benefits and huge market need. For the past few years, with the increasing amount of castor-oil plant in China, hulling machine has been playing an increasingly important role in the process of castor-oil plant production. At present, there exist some common defects for most domestic hulling machines, such as low hulling ratio, low productivity and high loss ratio. This cannot meet both the quality and quantity requirements in the process of agricultural modernization. In addition, as there is little research on the shelling mechanism for castor-oil plant/with the scarcity of shelling mechanism for castor-oil plant, it is difficult for the designer of hulling machine to get theoretical guidance. Based on the above, research on castor shelling is quite necessary. The contents of this thesis are as follows:1) The castor-oil plant type Xiang Bi#1produced by Hunan Provincial Academy of Forestry is used as the research object. The influence of shape parameters and moisture content on the performance of shelling has been analyzed. Meanwhile, measurement on shape parameters and moisture content from maturation period to harvest time has also been finished.2) The influence of imposing force and acting position on b shelling capability has been studied and analyzed. Experiment on castor beans under the condition of imposing force is accomplished and their mechanical properties are analyzed.3) Finite element method is adopted to study the mechanical properties of castor bean. Finite element model of the castor bean is established and simplified. After the shelling test, the experimental result is compared with finite element simulation of the mechanical characteristics under pressure loads with the aim to verify the feasibility of the finite element method. The simulation is compared to the experimental result which proves the accuracy of simulation. The mechanism of shelling is further analyzed.4) Rolling and rubbing is proposed as the shelling method based on the physical characteristics and mechanical performance of castor beans. The design theory on key parts of this type castor hulling machine is proposed and the parameters of the key parts are extracted. Further, the3-D model of the key parts is established and modal simulation is done. Finally, the mathematic model between productivity rate and hulling ratio is established.5) Improvement is made to the existing rolling and rubbing type hulling machine based on the design theory. Through statistical knowledge, the orthogonal experiment and quadratic regression general rotation tests is designed to explore the impact of this type hulling machine’s parameters on experimental indexes and to explore mutual restraint relationship among these factors.