Research On Pressure Swing Shelling Of Fresh Lotus Seed Based On FEA And Experiment

Fresh lotus seeds is an effective traditional Chinese medicine and tonic.As the demand of fresh lotus seeds and its products increases greatly,the planting scale of lotus seeds and the sales of lotus seeds related products also increase greatly,which brings great opportunities for lotus seeds production and processing enterprises,but it also brings great challenges.Although the domestic has developed a variety of models of semi-automatic,automatic lotus seed sheller,compared with the traditional manual sheller method,in the efficiency has been greatly improved,but because of different shapes and sizes of lotus seeds,in the production of mechanical force will lead to failure or damage lotus seed sheller.According to the above problem,this paper proposes a pressure swing shelling for fresh lotus seed,fresh lotus seed shape and the size and the relevant physical parameters for mass test,in-depth analysis of the feasibility of this method and the pressure swing shelling is obtained by simulation and experiment the optimal condition,fresh lotus seed for the future pressure swing sheller design and the research provides a theoretical support.The main work contents of this paper are as follows:(1)The mechanism of the method of pressure swing shell removal is analyzed and the preliminary tests are carried out.A new method for removing shell of fresh lotus seeds is proposed by using energy theory: the method of pressure swing of fresh lotus seeds is used to remove the shell.The feasibility of the method is analyzed theoretically.Then,the preliminary pressure shelling test of fresh lotus seed was carried out by using the purchased simple pressure device,which preliminarily proved the feasibility of this method,and got the conclusion that slit pretreatment was needed before fresh lotus seed was shelled.(2)The geometric dimensions and physical parameters of Hunan lotus seeds were measured,including middle diameter,long diameter,shell thickness,density,weight,sphericity,overall size of fresh lotus seed and lotus shell structure,lotus shell hardness and elastic modulus,lotus kernel elastic modulus and Poisson’s ratio.(3)The finite element model of fresh lotus seeds under different pretreatment conditions was established,and the process of pressure deformation and shelling of fresh lotus seeds was simulated by ANSYS software in finite element.The maximum stress and the maximum deformation of lotus shell were used to measure the effect of pressure swing shelling method.The key process parameters(different pretreatment conditions,different pressures)that affect the effect of shelling were simulated and analyzed.(4)In order to verify the accuracy of the simulation,the experiment of fresh lotus seed pressure swing shelling was carried out by using the laboratory scale pressure swing shelling machine.Through the above theoretical analysis,finite element simulation and experimental results,it was shown that with the increase of pressure,the maximum stress and the maximum deformation of lotus shell of fresh lotus seed with the same slits and slits depth also increased.The maximum stress and the maximum deformation of the lotus shell under the same pressure also increased with the increase of the depth of the slit.Under the same pressure and slitting depth,the effect of shelled fresh lotus seeds with long diameter slitting was better than that of fresh lotus seeds with middle diameter slitting.The failure rate of shell kernel separation and failure rate of lotus kernel caused by traditional mechanical method of shelling fresh lotus seed can be effectively reduced by using pressure swing shelling method,which provides a new method and reference for the research and development of fresh lotus seed sheller in the future.