鲜莲子去皮机设计与参数优化

Design and Parameter Optimization of Fresh Lotus Seeds Peeling Machine

鲜莲子莲皮紧紧依附在莲仁表面,采用手工去皮成本高、效率低,难以满足生产需求。由于缺乏对水射流去皮机理及参数的研究,造成莲子去皮率低、损伤率高,为此设计一款基于水射流去皮的鲜莲子去皮机。将水射流压力、水射流倾角以及带轮直径作为影响去皮效果的因素,以去皮率、损伤率、带帽头率、开边率、掉莲率为评价指标,采用Design-Expert软件进行三因素三水平的响应曲面优化试验。结果表明:对去皮率、损伤率以及带帽头率的影响程度从大到小均依次为水射流压力、水射流倾角、带轮直径;对开边率的影响程度从大到小依次为水射流倾角、水射流压力,带轮直径对开边率的影响非常小;掉莲率都在1%左右,与3个影响因素无关。优化后最佳作业参数分别为:水射流压力0.7 MPa、水射流倾角18°、带轮直径68 mm,其指标预测值分别为:去皮率91.16%、损伤率0.96%、带帽头率2.40%、开边率0.04%。采用优化后的参数进行验证试验,得出去皮率为92.63%、损伤率为1.24%、带帽头率为2.72%、开边率为0.21%,各项指标的试验结果与理论预测结果的绝对误差均小于1.5%,验证了模型与所优化参数的合理性。

Lotus seed is a kind of nourishing food,which can be eaten and used medicinally.The fresh lotus seed is mainly composed of lotus shell,lotus kernel,lotus seed coat,lotus core,etc.The lotus shell is wrapped in the outside of the lotus kernel,and the lotus seed coat is tightly attached to the surface of the lotus kernel,while the lotus core grows in the inside of the lotus kernel.In order to improve the taste,the seed coat usually should be removed before eating due to the bitter astringent taste.However,the lotus seed coat is very difficult to be removed,and manual peeling is laborious.A fresh lotus seed peeling machine was designed based on water jet.To improve the operation performance of the machine,the operation parameters of the peeling machine were studied.The water jet pressure,water jet angle and the processing speed were chosen as the main factors,and the peeling rate,damage rate,with head rate,openside rate and drop rate were chosen as the main evaluation indicators.The three-factors and three-level response surface was designed by the Design-Expert software.The test results was showed as follow:considering the effect of peeling rate,damage rate and with head rate,the degree order of influence from big to small was water jet pressure,water jet angle and processing speed;considering the effect of openside rate,the degree order of influence from big to small was water jet angle,water jet pressure and processing speed,but the effect of processing speed on the openside rate was very small;these test factors had almost no effect on the drop rate,and the drop rate was almost 1%,which was perhaps caused by other unknown factors.The optimal operating parameters of the machine were as follows:the water jet pressure was 0.7 MPa,the water jet angle was 18°,and the pulley diameter was 68 mm.The predicted value was as follows:the peeling rate was 91.16%,the damage rate was 0.96%,the with head rate was 2.40%,and the openside rate was 0.04%.The machine was adjusted to the optimized parameters for verification tests,the peeling rate was 92.63%,the damage rate was 1.24%,the with head rate was 2.72%,and the openside rate was 0.21%.Comparing the above results,it can be seen that the absolute errors of the experiment results and theoretical optimization results were controlled within a relatively small range,which verified the rationality of the model and the optimized parameters,these work would provide a theoretical basis for the performance improvement of fresh lotus peeling machine.