油茶果脱壳机的设计与工作参数优化

为改进油茶果脱壳机性能,提高脱壳率、降低茶籽破损率,该文研究了油茶果的物性参数和常用脱壳机的工作原理及结构特点,采用挤压、搓擦原理,设计了一种脱壳间隙可调节的油茶果脱壳机。选取脱壳电机转速、分离电机转速和脱壳间隙3个因素,以脱壳率和茶籽破损率为指标进行正交优化试验。研究结果表明:新收获的油茶果含水率平均值为60.08%,粒径分布范围为20~50 mm。脱壳间隙对指标的影响最为显著,优化后的脱壳电机转速为125 r/min,分离电机转速343 r/min,脱壳间隙12 mm,此参数条件下脱壳率为96.91%,茶籽破损率为3.38%,处理量可达2 t/h。该研究满足实际生产要求,可为油茶果脱壳加工提供参考。

Design of shelling machine for camellia oleifera fruit and operating parameter optimization

Abstract: In China, camellia oleifera fruit is deeply loved by consumers as specific woody oil resource. Because of the composition of fatty acid for camellia seed oil is highly similar to olive oil, it is also known as "Oriental olive oil". However, the shelling operation of camellia oleifera fruit largely relies on natural drying, which is of low efficiency, high labor intensity, high processing cost, and great dependence on weather. In order to improve the performance of shelling machine for camellia oleifera fruit, increase the shelling rate and reduce the seed breaking rate, choosing the shelling rate and seed breaking rate as the indices, 3 aspects were studied based on the existing shelling equipment and practical engineering experience in this paper. Firstly, the physical parameters of camellia oleifera fruit were studied. The parameters such as density, bulk density, grain size, water content and proportion of each component of camellia oleifera fruit from Changning City were measured, which provided the data for the design of shelling machine parts. Secondly, the mechanism and main structure of the shelling machine were studied. In the beginning, the merits and defects of commonly-used methods for shelling were summed based on their working principle and mechanism. According to practical engineering experience and the measured data above, the final squeeze-rub shelling method for camellia oleifera fruit was determined. Then the structure of main parts was designed, which included the shelling device consisting of the roller, annular plate and the regulating mechanism, and the separation device consisting of stirring shaft and circular groove structure screen. Finally, the three-dimensional (3D) prototype model was established and the drawing design was completed. Thirdly, the operating parameters of shelling machine for camellia oleifera fruit were studied. The shelling machine for camellia oleifera fruit was manufactured based on the structure design, and then the operating parameters' optimization test was made. In the experiment, camellia oleifera fruit's particle size, shelling gap, speed of shelling motor, speed of separation motor were taken as single factors, respectively, and the shelling rate and seed breaking rate were taken as indices. The influence trend of these factors on the indices was drew out. Based on the result, the orthogonal experiment was designed, which aimed at studying the effects of the speed of shelling motor, the speed of separation motor and the gap of shelling on shelling rate and seed breaking rate. The results indicated that the water contents of the fresh camellia oleifera fruit, shell and seed were 60.08%, 74.55% and 45.60%, respectively. The particle size distribution was 20-50 mm, and the bulk density was 0.52 kg/L. The optimal combination parameters were that the speed of shelling motor was 125 r/min, the speed of separation motor was 343 r/min and the shelling gap was 12 mm. And under the condition, the shelling rate was 96.91%, the seed breaking rate was 3.38% and the production capacity was up to 2 t/h. The optimal parameters achieved in this paper can provide reference and technical support for the actual application of shelling machine for camellia oleifera fruit. And it will benefit the processing industry of camellia oleifera fruit.