Design And Experimental Study Of Shelling Machine For Camellia Oleifera Fruit

Camellia oleifera is China’s unique woody oil resources, which is known as the four major woody edible oil resources together with olive, coconut and palm. The camellia seed oil has high nutritional value, in which the content of oleic acid and linoleic acid amounts to 90%. And it is rich in tea polyphenols and other active ingredients. However, the shelling of camellia oleifera fruit still 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 index, three following aspects were studied based on the existing shelling equipment and practical engineering experience in this paper.Firstly, the physical parameters and mechanical properties of camellia oleifera fruit were studied. Using the camellia oleifera fruit from Changning city of Hunan Province as experimental subject, the parameters such as water content, grain size, density, bulk density and the proportion of each component were measured. And the maximum damage load were measured by squeezing the camellia oleifera fruit with different forces. The results indicate that the water content of the fresh camellia oleifera fruit, shell and seed is 60.08%,74.55%,45.60%, respectively. The particle size distribution is 20-50 mm, the density of the fresh camellia oleifera fruit, shell and seed is 0.978g/cm3、0.852g/cm3、1.021g/cm3, respectively, and the bulk density of camellia oleifera fruit is 0.52 kg/L. All of those provide data for the design of shelling machine components.Secondly, the mechanism and main structure of the shelling machine were studied. In the beginning, the merits of commonly-used methods of shelling were summed based on their working principle, together with the practical engineering experience and the data measured 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, arc grid plate and the adjusting rod, and the separation device consisting of stirring shaft and circular groove structure screen. Finally, the 3-D prototype model was established and the drawing design was completed.Thirdly, operating parameters of shelling machine for camellia oleifera fruit were studied. Based on the structure design, the shelling machine for camellia oleifera fruit was manufactured, and then the operating parameters optimizing test was made. In the experiment, the water content, shelling gap, speed of shelling motor and speed of separation motor were made as single factors, respectively, and the shelling rate and seed breaking rate were made as index. The effect trend of these factors on the index was drew out. Based on this conclusion, the orthogonal experiment was made, from which the optimal aggregative parameters are that the speed of shelling motor is 125 r/min, the speed of separation motor is 343 r/min and the shelling gap is 12 mm. And under this condition, the shelling rate is 96.91%, the seed breaking rate is 3.38% and the production capacity is up to 2 t/h. The optimal parameters achieved in this paper can provide reference for the actual application of shelling machine for camellia oleifera fruit, which meets the actual production requirements and can provide technical support for camellia fruit shelling. And it will benefit the processing industry of camellia oleifera fruit.