| In recent years, the demand for small berries is increasing rapidly in the food, medicine, chemical and other aspects,the market continues to expand, the economic benefits of its related industries were significantly enhanced.However, small berries harvest way in China is mainly artificial operation.due to the defects that short maturity of the small berries and heavy labor intensity, low efficiency, expensive investment of artificial havesting, its ascension of output and quality are limited.So the mechanization of small berry harvesting becomes the inevitable way of the development of small berry industry.At present,the harvesting machinery of the small berries harvesting operation in China is mainly vibration picking, because of huiting fruit tree mother branch easily, mixing with impurities easily and other defects, the application is not universal;However,the small berry air suction type harvester has the advantages of high efficiency and low fruit breakage rate, there are many applications of it abroad.Our research and development of small berry picking machine is still in infancy stage, the small berry air suction type havesting machine products is more rare.In order to meet the growing demand for small berry and expand the development of related industries, research and development of small berry air suction type havesting machine has important significance.Based on a comprehensive analysis of overseas and domestic research on the pneumatic harvesting techniques, we design a small berry air suction type harvester according to the physical characteristics of the small berries, and the main technical parameters were determined, establish a small berries air suction type harvester three-dimensional entity model. The small berry harvester has simple structure and low energy consumption, it can complete the small berry picking, gathering, conveying and other aspects of the joint operations. It mainly consists of fruit picking system, fruit conveying system, fruit selection system, fruit removal device and speed control system. This paper further develop the small berry air suction type harvester prototype, and select the black-gallon fruit as the conveying object, and we adopt 3 kinds of conveying pipes with different diameters. We take an experimental study on the working parameters of the prototype conveying system.Under the experimental conditions of this paper, with the increase of flow, the conveying efficiency of the 3 kinds of conveyer is all increased, and the fruit breakage rate also followed. The conveying efficiency of the diameter of 40 mm better than 32 mm and 50 mm, and the fruit breakage rate below 5%, which is based on experiment, has achieved the desired results. The optimum conveying efficiency diameter is 40 mm.By Fluent software and EDEM coupling numerical simulation software, the wind speed value in a pure gas phase conveying system simulation close to the test measured wind speed value, within the scope of the permit, proved that the simulation was feasible. Further expanding the scope of the blackcurrant’s conveying parameters, under the condition of same conveying flow, after the three kinds of pipeline simulation experiment, obtained the conveying system pressure distribution nephogram and velocity distribution nephogram, Then the pipeline pressure loss are obtained by pressure distribution nephogram convert the energy of the fruit and turbulence kinetic energy, according to the pressure loss, indirectly calculated the pipeline transport efficiency. The simulation test concluded that: The 30 mm diameter for phi duct, best work flow range is 1010-3-2010-3 m3 / s. The 40 mm diameter for phi duct, best work flow range is 1010-3-010-3 m3 / s. For phi 50 mm diameter pipeline, within the scope of the test failed to achieve the best value.The research results in this paper can provide technical basis for the development of new type of air suction small berry picking machine and has a certain guiding role for small berries mechanized harvesting operation. |
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