In the patents pavilion of the Fifth Asia-Pacific Fair, the attention of numerous visitors was riveted by an onthe-spot demonstration. Standing before them was a machine with a stainless steel casing partly in a conta...In the patents pavilion of the Fifth Asia-Pacific Fair, the attention of numerous visitors was riveted by an onthe-spot demonstration. Standing before them was a machine with a stainless steel casing partly in a container of clear water. The operator pressed a button and ripples appeared on the surface of the water. The operator took watch chain s and jewellery from the visitors and put them in展开更多
In order to clarify and enhance the work performance of the threshing and cleaning machine for plot-bred wheat and further reduce the grain retention in all working areas in the machine,in this study,a discrete elemen...In order to clarify and enhance the work performance of the threshing and cleaning machine for plot-bred wheat and further reduce the grain retention in all working areas in the machine,in this study,a discrete element model for the threshing material of plot-bred wheat and a gas-solid coupling simulation model for the machine were established by ensuring all the harvesting criteria for the machine.Then numerical simulation was completed on the movement process of the threshing material in the threshing and cleaning machine for plot-bred wheat,the movement law and motion trajectory of all components of the threshing material were explored,and the impact forms of unreasonable work parameters on the separating and cleaning process were analyzed.First,four working areas were divided in the threshing and cleaning machine for plot-bred wheat.Under gas-solid flow coupling effect,the number variation of threshing material in each working area was analyzed under the effect of gas-solid coupling,and the operation characteristics of“no retained seeds and convenient cleaning”of the threshing machine for plot-bred wheat were further improved.The verification test results showed that,when the feeding amount of wheat was 0.30 kg/s,the rotation speed of the shaft of the tooth-type threshing cylinder was set to 1350 r/min,the rotation speed of the winnower was set to 500 r/min,the rotation speed of the residue absorption fan was set to 1000 r/min,the average total loss rate in threshing of the sample machine was 0.56%,and average impurity rate of the threshing material was 5.26%,average damage rate in threshing was 0.68%.In the test,the status of material discharged from the residue absorption fan outlet and bottom of the cyclone separator was similar to that of the simulation results,showing that it was feasible to use the method of gas-solid coupling to simulate the movement law of threshing material in the threshing and cleaning machine for plot-bred wheat.展开更多
文摘In the patents pavilion of the Fifth Asia-Pacific Fair, the attention of numerous visitors was riveted by an onthe-spot demonstration. Standing before them was a machine with a stainless steel casing partly in a container of clear water. The operator pressed a button and ripples appeared on the surface of the water. The operator took watch chain s and jewellery from the visitors and put them in
基金The authors acknowledge that this work was financially supported by China Agriculture Research System of MOF and MARA(Grant No.CARS-14-1-28)Agricultural Research Outstanding Talents Training Program(Grant No.13210261)+1 种基金Fuxi Young Talents Fund of Gansu Agricultural University(Grant No.Gaufx-03Y01)Youth Tutor Fund of Gansu Agricultural University(Grant No.GAU-QDFC-2021-08).
文摘In order to clarify and enhance the work performance of the threshing and cleaning machine for plot-bred wheat and further reduce the grain retention in all working areas in the machine,in this study,a discrete element model for the threshing material of plot-bred wheat and a gas-solid coupling simulation model for the machine were established by ensuring all the harvesting criteria for the machine.Then numerical simulation was completed on the movement process of the threshing material in the threshing and cleaning machine for plot-bred wheat,the movement law and motion trajectory of all components of the threshing material were explored,and the impact forms of unreasonable work parameters on the separating and cleaning process were analyzed.First,four working areas were divided in the threshing and cleaning machine for plot-bred wheat.Under gas-solid flow coupling effect,the number variation of threshing material in each working area was analyzed under the effect of gas-solid coupling,and the operation characteristics of“no retained seeds and convenient cleaning”of the threshing machine for plot-bred wheat were further improved.The verification test results showed that,when the feeding amount of wheat was 0.30 kg/s,the rotation speed of the shaft of the tooth-type threshing cylinder was set to 1350 r/min,the rotation speed of the winnower was set to 500 r/min,the rotation speed of the residue absorption fan was set to 1000 r/min,the average total loss rate in threshing of the sample machine was 0.56%,and average impurity rate of the threshing material was 5.26%,average damage rate in threshing was 0.68%.In the test,the status of material discharged from the residue absorption fan outlet and bottom of the cyclone separator was similar to that of the simulation results,showing that it was feasible to use the method of gas-solid coupling to simulate the movement law of threshing material in the threshing and cleaning machine for plot-bred wheat.
