Analysis Of Pneumatic Conveying System Of Ferlizer Applicator On The Side Of Rice

The way and amount of fertilizer applied in rice planting are the key factors to improve the yield.The traditional artificial fertilization will cause the problems of low fertilizer utilization rate and excessive fertilizer application.Many problems caused by artificial fertilization can be solved and the utilization rate of fertilizer can be improved by using the method of deep lateral fertilization.In view of the problems existing in the side deep fertilizer applicator of rice in China,this paper analyzes the characteristics of the pneumatic conveying system of the side deep fertilizer applicator of rice,studies the key component of the fertilizer exhauster throat channel by using the theory of gas-solid two-phase flow,and optimizes the working parameters and structural parameters of the pneumatic conveying system.On the basis of theoretical analysis,a kind of rice side deep fertilizer applicator with discontinuous fertilizer box in the middle was designed,and a prototype was developed to complete the field experiment.The main research work of this paper is as follows:1)CFD-DEM is used to simulate the gas-solid two-phase flow in the throat of the fertilizer exhauster by the coupling method of computational fluid dynamics and discrete element method According to the proportion of the volume concentration of the fertilizer particles,the coupling method of Euler langrand is selected to study the stress of the fertilizer particles,and the appropriate fluid drag model and lift model are selected according to the shape and size of the fertilizer particles and the shape of the materials.FL is used to simulate the flow Uent-edem software carries out gas-solid coupling calculation for gas fertilizer and establishes coupling numerical simulation model.2)The movement state of fertilizer in the throat channel of the fertilizer exhauster and the change rule of the pressure and velocity of the gas in the cavity were analyzed.Through the study of the influence of different throat section shape,throat length,fertilizer falling rate and air inlet pressure on the two-phase flow in the throat of the fertilizer exhauster,the better working and structural parameters of the pneumatic conveying system were determined,which provided theoretical and technical support for the improvement of the pneumatic conveying system of the rice side deep fertilization machine.3)The flow field of U-tube pneumatic system of rice side deep fertilization machine was analyzed.By using FLUENT software,the influence of air supply pipes with different diameters,elbows with different radii of curvature,windshields of branch pipes with different lengths,the ratio of air duct and air supply pipe diameter in the middle air intake mode on the air flow velocity of branch pipes is calculated.The velocity distribution diagram of each branch pipe under different conditions is drawn by using MATLAB software,and the better structural parameters of air supply pipes are analyzed.The air flow characteristics of the U-shaped air supply pipe and the straight air pipe with one side air inlet and the middle air inlet are compared and analyzed,and a more reasonable design scheme of the pneumatic system of the rice side deep fertilization machine is obtained4)On the basis of theoretical analysis,a kind of rice side deep fertilizer applicator without connecting fertilizer box in the middle is designed,the fertilizer exhausting fan is optimized,the prototype manufacturing and field test are carried out to verify the correctness of the theoretical design,and at the same time,the problem of poor safety and easy injury of the operators who install seedlings in the transplanter during the fertilization operation is solved.In view of the fact that the U-tube pneumatic system of the single side air inlet of the rice side deep fertilizer applicator in Dongfeng well is often blocked at the end of the fertilizer outlet,the simulation and test of the pneumatic conveying system are carried out,which further verifies the correctness of the theoretical research in this paper.