Design And Experimental Research Of Centrifugal Cone Disc Fertilizer

Rice is the main food crop in my country.Appropriate application of chemical fertilizers during rice production can effectively increase rice yield.Mechanized fertilization plays a vital role in rice production.Given the complex structure of and poor performance of existing machines for fertilizing rice,this research designs a mechanical centrifugal centralized fertilizer discharging device,which adopts the method of "spiral quantitative supplying and centrifugal cone uniform fertilization" for fertilization.The main contribution of this research is shown as follows:First,we measured the physical and mechanical properties of compound fertilizer particles.This research took Huangmailing compound fertilizer,a compound fertilizer commonly used in south china,as the research object.Through basic experiments in physics and material science,we measured the three-axis size,thousand-grain weight,bulk density,real density,angle of repose,static friction coefficient,dynamic friction coefficient,collision recovery coefficient,and other parameters of Huangmailing compound fertilizer particles.These measurements can provide basic data for the design of key components of the fertilizer device and the establishment of discrete element simulation models.Second,we designed a centrifugal cone-disc fertilizing device based on analyzing the development status of rice fertilizing machinery and comparing existing relevant machinery at home and abroad.We calculated and designed the structural parameters of key components of this fertilizing device.Besides,we also analyzed the movement of the fertilizer particles in the centrifugal cone and used Matlab 2014 to calculate and draw the trajectory diagram of the fertilizer particles in the centrifugal cone.Third,we used EDEM 2018(i.e.,a discrete element software)to simulate and analyze the centrifugal cone-disc fertilizer device.The three-dimensional model of the centrifugal cone-disc fertilizer discharging device and the discrete element model of compound fertilizer particles was established,and the simulation parameters were calibrated through the simulation test of the angle of repose of the fertilizer particles.Taking the centrifugal cone disc as the key parameters,the inclination angle of the centrifugal cone disc,and the minimum radius of the centrifugal cone disc as the test factors,we selected the coefficient of variation of the consistency of fertilizer discharge in each row as the evaluation index to conduct single factor test and orthogonal test.Finally,we clarified the inclination angle of the centrifugal cone and the effect of the minimum radius of the centrifugal cone on the fertilizer performance of the fertilizer discharging device.We also analyzed variance to determine the optimal parameter combination.Specifically,under the optimal parameter combination condition,the inclination angle of the centrifugal cone was 45°,and the minimum radius of the centrifugal cone was 60 mm.We also marked a fertilizer particle in the simulation test,derived the three-dimensional coordinate data of its motion trajectory,and used the Origin 2018 soft to draw the motion trajectory of the simulation test fertilizer particle.Last but not least,we designed and manufactured a test bench for a centrifugal cone-disc fertilizer device,and conducted a bench test.Taking three factors(i.e.,the spiral speed,the centrifugal cone speed,and the travel speed of the fertilizer discharging device)as the test factors,we selected the variable coefficient of fertilizer discharge stability,the coefficient of variation of fertilizer discharge consistency of each row,and the coefficient of variation of fertilizer uniformity as evaluation indicator to conduct the fertilizer performance test,static fertilizer test,and dynamic fertilizer test according to the NY/T1003-2006 fertilization machinery quality evaluation technical specifications.Finally,we established a regression mathematical model between evaluation indicators and various factors,analyzed the influence of each factor on the evaluation index through the response surface analysis,and performed the numerical solution of the evaluation index optimization simultaneously to obtain the optimal parameter combination of each operating parameter.Through the tilting discharge test,we simulated the field conditions to verify the fertilizer discharge performance of the fertilizer discharge device.The results show that the arithmetic mean of the coefficient of variation of fertilizer uniformity is 29.64%,which meets the requirements of NY/T1003-2006 fertilization machinery quality evaluation technical specifications(i.e.,the coefficient of variation of fertilizer uniformity should be no more than 40%).