Design of Orchard Fertilizer-Soil Mixing Device Based on Discrete Element Method

Given the uneven distribution of fertilizers of traditional orchard furrowing fertilizer spreaders, a spiral fertilizer mixing device based on furrowing fertilization was designed.The key components of the fertilizer mixing device were designed by analysing the force and movement of the particles in the proposed device.With the help of the discrete element software, an orthogonal combination test of secondary rotation was conducted for the fertilizer mixing device, with the blade angle and rotation speed of the screw auger as the test factors and Lacey index as the test index.Results shows that, when the spiral angle of the auger blade is 18° and the rotation speed of the auger is 104 r/min, the Lacey index of the fertilizer-soil mixture is 0.8 at a furrow soil thickness of 20 cm.When the soil thickness is 40 cm, the Lacey index of the fertilizer-soil mixture is 0.76, and the errors, with predicted values, of the model are 13.04 % and 9.52 %.The uniformity of the fertilizer-soil mixture of the device meets the operating requirements of furrowing fertilization and can provide a significant reference for improving the uniformity of fertilizer-soil mixtures for furrowing fertilization in orchards.