Results of determination of aerodynamic parameters of feed preparation crushers in Ansys CFX software

Abstract

Compound feed production requires grinding of grain, coarse feeds and other ingredients. To perform these operations, hammer crushers with pneumatic supply of material are used which do not always meet the requirements of agricultural producers. The use of modern programs of numerical modeling of processes and phenomena in the field of dynamics of liquids and gases at the stage of creating crushers will determine the most rational structural and technological schemes of such devices. The research goal was to determine the effect of the design features of crushers on their aerodynamic parameters through computer modeling in the Ansys CFX software. To determine the impact of additional blades, Ansys CFX has developed computer models of a commercially available DKR-1 grain crusher and an advanced DKR-1-based crusher (with a fan rotor), and to study the circulation of air flow in the crusher depending on the total area of the outlet sieve, computer models of the crusher for producing wood meal with two values of the total sieve area S₁ = 0.070 m² and S₂ = 0.157 m² at the outlet of the grinding chamber. It has been found that the installation of additional blades increases the suction at the crusher inlet by 457 Pa and increases the hydraulic power by 20%. When installing blades, the zone of reduced pressure in the vicinity of the center of the rotor is more developed, as well as the zone of increased pressure at the periphery of the rotor. In general, the blades participate in the impact on the grains, as do the rotor hammers. It was obtained that the pressure difference at the inlet and outlet of the stream at the larger sieve diameter S₂ = 0.157 m² was equal to p₂ = 578 Pa, and at S₁ = 0.070 m² - p₁ = 1145 Pa. At the same time, to ensure equal volumetric flow rate Q = 0.2885 m³ s, it is necessary to double the hydraulic flow power from N₂ = 166.8 W to N₁ = 330.3 W.