Influence of grain feed method relative to rotor axis position on technological parameters of hammer crusher

Abstract

One of the main processes in the production of formula feeds is crushing. This is the most energy-consuming process and it largely determines the quality of the finished product. Crushers with a horizontal shaft, i.e. with a radial feed are considered more energy-intensive. However, this estimate was made from the specific energy intensity, and the designs of the crushers as a rule differed from each other. To obtain objective indicators, it is necessary to have the same designs but providing only radial or axial feed. For experimental studies, this requirement was met and a series of experiments were conducted to determine the energy intensity, fineness modulus and output capacity of the hammer crusher. Wheat and barley were the tested components. The developed design is a closed-type crusher with a hexagonal body, three faces of which are a deck, and the remaining three are a sieve. The conducted experiments have shown the importance of grain feeding on the studied factors. The radial feed was in a more advantageous position since there was less material in the chamber which affected the kinetic energy of the grain. At the same time, the air density is also lower because there is no suction from the central hole, the effect of vacuuming the annular volume of the grain mixture along the perimeter of the hammers is higher. The effect of the centrifugal air pump in this scheme is minimized while the axial flow refers to the design of the fans. With radial feed, there is a smaller contact area with the grain with the surfaces which minimizes the friction forces of sliding the material over the steel, thus affecting the power. The fineness modulus in the studies corresponded to the animal industry requirements. The deviation of particle size was within 5% and varied depending on the crops studied.