Improvement of the crushing feed method with hammer crushers

Abstract

The advantages and disadvantages of the method of grinding grain with hammer crushers are given. At the same time, the general disadvantages of various types of grinders include: high energy consumption, the need for additional grinding of particles, intensive wear of the working bodies and, therefore, a short operating period of the hammer crusher, low quality and uniformity of grinding. As the main disadvantage of multistage methods of grinding feed, it is indicated that the feed material is processed through several grinders and the final degree of grinding is achieved gradually, while more complex, and therefore less reliable equipment is used. The use of a one-stage grinding method is substantiated. The paper describes a technology for increasing the operating period of a hammer crusher and improving the quality and uniformity of feed grinding by improving the process of a one-stage grinding method, due to the formation of coatings made of wear-resistant materials by the method of electrospark alloying (ESA) on the working surfaces of the hammer and the comb. The results of alloying samples of steel 65G, using different modes of the "Elitron 52A" model equipment, in order to determine the influence of the energy parameters of ESA on the quality parameters of coatings deposited with electrodes of composition 10% 1M + 90% VK6. A new method of crushing feed of a hammer crusher is proposed. The method differs in that on more approximate surfaces of the hammer and the comb (deck) by the ESA method, a coating of wear-resistant materials is applied, and applied in such a way that their thickness and roughness gradually increase as the hammer moves along the surfaces of the comb (deck), and the gap size between them, respectively, decreases. The coating is applied in air in separate sections 5-7 mm wide, at a discharge energy of 0.2; 0.52; 2.6 and 4.6 J; productivity - 0.5 – 0.8; 1.0 – 1.3; 1.5 – 2.0 and 2.0 – 2.5 cm2/min; thickness - 0.02; 0.12; 0.19 and 0.23 mm and roughness, (Rz) - 7; 21; 65 and 117 microns, respectively. An electrode-tool of composition 10% 1M + 90% BK6 is used as the electrode material. As a result, the operating period of the hammer crusher is extended, energy consumption is reduced, and the quality and uniformity of grinding are improved.