POWER ANALYSIS OF THE PROCESS OF BRITTLE MATERIALS DESTRUCTION IN UNIVERSAL CRUSHING MACHINE WITH ROLL LOCKER

Abstract

The processing of friable materials used in metallurgical industry for production of definite size classes requires operation of crushing machines, including single-roll machines. Parameters of crushing process are degree and efficiency of crushing. The crushing degree is estimated by the ratio of dimensions of the initial crushing and resulting pieces and depends on the size of gap between the roll and the fixed jaw. Crushing efficiency is determined by mass of material crushed by consumed electric energy unit, and depends mainly on strength of crushed material. In order to reduce energy consumption needed for crushing, a single-roll crusher was developed at Siberian State Industrial University with forced feeding of crushing piece into the fracture zone due to the locker located on the roll. Forces of technological resistance appearing during machine operation are the main initial values for machine drive power and structural elements strength testing, thus, the operation power analysis is an integral stage in the design of any machine, including a crushing one. In the present work, forces acting on a crushing piece from roll side and fixed jaw in vertical and horizontal planes are identified. Based on the results obtained, it was determined that internal compressive forces acting on piece of crushing material cause action of normal compressive stresses in a piece, as well as an internal torque effect, which causes shearing stresses action, i.e. a complex stress state is generated in a fractioned piece with simultaneous action of normal and shearing stresses, under which action a fractioning piece is destroyed. Thus reduction in energy consumption for crushing is achieved, with all other conditions being equal. It reduces energy consumption of a single-roll crusher with forced feeding of material into the crushing zone.