Local exhaust ventilation with reduced energy consumption during bulk materials overloads into receiving cones of coarse crushing plants

Abstract

An intense dust emissions occur when bulk materials are unloaded by wagons into receiving cones of coarse crushing bodies (CCB). The most reliable, but energy-intensive way to localize dust emissions is the use of local exhaust ventilation systems. For the correct calculation of the performance of the exhaust ventilation system, it is necessary to determine the flow rate of air entrained in bulk material (flow rate of ejected air), which is the main source of dust emission distribution. The volume of air carried away by bulk material is determined based on the use of the classical theory of mechanics of two -component flows. Using the methods of boundary integral equations, a mathematical motion of the air flow in the cavity of the receiving cone of the CCB has been developed. A laboratory model of the CCB receiving cone was created, where the air flow carried away by the bulk material was modelled using a smoky jet flowing out of the supply nozzle. Based on the conducted computational and field experiments, the location of the local ventilation suction and mechanical screens are selected to increase the efficiency of local exhaust ventilation and reduce the energy consumption of the aspiration system.