Defining Parameters of Thermal Exposure Equipment for Buckets of Mine Excavators

Abstract

Abstract The paper enlists experimental materials of research on effect of thermal exposure on mined rock exploiting by mine excavators. When extracting thawed mine rock under subzero air temperature, intensive freezing of cohesive ground to contacting bucket surfaces, pickup apparatus elements, conveyor belts, treating facilities and links takes place. Freezing intensity depends on humidity, grain size composition, physical properties and temperature of mined rock. Material properties of working bodies which contact mined ground also have significant impact on adhesion of freezing of mined rock. Clay rocks are the most prone to freezing on. Experimental research was carried on thermal exposure on adhesion of cohesive overburden rocks to mine excavator buckets under subzero temperatures. Two elastic heating units, ENGL-1 (ЭНГЛ-1) and ENGLU-400 (ЭНГЛУ-400) were considered as possible options for using directly on excavator bucket. As a result of aforementioned experiments shearing force between ground and surface of thermally exposed working body simulator device was calculated for each of the heating units. The experiments proved that shearing force with thermal exposure decreases sevenfold for ENGL-1 heating element and eightfold – for ENGLU-400 heating element (compared to shearing force without any exposure), which can improve performance of mechanization of stripping operations when overburden rocks exploiting. Results of experimental research are presented and optimal equipment parameters are defined. An engineering solution for excavator bucket with integrated heating unit is proposed.