Study on new hydraulic support and technology of top-coal caving at the ends of fully-mechanized working face

Based on the top-coal caving fully-mechanized working face No. 43B2 at Wangzhuang Coal Mine, we have analyzed the moving law of overlaying strata above the ends of working face, and determined the relationship between the end-support and surrounding rock, and designed the new top-coal caving hydraulic end-support i.e. the host-vice transitional inner-end-support and the symmetric end-support, and then mathematical simulated and analyzed the caving character of top-coal at the ends of working face. We have solved two key problems in the design process of end-support; one is that the end-support has enough space to place the rear conveyor of working face, other one is that the loose drop-coal on the floor can be carried into the high troughs of conveyor head and tail. The core content of new end-support includes the low coal-raking system which has the tilt scraper and the symmetric pair wheels and the high coal-caving system which has the unsymmetrical pair-open troughs. It should improve the coal recovery significantly, produce good economic and social benefits, and have very important significance and broad application prospect that to solve the difficult problem of top-coal caving at the ends of fully-mechanized working face.