The article describes the advantages of the widely applicable tangential rotary picks of cutter-loaders. On the other hand, the current design of the picks is found to disagree with the up-to-day standards of the resource-efficient production as the picks are expendable and weakly answer the purpose of a "cutter." As a consequence, rock breaking results in high metal consumption. Furthermore, the rupture and cleaving effect to be exerted by the tool on rocks needs high penetration force and high destruction energy to break coal and rocks, and induces dynamic response of rocks, which results in quick failure of the tool point and in friction sparking. Intense dust generation and friction sparking are the risk factors of inflammation of explosive mixtures of dust and methane in gateways and breakage headings. In order to eliminate the disadvantages, it is proposed to improve the picks by means of changing the mechanism of impact from rupture to cutting. The new mechanism requires replacing the cone point of the pick by a cutting edge. The cutting edge can be a carbide blade placed in an axial slit of the pick head. The part of the head with the carbide blade should be replaceable and capable of axial rotation on the holder. The effective penetration of such reinforced pick on the cutting drum will be higher than the current cone picks have. Rock cutting will take lower force and energy. The cut-out fragments will have more regular shapes, which will improve coal sizing and essentially reduce yield of fines and generation of dust. The proposed new-class edge picks feature extended active life, lower energy to break rocks, reduced yield of dust and improved sizing of produced coal. The designs of the new-class picks have been developed. The classification of the tangential rotary picks is performed to show the path of the further development of the rock-breaking tool.
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology