Open AccessStudy on drilling mechanism of combined bit in hard coal seam
Author(s) -
Yan Li,
Wenbao Shi
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1549/4/042138
Subject(s) - drilling , coal , coal mining , bit (key) , borehole , petroleum engineering , geology , mining engineering , drill bit , work (physics) , rotation (mathematics) , computer science , geotechnical engineering , engineering , mechanical engineering , artificial intelligence , computer security , waste management
Borehole pressure relief can effectively reduce the accumulation of elastic energy of working face and surrounding rock mass, and reduce the regional impact risk. But in hard coal seam, drilling jam, holding and other dynamic phenomena often occur in drilling, which seriously reduces drilling efficiency. Therefore, aiming at the problem of poor coal breaking effect of traditional geological drills in hard coal and rock, the coal breaking characteristics of new type combined drills are studied by theoretical analysis and numerical simulation. Considering the traction, rotation and impact movement in practical work, the trajectory model of combined drills is put forward. The coal breaking characteristics of the two kinds of drills are compared and analysed from the aspects of the difficulty of coal breaking and the force fluctuation of the drill bit. The results show that the combined bit can reduce the difficulty of coal breaking by 50% when its hardness value is twin 6, and the combined bit can reduce the force of nearly 7000N in hard coal and rock in the fluctuation of force acting on the geological bit. Therefore, the study of coal breaking characteristics of the combined bit can effectively improve the special rock mass such as broken hard coal and rock.