The Research Of Large Mining Height Hydraulic Support Selection In The Residual Coal Mining

Improve resource recovery is an eternal subject of coal mining, the old room and pillar, the pillar mining recovery rate less than30%in a lot of resource waste, in old residual coal mining process, improve the level of mechanization is an important issue. The residual coal mining Taking xinzhou mitac group at the field of coal seam8large residual coal longwall mining height are broken fully mechanized as the research background, the field observation and theoretical analysis, numerical simulation method, mining working face of large mining height are broken residual coal hydraulic support and surrounding rock relationship, working resistance, selection of bracket and coal wall to help control research, the main research contents and conclusions are as follows:1.the research analyzes the survival status quo of coal pillar and occurrence of coal seam structure and the position and state of hydraulic support.2. Set up the old mining residual coal basic mechanics model, research the relationship between supports and surrounding rock, pressure analysis and the instability of coal pillar in advance, the reasonable working resistance by means of estimation of8161kn.3.According to the large mining height are broken two of the most commonly used four pillars supporting column cover type and cover type two kinds of type hydraulic support frame, this paper compares and analyzes two column frame type selection screen type hydraulic support. Top beam structure choice overall top beam with telescopic girder structure, is conducive to increase the top beam support at the front and back end, telescopic girder on the belt guard help plate device to solve issues of coal face roof caving and wall piece of help.4.Condition analysis of hydraulic support work environment, including hydraulic support under partial load, reverse, single point, two point such as concentrated load, by improving the key structures such as hinged roof beam hydraulic support parts, main floor, roof beam and cover beam between the pin hole, etc. To strengthen the torsional stiffness and strength, partial load resistance. Design mechanical limit switch for jack’s maximum minimum travel allowance to prevent the equilibrium jack pulled bad.5. Through the state of the software for CanCai face influencing factors of coal wall piece for numerical simulation of coal and residual coal mining entity found when coal mining entity protection height for board design should be not less than0.28times the mining height are broken, stumping, protect height for board design should be not less than0.32times the mining height are broken, so at the time of stoping residual coal guard help plate should be designed not less than1.76m. Support protection of help agencies choose telescopic girder and help plate fission structure, level3protection device, primary care help height is1.2m, total protection for1.8m. Through coal mining entity and stumping comparison found that the same working resistance or with the mining height are broken stumping the maximum damage depth in the coal wall is bigger than when coal mining entity. With the increase of working resistance, the maximum failure depth of coal wall are reduced, but the residual coal than the entity coal mining depth of coal wall under control the working resistance. Along with the increase of mining height are broken, depth of the coal wall piece of help are increasing, but the residual coal during coal mining height are broken more than4.5m wall speeding up, the damage depth and damage depth is bigger than when coal mining entity...