Intelligent fully mechanized mining support technology and equipment for thin-medium-thick coal seam

Abstract

In the context of the complex geological conditions such as large thickness variation of thin-medium-thick coal seam, development of strike fault and broken roof in Southwest China, intelligent fully mechanized mining support technology and equipment for thin-medium-thick coal seam are proposed. Through the implementation of grouting reinforcement and roof-lifting transformation for broken roof in the hanging wall and the footwall of fault layer, as well as the adoption of the coupled support technology of bolt-mesh-anchor combined support+advance reinforcement+blasting roof cutting+pillar hanging net gangue retaining+delayed shotcrete reinforcement+finishing wall in gob-side entry retaining, the stability of the roadway is greatly improved. A lateral self-advancing advanced support group consisting of eight advanced supports and two end supports is designed to realize the coordination and cooperation of the roof support at the end of the working face and the rapid advancement of the advanced supports. The intelligent fully mechanized mining equipment for thin-medium-thick coal seam and its optimal layout scheme are proposed. When the mining height at both ends of the working face is less than the height of the roadway, a cushion frame is used to support the head and tail of the shearer. The length of the scraper conveyor head and tail beyond the coal wall is controlled at 800 mm to ensure that the undercover amount reaches 97 mm so as to clear the floating coal in time. The scraper conveyor head is equipped with a trailer parallel to the floor, and the scraper conveyor head and tail are directly pushed as a whole through the transition support auxiliary pushing device, which effectively solves the problem of mutual interference between the rocker arm of the shearer and the scraper conveyor. The study proposes an active preventive intelligent coal cutting technology in the fault zone, which is composed of end cutting triangular coal following section process and middle oblique cutting following section process. The technology uses half cutting depth and fractional cutting methods to improve the safe coal cutting speed of the shearer under the fault zone condition.

Keywords

• coal mining; thin-medium-thick coal seam; intelligent fully mechanized mining; coupled support; lateral self-advancing advanced support group; fully mechanized mining equipment; coal cutting technology