Abstract:
In order to ensure the safe support of steeply inclined coal seam roof, improve the recovery rate of steeply inclined coal seams and reduce the working intensity, a new self-moving flexible shield hydraulic support has been developed.Firstly, according to the actual needs of the steeply inclined coal seam mining support, the performance of the bracket needs was determined:the bracket can move freely in a certain direction, but the displacement of the bracket can be controlled in other directions; the operating space under the bracket is completely closed and does not leak; and the moving walking mode of the bracket mainly relies on the pushing of the meteorite in the goaf above the bracket and the self-gravity of the bracket to realize the automatic moving.Thereafter, the applicable conditions of the bracket were determined:the inclined, steeply inclined and reversed working face with a coal seam inclination angle greater than 25°; the coal seam with a large change in the thickness of the coal seam; the working surface arranged by the inclined or pseudo-sloping wall type oblique mining; and the roof is broken with the coal seam.Finally, according to the performance and applicable conditions of the support, a self-moving flexible shield hydraulic support with no power, small size, light weight, flexible movement and strong adaptability was designed.The bracket consists of three to four parts:guide beam, main beam or top beam, shield beam or back beam, pendulum beam or tail beam.Each part has a fixed or adjustable angle.The adjacent bracket is connected by three to five connecting devices.The force received by the bracket is mainly the gravitational force of the meteorite in the goaf.At the same time, in the supporting system constructed by the self-supporting of the bottom plate, the self-supporting of the roof, the gauge of the goaf, the support of the coal wall and the support of the bracket, the support only plays a auxiliary supporting role.This effectively reduces the rigidity required for the cross-section of the stent, thereby reducing the weight of the stent, reducing the cost of the stent and the labor intensity of the worker.The brackets have been used in 37 working faces in countries such as Turkey, Vietnam and China, and have achieved good results.The brackets provide a new way of safe support for steeply inclined coal seam mining.