Moving mechanism and active control method of scraper conveyor in fully mechanized mining face

In order to study the movement mechanism of the scraper conveyor in the fully mechanized mining face, the influence of cutting process, working face dip angle and thrust force of hydraulic support on the movement of scraper conveyor are analyzed comprehensively, the movement mechanism of scraper conveyor is clarified, the critical position and permissible movement value of the scraper conveyor are defined, the moving alert areas are set up, the movement states of scraper conveyor are clarified, ulteriorly the effective monitoring method and initiative control of scraper conveyor movement are put forward. The research shows that the propulsion difference of both ends, the change of working face dip angle, the relationship between support thrust and the scraper conveyor movement trend are the main reasons for the movement.The critical position and moving value at both ends are determined by the minimum width (0.8 m) of the safe exit of the coal mining face and the coal mining machine only just complete end oblique cutting. When the coal mining machine can just complete the oblique cutting at the head, the head position of the scraper conveyor is the critical position of rearward movement ; when the distance between the coal retaining plate of the bridge stage loader and the coal pillar is 0.8 m, the head position of the scraper conveyor is the critical position of forward movement. When the the coal mining machine can just complete the oblique cutting at the tail, the tail position of the scraper conveyor is the critical position of forward movement. When the distance between the tail of the scraper conveyor and the coal pillar is 0.8 m, the tail position of the scraper conveyor is the critical position of rearward movement. The permissible movement value of the scraper conveyor is the interval length between the critical position of rearward movement and the critical position of forward movement of scraper conveyor movement. For conducting timely warning and initiative measures to control scraper conveyor movement, permissible movement value is divided equally into five areas:serious area of foward movement, warning area of foward movement, normal area, warning area of rearward movement and serious area of rearward movement. The laser positioning method is used to record the horizontal offsets between the laser positioning point and the fiducial mark point, and the moving area of both ends is determined accurately. According to the moving areas of both ends of scraper conveyor, the moving states can be divided into normal state, single moving state and double moving state. Aiming at the specific movement state, according to local conditions, effective measures for initiative control of movement are put forward, such as adjusting cutting process, obliquity of working face, thrust direction of support and other measures. The relevant results have been applied in No.2 Coal Mine of Huayang New Material Co., Ltd., the permissible movement value of the head and tail of the 80807 working face are 0.8 m and 1.0 m respectively, and the moving alert area is divided, the moving state of scraper conveyor is accurately determined by laser monitoring, and initiative control measures are taken in time, and good control results have been achieved.