Monitoring the Remnant Roof Coal Thickness by Automatic Vertical Steering of Shearer Drum

摘要

When the natural gamma rays pass through the coal seam, the radiation strength of gamma rays will decay, and the decay quantity is a function of the remnant roof coal thickness. Based on the physical characteristic, a mathematical relation of the roof coal thickness with the count rate of the natural gamma rays is developed. In accordance with the principle, a roof-coal monitor is designed, and the construction and the software function of the monitor. The theoretical analyses and the function of the monitor were verified by the data of the coal face simulation tests in the surface.