Method and apparatus for controlling water sprays of an underground

Abstract

Water is discharged from spray nozzles toward cutting tools of a drum-cutting mining machine only during the actual time when material is released from the face of a mine. A pulse generator is driven by the traversing drive of the mining machine. The pulse output is fed to a controller which may include a computer that also receives an enabling signal produced by the secondary winding of a transformer in the power supply lines for the drive motor which is used to rotate the cutting drums of the mining machine. The enabling signal indicates an actual mining operation on the basis of the flow of current to the drive motor about a predetermined idle current load. Additional signals are fed to the controller such as a signal representing properties of the mine materials, and a signal representing characteristics of the drive system for the mining machine such as the dimensions of the capstan's chain drive wheel. The controller produces a signal which is used to operate a servo-type flow control valve in water supply lines coupled to the spray nozzles. Instead of a single flow control valve, there may be a plurality of valves arranged in parallel water lines and controlled by a stepping mechanism to open the valves in succession and increase the quantity of water discharged by the spray nozzles.