Reduce Methane Concentrations Around Longwall Shearers - Objective

Reduce methane levels around the shearer machine during longwall mining by directing more of the available airflow along the face and over the shearer body. Approach To address the entire mining cycle, two techniques were combined to dilute and clear the methane liberated from the face by the shearer during cutting. The first is the modified shearer clearer system, which is used during the entire face pass. This is combined with the walkway curtain which is used only during the headgate cutout. How It Works Methane ignitions are one of the most potentially serious hazards facing longwall mine operators. The high rate of coal extraction on longwall sections can liberate a significant quantity of methane during a pass. The modified shearer clearer is used to dilute methane concentrations along the entire face for both cut directions. The shearer clearer system, originally designed as a dust control technique, uses a series of water sprays located on the shearer body to direct more airflow along the face and over the shearer. (See Technology News issues, #112, #118, and #221). The only change from the original shearer clearer design is the addition of three sprays to the return-side splitter-arm/ shearer interface. The additional sprays help to ventilate the area behind the shearer body.