Longwall Shearer Performance Using Water-Jet-Assisted Cutting

摘要

The Bureau of Mines equipped a longwall shearer with a water-jet-assisted mechanical cutting system to determine the effect of the high-pressure sprays on machine performance, airborne dust levels generated, and size of particles formed. Testing was conducted on a simulated coal block (coalcrete) while cutting a water pressure of 190 psi and at water-jet-assisted pressures ranging from 1,000 to 6,000 psi. Results indicate that the motor energy required by the shearer for each ton of material cut did not vary significantly as the water pressure was increased. Results of dust measurements recorded near the cutting drum indicate that at water pressures above 3,000 psi, dust reductions up to 85% were achieved compared with cutting with conventional sprays. Analysis of the particle size distribution during cutting showed that increasing the water pressure resulted in increased median particle size. In light of these results, various mechanisms for water-jet-assisted cutting are discussed.