Dust control on longwall shearers using water-jet-assisted cutting.
Taylor-CD; Kovscek-PD; Neihaus-K; Thimons-ED
NIOSH 1990 Sep:64-69
The ability of water jet assisted shearers to control dust generated by longwall cutting was evaluated. A Joy 1-LS1 double drum shearer was tested. The left or leading drum was fitted with water jets faced in front of each of the 32 cutting bits in a 13 degree Leach/and/Walker configuration for surface cutting operations (surface water delivery system). Water was supplied to the jets by a 112 kilowatt Aqua-Dyne triplex pump using 5.1 centimeter flexible hose. The pump was placed next to the coal face. For underground cutting operations 41 conical spray nozzles were mounted on the left drum (underground water delivery system). The average angle of the arc of rotation of each cutting sector that was supplied with water was 195 degrees. Water was supplied to the spray nozzles from a five piston pump that was mounted on a trailer pulled by the shearer. Testing was conducted on the surface at a simulated longwall face and at an underground longwall panel in a mine in Germany. Water pressures ranged from 190 to 7200 pounds per square inch (psi). Airborne respirable dust concentrations were monitored using real time dust monitors and strip chart recorders. During surface testing increasing the water pressure from 190 to 1000psi had little effect on dust levels. Increasing the water pressure from 1000 to 3000psi caused a 79.2% reduction in respirable dust concentration. Increasing the water pressure beyond 3200psi caused only a small additional decrease in dust concentration. During underground testing, increasing the water pressure from 340 to 1800psi reduced airborne dust concentrations by 70 to 80%. Increasing water pressures from 1800 to 7200psi caused little additional reduction in airborne dust concentration. The authors conclude that the use of water jet assisted cutting significantly reduces airborne dust generated by a longwall shearer. Optimum dust suppression is achieved by water pressures of 1000 to 3000psi.
Dust-suppression; Coal-mining; Control-technology; Occupational-health; Mining-equipment; Equipment-design; Coal-dust; Equipment-reliability;
(NIOSH) 90-108; OP 32-91
Control Technology and Personal Protective Equipment; Research Tools and Approaches; Control-technology;
Proceedings of the VIIth International Pneumoconioses Conference