Abstract
A recent advance in dust collection on continuous mining machines has proven successful in reducing dust on blowing ventilation sections. The system is a water-powered scrubber built into the machine and has the advantages of not increasing machine height, no moving parts such as a fan, or filters to clog or clean. Airflow induction and scrubbing are accomplished simultaneously by water sprays. Using two units (one in the center of the machine and one in the left boom), the scrubber delivered 4,000 cfm of air at water pressures of 300 psi. Airflows of 9,000 cfm are possible at higher water pressures, and the collection system is compatible with left- or right-hand ventilation since it has a scrubber built into each side of the machine. Field test results showed that the scrubber system reduced dust by 67 pct on the immediate return air side of the machine and by 54 pct at the operator's position. Tracer gas tests indicate that the scrubber system significantly reduced the methane gas peaks, although it did produce a higher average entry methane concentration than if the scrubber were not used.
