Laboratory Determination of Coal Dust Cleaning Efficacy of a Fibrous Filter for Flooded-Bed Dust Scrubber

Abstract

Fibrous-type dust filters are used in flooded-bed dust scrubbers to capture dust from underground room and pillar mining atmospheres. They have 10–30 layers of finely woven strands that trap particles through the interception and impaction process. A full-cone water spray is installed upstream of the filter, which floods the screen. A scrubber’s efficacy is usually measured and reported in terms of reduction in gravimetric dust concentration at a known location in a mine. This paper reports the particle-size-dependent dust removal efficiency of a fibrous filter obtained from an instrumented test-set up. A variable frequency drive and an inline flow control knob were used to control the airflow through the filter and water flow onto the filter. Optical particle counting of coal dust particles upstream and downstream was carried out to determine the cleaning efficacy. Experiments showed an increase in cleaning efficiency for all the dust particles with their size. A progressive decrease in dust concentration downstream of the filter with an increase in water flow through the nozzle affirmed the capture of dust particles by water sprays.