Separation efficiency of a wood dust collector-field measurement using a fluorescent aerosol

Given the dangerous nature of the dust emitted in the wood industry, the qu ality of the recycled air in the work premises after cleaning must be stric tly controlled. A method of measuring the efficiency of a wood dust collector as a function of the particle diameter has been developed using a fluorescein tracer aer osol generated upstream of the equipment. The separation efficiency is dete rmined from the particle size mass distribution of the tracer, both upstrea m and downstream, measured by means of two cascade impactors. The mass effi ciency measured by tracer technique was compared on a test rig to the numbe r efficiency measured using a reference method based on optical counting. T he agreement between the two efficiencies is quite good; nevertheless, the tracer method leads to results that are slightly below those obtained using the reference method. The method was applied to measure the efficiency of a 11 500 m(3) h(-1) woo d dust collector, The results are presented along with those obtained from a sample of plane filter media making up the bags of the dust collector. (C ) 2000 British Occupational Hygiene Society. Published by Elsevier Science Ltd. AIL rights reserved.