Design, build, and test an air-cleaning system for working-level control in uranium mines. Open file report October 1979-April 1984

The health hazard from 222 radon byproducts, radon daughters, will be increasingly difficult to control by dilution with primary ventilation as the uranium industry digs farther and deeper for ore of diminishing grade. One solution is removal of daughters from air at the work place by filtering out respirable-size dust particles to which most daughters attach. This report describes design and testing of a filtration unit that reduces the working level in ventilating air 95% on an airflow of 10,000 cfm. Buildup of dust on the filter is controlled by periodic back-pulsing, so that the unit can operate for an extended period without changing elements. The effectiveness of the self-cleaning action was satisfactory under a contaminant loading that was 43% diesel smoke. Back-pulsing was able to control filter loading or buildup to a degree even under 100% diesel. The report describes testing of the filter medium and filter unit in both an experimental and an active mine and concludes with an analysis of the prototype design.