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PubMedDate not supplied

Particle emission characteristics of filter-equipped vacuum cleaners.

Industrial vacuum cleaners with final high-efficiency particulate air (HEPA) filters traditionally have been used for cleanup operations in which all of the nozzle-entrained dust must be collected with high efficiency, for example, after lead-based paint abatement in homes. In this study household vacuum cleaners ranging from $70 to $650 and an industrial vacuum cleaner costing more than $1400 were evaluated relative to their collection efficiency immediately after installing new primary dust collectors in them. Using newly developed testing technology, some of the low-cost household vacuum cleaners equipped with a final HEPA filter were found to have initial overall filtration efficiencies comparable to those of industrial vacuum cleaners equipped with a final HEPA filter. The household vacuum cleaners equipped with a final HEPA filter efficiently collect about 100% of the dry dust entrained by the nozzle. For extensive cleaning efforts and for vacuum cleaning of wet surfaces, however, industrial vacuum cleaners may have an advantage, including ruggedness and greater loading capacity. The methods and findings of this study are applicable to field evaluations of vacuum cleaners.

Aerosols↗

PubMedDate not supplied

Comparison of filter bag, cyclonic, and wet dust collection methods in vacuum cleaners.

In this study, methods were developed for comparative evaluation of three primary dust collection methods employed in vacuum cleaners: filter bag, cyclonic, and wet primary dust collection. The dry collectors were evaluated with KCl test aerosols that are commonly used in filter testing. However, these aerosols cannot be used for evaluating wet collectors due to their hygroscopicity. Therefore, the wet collectors were evaluated with nonhygroscopic test particles. Both types of test aerosol indicated similar collection efficiencies in tests with dry collectors. The data show that high initial collection efficiency can be achieved by any one of the three dust collection methods: up to 50% for 0.35 microm particles, and close to 100% for 1.0 microm and larger particles. The degree of dependence of the initial collection efficiency on airflow rate was strongly related to the type and manufacturing of the primary dust collector. Collection efficiency decreased most with decreasing flow rate for the tested wet collectors. The tested cyclonic and wet collectors showed high reentrainment of already collected dust particles. After the filter bag collectors had been loaded with test dust, they also reemitted particles. The degree of reentrainment from filter bags depends on the particulate load and the type of filter material used. Thus, the overall particle emissions performance of a vacuum cleaner depends not only on the dust collection efficiency of the primary collector and other filtration elements employed, but also on the degree of reentrainment of already collected particles.

Aerosols↗