QUASI-VIRTUAL IMPACTOR'S APPLICATION FOR THE DISPERSION ANALYSIS OF INDUSTRIAL DUST

Abstract

In order to estimate impartially the particle size distribution of the dust formed during production of refractories, ceramics, bituminous concrete surfaces, in both ferrous and non-ferrous metallurgy, as well as in chemical industry the quasi-virtual impactor developed by the Scientifi c Research Establishment «NIIOGAZ» was recommended by the reason that in a single device it combines the values of both traditional impactors (compactness and ease of operation) and virtual ones (zero re-entrainment of the particles deposited in the cascade). The calculating formulae for the log-normal characteristic's evaluation of the dust particle size distribution are given in the article. The engineering characteristics are described for the most promising quasi-virtual impactors of model V, and as an example the carbon periclase's particle size distribution is presented. The following sampling conditions for the dust-gas fl ow are recommended: the equal-criterion dust-gas samples near the intake tube mouth and around it; the maintenance of the sample temperature higher than the dew point; the suffi cient representative dust portion on the impactor's cellular substrate layer; the installation of the impactor on the straight part of the gas fl ow. These recommendations have been validated experimentally. Ill. 2. Ref. 5. Tab. 2.