PROTECTION OF THE ATMOSPHERE OF URBANIZED AREAS FROM DUST EMISSIONS DURING THE MANUFACTURE OF AERATED CONCRETE STRUCTURES

Abstract

The article provides a solution to the urgent task of ensuring the protection of the natural environment and vital human interests from the negative effects of dust emissions generated during the production of aerated concrete and construction products based on it. It has been established that when traditional dust emission cleaning systems with cyclones is used, dust is emitted into the atmospheric air, and up to 100 % of the mass of dust is represented with particles of up to 20 microns in size. At the same time their median diameter is 12 microns, the percentage of particles with sizes less than 10 microns (PM10) is 40 %, the percentage of particles with sizes less than 2,5 microns (PM2,5) is 0.5 %. The percentage of particles in the atmospheric air near the industrial site in the summer varies: for PM10 – from 12 % to 40 %; for PM2,5 – from 0.3 % to 0.5 %. At the border of the sanitary protection zone these values are 80 % and 0.5 %, respectively. In order to reduce dust entering the atmosphere during the production of aerated concrete and construction products based on it, two options for the layout of emission dust removal systems with two consecutively installed dust collectors with counter-rotating flows, two additional devices of smaller sizes, with the organization of suction from the hopper of the main dust collector of the second stage are proposed and from the bunker of one of the additional devices. The use of the proposed dust cleaning system showed that the content of PM10 particles in the stream, emitted into the atmosphere, was decreased by 40 %, the content of PM2,5 particles – by 20 %. At the same time, the emission of dust into the atmosphere was decreased by 8.9 times. Dependencies characterizing the degree of reduction of dust emissions into the atmosphere were established, as well as the ranges of changes in the regime and design parameters of the proposed dust cleaning systems, which ensure the least amount of dust entering the environment and the least energy costs for carrying out dust removal processes during the production of aerated concrete and building structures based on it.