APPLICATION OF ELECTROMAGNETIC SHIELDS IN A SET OF MEASURES TO NORMALIZE THE LEVELS OF PHYSICAL ENVIRONMENTAL FACTORS

Abstract

Shielding is the most effective means of reducing the levels of electric, magnetic and electromagnetic fields of a wide frequency range in industrial and domestic conditions. But in real conditions, other physical factors also need to be corrected. It is shown that the most critical of them are acoustic noise and air ion composition. This necessitate s the normalization of physical factors on an integrated basis. The use of pinolatex and an iron ore concentrate filler as a matrix for the electromagnetic shield allows the levels of electromagnetic fields and acoustic noise to be reduced to standard values. Even for the frequency bands of 31.5 Hz and 63 Hz with a screen thickness of 10 mm, the noise reduction indices are 15-20 dB. For frequencies 6-8 kHz, this figure is 40-45 dB, which is accepted for most industrial conditions. At the same time, the screening coefficients of magnetic fields of industrial frequency and electromagnetic fields of ultrahigh frequency comply with regulatory requirements. It is shown that electrostatic charges which accumulate in the polymer air are the main factor in air deionization and they cause the directional movement of finely dispersed dust. Latex has the advantage of having a non-electric surface, which makes it possible to use it for cladding surfaces of large areas. At the same time, it has elastic modules, which are close in values to the modules of materials that are traditionally used for noise reduction. The most effective method for normalizing and maintaining the concentrations of air ions of both polarities at the standard level is the use of artificial air ionization devices. For uniform distribution of air ions in the volume of the premises, scattering screens are used. The advantage of latex screens is the absence of partial absorption of ions during scattering. The proposed approach to normalize the levels of electromagnetic fields of acoustic noise and the concentration of air ions, together with the use of climate control systems, allows maintaining the entire complex of physical factors of the industrial environment at the standard level. This is most relevant for the premises of critical infrastructure facilities (main control rooms, control rooms, etc.)