Measurement of Impurity Concentration in Turbulent Flows of Ventilation Systems Channels

Abstract

The work is devoted to the experimental study of the process of impurities diffusion in the circular cylindrical channel and the determination of the coordinates of the average concentration of impurities in the turbulent flow. To ensure the uniformity for the aerosols composition during the studies, the experiments were carried out with solid particles of narrow fractional composition. The use of fine-grained oxide catalyst made it possible to obtain the almost monodisperse material. The experimental installation included the volumetric doser for impurity material, the ejector, the concentration sensor, the section of the vertical pipeline, and manometers for recording the pressure in the system. It is shown that the theoretical and experimental results are in satisfactory agreement with each other, and the existing discrepancy can be explained both by the measurement error and by the presence of spiral motion for the solid phase in the ascending flow. Based on the experiments, it was concluded that the known mathematical positions are adequate and internally not contradictory models of the diffusion process of the impurity substance in the turbulent flow, which can be used to analyze the distribution of the impurity concentration in the channels of the ventilation systems. The results of the studies performed should be taken into account when developing systems for measuring and monitoring the gas-air emissions characteristics of the ventilation systems of industrial enterprises.