7. Optical methods for determining the concentration and particle size

E.I. Vedenin, V.S. Kaunov, P.V. Charty, V.G. Shemanin
Novorossiysk polytechnic institute KubSTU, Russia

Laser sensor for the aerosol flows parameters controlling

The efficiency of the aerosol flows parameters controlling by the laser probing in real time largely depends on the algorithm of the measuring procedure and the presence of a sufficient amount of a priori information about flows parameters. Therefore, this work goal is the creation of the laser sensor for given values of the aerosol flows parameters with regard to their influence on the interaction of laser radiation with aerosol particles. It has been shown previously that for a number of tasks sufficient information about of the aerosol flows parameters are the concentration value and the particles size distribution. The laser sensor using based on the spectral transmittance at several laser radiation wavelengths method has been suggested to control these parameters in the real time. For example, the radiation at two wavelengths λ1 and λ2 produced by two lasers were passed through the aerosol particles flow and the attenuated radiation were detected by the photo detectors. The photo detector output electric signal passing through the double synchronous detection was sent to ADC (analog-to-digital converter). This digital signal was sent to the PC processing where the particles mass concentration С, the particles average volume-surface diameter δ32 value and the particles size distribution function calculation can be realized. A possible application of the proposed laser sensor is such a flows laser probing, in which not only concentration, but also changes in the particles size distribution function were calculated. The different dust cleaning units failures have been appeared when the industrial flow was cleaned from the aerosol particles and it leads to change the particles size distribution and particle concentration increasing at the unit outlet. Such a sensor using can detect failure appearance process at the early stages and can prevent the excess emissions into the atmosphere by that way. So the suggested laser sensor allows controlling the aerosol flow concentration and the particles size distribution by the spectral transmittance at two laser radiation wavelengths method in the real time.
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