CALCULATING THE EFFICIENCY OF CAPTURING THE SUSPENDED PARTICLES BY FILTER FIBER, CONSIDERING THE SEDIMENT ACCUMULATION
The intensive development of the chemical industry leads to an increase in emissions of pollutants; therefore, more and more important becomes the issue of enhancing the efficiency of filtering out suspended gas at different processing cycles, which suspension represents a combination of solid or liquid particles in gas or in air. Designs and materials of filters are permanently improved; glassfiber-based materials or materials based on synthetic or carbon fibers are developed. However, for all types of materials, the issue of accumulating sediments built up as a result of precipitating the particles and influencing the hydrodynamics of the flow. Such sediments lower the filter quality, lead to growing the required power for pumping through gases, and finally, result in completely plugging the cost-intensive filtering materials to be replaced. In this connection, an important task is to study the mechanism of precipitating the particles on the filter fibers in order to forecast the service life of the filter with a predefined permeability for particles having certain dimensions. In this paper, we have built an iteration model of accumulating sediments of inertial aerosol particles on the surface of cylindric fibers, considering its effect provided upon the gas flow and the further precipitation of particles. Parametric calculations have been performed at different porosity values of some fibers and of Stokes number determining the intertiality of particles. Sediment form changes depending on particle sizes. For strongly intertial particles, the thickness of the layer of precipitated particles is close to uniform. For weakly intertial particles and low porosity of some fibers, the non-uniform distribution of the thickness of the precipitating layer over the streamlined surface is observed. It should be noted that the accumulating sediments are also permeable and changes the current lines and trajectories of the particles. The permeable sediments can provide a positive effect upon filtering up to the moment of plugging, since it enlarges the filtration area, insignificantly preventing the gas from moving. For this purpose, we have additionally performed the parametric calculations of forming a build-up at different values of fiber permeability and layer precipitated. The efficiency of precipitating the particles has been calculated, which is a key parameter that determines the filter quality.