Methods are proposed for designing interpolation models for the preliminary determination and subsequent forecasting of general and fractional breakthrough coefficients for dust used with granular filters, as employed in energy-saving and high-performance dust trapping from technological gases and ventilation discharges in refractory production. The models are supplied with nomograms, which makes them widely suitable for experts working in environmental protection at refractory-producing organizations. The main factors are identified that influence the performance. The results are of interest to experts in related areas of industry such as building materials and engineering ceramics and so on.The general and fractional breakthrough coefficients K and K j are major working characteristics of granular dust trapping filters in refractory production. The breakthrough coefficient isin which z i and z f are the dust contents of the gases or ventilation discharges before the trap and after it respectively in g/m 3 . The effects of actual conditions on the values of these quantities are so varied that it is impossible to present a unified and theoretically sound method of determining them. It is best to use interpolation models in the ranges for the actual physicochemical parameters of the flow and the geometrical characteristics of the trap. It has been found [1] that in generalin which w is the linear velocity of the dusty gas flow in m/sec; d e is the equivalent diameter of the pore channels in the filter layer in m; H is the thickness of the filter material in m; t is the filtration time in sec; d m is the mean median diameter of the dust particles in m; and s is the standard deviation of the logarithm for the particle diameters in a log-normal distribution (LND).Under those conditions, it is sound to plan an experiment to construct interpolation models by the Box-Wilson method with successive realization of short series of experiments on varying all the factors simultaneously. This enables one to approach the region of the optimum rapidly. In the experiments, the model dust was a polydisperse aerosol, which was used as two types of quartz dust with the following LND for the particle sizes: d m = 3.7´10 -6 m, s = 0.405, and d m = = 20´10 -6 m, s = 0.280; the factors d m and s are almost uncontrollable separately, so they are combined in a single control factor d m s. Table 1 gives the conditions, the planning matrix, and the results from the first series of experiments.In accordance with (2), we used the natural valuesx for the factors w, d e , Í, t, z i , d m s, which are denoted respectively byx 1 ,x 2 ,x 3 ,x 4 ,x 5 ,x 6 ; the encoded factors, variation levels, regression coefficients b i , and errors in determining them have been calculated by the method of [2]. Table 1 also gives the experimental values of the response function y = lnK -1 . The regression equation after checking the model for fit takes the form It follows from (3) that in these variation intervals for the factors, K increases with w and d e but ...

Advantages of granular filters with a connected layer structure over alternative means of ultrafine fine removal of mechanical impurities from gaseous process media are examined. Specific structural solutions for these vessels, and their operating parameters in the production of electronic devices, in biotechnology, during the production of electrolytic hydrogen, and in cryogenic engineering are presented. Methods are recommended for regeneration of multilayer filtering structures. Information on commercial and socioeconomic prospects of granular filters with a connected layer structure, which are employed for the fine removal of mechanical impurities from gaseous process media, are presented in the bibliography.Granular filters with a connected layer structure are widely used in various branches of industry; this is dictated by the availability of filtering material, the possibility of operation with marked variation in the physicochemical parameters of the dust-gas flow, entirely adequate efficiency, heat and corrosion resistance, high mechanical strength of the filtering elements, and the possibility of using various means of regeneration [1][2][3][4].These filters are effective for use, for example, in the electronic industry, where the functioning of miniature devices with very small gaps and tolerances may be disrupted when particles of dust, nap, organic substances, and various aggressive gases fall onto critical elements of a device. The reliability of miniature components of electronic devices is ensured by stringent cleanliness of initial materials and gaseous process media, rational structural shaping, and process hygiene [4]. The permissible size of dust particles and their number in an air medium will depend on the character and design of the device, its power parameters, and the distances (gaps, tolerances) between components. If a gap of 1 µm is specified between components of a microcircuit, no particles more than 0.3 µm in size should exist in the air medium. Particles, whose dimensions are smaller than the limiting size also present a risk, since may form conglomerates [5].In fact, the requirements of establishments manufacturing high-precision devices are more stringent, since their operation is disrupted when dust particles 0.3, and even 0.1 µm in size collect on their surfaces. Many production processes

The kinetics of filtering dust-gas flows by rotating self-regenerating filter membranes with decreased hydraulic resistance for energy-saving highly efficient dust collection from process gases and aspiration emissions in the production of refractories is considered. A nomogram is proposed for choosing regeneration parameters for filter membranes, and the advantages and prospects of this dust-collecting method in the production of refractories are formulated.Dust components emitted into the atmosphere in the course of production of refractories contain substantial amounts of materials that have to be recycled in the technological process. The cost of activities intended to protect the atmosphere from dust emissions at refractory works reaches 18% of the total capital investments [1,2]. In this context, it is especially important to develop self-regenerating structures with decreased hydraulic resistance in order to achieve energy-saving highly efficient dust collection from process gases and aspiration emissions. The advantages of cylindrical granular filter layers with a small curvature radius makes them rather promising for dust removal from gases in a centrifugal field [3,4].Theoretical and experimental studies have been carried out to develop a steady hydrodynamic filtering regime, which involves the specifics of resistance of rotating porous bodies, as a dust-gas flow passes through them. We relied on extensive information on separating heterogeneous gaseous systems with a disperse solid phase in a centrifugal field [5 -7].There are known original designs of self-regenerating rotary filters for separating dust-gas flows [8,9]. Therefore, it is interesting to estimate the effect of centrifugal force on pressure difference ÄP in a centripetal motion of a dust-gas flow. To derive a dependence describing the filtering process, we assume here that the pressure difference observed as the flow passes through the filter cake ÄP c.dyn is lower than the pressure difference for a stationary element ÄP c.st by a value ÄP c.cen determined by the effect of the centrifugal force on the cake:(1)The validity of equality (1) is obvious, considering that P c.st and P c.cen are oppositely directed.To determine P c.cen , the elementary pressure developed in the centrifugal field inside a coaxial cake element of a radius R and thickness dR is calculated from the following the formula [10]:where ñ c is the density of the filter cake (dust) on the surface of a rotating filter element; ù is the rotational speed. After integrating equality (2) in the corresponding limits, we obtain ÄP c.dyn = 1/2 ñ c ù 2 (R o.c 2 -R o.m 2 ),where R o.c and R o.m are the outer radii of the filter cake layer and the filter membrane.