Criteria for choosing optimal working media for the gas-dynamic separation of granular materials

The article describes main physical properties of some technically important gases, including those that directly influence efficiency of the gas-dynamic separation of granular materials with a laminar flow of gas. In particular, character of such influence was determined to propose a numerical criterion to assess feasibility of some gas for the gas-dynamic separation depending on its physical properties: density and dynamic viscosity. The article proposes a method for calculating such criterion, factoring into known density and dynamic viscosity of gas. An increase in its value shows an increase in maximum allowable linear speed of gas in an accelerating channel, contributing to ensuring its laminar movement. An increase in density and viscosity of working gas is stated to result in decreasing average distance of collection and their dispersion, and asymmetry of distribution of the collection distance is shifted to a positive field. The article presents a conclusion that a shape of distribution of every components of a separated mixture by receiving containers, in particular, asymmetry of the log-normal distribution depends on physical properties of working media. Consequently, by choosing some working gas, we can control the shape of distribution of components, improving efficiency of their distribution.