Terms and constructive measures of transition from laboratory installations to industrial design of vortex dryers

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Vortex and cyclone apparatuses are increasingly used for intensive flow of combined technological processes of pro-cessing (fine grinding, classification, drying, mixing, hydrophobization, etc.) dispersed materials. One of the types of equipment of this class with an active hydrodynamic regime is an apparatus with an upward (or downward) spiral-swirling gas-dispersed flow. The studies conducted by A.F. Frolov, V.I. Mushtaev, V.M., Ulyanov and B.S. Sazhin con-firm the high drying efficiency of highly moist dispersed materials. One of the tasks of a large-scale transition from laboratory facilities to industrial designs is the development of design features that determine the similarity of the hy-drodynamic regimes of heat and mass transfer processes. To determine the hydrodynamic characteristics of the gas-dispersed flow, methods based on the measurement of flow rates, velocities and hydraulic resistances were used. To establish the drying curves and the temperature curves of the polydisperse material (TPP hydraulic ash removal) of different fractions under various conditions of convective heat input, the kinetic method was applied. This method was based on measuring the moisture (mass) and temperature of the dried particles by selecting along their movement. The developed conditions and design measures allow for a large-scale transition from laboratory facilities to industrial de-signs without intermediate costly research on pilot plants. The generalized analytical and experimental data on the de-termination of the external heat and mass transfer characteristics of the drying process of dispersed material (hydraulic ash removal) in a vortex dryer depending on the hydrodynamic and structural parameters of the gas-dispersed flow have been presented. The presented experimental data allow suggesting the limiting effect of hydrodynamic phenomena that determine the efficiency of the drying process of dispersed materials in a gas stream.