The object of research is the efficiency of dust collection of fine dust in an apparatus with an intense turbulent mode of phase interaction. One of the most problematic areas of the existing dust and gas cleaning equipment is the low efficiency of collecting fine dust. Effective cleaning of exhaust gases from dust involves the use of multi-stage cleaning systems, including wet and dry dust cleaning devices, which entails high capital and operating costs. These disadvantages are eliminated in the developed design of the cyclone-vortex dust collector with two contact zones. The device implements both dry and wet dust collection mechanisms, which allows for high efficiency of dust removal at high productivity. The conducted studies of the total and fractional efficiency of dust collection when changing the operating parameters of the developed device showed that the efficiency of collecting fine dust is 98–99 %. The increase in the efficiency of dust collection in the dry stage of the device is due to an increase in centrifugal force. In the wet stage of contact, the efficiency reaches its maximum values due to the vortex crushing of the liquid in the nozzle zone of the apparatus. Studies of the fractional efficiency of the apparatus show that with an increase in the diameter of the captured particles, the efficiency of the dust collection process for dry and wet stages, as well as the overall efficiency, increases. With an increase in the density of irrigation, the overall efficiency of dust collection in the apparatus increases. It has been established that an increase in the efficiency of capturing highly dispersed particles occurs due to turbulent diffusion, the value of which is determined by the frequency of turbulent pulsations and the degree of entrainment of particles during the pulsating motion of packed bodies. To describe the results obtained, a centrifugal-inertial model for a dry contact stage and a turbulent-diffusion model of solid particle deposition for a wet contact stage are proposed, which make it possible to calculate the dust collection efficiency of the contact stages, as well as the overall efficiency of the cyclone-vortex apparatus. The results obtained show the prospects of using devices of this design at heat power plants and other industries.

Grinding processes, which are very common and occurring in almost any industry and agriculture, require large energy costs and are associated with irretrievable losses due to wear of working units of grinders. It is generally recognized that reduction in specific energy costs is possible when using mills in which grinding will be carried out mainly due to the impact loading of a material. The results of studies of a single impact grinding of materials with various physical and mechanical properties, depending on the impact velocity and design features of a grinder in an impact-centrifugal mill, are presented. Experimental dependences of impact-centrifugal grinding are presented. Graphic dependences of the median particle mass distribution of a ground material depending on the number of blades are obtained. The number of blades for a given rotor diameter (0.4 m) was 4, 6, 8, 12 pcs. The graph shows that when grinding chalk, the number of blades does not significantly affect the quality of grinding. When grinding sylvinite and in particular gypsum stone with an increase in the number of blades to 8, the grinding fineness improves, i.e., the median particle size decreases, however, with a further increase in the number of blades, the dispersed composition of the products remains almost constant. The analysis of known data on the theory of impact grinding is given, on the basis of which the principles of creating new energy-efficient machines for grinding materials, in particular to reduce energy costs, were formed.

Based on the analysis of the work of known designs of enthalpy exchangers, cooling-hydration towers in thermal phosphoric acid production, a design of an enthalpy exchanger with a regular ring tubular filling is developed. As a result of the research, curves of the mass transfer coefficients in the gas phase and the heat transfer coefficients on the gas velocity and irrigation density, the results of calculating the Sherwood and Nusselt numbers on the Reynolds numbers for gas and liquid, are derived. Based on the investigations carried out, an engineering method for calculating the hydrodynamic characteristics, mass transfer coefficients in the gas phase and the heat transfer coefficients, absorption parameters of an apparatus with a ring tubular filling is proposed. This method has been used to calculate the main indicators of the absorption of phosphorus anhydride carried out in the cooling-hydration tower, which has allowed recommending the proposed design of an enthalpy exchanger with a regular ring tubular filling to replace the existing cooling-hydration tower. Copyright © 2023 Praise Worthy Prize - All rights reserved.