Heat transfer in a centrifugal vortex tube

The results of an experimental study of the heat flux in a model of a centrifugal vortex apparatus with a lower rotating disk are presented. An experiment considered three cases at a distance between the disks H=R/2 and H=R: “water”, “water-air”, and “water-oil”. Using the colorimetric method, the dependence of the heat flux on Reynolds is shown. The case “water-air” was chosen to evaluate the contribution to heat exchange from the thermocapillary effect (Marangoni) at high Re. For the case of two immiscible liquids of different densities (water-oil), the effect of “centrifugal levitation” is found.

FEATURES OF MODELING THE TRACTION OF MOVEMENT OF MATERIAL PARTICLES IN A VORTICAL LAYER

In the given article the actual modern scientific problem is solved — on the basis of experimental data the mathematical model of movement of a particle in a vortex layer at heat treatment taking into account multiphase of a stream is created. At the current level of development of vortex devices, the relevance of research aimed at in-depth study of processes, improvement of structures and manufacturing technology of individual components has increased. The lack of a strict theory is felt most acutely in the design of systems and installations in which the vortex apparatus is one of the main units. In this regard, the priority remains the development of a theory that allows to obtain a fairly reliable mathematical description of the processes occurring in the vortex chamber of the apparatus. The patterns of propagation of the swirling jet depend on a large number of different conditions (design features of the nozzle, the intensity of the twist) and flow parameters (their density and speed). The flow in the jet has a complex non-automodal character, in connection with which in other works it was considered expedient to use for calculation numerical methods of integration of equations of motion to describe the non-automodal flow in ordinary jets. The disadvantage of these models is that when solving the model of vortex flows go into the model of laminar flows. In this case, many quantities cannot be determined analytically or experimentally. When dividing the flow into the zone of the vortex and the zone of the main vortex, the error in the calculations of the hydrodynamics of the flow, and especially the particles, increases significantly due to the use of different equations of the turbulent viscosity, which is taken for each zone constant. These models are written for a continuous medium and are therefore not suitable for multiphase flow. The peculiarities of the trajectory of the material particle in the vortex apparatus are determined and the dependences are obtained, which allow to control the heat treatment time and on the basis of which it is possible to design the optimal vortex device for drying dispersed materials. The mathematical models obtained in this work can be used in methods of calculations and design of vortex heat and mass transfer devices. The calculations performed according to the equations of the proposed model show satisfactory agreement with the experimental data. When estimating the relative velocities of the particle in the unloading part of the vortex apparatus, it is obvious that the use of equations for laminar flow, which are traditionally used in calculations, leads to significant errors.

STUDY OF THE INFLUENCE OF CONSTRUCTION AND MODE PARAMETERS ON THE HYDRODYNAMICS OF A HOLLOW VORTEX APPARATUS

The research was to determine the more efficient design of the swirler from the point of view of hydrodynamics and heat and its optimal parameters. Various swirl designs were manufactured and tested. After preliminary studies conducted on a laboratory installation with a glass working apparatus, several swirlers were selected taking into account their hydraulic resistance, the structure of the swirling gas-liquid flow, and the amount of liquid entrainment by gas. The results of an experimental study of the hydrodynamics of a hollow vortex apparatus with one and two tangential and axial swirlers. Hydraulic losses in the channel and in the swirls during the direct downward movement of gas and gas-liquid flow are determined. In addition, studies of the hydraulic resistance of a vortex-type device allow us to determine the energy consumption of this device for conducting complex processes of dust collection and absorption or contact heat exchange. The hydraulic resistance in the presence of a liquid film is higher than in the case of a single-phase gas flow. The pressure drop in the studied vortex apparatus does not exceed the resistance of high-performance cyclones and vortex-type devices of other designs. The effect of the twist coefficient of gas swirlers, gas velocity, and liquid flow on the pressure drop in the vortex apparatus is established

Modeling of the Electromagnetic Characteristics of the Inductor of an Electric Vortex Apparatus in the Comsol Multiphysics Environment

Electric vortex devices are a promising solution for intensifying a large number of technological influ-ences. However, depending on the area of application, the efficiency of use depends on a large number of fac-tors which are often difficult to optimize without a simulation model. The article discusses the possibility of modeling of the electromagnetic characteristics of the inductor of a vortex electric apparatus in the Comsol Multiphysics environment. The aim of the study was to evaluate the distribution of magnetic flux in the inductor of a vortex electric apparatus depending on the type of geometry and the level of occupancy of the technologi-cal zone. The object of study is the inductor of a vortex electric apparatus with an unmatched moving part, the subject is the distribution of magnetic flux depending on the type of geometry of working bodies and the level of their occupancy of the technological zone. The simulation of the distribution of the magnetic flux in the in-ductor, depending on the type of the used geometry of the working bodies, as well as the level of their filling of the technological zone was carried out. It was found that the most promising from the energy point of view is the use of spherical working bodies which is explained by the most preferable mass inertial characteristics rela-tive to rod working bodies with displaced centers of mass. The obtained results can represent the initial data for the development of elements of digitalization of the energy characteristics of vortex electrical devices dur-ing their operation in various industries, as well as when creating their simulation models.

KINETICS OF THE PROCESS OF DRYING THE PASTE OF TITANIUM DIOXIDE IN AN ORIGINAL DRYING VORTEX APPARATUS AND OBTAINING A FINE POWDER TIO2

The authors of the article justified the physical model of the drying process of titanium dioxide paste and the drying of TiO2 fine powder to a residual moisture content of 0.3%, on the basis of which a mathematical model of the drying process is developed. The result of solving the mathematical model is the kinetic parameters of the drying process, with the help of which the drying apparatus of the vortex type was designed, designed and manufactured. The results of the simulation were verified by experimental studies of the drying and drying of TiO2 paste, and experimental graphical dependences of the drying rate and product temperature on the drying time were obtained. The obtained dependences are analyzed and the necessary initial parameters of the coolant are established, which allow increasing the drying rate and reducing energy costs for the drying process. As a result of the experiments, the fine powder of titanium dioxide fits the requirements of state standards and possesses the necessary mechanical and consumer properties. Bibl. 10, Fig. 7.