Vol 51, No 5 (2017)

A mathematical model of the turbulent transport of liquid aerosol particles has been considered using an approach in which the transport of a finely dispersed phase is conditionally described as a diffusion process with mass-transfer theory equations. The main parameter in this formulation is the coefficient of the velocity of particle transport (turbulent migration), which is an analogue of the mass transfer coefficient. The use of flow pattern models with a bulk source of the mass of sedimenting particles in a random packed bed and wire-mesh demisters is demonstrated. The equations for calculating the separation zone length and the process efficiency have been derived with allowance for the inlet section and the back mixing of the gas flow. Some calculation results are given for the aerosol separation efficiency and the energy coefficient compared with experimental data.

The conditions of slow-downs, hang-ups, and turns when drops of sprayed liquid are in an opposite flow of high-temperature gases (temperature was around 1100 K) using panoramic optical methods of particle image velocimetry, interferometric particle imaging, shadow photography, and Tema Automotive software have been dedicated. The distances passed by the drops until the full slowing down have been measured. Investigations have been carried out on the change in the characteristic dimension (conventional average radii) of drops in the range of 0.05–0.5 mm. The initial velocities of their motion and gases were varied in the range of 0.5–2.5 m/s and 0.5–5 m/s, respectively. The processes of water drops slowing down at the comparable initial velocities with gases in the conditions of intensive evaporation have been studied. The possible directions of improvements of chemical technologies of water and emulsions purification on its basis in the field of energy conservation using the results of experimental investigations carried out have been set.

It has been shown based on the example of a representative sample of oil refinery wastes that the process of filtration combustion in the superadiabatic mode can be used for recycling problematic liquid combustible wastes. For the steady progress of the process, the concentration of liquid combustible wastes in the mixture should not exceed 20 wt %. The addition of a small amount (5–10%) of a solid fuel to the initial mixture promotes the stabilization of the process of gasification; here, the calorific heat value of gaseous products increases.

The effect of the scaling factor (the influence of the height and diameter of the initial cylindrical billet) on the temperature distribution in a material and on the completeness of the extrusion of long samples obtained the method of self-propagating high-temperature synthesis (SHS) extrusion has been theoretically studied. A numerical analysis has been carried out based on the mathematical simulation of the thermal conditions of the SHS extrusion process. It has been shown that the change in the scaling factor significantly affects the length and quality of extruded rods due to the uniformity of the temperature field. It has been found that there is a limiting value for the diameter of the initial billet above which material is hardly squeezed out of the camera.

As a result of the simulation of the functions of the probability distribution in systems with chaos in the chemical composition, which also includes difficult natural and technogenic mixes, e.g., oil hydrocarbonic systems, it is established that the normal distribution of the composition is observed with the probability of differences in the components in the range of 0.2–0.8. This means that the normal distribution of free energy, and the boiling temperatures are achievable in systems where the ratio of the number of components with different properties to the total number of components is 20–80%. The borders of the difference probability are established, which define the belonging of systems to different types of distribution. At a share of the differing on properties components of 1–8.5%, the distribution is close to Poisson’s distribution. When the differences in the probability components in range of 0.085–0.2, a region of unstable distribution is observed.

The results of calculations using the kinetic models of material balance of methane–hydrogen, propane–propylene, butylene–divinyl, and isobutylene regions were presented. Together with the previously calculated ethylene region, these regions constitute the chemical-technological complex for cracking and pyrolysis gas processing. The final scheme of the chemical-technological complex with indication of all of its inlet and outlet flows and connections between the material and recirculation flows between regions was presented. The production capacities of reactor elements were determined for all the desired products of the chemical-technological complex.

The gas-dynamic and heat-exchange processes in a coaxial type plasma torch with tangential stabilization of the gas flow and a central inlet for feeding the raw material into the high-temperature region of plasma at atmospheric pressure were studied. The temperature range in the high-temperature zone (3500–4000 K) and near the plasma torch walls (930–1400 K) and the residence time of the reaction mixture in the high-temperature zone were estimated. The peculiarities of the gas flow motion using a feed probe were considered. The results, in comparison with the experimental operating modes of the plasma torch, make it possible to proceed to the construction of a plasma torch of higher productivity.

The morphosyntactic algorithm for computer-assisted semantic graphical analysis of the systematic names of fundamental and modified aliphatic compounds has been proposed. The algorithm uses the procedure for the decomposition of the initial name of an organic compound as a composite word into simple constituent morphemes and the production rules of convolution grammar for descriptive graphical representation of the initial composite name of an aliphatic compound, which allows one to generate molecular graphs of chemical compounds are needed for the computer-assisted generation of texts of science and technology (chemistry) and linguistic support of the CALS-technologies at all stages of the life cycle of aliphatic compounds.

The data on synthesizing nanosized potassium aluminosilicates (PAS) with a ratio of Si/Al of 1–5 obtained in the KOH–Al₂(SO₄)₃ · 18H₂O–SiO₂ · nH₂O–H₂O multicomponent system have been presented. Their composition, morphology, and IR and NMR spectra have been studied.

The results of studying the process of modifying the composition of basalt raw materials using the magnetic separation method are reported based on the example of basalt of the Myangdukha deposit (Arkhangelsk oblast). The chemical and phase compositions of magnetically enriched and magnetically depleted fractions have been determined by mass spectrometry and X-ray powder diffraction. The process of sintering these fractions has been studied by the DSC/TG method. The phase composition of sintering products has been studied and some of the physicochemical properties of the obtained samples have been determined.

In the review, the features of the interphase distribution of weak acids (K_а < 10^–2) in the systems containing neutral extractants have been considered. Experimental results of studies of the extraction of monocarboxylic acids have been described. The possibilities of using extraction processes for the isolation and separation of monocarboxylic acids from solutions of various compositions have been shown.

The effect of preliminary thermal (100–300°C) and chemical (10% HCl) treatment of 95% glauconite concentrate exerted on the sorption removal of copper (II) cations from nitrate solutions with pH in the range of 5–7, including ammonia media. The effect of indifferent electrolyte (KNO3 in a concentration of 10^–3 and 10^–2 mol/L) on the sorption of copper(II) from a 3.4 × 10^–3 M solution of Cu(NO₃)₂ has been estimated. It has been shown that a 99% level of the sorption purification from Cu²⁺ cations can be achieved.

The results of a study aimed at developing a method and technology for modifying textile materials with nanosized silver particles have been presented. The preparation of silver hydrosol and some of its properties when used as a working solution, as well as the stages of studying the interaction of ions and nanosized silver particles with model dyes and textile materials stained with their use, have been described. Generalized data on the development of the norms of technological regimes for the treatment of textile materials of various types with a nanomodifying solution based on the results of the performed studies, as well as the examples of the testing of the developed technologies on a pilot scale, have been presented.

The oxidative desulfurization of material containing oil sludge using hydrogen peroxide and transition metal compounds followed by subjecting the products of the oxidation of sulfur compounds to thermal treatment has enabled an 83% degree of desulfurization to be achieved.

The promising character of the synthesis of europium polyniobates (EuNb₃O₉ and EuNb₅O₁₄) by the extraction-pyrolysis method has been demonstrated. The luminescence properties of the synthesized polyniobates have been estimated from excitation and luminescence spectra at 300 K. The dependence of luminescence characteristics of the rare-earth elements polyniobates under study on the temperature and duration of precursor pyrolysis has been established.

The extraction of medium–heavy rare-earth elements, such as gadolinium (Gd), terbium (Tb), and dysprosium (Dy), with extractant mixtures that comprise technical di-2-ethylhexyl phosphoric acid (D2EHPA) and tri-n-butyl phosphate (TBP) has been investigated individually and in their simultaneous presence. Synergistic coefficients and separation factors of the Tb/Gd, Dy/Gd, and Dy/Tb pairs of elements have been calculated. The mathematical simulation of the extraction isotherm has been performed based on the example of Gd and some assumptions about the chemical composition of the extracted complexes have been made.

A functional model that describes chemical production has been developed. The model is represented by a pattern that is convenient for interacting with a chemical engineer expert upon arranging the formal specification of industrial processes. A functional model of vinyl acetate production has been plotted as an example of using the presented pattern.

The conditions for the existence of an acoustic flow effect excited in a cylindrical liquid volume by the radial oscillations of its walls within the ultrasonic frequency range with the purpose of enabling the breakup and transfer of liquid substances in the axial direction have been revealed. The conditions for the efficient performance of this process have been analyzed, and the optimal scheme of implementation has been constructed for the developed method. The obtained formulas make it possible to calculate the resonance parameters of ultrasound and applied equipment such that they would provide the attainability of a desired efficiency for the studied phenomenon. The radius of the drops, into which liquid fractions are broken up; the liquid flow velocity along the cylinder axis; and the characteristic length of nonlinear interactions between oscillations, which limits the critical dimensions of the process flowsheet, have been estimated. The formulated analytical relationships and computer calculations are aimed at selecting the most significant dependences, which provide critically important guidance for the practical implementation of the studied technology.