Hydrodynamics of a reactor with updated structure of frame mixing device

This article is devoted to computer simulation of the hydrodynamic situation in a reactor with a standard design and an upgraded design of a frame stirrer. A comparative analysis of the hydrodynamics of fluid flows occurring in the volume due to the use of classical and modernized design was performed. An upgraded design of a frame stirrer for homogenizing the medium in a reactor has been proposed. The aim of this work was to study the influence of the geometry of the stirrer blades and their location in space on the speed and direction of flows in the reactor. The basis for the new design of the mixing device was the standard design of the frame mixer with two horizontal jumpers. Installation of additional blades and their placement at a certain angle to the vertical and horizontal planes and relative to each other was considered as one of the methods of improving the design. For this work, the study was conducted in the universal software system of finite element analysis ANSYS. Computer simulation is used to analyze complex systems and processes based on a computer model. The simulation was performed to analyze the influence of the geometry of the mixing device on the speed and direction of fluid flow in the apparatus. To conduct the study, 3D-models of two different types of geometry of the mixing device were built, physicomechanical parameters of the environment in the reactor were set and on the basis of these data the mixing process in the apparatus was modeled. In this work, the influence of plate geometry and their location in space on hydrodynamics is investigated. The basis of the proposed design of the mixing device is the task of intensifying the mixing process by increasing the mixing efficiency along the height of the apparatus. A comparative analysis of the direction of fluid flow, its velocity and temperature change using a standard and upgraded design of the mixing device was performed. It was found that when installing additional plates that are located at an angle to the horizontal and vertical planes in the reactor there are additional axial and radial fluid flows, which improves homogeneity and increases the intensity of mixing.

Prospects for oil and gas presence of Lower Sarmatian deposits in the north-western part of the Outer zone of the Carpathian foredeep (by hydrogeochemical and hydrodynamic indicators)

The hydrogeochemical parameters of the Lower Sarmatian aquifer of the north-western part of the Outer Zone of the Carpathian Foredeep have been studied. The waters of the chloride-calcium type (according to the classification of V. O. Sulin) are dominated. Other types of water are distributed locally. On the basis of the calculated genetic coefficients, the conclusion on sedimentogenic conditions of their forming during a geological history of the region is made. It is established that the general tendency for the deposits of the Outer Zone is increasing of TDS of water with depth and stratigraphy. The waters of the north-western part of the Outer Zone are characterized by reduced values of sulfate content and sulfation coefficient rSO42– • 100/rCl–, indicating the conditions of hydrogeological closed structures. The genetic index of formation water metamorphism (rNa+/rCl–) is mainly inversely dependent on TDS. Its values greater than one are inherent in waters of hydrocarbonate-sodium and sulfate-sodium types, which are not typical for the hydrocarbon deposits. The nature of fluctuations in the values of the chlorine-bromine coefficient is fully consistent with other hydrochemical parameters and the results of paleohydrodynamic reconstructions. A detailed analysis of the current hydrodynamic situation of Lower Sarmatian aquifer in combination with geochemical features and paleohydrodynamic reconstructions allowed to identify the perspective structures of the studying region. Our forecasts for the gas potential of the Krukenychy depression are consistent with the forecasts of researchers of Ivano-Frankivsk National Technical University of Oil and Gas. The results of their research are based on gravitational field anomalies.

Influence of the vibrations in the interfacial layer on the wettability of adhesized material interfacial formations in systems with d- and f-elements

The effect of local vibration at interfacial layer of a heterogeneous liquid system on the wettability of the material of interfacial formations based on the salt of the d- or f-element of di-(2-ethylhexyl)phosphoric acid adhered to glass has been investigated. It is shown that in the field of mechanical vibrations one can obtain a material with a given value of the wetting angle, which has hydrophobic properties. It is established that the influence of mechanical vibrations is due to changes in the hydrodynamic situation in the transition region and is the result of complex interactions mainly hydrodynamic and coagulation processes in the interfacial layer of the di-(2-ethylhexyl)phosphoric acid - solvent system / water solution of the d- or f-element salt. The dependence of the wettability of the material of interfacial formations adhered to glass on the parameters of the force field (vibration frequency, amplitude), the design features of the experimental setup, and the composition of the system is shown.

Environmental risks and assessment of the hydrodynamic situation in the mines of Donetsk and Lugansk regions of Ukraine

Modern environmental risks and threats relate with the negative impact of anthropogenic and natural factors on ecosystems, man-caused negative impact of industrial and potentially hazardous objects, pollution of drinking water sources, agricultural land, atmospheric air, deviation of the geological environment and subsoil on the safety of life in certain areas. Coal enterprises are one of the objects of high ecological danger and critical infrastructure. Today, environmental safety in the east of Ukraine should be considered in close connection with the ecological and man-made threats associated with combat operations in these territories. The authors carried out an analysis of scientific researches of past years and provided an assessment of environmental risks in the territories of coal mining enterprises in the present conditions considering the structural-geological, geofiltration and mining-geological parameters typically for the Donetsk and Luhansk regions of Ukraine. The article considers the location of mines in Donetsk and Lugansk regions as zones of high ecological danger. The existing ecological threats and risks are determined, recommendations for minimization threats and risks in case of anthropogenic and environmental disasters are provided. The equation of calculating the coefficient of filtration in rocks is made, mineral-technical parameters of coal mines are analyzed. It is shown that one of the most probable factors of the transition of the territory into a zone of an emergency situation of a regional scale is the emergence of real threats to the life of a large number of people in the conditions of mass flooding of mines due to the termination of power supply of drainage and ventilation systems. Also in the article scientifically substantiated the provision of an acceptable level of environmental safety of the constituent parts of the environment (water environment) for the population living within the mining and agglomeration, taking into account the environ- mental factors of the negative factor-forming factors, as well as forecasting the hydrodynamic situation.

ANALYSIS OF THE SANITARY PURIFICATION OF GAS EMISSIONS FROM DUST IN THE LIME MANUFACTURE

Experimental studies have been carried out to study the effect of the location of the blade vortex from the end of the flue (the flow outflow from the flue to the separation chamber) by the value Vjmax and the determination of the optimum cross section where Vjmax is reached, and also the study of the influence of structural changes on the purification efficiency. The dependence of this swirler on the value of the tangential velocity of the gas flow at its exit from the separator is established. The cross-sections of the flue duct in which, after the swirler, the maximum values Vj, Vr are reached, the features of the dust-gas flow in the studied sections are considered. Based on the studies of the hydrodynamic situation during the flow of a rotating flow in the flue after the swirler, the possibilities of agglomeration of dust particles in the investigated zones, as well as the destruction of NOx gas impurities, are analyzed. During the operation of the reconstructed vortex dust collector, qualitative indices are attained, which confirm the expediency of the conducted studies and the expediency of reconstructing the vortex apparatus. It is proved that the installation of the blade vortex enhances the purification efficiency of the dust-gas flow in a vortex dust collector and will allow for a comprehensive purification of the exhaust gases.

Modeling of Wastewater Treatment Process in a Flotation Setup with Ejection Aeration System Having a Disperser

The mathematical modeling of flotation process has been considered in this paper. It has been pointed out that in the event when there are different types of pollutants in water the generation of bubbles with wide size-consist is needed. A flotation setup with ejection aeration system having a disperser that allows generate the bubbles which size-consist is characterized by several sets with their own values of average diameters is considered. The mathematical model for flotation process description taking into account the division of bubbles into several groups in sizes and hydrodynamic situation in flotation chambers has been proposed. Based on proposed model have been obtained other models describing extraction of certain waste, considering their properties, in such a case the initial model has been complemented by stages of other processes: settlement stage during flotation of suspended substances with density higher than water density, self-floating stage during flotation of contaminations with density less than water density, and reverse stages during flotation of hydrophobic-hydrophilic contaminations. The example of time definition for the process of water treatment from suspended substances and oil products has been presented. It has been demonstrated that it is possible to considerate the two-chamber flotation setup with ejection aeration system having a disperser as a sequence of reactors providing ideal mixing and displacement. Taking into account the equations for the reactors providing ideal mixing and ideal displacement, and the proposed models for description of process passing in cameras, have been received dependences for determination of concentrations and cleaning time in each camera. The importance of mathematical modeling for flotation setups designing has been pointed out. Application of scientifically based approach at design allows create setups having bigger profitability and compactness at achievement of the required efficiency.

Numerical assessment of bed-load discharge formulations for transient flow in 1D and 2D situations

Two-dimensional (2D) transient flow over an erodible bed can be modelled using shallow-water equations and the Exner equation to describe the morphological evolution of the bed. Considering the fact that well-proven capacity formulae are based on one-dimensional (1D) experimental steady flows, the assessment of these empirical relations under unsteady 1D and 2D situations is important. In order to ensure the reliability of the numerical experimentation, the formulation has to be general enough to allow the use of different empirical laws. Moreover, the numerical scheme must handle correctly the coupling between the 2D shallow-water equations and the Exner equation under any condition. In this work, a finite-volume numerical scheme that includes these two main features will be exploited here in 1D and 2D laboratory test cases. The relative performances of Meyer-Peter and Müller, Ashida and Michiue, Engelund and Fredsoe, Fernandez Luque and Van Beek, Parker, Smart, Nielsen, Wong and Camenen and Larson formulations are analysed in terms of the root mean square error. A new discretization of the Smart formula is provided, leading to promising predictions of the erosion/deposition rates. The results arising from this work are useful to justify the use of an empirical sediment bed-load discharge formula among the ones studied, regardless of the hydrodynamic situation.

GEODYNAMICS

Paleohydrodynamic schemes of the Badenian-Sarmatian deposits of the north-western part of the Outer zone of the Pre-Carpathian foredeep are built on the basis of paleohydrodynamic reconstruction of paleopressures of formation waters of elision stage of sedimentary basin. Results of paleohydrodynamic reconstructions have demonstrated that the most part of the explored gas fields of the region is localized in the limits of the marked areas of inherited pressure minima. Comparison paleo- and modern hydrodynamic situation enable us to draw conclusion about conditions of field formation.

Problems of the Hydrosphere Engineering Protection in the Process of the Middle Urals Exhaust Mines Liquidation (the Lyovikha Mine as a Study Case)

Vindication of the hydrosphere engineering protection measures in the process of mines work-out and liquidation is based on monitoring and hydro/geo/migration simulation outcomes. Methods of hydrosphere pollution prevention after mines’ liquidation are reduced to localization of polluted sites and polluted waters treatment at the points of their concentrated outcome with obligatory monitoring. For the area of hydrodynamical effect of the closed Lyovikha mine (Sverdlovsk oblast) a conceptual mathematical hydrogeological model has been developed. In the condition of the information deficit the model parametric saturation was carried out in the process of solution of inverse problems for characteristic periods of hydrodynamic situation variations.

The Concomitant Model Testing Approach for the Development of the Pendulous Installation Method of Heavy Devices In Deep Water

This paper synthesizes a method for model testing of non-conventional devices and operations. The basic idea is to perform numerical analysis in advance (or concomitantly) of the model test itself. This has been very effective over the years and its application to the development Pendulous Installation Method (PIM) of deepwater heavy devices has been effective as shown in the paper. Specifically, the PIM does not require boats with compensation systems for the usual vertical launching. The device to be installed is released from the free surface. It is hold by an auxiliary cable from a boat and connected by the installation cable to another boat some distance away. The auxiliary cable is then released and after an almost vertical trajectory of the manifold, the installation cable traction increases and the device rotates (pendulous motion) about the turning point on the other support boat. During the development of novel systems or operations, the industry is learning the importance of model testing. During the model tests, it has been understood that a two-scale problem had to be faced by the model test design. There are large bodies (the device) together with slender bodies (cables) in the same hydrodynamic situation. These two bodies have different scaling laws. How cope with it depends on the several aspects (inertia, damping, etc). However, with the help of a modern numerical model computer code, these problems may be anticipated by creating a framework of results that help in the interpretation of the model testing result itself.