Hydrotransport System Research Articles

A new semi-empirical correlation for estimating settling dynamics of suspensions in viscoelastic shear-thinning fluids

The optimization of sedimentation and hydrotransport systems involving settling suspensions in viscoelastic fluids has been hindered by a lack of robust and scalable mathematical models that accurately characterize settling dynamics in such scenarios. This study aimed to enhance understanding of this problem by developing a semi-empirical correlation that is dependent on space and time. This correlation describes batch settling characteristics during the ‘acceleration phase’ of settling, including changes in settling velocity and solids concentration of suspensions in a viscoelastic shear-thinning fluid under quiescent conditions.A novel dimensionless ratio- the ‘particle-acceleration’ number- was developed to simulate time-dependent settling velocities. The correlation’s accuracy was confirmed through validation which involved predicting two key parameters- the duration of the acceleration settling phase (with 86–98% accuracy) and the final solids concentration at the sample depth once the acceleration phase ended (with 82–96% accuracy).

მრავალსაფეხურიანი სადაწნეო ჰიდროსატრანსპორტო სისტემების ჰიდრავლიკური დარტყმებისაგან დამცავი მოწყობილობა

Pipeline hydrotransport systems began to develop rapidly from the second half of the last century. This was especially the case in the mining and mineral industries, when it was used for hydraulic transportation of loose solid materials. One of the fragments of the fundamental works performed by the author at G. Tsulukidze Mining Institute – the construction performance and working principle of the hydraulic shock protection device of multistage pressure hydraulic transport systems – is reviewed. The construction includes a pneumohydraulic accumulator, the body of which is connected to the suction pipe of the pumping unit through a tube on which a foot is mounted, and the bottom is connected to the necessary pipeline with a transfer pipe. Additionally, reverse valves are installed on the supply pipe and the transfer pipe.

Гидравлические удары в напорных трубопроводах при надземной прокладке

To determine the factors having the greatest impact on the risk of occurrence of water hammers in above-ground installation of pipelines, typical of permafrost areas. Determine the velocities of shock wave front propagation in steel pipes for different types of steel pipes. To calculate parameters of possible water hammer depending on pipeline wall thickness. Methods: Method of characteristics used for solution of differential equations of unsteady motion of liquid is the basis of calculation model for determination of flow parameters at occurrence of water hammer. Results: On the basis of the calculations carried out in the article the diagrams of pressure changes in the pressure pipeline made of steel pipes are analysed. The influence of speed of propagation of water hammer wave and speed of steady movement of a liquid flow on character of flow of an unsteady process and size of pressure at water hammer in the pressure pipeline in above-ground laying is estimated. The use of measures to prevent water hammers, including combined ones, with the purpose of increasing their reliability is much cheaper than the replacement of damaged pipes and equipment, elimination of washouts by leaking water and loss of drinking water. Practical significance: In permafrost conditions, many factors complicate construction and operation of pressure hydrotransport systems. Elimination of consequences of emergency situations accompanied by water leakage is difficult in harsh climatic conditions, and thermal impact on soils is not always avoidable. Therefore when designing new pressure systems and reconstructing existing ones it is necessary to take into account possible unsteady processes in pressure pipes.

Study of the motion of modified solid particles in hydratransport systems

The article examines the movement of solid particles, the hydraulic calculations of pipes in the process of movement, the classification of reducing the impact of solid particles on hydrotransport systems. The effect of solid particle magnification on flow rate, pressure loss, speed reduction as a result of the effect of internal friction forces of solid particles, friction in the flow of solid particle hydroarations, pressure loss as a result of the impact of Resistance Forces, internal corrosion process observed in the pipe, increased energy consumption were analyzed using the example of hydrotransport systems Recommendations have been made to solve the problems of speed reduction and pressure loss due to the movement of solid particles in the hydroaration flow through the modification method. The prior and subsequent movement of solid particles in a pipe modification is shown through comparison graphs. Information about the gossipol Tar selected as a modifier is provided.

Simplified Numerical Model for Transient Flow of Slurries at Low Concentration

Rapid transients are particularly dangerous in industrial hydro-transport systems, where solid-liquid mixtures are transported via long pressure pipelines. A mathematical description of such flow is difficult due to the complexity of phenomena and difficulties in determining parameters. The main aim of the study was to examine the influence of the simplified mixture density and wave celerity description on satisfactory reproduction of pressure characteristics during the transient flow of slurry at low concentrations. The paper reports and discusses the selected aspects of experimental and numerical analyses of transient slurry flow in a polyethylene pipe. The experiments were conducted by using the physical model of a slurry’s transportation pressure. The aim of the experiments was to determine the wave celerity during a transient flow in slurries. A low concertation of slurries, which was used during experiments, is typical for one of the biggest slurry networks in Poland. A comparison of the effects of different wave celerity descriptions was performed. The research reported that the theoretical formulas for slurry wave celerity and mixture density were not sufficiently accurate to obtain satisfactory compliance between calculations and observations. To improve the model, the experimental values of wave celerity and the concept of equivalent mixture density have been applied to indirectly consider the influence of variable mixture parameters. With such modifications, the calculated pressure characteristics in all analyzed episodes demonstrated satisfactory compliance with observations. The simplified approach proved to be effective in properly reproducing the intensity and frequency of rapid pressure changes.

Specific pressure loss calculations for tailings hydrotransport at the Kachkanar GOK

Mining transportation systems are evolving through the introduction of continuous transportation solutions, hydraulic pipeline transport being the most common of them. Considering the high labor and energy intensity of equipment operation, accelerated hydroabrasive wear of pipelines, and elevated metal consumption, respective mining hydrotransport efficiency assessments indicate a significant streamlining potential. Energy intensity of any transportation process depends on the specific head loss Icm and the concentration of the solid phase. Lower pressure losses and higher concentrations reduce the energy requirements for pumping a given volume of solid materials (tailings) and, consequently, improve the resulting hydraulic transport efficiency. The purpose of this work was to establish the change patterns for specific head losses at varying solid phase concentrations in the flow during hydraulic transportation of overflow hydrocycloning products via 800–1000 mm metal pipes with a mass fraction of the solid phase of 17 % (±5 %), as well as to develop recommendations for the design of tailing facilities of the Kachkanar GOK. The experiments conducted have established that specific head losses are directly proportional to concentrations of the solid phase in the tailings slurry. Higher solid phase concentrations and hydrotransport system throughput lead to increased pressure losses. This happens because elevated solid phase concentrations trigger the manifestation of rheological properties of the slurry in the liquid flow, affecting the specific head loss. The research results obtained are reflected in the reconstruction and development design for the plant.

Reliability Assessment of Hydro Transport Systems’ Operation

The results of full-scale tests of hydro transport systems operation under real production conditions have been collected in Siberian Transport University. Statistical processing of information has been carried out while creating a database for random variables. The following parameters of hydro transport system operation have been studied: availability factor, coefficient of technical use, efficiency factor, operating time to failure, and coefficient of time use. Indices of technical (coefficient of technical use, the coefficient of readiness, the coefficient of efficiency and operating time to failure) and organizational-technological (coefficient of time use) reliability have been determined. Methodical, mathematical and software methods for estimating reliability of construction machines by the example of systems have been worked out. Using the software, the efficiency and reliability of the operation of systems, complexes, sets and individual machines at specific objects have been substantiated. This allowed the most accurate prediction of timing and cost of production at specific sites. A method for taking into account specific production conditions in a comprehensive assessment of the operation of machines, kits, complexes and systems has been proposed. The use of databases based on the results of field tests of machines made it possible to calculate more accurately the indicators of technical organizational and technological reliability of performing a given volume of work. Taking into account the probability of organizational and technological reliability makes it possible to plan the work of the system under specific operating conditions with a greater validity. It is more accurate to predict the main indicators of work production. The method, which allows taking into account the specific working conditions of the performance of works and forecasting the main indices of the reliability of a particular machine, is proposed. The proposed toolkit of indicators of technical and organizational-technological reliability of hydro transport systems for making informed management decisions has real reliability.

Analysis of actual head losses in hydraulic transportation of WMS tailings along steel and polyurethane-lined slurry pipelines at Kachkanarsky GOK

The research focuses on the hydrotransport system for iron ore processing tailings of the Kachkanarsky GOK. Its aim was to establish the actual pressure losses in the hydrotransport system for iron ore processing tailings comprised of steel and polyurethane-lined slurry pipelines, to substantiate the preferred use of polyurethanelined slurry lines, and to develop practical recommendations for the facility. The respective industrial studies of the hydrotransport parameters for tail slurries were carried out using instrumental methods of direct pressure measurements in respective measuring sections of the slurry pipelines and mathematical statistics-based data processing methods. Using the major design, industrial, technical and operational characteristics, it has been confirmed that the use of internal polyurethane lining significantly reduces the specific head losses in hydraulic transportation of thickened iron ore processing tail slurries. The respective feasibility calculations confirm the economic efficiency of steel pipes with internal polyurethane lining in hydrotransport pipelines. The results of the studies are reflected in the reconstruction and development design for the tailings facility of the Kachkanarsky GOK. A transition to polyurethane-lined slurry pipelines will ensure energy saving in the hydrotransport process.

СИСТЕМА АВТОМАТИЧНОГО КЕРУВАННЯ ГІДРОТРАНСПОРТНОЮ СИСТЕМОЮ ЗІ СТАБІЛІЗАЦІЄЮ ТИСКУ

Purpose. The work is devoted to the development of a closed-loop control system of hydraulic transport system with pressure stabilization and its research on a mathematical model. Originality. The expediency of application of a closed-loop control system of electric water transport system with pressure stabilization as the most promising way of resource saving in the operation of pumping complexes is substantiated. The realization of the closed-loop pressure stabilization system using a discrete program regulator is proposed. The studies of parametric sensitivity of the closedloop pressure stabilization system have confirmed the high robustness of the proposed solution. Methodology. General methods of physics, hydraulics, mathematical analysis and computational mathematics were used to solve the tasks. Numerical solution of mathematical model equations and visualization of obtained results were performed in MATLAB®/Simulink environment. Results. The expediency of using closed-loop control systems of pumping units with pressure stabilization as the most promising way of resource saving in the operation of pumping complexes is substantiated. The impossibility of implementing the pressure stabilization system based on the classical PID controller is shown, which is caused by the influence of wave processes in the pipeline system with distributed parameters. The closed-loop pressure stabilization system with the use of a discrete program regulator is realized, its stability and robustness in a wide range of changes in the regulator parameters is shown. Practical value. The possibility of implementing a closed-loop pressure stabilization system of electric hydrotransport system has been substantiated; a method of calculating the discrete program pressure regulator based on the regression analysis of the results of mathematical modeling has been proposed. Figures 12, tables 2, references 9.

Technical and economic indicators of a slurry tailings hydrotransport system when replacing steel slurry lines with polyurethane-coated slurry lines

The hydrotransport system of Andrei Varichev Mikhailovsky GOK JSC used for iron ore processing tailings was studied with the aim of establishing its performance when using slurry pipelines with and without polyurethane coatings of their internal surfaces under mass concentration variations of 10 to 70 %. It has been established that the use of internal polyurethane coatings significantly reduces the specific head losses in hydraulic transportation of thickened slurry tailings for iron ore processing tailings. However, the technical and economic calculations performed failed to confirm the economic efficiency of their application for the slurry pipelines of the tailings facility hydrotransport system of Mikhailovsky GOK at any slurry thickening values, due to the significant payback period of capital investments caused by the relatively high current cost of polyurethanecoated pipelines. At the same time, a significant reduction (almost by a factor of four, provided that the current production volumes are maintained) in hydrotransport (energy) costs and maintenance costs of pressure slurry pipelines were identified for a transition to slurry tailings thickening to 50 % solids (excluding the capital and operating costs for the thickening system, reconstruction of the slurry pumping stations and additional measures for the distribution of a thicker slurry at the tailings storage facility). It is proposed to use the results obtained in the reconstruction of the slurry tailings hydrotransport system at the tailings facility of Mikhailovsky GOK with a conversion to hydraulic transportation of bulk concentration tailings thickened to 50 % in ∅820 mm slurry pipelines.

Theoretical bases of hydraulic mixture in round cylindrical pipelines

Hydro transport is characterized by the combined movement of liquid and solid particles, which in a mixture form two-phase or multiphase flows with different physical and mechanical properties. One of the main tasks of hydraulic transport is to study the throughput of pipelines, where taking into account the distribution of sediment concentration over the cross section of the pipeline formed under the influence of gravitational force is of great importance in describing the nature of the two-phase flow. Pressure-bearing suspended flows in hydro transport systems are usually characterized by high volumetric concentrations and a wide range of sizes and densities of solid particles that are part of hydraulic mixtures. The flows under consideration are more complex in their structure than turbulent flows of homogeneous liquids in pipes. Therefore, the methods for calculating these flows are much more complicated than the usual methods of hydraulics of pressure flows of homogeneous liquids. To develop scientif-ically based methods for calculating the parameters of the movement of hydraulic mixtures in pipes, widely used the averaged equations of the weighted flow and experimental data. When moving slurries through pipes, gravity plays a significant role. The article discusses the influence of gravity on the throughput of pressure systems with different slopes and obtains new dependences of the flow rate of turbid flow on the slope of the pressure pipe.

The effectiveness of polyurethane coatings on internal surfaces of slurry lines in tailings slurry hydrotransport systems

The effectiveness of polyurethane coatings on internal surfaces of slurry lines in tailings slurry hydrotransport systems

Effective Parameters of Tail Processing of Gold-Bearing Ore Hydrotransport for Verninskaya Processing Factory

The article is devoted to the analysis of the composition and properties of the materials and liquids during transportation using pipeline and shows that in order to increase the efficiency of hydraulic transport systems in mining a transition to the transportation of slurries with a high concentration of solids in the slurry flow is necessary. Experimental studies have shown that slurry tailings of gold-containing ore with mass concentrations of more than 55 % are viscoplastic fluids. Experiments on a rotational viscometer allowed us to establish the main rheological characteristics of the studied slurries – shear stress and the dynamic effective viscosity. It has been established that over the entire range of concentrations from 55 to 65 %, the flow of slurries is described by the Bingham rheological equation. Experimental studies of hydraulic transport performed on a laboratory setup with a pipeline diameter of 50 mm confirmed the results obtained on a rotational viscometer. The curved of mixture stream is inclined straight lines that are cut off on the axis of the head in the sections, which determine the initial hydraulic slope corresponding to the yield shear stress on the rheological curves. According to the results of the experiments, a method has been developed for calculating the hydraulic transport of high concentrated slurries of tailings of gold-bearing ore. Calculations showed that in a given range the performance of the hydrotransport system and the mass concentration of the solid phase pressure losses vary from 11 to 84 m of water column/m. Head loss values increase with the increasing concentration. A sharp increase in the head loss occurs in the concentration range from 60 to 65 % and higher.

Свободный, нерастворенный в жидкости воздух – эффективное средство для гашения гидравлических ударов в напорных гидротранспортных системах

Свободный, нерастворенный в жидкости воздух – эффективное средство для гашения гидравлических ударов в напорных гидротранспортных системах

Application of Soft Fabric Structures for Improvement of the Selective Irrigation Intake of the Partisan Water Reservoir

To protect irrigation intake structures from the deposition of sediments (from bottom, middle, upper layers), which can be a source of secondary water pollution, a large number of different designs of sediment interceptors have been developed. Increasing requirements for withdrawn water quality from the watercourses for irrigation and water supply, necessity of reconstruction on a large part of the previously constructed headwaters and have led to the development of an effective protective device.In the 20th century, world population has tripled from 1.6 to 6 billion people, irrigated farming area increased from 50 to 267 million hectares, and water consumption increased six-fold - from 500 to 3,500 km3 / year. The real water shortage is provoked by increased demand, associated, according to experts and international organizations, with demographic boom, change in food intake of large groups of population, industry and energy development, urbanization and popularization of biofuels. Factors that reduce available water resources include inefficient water use, water pollution and, increasingly, climate change. This issue remains very important for the Crimea and its successful resolution will become one of the foundations for the sustainable development of the peninsula.Water resources are one of the factors of sustainable development of the territories on global and regional levels. Entire hydro transport system improvement of water resources delivery to the final consumer of the Crimea (population, agriculturally used areas, industry, tourist complex, etc.) is the main strategic issue on optimization of water resources potential and sustainable development of various sectors at the socio-economic sphere.It is supplied up to 80,000 m3 / day water for drinking purposes from the Partizansky Reservoir, 215,000 Simferopol residents use water from the Partizansky Reservoir for living. Partisan reservoir is the main source of water supply for settlements in Simferopol and Bakhchisaray districts.

Increasing the efficiency of highly concentrated coal-water fuel based on the simulation of non-Newtonian fluid flow

The analysis of further prospects for increasing the efficiency of transportation of coal-water fuel in hydro-transport systems of industrial enterprises is carried out. The mathematical model of the spatial three-dimensional flow of coal-water fuel was developed on the basis of SST turbulence model based on the solution of Navier-Stokes equation. As a result of the calculation, the values of pressure loss, flow rate and velocity distribution over the cross section of the pipeline in the straight section and in the turn were determined, which allowed determining the energy consumption during coal-water fuel transportation in the industrial hydro-transport system. The performed studies allowed us to refine the mathematical model of water-coal suspension flow and, thus, improve the patterns of influence of hydro-transportation scheme and parameters of coal-water fuel on energy consumption for its supply to enterprise consumers. By means of mathematical model of non-Newtonian fluids flow, the patterns of influence of hydro-transport system parameters and transportation modes of coal-water fuel on its energy indicators in industrial hydro-transport systems are determined. The obtained results are related to reduction of energy consumption, optimization of enterprise transport network configuration and increase of efficiency of coal-water fuel transportation to enterprise energy facilities.

Determining the Parameters of the Hydraulic Transport of Tailings for Processing Iron Ore

The system for hydrotransport of tailings for iron ore processing at JSC EVRAZ Kachkanarsky GOK (Kachkanarsky Ore Mining and Processing Plant) acts as an object of research. The aim of the work was to determine the parameters of the hydraulic transport of tailings for processing iron ore at mass concentrations of the solid phase from 30% to 70% and to develop recommendations for the industrial operation of the hydrotransport systems of highly concentrated pulp from the Kachkanarsky GOK. Methods of carrying out the work include laboratory studies of hydrotransport parameters of thickened tail pulps with the development of a calculation technique; pilot-industrial tests of the hydrotransport system in the conditions of the Kachkanarsky GOK. As for the main structural, technological, technical and operational characteristics, it is established that when using polyurethane coatings on the inner surface of the pipes, the specific loss of pressure of thickened mixtures on hydrotransport is significantly reduced (1.75). This makes it possible to significantly increase the transportation range for laying the tailings for processing to the far parts of the tailing dump. Completed technical and economic calculations confirm the economic efficiency of using steel pipelines with an internal polyurethane coating. The degree of implementation of the research results is in the project for the reconstruction and development of tailing dump of the Kachkanarskiy GOK for the period of 2018-2020. As a recommendation for implementation of the research results, it is proposed to use the results of work in the project of reconstruction of the hydrotransport system at the Kachkanarsky GOK (ore processing plant) by switching to hydrotransport of slurries thickened to mass concentrations of 35-40% in pipes with an internal polyurethane coating, which will provide energy saving in the technological process of hydrotransport.

ГИДРОТРАНСПОРТ СГУЩЕННЫХ ХВОСТОВ ОБОГАЩЕНИЯ ЖЕЛЕЗНОЙ РУДЫ НА КАЧКАНАРСКОМ ГОКе ПО РЕЗУЛЬТАТАМ ОПЫТНО-ПРОМЫШЛЕННЫХ ИСПЫТАНИЙ СИСТЕМЫ ГИДРОТРАНСПОРТА

В качестве объекта исследования выступает система гидротранспорта хвостов обогащения железной руды на АО «ЕВРАЗ Качканарский ГОК». Целью работы являлось определение параметров гидравлического транспорта хвостов обогащения железной руды при массовых концентрациях твердой фазы от 30 до 70 % и разработка рекомендаций для промышленной эксплуатации систем гидротранспорта высоконцентрированных пульп ЦХХ Качканарского ГОКа. Проведены лабораторные исследования параметров гидротранспорта сгущенных хвостовых пульп с разработкой методики расчета; опытно-промышленные испытания гидротранспортной системы в условиях ЦХХ Качканарского ГОКа. Установлено, что при использовании полиуретановых покрытий внутренней поверхности пульповодов значительно (в 1,75 раза) снижаются удельные потери напора на гидротранспорт сгущенных смесей. Это позволяет значительно увеличить дальность транспортирования для укладки хвостов обогащения в дальние участки хвостохранилища. Внедрение результатов исследований – в проекте реконструкции и развития хвостохранилища ЦХХ Качканарского ГОКа на период 2018-2020 гг. Предлагается использовать результаты работы в проекте реконструкции системы гидротранспорта в ЦХХ Качканарского ГОКа путем перехода на гидротранспорт гидросмесей, сгущенных до массовых концентраций 35-40 % в пульповодах с внутренним полиуретановым покрытием, что обеспечит энергосбережение в технологическом процессе гидротранспорта.

Slurry erosion–corrosion wear behavior in SiC-containing NaOH solutions of Mo2NiB2 cermets prepared by reactive sintering

The slurry flow unit, such as coal-mining industry, erosive wear and erosion-corrosion can cause high rates of material loss, particularly in the hydrotransport system where corrosive slurries are encountered. Stainless steel, Metal Matrix Composites (MMCs) and so on, comprising a ductile binder with a reinforcing hard phase, are seeing greater applications as coatings and hard facing for critical components, where there is a requirement for high durability. In this paper, the erosion-corrosion performance of Mo2NiB2-based cermets applied by the reaction sintering process is evaluated. Three cermets, with varying volume fraction of Mo2NiB2 phase range, all with a Ni binder, have been considered. The microstructure and properties of Mo2NiB2-based cermets are investigated and discussed. The influence of volume fraction of Mo2NiB2 phase on the erosion and erosion–corrosion resistance is researched under alkaline conditions. Results reveal that the increasing of boron percent along with Mo2NiB2 phase pile up. Meanwhile, the hardness has direct relationship with the volume fraction of Mo2NiB2. The Mo2NiB2 phase plays an important role in wear behavior. The effect of Mo2NiB2 phase volume fraction on erosion–corrosion only containing NaOH solution of Mo2NiB2-based cermets is different from that on erosion containing both NaOH solution and SiC. It is advantageous for the corrosion resistance to contain more Mo2NiB2 phase. In alkaline slurry impact, the cermets with less Mo2NiB2 phase deteriorate largely due to corrosion which decreases the mechanical properties and speeds up the total loss of material. In alkaline slurry with SiC particles, the weight gain is produced by the synergistic effect of erosion and corrosion on the contrary. When the volume fraction of Mo2NiB2 is low, corrosive production is the main cause of weight gain due to increasing interference between impinging and reflected erodent. The Mo2NiB2 phase is more, the corrosion resistance is higher and the corrosive production is much less.

КЛАССИФИКАЦИЯ КОРМОВЫХ МАСС ПРИМЕНИТЕЛЬНО К ИХ ГИДРОМЕХАНИКЕ

The current stage in the development of agricultural production in livestock is characterized by the extensive use of pipeline transport to move the forage masses, which are related to non-Newtonian fluids. Production experience and scientific work on the study of hydrotransport systems showed that this method of transportation is the most economical and promising, it has high reliability of structural elements, improves sanitary and hygienic working conditions and makes it possible to fully automate the transportation process. The complex nature of the transportation of mixtures has not allowed to create a unified theory of hydrodynamic calculation of their parameters to date, therefore, various models are used for theoretical investigation of the nature of motion. To select a particular model, it is always important to correctly classify viscous semiliquid media with respect to hydrodynamics. Therefore, the article did not set out the specific goal of choosing a method for studying non-Newtonian systems, but solved the problem of their classification by known defining characteristics. The proposed classification does not pretend to be exhaustive in terms of the physical and chemical nature of the fluid, especially their combinations, but it covers almost all the anomalous phenomena that occur in the fluid during its transportation and helps to select a quantitative method for calculating the transporting fluid. The classification of non-Newtonian fluids with respect to their hydromechanics is based on the dependence of the shear stress on the shear gradient. For this dependence, each type of liquid is considered. The developed classification scheme further promotes a more complete account of the rheological properties of high-viscosity liquids during their transportation through pipes and facilitates the development of quantitative calculation methods.