Hydraulic Mixtures Research Articles

К безопасности труда при транспортировании гидросмесей по трубопроводу

The article describes the technology of pipeline transportation of hydraulic mixtures for stowing at underground mining. The relevance of optimization of the hydraulic mixture transportation processes is based on the fact that filling the excavated space during its abandonment is the main factor of injury prevention among workers and the integrity of industrial facilities. The aim of the study is to detail the hardening mixture transportation methods for increased distance compared to the reached distance. The maximum damage factor is a rockslide into the open excavated space; therefore, the delivery of stowing pulp to the location of use minimizes the hazard for miners. The advantages of the proposed solution are substantiated by the adopted study methods. The study results can be used for the development of a set of protective measures. The applied mixture transportation methods have been analyzed. The practices of hydraulic mixture transportation for the distance of 2.5 km, which exceeded the best global achievements, have been described. Models of the description of hydraulic mixture transportation have been provided including the models obtained by calculations and experimental pressure loss. The operation schedules in forced mode for pipeline transport have been provided. It has been demonstrated that the optimization of aspects of the issue is specifically relevant for the intensification of processes of metal deposit development. The outcomes of the experimental study can be used when involving accumulated washery refuse in the treatment. It is recommended to determine the parameters of efficient delivery of hydraulic mixtures in vibration-induced mode by modelling in accordance with the criteria of distance and reliability of transportation. The recommendations on the use of hydraulic mixture delivery technology in forced mode can be required when developing mineral deposits by open and underground methods and training highly qualified personnel.

Analysis of the geotechnological potential of heavy oil/bitumen production based on the improved method of well hydraulic production

The work provides an analysis of technologies for the intensification of heavy oil and bitumen production. A variant of its improvement based on the technology of borehole hydraulic production supplemented by the processes of dissolution with hydrocarbon solvents and catalytic aquathermolysis is proposed. The technology involves transfer of main operations of technological chain “extraction-preparation” to the productive layer (transfer of rock to composition of hydraulic mixture; viscosity reduction as a result of heating, dissolution with hydrocarbon solvents, destruction as a result of catalytic aquathermolysis; flotation of oil/bitumen droplets and gravitational separation of the rock). At the same time, in order to increase the efficiency of the technology and use of catalyst, it is proposed to implement the catalytic destruction of asphaltenes starting from mining and continuing after extraction to the surface in a technological installation. Moreover, the required volume of the solvent fraction (taking into account its irreversible losses) is expected to be obtained directly at the deposit as a result of catalytic aquathermolysis and distillation at the final stage of preparation. The improvement will allow to ensure the maximum coefficient of extraction of hydrocarbons with simultaneous modernization to the level suitable for transportation by pipelines without additional preparation.

Mathematical modeling of the transport of hydraulic mixtures in turbulent flow in pipes

Mathematical modeling of the transport of hydraulic mixtures in turbulent flow in pipes

To the question of parameter optimization of hydraulic transportation technology

Background. The selection of rational schemes for the technology of hydraulic transportation of rock mass requires optimization of the main parameters of this technology. A large number of factors determining the efficiency of hydraulic transportation hamper the formalization of relationships of the main transportation processes both between themselves and other mining and processing processes.Aim. To identify specific features of the main processes in hydraulic transportation technology, to establish the factors and parameters that determine their optimal operation, and to propose an optimization tool for both individual links and the entire chain of hydraulic transportation of rock mass.Materials and methods. The problem of parameter optimization of hydraulic transportation of mineral raw materials is solved based on the integral characteristics of the pressure movement of ore and rock hydraulic mixtures. These characteristics were previously obtained empirically or theoretically by the authors of the present paper and other researchers at various mining companies.Results. Among the variety of factors determining the efficiency of hydraulic transportation, the size of the transported piece (ore, rock, coal) was found to play the major role. At the same time, the nature of changes in economic expenditures and results of evaluating the effectiveness of hydraulic transportation technology will always relate to a specific field, the accepted technological scheme, and the equipment used.Conclusion. The problem of parameter optimization of hydraulic transportation processes can be solved using digital twin technology. This technology can be used to address the issues of managing complicated technological processes, as the same time allowing timely adjustments to the modes and parameters of operational processes both on individual production lines and at the enterprise as a whole.

Research of resistance to hydro-abrasive wear of thermoplastic polymers used to protect the inner surface of hydraulic transport systems

The results of tests of materials for hydro-abrasive wear resistance, as well as the erosion values of studied materials, are presented. It has been found that the use of thermoplastic vulcanizates (TPV) as a co-extruded coating of the inner surface of polymer pipe systems can significantly increase the lifetime of slurry pipelines when exposed to hydraulic mixtures, in particular iron ore tailings. In a model test simulating actual operating conditions of the pipeline, it was shown that TPV and thermoplastic polyurethane (TPU) coatings are signifi cantly superior in wear resistance to high-density polyethylene (HDPE) and steel.

Research into the pressureless flow in hydrotechnical systems at mining enterprises

Purpose. The research purpose is to develop a mathematical model of a pressureless flow in a channel with the occurrence in some areas of overflow layer through the wall. Using this model, it is possible to calculate the overflow layer height and length, as well as the change in flow rate in the channel due to the withdrawal of part of the fluid as a result of the overflow. Methods. The research uses a comprehensive multi-stage analytical approach. Firstly, in order to develop a mathematical model for a pressureless flow in the channel with the occurrence in some areas of overflow layer through the wall, this research analytically determines the dependence of the flow rate through the channel wall based on formulas for calculating the weir discharge coefficient. At the second stage, a mathematical model of a hydraulic mixture pressureless flow in a rectangular channel with an overflow through the wall is developed to determine the parameters and flow regimes of the stream. Findings. The dependences of the dimensionless height of the overflow through the channel wall and the effective critical flow depth on the dimensionless current channel length have been obtained for various values of the acting force parameters and the process parameter of the fluid overflow through the channel wall. This made it possible to study the dynamics of changes in these values along the channel for various values of the specified parameters, and to assess the degree of influence of the relevant factors on the characteristics of the pressureless flow along the channel and the process of fluid overflow through wall. Originality. For the first time, the model of the pressureless flow in the channel is generalized for the case of occurrence in some areas of overflow layer through the wall, when the length and height of the overflow layer are not determined by a hole in the side surface, but are controlled by a decrease in the corresponding flow rate. For the first time, this model makes it possible to calculate the height and length of the overflow layer and the change in the flow rate in the channel due to the withdrawal of part of the fluid as a result of the overflow in cases of overflowing condition of the channel with the stream under unstable and non-calculated flow regimes. Practical implications. The mathematical model and the calculation results can be used to ensure the environmental safety of the logistics systems of mining enterprises, as well as to assess the volume of the environmental pollution in case of overflowing through the wall of the channels of pressureless hydraulic transportation of waste from mineral processing and metallurgical plants.

Assessment of Changes in the Abrasiveness of Solid Particles in Hydraulic Mixtures Pumped with ESPs

The statistics of using downhole electric submersible pump (ESP) units in the oil fields of Eurasia show that hydroabrasive wear is a common cause of ESP emergency failures. The authors of this study theoretically and experimentally investigated the peculiarities of water–abrasive wear of ESP components. The research methodology and construction of the laboratory bench are described, and the results of experimental studies of determination of changes in the abrasivity index of impurity particles contained in the mixture pumped with the working stages of an ESP section are given. It is shown that large particles of mechanical impurities in contact with the metal of the working stages are subjected to intensive grinding of up to 0.25…0.3 mm; after that, particle size remains practically unchanged. An increased abrasiveness index of mechanical impurities causes an increase in the intensity of wear of interstage seals along the flow of a water–abrasive mixture (from the inlet to the outlet of the pumping section). Based on the obtained results, recommendations for selection of devices for formation-fluid cleaning during development and operation of oil wells are given. The relevance of work on improving the design of interstage seals of ESP units is substantiated.

ОБОСНОВАНИЕ ПАРАМЕТРОВ ТЕХНОЛОГИИ ОЧИСТКИ ИЛОНАКОПИТЕЛЕЙ УГЛЕОБОГАТИТЕЛЬНЫХ ФАБРИК ГИДРОЭЛЕВАТОРНЫМИ ЗЕМСНАРЯДАМИ

A methodological approach has been developed to determine the conditions that ensure the stable and safe operation of a hydraulic elevator dredger during the development of enrichment tailings. The conditions of stable and safe operation of a hydraulic elevator dredger during the development of enrichment tailings are determined. An algorithm has been developed for calculating the hydraulic transport system, performance and the main parameters of this technology, depending on the mining conditions of the complex. The productivity and the area of use of the UGB-2M hydraulic elevator dredger in the development of enrichment tailings for each of the technically possible diameters of the pulp duct under various mining conditions of its operation - the distances of transportation of the hydraulic mixture and the geodetic height of its lifting.

მრავალსაფეხურიანი სადაწნეო მაგისტრალური ჰიდროსატრანსპორტო სისტემების სქემები

G. Tsulukidze Mining Institute performed the fundamental studies of the operation of pressurized main water transport systems (slurry pipelines). These studies have been performed on both laboratory and semiindustrial experimental installations as well as on many large industrial systems. Based on these studies, it has been established that the efficiency of the studied systems is particularly increased by growing the hydro transmission distance of solid loose materials. This efficiency especially increases in the case of pulses when the concentration of loose solids in the hydro aeronautics in the pipelines increases. Because centrifugal ground pumps used for the transport of hydraulic mixtures develop relatively low pressures, the hydraulic transport systems studied are typically multistage. To do this, it is necessary to turn on the pumps in the main pipeline in sequence, or the main system consists of several separate systems, which complicates the operation of the system and worsens their technical and economic performance. Due to the peculiarities of operation, pulsed pipes are the most difficult, which lies in the fact that during their operation, hydraulic shocks occur very often, which has the worst impact on the efficiency of similar systems. Therefore, the schemes of multi-stage main hydraulic transport systems are discussed, equipped with such necessary devices which allow the sustainable operation of systems with maximum technical and economic indicators.

New technology of reclamation of slopes of waste and excavated rocks of mines and quarries

The urgent environmental problem of industrial Kryvbas is the reduction of dust formation from wind erosion of bare surfaces, especially slopes, dumps of iron ore mines and quarries. The best way to reduce the dusting of dumps is to afforest their surface with trees and bushes, but naturally this process can take up to 15-20 years, and the well-known scientific developments to solve this problem are ineffective or too time-consuming. The objective of our work is to create the innovative technology for active stimulation of self-organized vegetation of hard-to-reach steep slopes of dumps. To implement the idea, it is proposed to use standard hydroseeders for a new purpose, in particular, HM-0-HARV Turbo Turf hydroseeder, which is able to create hydroflow at a distance of 30-50 m. The article describes in detail the essence of the developed technology, method of organizing and conducting hydraulic sowing from both the lower and upper edge of the dumps. It is recommended to include seeds of herbaceous grass and legumes, deciduous trees and shrubs, mineral fertilizers and nutrient substrate (sewage sludge) in the seeding hydraulic mixture. The proportion of seeds of various plant species, fertilizers and nutrient substrate in the hydraulic mixture for sowing on the slopes of Kryvyi Rih dumps, which have a neutral soil acidity and contain at least 3% of the fine fraction of rocks in the surface structure, is substantiated. According to the results of testing the proposed technology, it is concluded that applying a mixture of seeds of herbaceous plants, trees and shrubs in combination with mineral fertilizers and nutrient substrate to the surface of dump slopes by hydroflow accelerates their self-organized vegetation by about 3-4 times. It is shown that crop care measures in the first year of plant vegetation (periodic watering and, if necessary, fertilizing using hydroseeder) can save up to 60-75% of seedlings and help stabilize newly created biogeocenosis in subsequent years.

ВИРОБНИЦТВО ЛЕГКИХ НАПОВНЮВАЧІВ НА ОСНОВІ ТЕХНОГЕННОЇ СИРОВИНИ

In Ukraine, along with the growing demand for tonnage production of light fillers, the need for raw materials is growing, considering that most of the range of light fillers is made from natural raw materials. Thus, a promising direction of utilization of TPP slags and coal concentrate obtained by enrichment of primary coal sludge is there involvement to the production process after preliminary drying. Drying of the thermal power plant slag and the coal concentrate, which are hydraulic mixtures, by the filtration method will reduce energy consumption due to the displacement and removal of significant amount of moisture by the moving thermal agent due to the pressure drop. The results of studies of the thermal agent velocity effect on the drying process duration of TPP slag and coal concentrate, as well as the obtained values of heat transfer coefficients at different velocities of the thermal agent for TPP slag α = 40 ÷ 112 and coal concentrate α = 92,5 ÷ 294 will allow to calculate energy consumption and scientifically substantiate the optimal technological parameters for intensification of the drying process of the charge components for porous fillers production.

Comparison of Thermally Measured Setting of Cement Paste and Penetrometer Measured Setting of Ready Mixed Concrete

Abstract Expedient materials and proportions screening methods are needed prior to trial concrete mix design as ingredient complexities continue to increase. Cement paste thermal measurements (e.g., the recently published ASTM C1753, Standard Practice for Evaluating Early Hydration of Hydraulic Cementitious Mixtures Using Thermal Measurements [Superseded]) are a minimal labor screening tool in which the temperature of a hydrating specimen is recorded over time but no attempt is made to quantify heat evolution (i.e., thermal methods as used herein are not calorimetry). Thermal methods have promise to reduce the combinations evaluated in trial concrete. This article evaluates setting tendencies because they are of first order concern for many projects. Although ongoing work in ASTM may soon produce a Standard Test Method for thermal measurement–derived setting indications of mortar or concrete, the use of laboratory paste mixtures to better understand and predict setting trends of concrete using the same or similar materials and proportions has not been widely studied. The specific emphasis of this article was to compare ASTM C403 (Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance) penetrometer measured setting on sieved concrete to thermally measured setting on cement paste in general accordance with ASTM C1753 and to provide guidance on aspects of thermally measured setting that have not been fully studied. Two of this article’s findings validated statements already present in ASTM C1753: that thermal methods are a within laboratory method and that thermal measured setting is not sensitive to a specimen’s water to cementitious ratio. Additional findings showed there is not a single factor that relates setting times between penetrometer and thermal methods, and that one adjustment factor is unrealistic for a wide range of conditions. Cement source and fly ash class meaningfully affected thermal to penetrometer relationships. Correlations were reasonable for thermal and penetrometer setting if there were 50 % or less supplementary cementitious materials present.

Combined operating process of torque flow pump

Due to a simple design and hydraulic passage that is the least susceptible to clogging, torque flow pumps (TFP) of Turo type are the most common pumps used for pumping various hydraulic mixtures. These pumps are referred to vortex pumps, operation of which is accompanied by energy loss and vortex formation resulting in low economic efficiency. Since the TFP is a vortex hydraulic machine, the ratio of the fluid velocity in the free pump passage to the impeller rotational speed ωfluid /ω is an indicator of the TFP efficiency. The higher the value of ωfluid , the more efficient the pump is. The mechanism of the energy transfer in the TFP is caused by both blade and vortex operating process, or a combined operating process. The efficiency of the pump can be improved by increasing the portion of blade operating process. The aim of the study is to improve the efficiency of the TFP of Turo type by modifying the impeller design, to obtain a basic equation of the TFP with a new impeller which has several extended blades, and to study the influence of the impeller geometry on the pump performance experimentally. The study was carried out by analytical and experimental methods. The equation describing the head dependence on the hydraulic passage dimensions of the pump with a new impeller was obtained analytically. This equation can be used to clarify the methodological recommendations for designing the pump. The energy balance in the TFP was analyzed. During the testing on a test rig, the characteristics of the pump were obtained, which confirmed the advantages of using the modified impeller with extended blades resulting in increase of the portion of the blade operating process.

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.

Research of resistance to water-jet wear of plastic and steel pipes. Assessment of the main parameters that affect the wear rate of hydraulic transport systems

It has been found that the use of certain types of thermoplastic elastomers as a co-extruded coating of the inner surface of plastic pipe systems can significantly increase the lifetime of pipeline hydrotransport when exposed to hydraulic mixtures, in particular tailings of iron ore processing. The comparison of polyethylene and steel pipes resistance to water-jet wear is made. The influence of the concentration, dispersion, and speed of hydraulic mixtures on the wear rate is estimated.

Optimization of the coupling parameters and mixing uniformity of multiple organic hydraulic mixtures based on the discrete element method and response surface methodology

To address the mixing uniformity of multiple organic hydraulic (MOH) mixtures in a continuous mixer, three types of mixing parameters and their coupling effects were studied by the discrete element method (DEM) and response surface methodology. To achieve the research goal, only one parameter was selected for each type of parameter, and the corresponding model was established. Numerical simulations and optimization were implemented. A three-level, three-factor Box-Behnken Design method combined with response surface methodology was applied for the numerical design. The influence of the parameters on the mixing uniformity of the mixture was analyzed by analysis of variance (ANOVA). The ANOVA results show that the rotation speed, the installation angle, the filling ratio and the coupling between the rotation speed and the filling ratio have a significant effect on the mixing uniformity of the mixture, that the rotation speed and the filling ratio have the strongest effect on the response, and that of the fitting model of the mixing uniformity can fit the simulation data well. The coupling effect results show that the influence of coupling between the revolution and installation angle on the mixing uniformity is consistent with that between the filling ratio and installation angle and that the coupling effect between the rotation speed and the filling ratio is different. It is also found that the optimal parameter range under one factor is different from that under multivariable coupling. The optimization results show that when the discrete coefficient is the smallest, the optimal combination of the parameters is a revolution of 350 r/min, an installation angle of 25°, and a filling ratio of 70%. The experimental results are consistent with the optimization results, which indicate the correctness of the parameter optimization results.

Detritus removal from a pumping-plant intake chamber with hydrajet pumps

Issues of excessive sedimentation of sediment in the pre-chambers of reclamation pumping stations are important in ensuring their reliable operation. Examinations have established that excessive detritus deposition in the intake part of the chamber complicates the water intake by pumps, increases energy consumption. For the timely cleaning of the intake chamber from detritus, a new device, equipped with a hydrajet pump fed from the pressure pipe of the main pump of the station is proposed. An equation for the pressure-flow characteristics of a water-jet pump used to drain the hydraulic mixture (water + solid mass) based on the of E.A. Sokolov and N.M. Singer methodology and the parameters of the hydrajet pump at given pressure values and the planned value of the flow rate of the solid mass have been obtained. The optimal values of the relative head h = 0.19 and the relative flow q = 0.6. At these values, the efficiency of the installation will be maximum. The results of the experiments carried out according to the estimation design have shown their satisfactory convergence with the calculated data and made possible to determine the optimal pressure and flow parameters of the hydrajet pump from the maximum efficiency.

Hydraulic elevator for cleaning sediment of a water outlet of a reservoir

Many scientists of the world were engaged in the study and development of various schemes and models of hydraulic elevators for the purpose of excavation and hydraulic transport of hydraulic mixtures [1-22]. For the specific conditions of the selected research object, we determined the main sizes and parameters of the hydraulic elevator, which allows cleaning the water area of the bottom water intake of the spillway of the Tupalang hydroelectric station, using the hydrostatic pressure at the object concentrated in front of its dam. To clarify the particle size distribution of sediment deposited at the inlet head of the water intake of the Tupalang reservoir water outlet, samples of bottom sediments were taken and their particle size distribution was analyzed in laboratory conditions. At the water intake area of the 1st tier of the Tupalang reservoir, the deposited sediments are represented by smaller particles, the diameter of which is from 5 mm to 0.1 mm, and in percentage terms, their share is 95%. The main results are given for calculating and justifying the parameters of a hydraulic elevator for cleaning sediment from the water area of the inlet head of the water outlet structure of the first tier of the Tupalang reservoir. When determining and substantiating the main sizes of the hydraulic elevator, theoretical and experimental research methods were used, and the method of S.M.Shtin was applied.

Hydrotransport of river sediments in hydroelelators

The article considers the hydrotransport of river sediment in a cylindrical pipeline. To describe the nature of hydraulic phenomena, experiments were carried out for single-phase and two-phase flows. Based on the results of the experiments, the main hydraulic parameters of the suction pipeline of the hydraulic elevator were determined during hydrotransport of river sediment. Based on the processing of available data, as well as data from specially designed experiments, the dependences of the flow coefficient at the expiration of the slurry flow from the hydraulic elevator pipeline on the Reynolds number are valid, which are valid for certain limits of the change in Reynolds numbers. The design parameters of the hydraulic elevator are substantiated, calculation formulas are given for determining the characteristics of a hydraulic mixture consisting of a solid particle and a carrier fluid. The methodology for calculating the concentration distribution and the method for determining the bottom concentration are given. A calculation formula is proposed for determining the flow rate and flow rate of a hydraulic elevator slurry. As a result of the analysis of these experiments, the dependences of the concentration of solid particles on the relative pressure in the hydraulic elevator are established.

Scanning Electron Microscope in Rocks and their Comparison with Physical-Mechanical Properties

. Banks of stone materials from Michoacán, Mexico were characterized, since they are used in the construction of infrastructure in the area. With these materials are made hydraulic concrete mixtures or asphalt mixtures, foundations, paving stones and in restoration of historical monuments. The rocks analyzed and characterized, come from banks of volcanic stone materials and banks of crushed stone materials, which were subjected to mechanical tests such as uniaxial compression resistance (UCR), in addition was used scanning electron microscope (SEM), by means of which the characterization was carried out, obtaining morphological information of the material. The comparison of physical-mechanical properties with the elements they possess is important to estimate their behavior within ceramic matrices or as a structural element.