Hydroabrasive Wear Research Articles

Hydro-abrasive wear reduction of irrigation pumping units

Uzbekistan is one of few countries in the world where more than 50% of the irrigated lands are provided with water by pumping stations. The main water sources are the transboundary rivers, the Amu Darya, and the Syr Darya, which transport a large amount of bedload and suspended sediments. In these water sources, the average annual turbidity is up to 5-7 kg/m3, and the average monthly turbidity reaches 10-12 kg/m3. The content of abrasive particles with the Mohs hardness of 5 and more reaches 50-60% of the total amount of suspension. When these sediments pass through the pumping units, their hydro-abrasive wear is observed; this leads to a change in the main parameters of the pumps. Bedload sediments with the size of more than 1 mm cause the most intensive pumps hydro-abrasive wear. Therefore, in our research, much attention was paid to developing methods to prevent the ingress of bedload sediments into the flow part of pumping units. For this purpose, based on laboratory tests, taking into account the heterogeneity of bottom sediments, the dependence for determining the ridge forms' height was revealed. On the basis of this dependence was developed methods for determining the height of the threshold damless intakes and the height of the inlet of the suction pipe pumping unit relative to the riverbed bottom. The developed methods reduce abrasive wear of pumping units and increase their repair period.

Method of accelerated industrial testing of hydroabrasive wear of polymer coatings of steel pipes

The article is devoted to the discussion of the problem of choosing a protective coating for the inner walls of the slurry pipeline of mining enterprises. For the correct choice among the many polymer coatings, it is necessary to test various coatings for water-jet wear. Standardized test methods are not entirely suitable for assessing the durability of coatings in a specific production environment, they do not take into account the nature of the slurry flow, temperature, etc. Solid inclusions of a different particle size and chemical composition are often used in ready-made and published studies, which makes them irrelevant for mining specialists. Often, for a comparative assessment of the wear resistance of various coatings, enterprises conduct their own industrial tests for hydroabrasive wear, in which they recreate the same granulometric composition of the pulp and its concentration. However, they come with a significant investment of time and energy. The article proposes to use a method of accelerated wear testing based on a comparison of the wear of a straight section of a pipeline and a shaped one in the form of a rotary insert at an angle of 90°.

Epoxy Nanocomposites with Increased Hydroabrasive Wear Resistance for Use in Vehicles

Epoxy Nanocomposites with Increased Hydroabrasive Wear Resistance for Use in Vehicles

Ecological process for depositing thin layers with high tribology resistance for reconditioning the hydraulic turbines

Plasma thin-film deposition can be used to refurbish hydraulic turbine assemblies and subassemblies. In the case of reconditioning by the plasma jet deposition method, one or more plasma jet passes may be carried-out over the worn surface until the gaps achieved by the effect of the hydro-abrasive wear are filled with the depositing material. This paper presents the results obtained at the hardness tests of the thin layers deposited by plasma jet with powders based on Nickel and Boron (Deloro 60). Also, the adhesion of the multiple layers to the base material as well as the adhesion between the layers and the defects that appear on its separation surface were studied. The samples were also analysed from the point of view of the chemical composition by EDX probe and structurally by optical and electron microscopy Vickers-type micro-hardness tests were performed to determine the micro-hardness of the base material and the deposited layer. The VEGA II LMH electron microscope (TESCAN) with TAX QX2 EDX module was used to determine the material structure. The samples were obtained by the method of spraying in mesh spray with Ni powder. By this type of deposition, an easy method of obtaining and rectifying the blades of the hydraulic turbines is obtained with aims to harden the turbine’s blades, in order to increase the wear resistance without affecting the corrosion resistance.

Assessment of Hydroabrasive Wear Resistance of Construction Materials with Functional Coatings, which are Formed by Resource-Saving and Environmentally Friendly Technologies

The work presented in this paper is devoted to the formation of thick-layer wear-resistant coatings by technologies based on electrospark alloying, an example of essential components hardening for the heavy-duty processing equipment operating under hydroabrasive wear conditions. The aim of the paper is to improve the manufacturing and repairing technologies for the helical surfaces of the screws made of 65Г, 30X13 and 40X steels and corrosion-resistant stainless steel 12X18H10T. The above aim has been achieved owing to applying the new environmentally friendly technologies for the formation of the surface layers, and also due to the choice of the surface layers that are most resistant against hydroabrasive wear, which choice being provided for by conducting the comparative tests on the samples made of the above said steel grades and strengthened in various ways. The analysis results of the hydroabrasive wear resistance of the samples made of steel and provided with protective coatings is presented.

Assessment of erosive wear of Pelton turbine injector: Nozzle and spear combination – A study of Chenani hydro-power plant

This study concerns with erosion of Pelton turbine injector i.e. (nozzle spear tribo pair) by sediment particles for a typical power plant located in Himalayan belt of Jammu and Kashmir in India. Erosion of hydro turbine/runner and its allied parts by the sediment particles suspended in the river water is one of the challenging problems (faced by maintenance personnel of hydro power plants). Injector assembly is subjected to severe erosion which renders it dysfunctional in relatively short span of time compared to other parts of the hydro power plant. A detailed study regarding erosion measurement has been conducted using novel technique of 3D optical scanning to assess material loss and identify type of wear for spear and nozzle combination used at Chenani power plant (5 units each with a 4.66 MW capacity). Hydro-abrasive wear was quantified on the basis of measurement of material removed by process of erosion on spear and nozzle (virgin parts) compared with weight of eroded parts (scanned). The erosion was found to be 3.71% and 5% on spear and nozzle respectively (of virgin volume).

Diagnostic tests of vertical pumps modernized pump stations

The article discusses the methods of maintenance and technical diagnostics of large vertical pumping units of modernized pumping stations of the largest cascades of the Amu-Bukhara and Karshi channels to ensure reliability during their operation, assesses the qualitative and quantitative changes in their modes. The operation of large pumping stations poses a number of problems that cannot be solved without experimental studies. The aim of the research is the problem of comprehensive diagnostics of pumping units and the development of new export-oriented diagnostic devices. The use of new designs of pumping power and diagnostic equipment involves the use of mathematical modeling of control of the operating modes of machine channels, which gives significant savings. Methods of accounting for cavitation – hydroabrasive wear of the blades are based on the study of the movement of the hydroabrasive flow along the radius of the impeller. Recommended elimination of pump operating modes with a maximum wear rate of their parts.

The height of a damless water intake structure threshold

More than 80% of the annual water consumption in Uzbekistan comes from large transboundary rivers such as the Amu Darya and Syr Darya. The rest of the water is formed on the territory of the Republic. Almost all year round, the turbidity of the Amu Darya and Zaravshan rivers is 3÷5 g/l, reaching 15÷18 g/l during flood periods.in most cases, water from the rivers is taken into irrigation channels using damless water intake structures. In order to prevent the ingress of bottom sediments from rivers into channels, thresholds have been constructed at water intake structures, the height of which is set constructively. As a result, bottom sediments pass through thresholds and move along the bottom of channels, reducing their cross-sections, as well as filling the chambers of pumping stations and pressure basins of hydroelectric power plants with sediments. After getting into the flow parts of pipelines and hydraulic machines (pumps and hydraulic turbines), they lead to abrasive wear, as well as other negative consequences. A lot of work has been done to prevent sediment from entering through water intake structures, but so far none of these proposals has provided an effective solution. In the laboratory of the Tashkent Institute of irrigation and agricultural mechanization engineers, a series of experiments were conducted on a glass hydraulic tray to determine the height of bottom sediments, taking into account their heterogeneity. Based on experiments, the dependence on determining the height of the ridge is derived. Based on the obtained dependence, a method for determining the height of the threshold of a damless water intake structure is proposed. This technique was experimentally tested on a laboratory tray. Specifying the threshold height will lead to optimization of capital costs for the construction of the threshold of the water intake structure, as well as reduction of operating costs for cleaning channels from sediment and repair work of hydraulic machines from hydroabrasive wear.

Conceptual features of improving the flow-through parts of gas separators of submersible electric pumps systems f for the production of formation fluid in order to improve the separating properties, energy efficiency and reliability

This article analyzes the design of the power part of gas separators of various manufacturers, reveals the causes of backflows, which can lead to hydro-abrasive wear of the elements of the flow-through part, reduction of the separation properties as a result of the gas-liquid mixture flow dispersion, and decrease of pressure gradient in the separation chamber. A mathematical model was selected, hydrodynamic calculations of design options and upgrading were carried out, and animproved flow part of the separator was developed. Bench tests were conducted to confirm the improved parameter of the product.

РОЗРОБКА ТОНКОШАРОВИХ ПОКРИТТІВ НА ОСНОВІ ФЕНІЛОНУ ДЛЯ ЗАХИСТУ ПОВЕРХОНЬ ВІД ГАЗО- ТА ГІДРОАБРАЗИВНОГО ЗНОШУВАННЯ

Relevance of the research topic. The task of increasing the wear resistance of parts and friction units is due to the tendency to increase their productivity and, consequently, workloads, speeds, temperatures and other parameters. Formulation of the problem. To improve the performance of friction joints, it is necessary to use materials that combine good adhesive and antifriction properties. Analysis of recent research and publications. There are a significant number of publications on materials with high antifriction properties and separately with high adhesion properties. Selection of unexplored parts of the general problem. There is no information on materials that would combine high adhesive properties and good antifriction properties as surfaces that are under gas and hydroabrasive wear. Setting objectives. The aim of this research is to investigate the combination of adhesive and antifriction properties of phenylon-based materials. Presenting main material. The adhesion ability of phenylon to classical materials of machines parts and its wear resistance at gas and hydroabrasive wear are investigated. The dependence of intensity of wearing from the angle of attack of the abrasive material is given. Conclusions in accordance to the article. It was found that, independently of the mode of operation, the greatest wear of phenylon-based coatings occurred at angles of 45°-60°, and starting from the angle of attack of 45 ° changed the mechanism of wear from microcutting to knocking out the polymer in the middle of the test sample. In both modes of operation, phenylon-based coatings were quite stable, which indicates the possibility of using phenylone as a coating to protect against gas-abrasive wear. But further research is needed, which will be closer to the real operating conditions, with the search for fillers to increase the wear resistance and adhesion of the coating based on phenylon.

Study of the influence of the addition of an exothermic mixture and the ratio of the components of the exothermic mixture on the melting indices at FCAW

An important issue in the processes of strengthening and restoration of surfaces exposed to abrasive, abrasive-corrosive and hydroabrasive wear, using the process of self-protective flux-cored arc welding (FCAW), is to increase the productivity of hardfacing and the quality of the hardfacing metal. The literature review showed that one of the ways to increase the productivity of hardfacing and improve the quality of the hardfaced metal is to add an exothermic mixture to the core filler of flux-cored wire electrode. The effect of composition of filler core during FCAW on the fusion parameters, namely the addition of exothermic mixture (TM), the ratio of exothermic mixture components (CuO/Al), and the ratio of exothermic mixture oxidant to carbon content in the core composition (CuO/C) has been studied. It has been found that the optimum areas for the deposition rate (Gd), deposition factor (ad) and spattering factor (ψs) are observed for the following values of the core components: TM = 25…39, CuO/C = 5…6, CuO/Al = 3…4.

IMPROVEMENT OF A DESIGN OF A BOREHOLE PLUNGER PUMP FOR PRODUCING A LIQUID WITH SUSPENDED PARTICLES INCREASED CONCENTRATION

When a large amount of solid impurities (sand) is contained in the produced formation fluid, the operation of production wells is complicated. Their presence leads to an increase in hydroabrasive wear of parts and components of a downhole sucker rod pump and causes its plunger pair to be wedged. In addition, this leads to cork formation, which requires cleaning and flushing. To prevent this phenomenon, various types of sand filters and structural changes of plunger pairs of the rod pump are used. The analysis of the operation of sucker rod pumps for oil production at the Tuymazaneft NGDU fields of Bashneft-Dobycha LLC revealed the following main reasons for the failure of the underground part of well sucker rod pump units: blockage of suction and discharge valves (52.2 %), jamming of the plunger in the pump cylinder (36.5 %), gaps in valves (4.8 %), disconnection of the plunger from the rod (1.8 %), breakage of the rod string (1.7%), lack of tightness in the support of the plugin pump (1.1 %). As a result, the average operating time of the pump is reduced to failure and the presence of sand in the formation fluid can be considered the main problem. Based on the analysis of field data on the operation of the plunger pump under complicated conditions (increased concentration of suspended particles in the produced fluid), it is proposed to change its design. Improvement affected the pump plunger and its filter. The proposed developments have a detailed description of their design and principle of operation. Detailed field tests of the developed devices are presented, showing the effectiveness of its use. As a result of the use of pumps with shortened plungers (and the previous modes of operation of the wells did not change), good results were achieved in reducing the load in the TPS and increasing the pump coefficient, and the durability of the elements of the plunger pairs of sucker rod pumps. After examining the plungers, slight wear of the eccentric rings to center the plunger was detected. For the purpose of further use of shortened plungers, only the replacement of all rings is necessary. There is no need for expensive repair of plungers. In addition, there was no seizure of the plunger in the cylinder. Sand filters were installed in 2018 at the well Nos. 1246, 1356, 1623 NGDU Krasnokholmskneft LLC Bashneft-Dobycha. Before the filter was lowered into the wells, samples were taken that established the presence of mechanical impurities in the product. The concentration of suspended particles exceeded the norm by several dozen times, which can lead to premature failure of the pump. In addition, sludge traps were located between the filter and the shank to increase efficiency. The use of new developments together allows to increase the efficiency of the use of a sucker rod pump in difficult operating conditions.

Structure and Properties of Heterocomposite Polymeric Materials and Coatings from them Obtained by Heliotechnological Method

The paper presents the results of the study of the creation of new hetero-composite casting polymer materials and coatings from them. The effect of ambient temperature on microhardness and impact strength of polymer coatings is studied. It has been found that treatment of the polymer composition with solar radiation is an effective way of controlling the curing reaction, saving energy in the preparation of high viscosity epoxy compositions, which is important for their practical implementation in the industry for process equipment and products operating under conditions of corrosive hydroabrasive wear.

Improvement of the design of hydraulic transport devices for the transport of hydroabrasive media in the enrichment industry

Hydrotransport equipment of mining and processing plants has low operational reliability, insufficient service life due to intense hydroabrasive wear of the working surfaces of pipelines and pumping equipment, design flaws of some ground pump units and their operation. Significant hydroabrasive wear of the main structural element of the ground pump – impeller, causes additional disturbing dynamic forces, which leads to increased vibration of the unit and, therefore, to its premature failure. To date, insufficient attention has been paid to the impact of hydroabrasive wear of the impeller of ground pumps on the service life of their plants.The analysis of manifestation of cavitation wear of parts of the ground pump flow part is carried out, measures to reduce cavitation due to favorable conditions for the liquid flow into the pump and to reduce the vacuum gauge suction lift are outlined. A number of technological and constructive solutions are also proposed to reduce the harmful effects of cavitation.Materials for manufacturing parts of a centrifugal ground pump with high performance and service life are selected and analyzed. These alloys showed high corrosion resistance due to high chromium content.The ways of improving the design of centrifugal ground pump parts are outlined, which allows increasing the service life, creating an automated system for diagnosing the state of the structure as a whole

Estimation of wear resistance of oxide and ceramic coatings in the hydrobrasive wear conditions

For wear compensation of the components made from aluminum alloys and operated in the conditions of hydroabrasive wear, we suggest the method of reconditioning and hardening, which combines the advantages of deposition in the argon medium and plasma electrolytic oxidation. The model of hydroabrasive wear of oxide and ceramic coatings obtained by plasma electrolytic oxidation is suggested. The requirements to the composition and structure of coatings at their usage in the hydroabrasive wear conditions are reasoned.

SOME REGULARITIES OF WEAR OF COMPLEXED SURFACES, BASES AND MIDDLE BANDS OF DETAILS OF CONICAL TRIBOSYSTEMS

The basics and average jumpers of the rotor and the body are studied, which perform the following functions: provide autonomous work of two sections; carry out autonomous operation of circulation of high and low pressure alkaline; is a frame in which other parts are held to support all functions of the high pressure feeder; support the difference in pressure between the sections. Thus, indicative drawings of the wear of the working surfaces of the rotor and the shell between the windows are formed by the action of alkali in the gap, and its value (at a constant gap) depends on the length of the gap. hus, indicative drawings of the wear of the working surfaces of the rotor and the shell between the windows are formed by the action of alkali in the gap, and its value (at a constant gap) depends on the length of the gap. With a minimum clearance gap between the rotor sections and the feeder housing, the flow rate and the flow rate of the alkali are maximal, and at the maximum length of the gap the flow rate and the flow rate of the alkali are minimal and, consequently, the wear is small. Due to the sinusoidal gap change law, the uneven wear of the working surfaces of the rotor and the body along the length of the circle can be explained.It has been established that on the two working surfaces of the rotor and the body there is a hydro-abrasive wear due to leakage of alkali in the mobile gap and shock hydraulic abrasive wear as a result of the formation of hydraulic shocks in the rotor pocket. The values of these types of wear depend on the time of compensation gap. Compensation for wear on these polling stations is higher than at other polling stations.The nature of the wear and tear of the bases and middle jumpers of the rotor and the body is revealed. The value of this wear is linear in time and its size is comparable to wear on other sections with compulsory micro-impulse gap compensation and not comparable (much less) when compensating for the critical gap. Wear on the bases and mid-joints of the rotor and the body occurs under the influence of hydraulic wear with the forced transfer of solid particles to the friction zone. With an uneven height of 8-10 microns and a minimum clearance of 50-100 microns, abrasive particles are constantly and coercive at these gaps due to cyclic hydraulic shocks. The presence of abrasive particles in the friction zone results in the destruction of both the particles itself and intercontact friction pairs of the surfaces of the bases and middle jumpers of the rotor and the case. As a result, there is a new kind of abrasive wear – hydro-abrasive deterioration in a narrow slit with the forced passage of solid particles into the friction zone.

Methodical complex for investigation dependencies between micro structure and macro properties of materials and operating characteristics of products

The work presents a methodical complex of studies of base metal and its coating composition, that allows to study the change in structural characteristics of material at micro-level, mezzo-level and macro-level. The effect of changes in structural state on the properties of coatings and base materials during treatment of cast iron parts working surfaces by air plasma spraying (APS) was established. Physico-Mechanical properties of coated samples and the features of their structure formation has been evaluated during experiments. An optimal composition of a powder mixture containing self-fluxing solid alloys and wear-resistant fillers, which provides enhanced performance in conditions of hydroabrasive wear is proposed. It is established that plasma spraying of the coating (65% PR-NH17SR4 + 35% KHNp-30) with subsequent heat treatment and reflowing leads to an increase in wear resistance up to 1.5-2 times.

ОПЫТ ЭКСПЛУАТАЦИИ ЦЕНТРОБЕЖНЫХ ОДНОСТУПЕНЧАТЫХ НАСОСОВ В АКЦИОНЕРНОЙ КОМПАНИИ «АЛРОСА»

When mining diamond-bearing raw materials and further extracting diamonds from it in the joint-stock company ALROSA, which is a city-forming enterprise in the north-east of the Russian Federation, various pumping equipment is used, in particular, centrifugal single-stage pumps. In the present work, it is noted that the least reliable in terms of absence of failures of centrifugal single-stage pumps used in the joint-stock company ALROSA are the impellers, seals and bearing assemblies. Using linear correlation and regression analysis, it was found that the durability of the seals and bearing assemblies of the investigated pumps largely depends on the durability of their impellers. In the course of research, it was found that unbalancing the pump rotor due to excessive hydroabrasive wear of the impeller also leads to deformation and fracture of the shaft. In general, residual deformations and destructions are characteristic of the shafts of domestic pulp pumps of GrAT, GrT and Gr types. The most loaded sections of shafts of centrifugal single-stage pumps are installed. The most effective from the point of view of application among the pulp (ground, slurry and sand) pumps are pulp pumps of the Finnish company «Metso». When working on highly mineralized water (brines), the «X» type pumps have proven to be the best among centrifugal single-stage pumps.

Hydroabrasive wear on high carbide infiltration materials

Hydroabrasive wear, a subtype of erosion, is a frequently occurring wear phenomenon. The type and extent of the damage depend on a large number of material characteristics and process conditions. In this research project, high carbide infiltration materials used in deep drilling technology were tested for their resistance to this erosive stress. The flow angle was varied stepwise between 15° and 90°. The resulting damage was quantified by volumetric material loss. Furthermore, the wear mechanisms were determined by surface examinations using SEM. The result of this project is an improved understanding of the effect of different process and material parameters on the tribological system. An improved knowledge of the critical quantities will allow the estimation of the effects of changes in tribological systems under erosive load and finally a reduction of material removal in process plants by adaptation of single variables.

Research of the Resistance of Reinforced Polymeric Composite Materials to Hydro-Abrasive Action

The results of the research of the resistance of reinforced polymeric composite materials to hydro-abrasive action are presented. Hydro-abrasive wear research was carried out on a specially developed device that makes it possible to study the wear resistance of materials and coatings under impact conditions of loosely suspended abrasive particles simulating the flow of a hydro-abrasive medium. Composites based on polyester resin and polyurethane reinforced with ultra-high molecular weight polyethylene (UHMWPE) fibers and glass fibers were chosen as the objects for the study. An analysis of the intensity and nature of wear of these composites in compared with structural steel, UHMWPE and polyurea was carried out.The analysis of the obtained research results shows that UHMWPEis the most resistant to hydro-abrasive effects. However, the high cost and variation of the traditional technology of manufacturing composite products using UHMWPE as a lining material shows the advantage of using composite materials reinforced with oriented UHMWPE fibers.