Slurry Pump Research Articles

Influence on the Solid—Liquid Two-Phase Flow from Cross-Section Area of Slurry Pumps for Deep-Sea Mining

Influence on the Solid—Liquid Two-Phase Flow from Cross-Section Area of Slurry Pumps for Deep-Sea Mining

Performance of thermal-sprayed WC-Cr3C2-Ni coatings in slurry erosion for hydrodynamic turbines

ABSTRACT Hydrodynamic turbine and slurry pump components are frequently influenced by severe wear due to the impact of solid particles present in the water. A WC-based coatings deposited by thermal spray techniques is known for the protection against slurry erosion. In the present work, WC-Cr3C2-Ni powder was sprayed on a turbine steel substrate using high-velocity oxy-fuel (HVOF) and atmospheric plasma spray (APS) techniques. Microstructural and phase constitutions of as-sprayed coatings were examined. The effect of speed, slurry concentration and particle size on slurry erosion resistances of both coatings and substrate materials was comparatively studied in a slurry pot erosion tester. The results exhibit that the HVOF coating has better properties in terms of density, micro-hardness and slurry erosion resistance than those of APS coating. The improvement in slurry erosion resistance of bare turbine steel by using APS and HVOF coatings is approximately 37% and 62%, respectively.

A Novel Framework for Online Remaining Useful Life Prediction of an Industrial Slurry Pump

An efficient Remaining Useful Life (RUL) prediction method is one of the most important features of a condition-based maintenance system. A running machine’s RUL prognosis in its real-time is a challenging task, especially when there is no historic failure data available for that particular machine. In this paper, an online RUL of an in-operation industrial slurry pump having no historical failure data has been predicted. At first, the available raw vibration datasets were filtered out for valid datasets. The obtained valid datasets were utilized for constructing the Health Degradation Trends (HDTs) using principal component analysis and a moving average method. Then, a novel procedure for automatically selecting the HDT’s data points for initiating the iteration process of prediction was formulated. Afterward, a hybrid deep LSTM model embedded with a smart learning rate mechanism was developed for estimating the online RUL using the selected points of HDTs. The online RUL prediction results produced by the developed model were quite satisfactory when they were compared with other online RUL prediction methods.

Resistance Loss in Cemented Paste Backfill Pipelines: Effect of Inlet Velocity, Particle Mass Concentration, and Particle Size.

Cemented paste backfill (CPB), a technology placing the solid waste into mined-out stopes in the mine through pipeline transportation, has been widespread all over the world. The resistance loss is an important parameter for pipeline transport, which is significantly affected by the slurry characteristics. However, the coupling effect of inlet velocity (IV), particle mass concentration (PMC), and particle size (PS) has not been well evaluated and diagnosed. Hence, the CFD-based three-dimensional network simulation of CPB slurry flow in an L-shaped pipe at different combinations of the three parameters was developed using COMSOL Multiphysics software, and the findings were validated through a loop experiment. The results show that increasing IV and reducing PS will contribute to the homogeneity of the slurry in the pipeline, while the PMC presents little effect. The pipe resistance loss is positively correlated with IV and PMC and negatively correlated with PS. The sensitivity to the three parameters is IV > PS > PMC. In particular, the resistance loss is minimal at IV of 1.5 m/s, PMC of 72%, and PS of 1000 um. The calculation model of resistance loss regressed from simulation presented a high accuracy with an error of 8.1% compared with the test results. The findings would be important for the design of the CPB pipeline transportation and provide guidance in the selection of transfer slurry pumps, prepreparation of backfill slurry, and pipe blockage, which will improve the safety and economic level of a mine.

Coupling of an IOT wear sensor and numerical modelling in predicting wear evolution of a slurry pump

Slurry pump is an integral system between upstream and downstream mineral processing circuit to transport product streams. It is critical to monitor the slurry pump liner wear to ensure safe and efficient circuit operation, as well as achieving targeted product quality. This study aims to develop a digital wear sensor to monitor slurry pump liner wear and to predict its wear evolution by coupling to a numerical modelling framework. The digital sensor is designed to track and report live point-wise thickness on a slurry pump liner while in operation. A liner wear evolution model was then developed by integrating the wear sensor reading and wear intensity results obtained through numerical modelling. The wear intensity was obtained by coupling Smoothed Particle Hydrodynamics and Discrete Element Modelling. Liner wear evolution prediction results were subsequently compared with site measurements after operating for 95 days. Results suggested that the liner wear evolution prediction showed good agreements with measured results in terms of high wear zone as well as quantitative wear rate prediction. Outcome of this study can be utilised in mineral processing industry for safer operation as well as automated plant monitoring.

Control and regulation of the density of technical fluids during their transportation by sea specialized vessels

The object of research is the process of transporting drilling slurry through specialized marine vessels of the Platform Supply Vessels class. The subject of research is the sedimentation stability of the drilling slurry along the height of the cargo tank, which is proposed to be defined as a relative change in vertical density near the surface and bottom of the cargo tank. The studies were carried out on a specialized sea vessel with a displacement of 7320 tons. The design of the vessel provided for the reception and transportation of drilling slurry in four cargo tanks located on the port and starboard sides of the vessel. It has been experimentally established that during the 48-hour transportation, the density of the drilling slurry in the bottom part increases to 19.7 %; decrease in density on the surface – up to 7.8 %; decrease in the sedimentation resistance of the drilling slurry along the depth of the cargo tank – up to 29.85 %. A variant of modernization of the drilling slurry transportation system by installing additional circulation pumps providing forced circulation of the drilling slurry between cargo tanks is proposed. By using programmable microcontrollers (performing turning on/off the circulation pumps), it is possible to provide the following conditions for transporting the drilling fluid: an increase in the density of the drilling fluid in the bottom part up to 0.3 %; decrease in density on the surface – up to 0.25 %; decrease in the sedimentation resistance of the drilling slurry along the depth of the cargo tank – up to 8.01 %. It has been experimentally established that the creation of additional circulation and automatic support of the sedimentation resistance of the drilling fluid in the range of 2–7 % contributes to: – increasing the relative performance of cargo pumps from 38–55 % to 92–96 %; – reducing the time of pumping drilling slurry from cargo tanks to the drilling platform from 7.1 to 3.2 hours; – maintaining the technical condition of equipment, pipelines and elements of the drilling slurry transportation and pumping system.

Analysis of Erosion Minimization for a Slurry Pump Using Discrete Phase Model Simulations

A slurry pump is a device used to transport slurry, which is a mixture of solids and liquids. The slurry pump is subjected to physical erosion, generally resulting from erosion by friction between the solid and liquid particles. This study aimed to analyze the effects of process parameters on the erosion wear of a throat bush, which is the main component of a slurry pump. The erosion rate density (E) was analyzed based on the process parameters, that is, the slurry particle diameter, rotation speed of the impeller, and gap between the impeller and the throat bush. The discrete phase model (DPM) of the slurry pump was simulated using the process parameters. These parameters were optimized to minimize the erosion rate density. The optimization method using design of experiments (DOE) to derive a specific location with the greatest influence of the design variables through the one-way layout method and optimize the response value at that location is a method that efficiently analyzes a large number of cases. The optimization results confirmed that the erosion rate density was reduced in the optimization model compared with the earlier model.

Two-Way Coupling Simulation of Solid-Liquid Two-Phase Flow and Wear Experiments in a Slurry Pump

The slurry pump is one of the most important pieces of equipment in mineral transportation and separation systems, and it has complex two-phase flow characteristics and wear mechanisms. By employing numerical and experimental methods, the solid–liquid two-phase flow characteristics and wear patterns were investigated in this study. A two-way coupling discrete phase model (DPM) method was used to predict the flow pattern and the wear location and shows good agreement with the experimental observations. The pump performance characteristics of numerical results under pure water conditions were consistent with the experimental results. The effects of particle parameters and operating conditions on the internal flow field and wear were compared and discussed. The results show that the wear degree increased with the increase in volume flow rate and solid volume fraction. With the increase in particle size, the wear range at the impeller inlet became significantly smaller, but the wear degree became obviously larger. This study provides a basis for reducing the wear and improving the hydraulic performance of slurry pumps.

Study on the Solution of Sand Slabbing in the Tailing Sand Bin of Huanggang Iron Ore Mine

In order to improve the tailings utilization rate and realize full tailings’ filling in Huanggang iron mine in Inner Mongolia, a flocculation settlement system was added, which resulted in silting and consolidation of tailings in sand silts. Based on this, the reason for the deposition and caking of tailings was obtained through analysis, and a set of coarse and fine tailings bin filling system was proposed. The tailings of the plant were pumped to the filling station by slurry pump. Firstly, the tailings with large particle size difference were divided into coarse tailings and fine tailings by hydrocyclone so that the fine tailings entered the No. 1 sand bin and the coarse tailings entered the No. 2 sand bin. Then, flocculant was added by automatic flocculant dosing device to flocculate and settle the coarse and fine tailings, and then, it was mixed, stirred, and filled into the well. The results showed the following. (1) The particle size difference of tailings in Huanggang Iron mine increased and resulted in unstable flocs. The coarse tailings settled to the bottom of the silo before the fine tailings, and the compression time was too long, leading to the phenomenon of silting and consolidation. (2) Flocculation and settlement of coarse and fine tailings in different sand silos can avoid deposition and compaction of tailings in sand silos. (3) According to the different requirements of the concentration and ratio of the filling slurry, the proportion of coarse sand and fine sand in the filling slurry can be controlled by controlling the flow size of the coarse sand and fine sand chamber, to achieve the design of reasonable particle size composition and concentration requirements. The research results are expected to provide technical support and theoretical guidance for the construction of full tailings cemented filling system in Huanggang iron mine.

Design and fabrication of a low-cost one-way abrasive flow finishing set-up using 3D printed parts

Advanced manufacturing technologies have changed dramatically in the last decade due to advancements in manufacturing technologies. Since the introduction of low-cost 3D printers, i.e., fused deposition modeling (FDM) based on 3D printers, FDM-based 3D printer has become widely available to researchers in universities and academic institutions. As a result, the number of manufacturing setups that use 3D printed parts has grown. This paper discusses designing and developing a low-cost one-way abrasive flow finishing setup using 3d printed (FDM) parts. A one-way abrasive flow machining (AFM) setup was constructed with as many 3D printed, i.e., attachment for holding fixture, attachment for holding the pipe, and AFM fixture. The extrusion pressure is created using the submersible slurry pump to flow the AFM media. Due to its simplicity, the proposed AFF is suitable for finishing any complex shapes and materials using 3D printed AFM fixtures. In the present work, this low-cost one-way AFM setup is utilized to surface finish the FDM printed parts using environmentally friendly based AFM media. The results show a significant improvement in surface roughness by 96% of surface roughness improvement.

Numerical and Experimental Study of Hydraulic Performance and Wear Characteristics of a Slurry Pump

The slurry pump is widely used in ore mining, metal smelting, petrochemical, and other industries, mainly to transport fluid media containing large solid particles. Importantly, it is easy to damage the impeller of a slurry pump in the operation process, which greatly affects the performance of the pump. In this paper, a 25 MZ slurry pump was selected as the research object, and the Euler–Euler multiphase flow model was employed to analyze the internal flow characteristics of the slurry pump under the conditions of clear water and solid–liquid two-phase flow. Additionally, the flow characteristics of each part under different flow conditions were studied, and the effects of different particle volume concentrations, particle sizes, and pump speeds on the impeller’s wear characteristics and hydraulic performance were analyzed. In order to verify the reliability and accuracy of the numerical simulation results, clean water and solid–liquid two-phase flow wear tests of the slurry pump were carried out, and the results showed that a high solid volume fraction and solid–phase slip velocity were generated at the junction of the blade leading edge and the rear cover plate, thus leading to easier wear of the blade. Therefore, enhancing the strength of the junction between the blade leading edge and the rear cover plate is beneficial for improving service life and should be considered in the design of slurry pumps.

Development of a Novel Methodology for Remaining Useful Life Prediction of Industrial Slurry Pumps in the Absence of Run to Failure Data.

Smart remaining useful life (RUL) prognosis methods for condition-based maintenance (CBM) of engineering equipment are getting high popularity nowadays. Current RUL prediction models in the literature are developed with an ideal database, i.e., a combination of a huge “run to failure” and “run to prior failure” data. However, in real-world, run to failure data for rotary machines is difficult to exist since periodic maintenance is continuously practiced to the running machines in industry, to save any production downtime. In such a situation, the maintenance staff only have run to prior failure data of an in operation machine for implementing CBM. In this study, a unique strategy for the RUL prediction of two identical and in-process slurry pumps, having only real-time run to prior failure data, is proposed. The obtained vibration signals from slurry pumps were utilized for generating degradation trends while a hybrid nonlinear autoregressive (NAR)-LSTM-BiLSTM model was developed for RUL prediction. The core of the developed strategy was the usage of the NAR prediction results as the “path to be followed” for the designed LSTM-BiLSTM model. The proposed methodology was also applied on publically available NASA’s C-MAPSS dataset for validating its applicability, and in return, satisfactory results were achieved.

Feasibility of Coupling Anaerobic Digestion and Hydrothermal Carbonization: Analyzing Thermal Demand

Anaerobic digestion is a biological process with wide application for the treatment of high organic-containing streams. The production of biogas and the lack of oxygen requirements are the main energetic advantages of this process. However, the digested stream may not readily find a final disposal outlet under certain circumstances. The present manuscript analyzed the feasibility of valorizing digestate by the hydrothermal carbonization (HTC) process. A hypothetical plant treating cattle manure and cheese whey as co-substrate (25% v/w, wet weight) was studied. The global performance was evaluated using available data reported in the literature. The best configuration was digestion as a first stage with the subsequent treatment of digestate in an HTC unit. The treatment of manure as sole substrate reported a value of 752 m3/d of biogas which could be increased to 1076 m3/d (43% increase) when coupling an HTC unit for digestate post-treatment and the introduction of the co-substrate. However, the high energy demand of the combined configurations indicated, as the best alternative, the valorization of just a fraction (15%) of digestate to provide the benefits of enhancing biogas production. This configuration presented a much better energy performance than the thermal hydrolysis pre-treatment of manure. The increase in biogas production does not compensate for the high energy demand of the pre-treatment unit. However, several technical factors still need further research to make this alternative a reality, as it is the handling and pumping of high solid slurries that significantly affects the energy demand of the thermal treatment units and the possible toxicity of hydrochar when used in a biological process.

Numerical and Experimental Analysis of Influence of Impeller Structures on Slurry Pump Performance

Slurry pump as an important equipment for transporting coal, which are widely used in power plants, mines and other fossil energy field. Therefore, the improvement of slurry pump performance can effectively reduce the energy loss of fossil energy industry. In this paper, a novel impeller with splitter blade structure was proposed, and the internal flow field of slurry pumps with different impeller structures was analyzed. Meanwhile, according to the shape and structure of the vortex in slurry pump, the vortex can be divided into leading edge vortex, trailing edge vortex and gap leakage vortex by employing the Q criterion, and the generation mechanism of each vortex and relationship between vortex strength and flow condition were analyzed. What is more, the entropy generation theory was employed to study the energy loss of slurry pump. The pressure distribution and wear characteristics of different impeller structures under two-phase flow conditions are studied. The result shows that the energy loss caused by entropy production in the slurry pump can be declined by employing the splitter blades, which can restrain the flow separation at the impeller outlet. Thus, the impeller with splitter blades not only can reduce the energy loss of the slurry pump, but also enhance the wear characteristics of impeller under two-phase flow conditions. Finally, the result can provide the guidelines for the design optimization of slurry pump.

Numerical Investigation of the Flow Field and Mass Transfer Characteristics in a Jet Slurry Pump

A jet pump is used to transport a variety of working media and is especially suitable for dredged soil transporting. In this study, a three-dimensional numerical study of a jet pump that is used for slurry delivery was carried out. The characteristics of the internal flow field of the mixing chamber with different working parameters were comprehensively analyzed. The results indicate that the pressure of the axial line decreases with increasing flow ratio (ratio of suction flux and inlet flux) while the pressure of the injected slurry shows a downward trend. With the increase in the flow ratio, the pressure ratio (difference between inlet pressure and suction pressure divided by the difference between exit pressure and suction pressure) falls off while the efficiency presents a parabolic distribution. The pressure ratio can be promoted by properly increasing the length of the mixing chamber so that the available efficiency is broadened. When the mixing chamber length is L = 2.5Dn~4.0Dn (Dn is nozzle outlet diameter), the highly efficient area is wide; in particular, when L = 3.5Dn, the jet slurry pump with the highest efficiency of 27.6% has the best performance.

The Effect of Blade Design on Wear Rate and Life Span of Slurry Pumps

The Effect of Blade Design on Wear Rate and Life Span of Slurry Pumps

On the causes of slurry pump failures in the processing of diamond sands and ores (review)

Hydraulic transportation units, namely, Russian and foreign-made slurry pumps, form an important link in the process chains for the processing of diamond-bearing mineral raw materials operated at such Russian mining companies as «Almazy Anabara» and «ALROSA». Despite their criticality, slurry pumps at the processing facilities of these companies are generally operated inefficiently and are unreliable. Low availability of the slurry pumps at «ALROSA» processing plants is due to the frequent failures of their wet end parts and, to a lesser extent, to the failures of bearings, shafts, and seals. Slurry pump downtime at the screening plants of «Almazy Anabara» mines is mainly caused by impeller failures. The abrasive slurry pumped in the process is the leading cause of malfunctions of the above-mentioned parts, which has been confirmed by relevant statistical studies. It has been established that durability of wet end parts in the slurry pumps of «ALROSA» concentrators, determined as their hydroabrasive wear resistance, largely depends on the wear resistance of the material of the part itself, the density of the slurry pumped, and the coefficient for the pump shaft rpm. The wear life of impellers in the slurry pumps at the screening plants of «Almazy Anabara» mines depends on the wear resistance coefficient of the impeller material and on the grainsize composition of the solid phase of the slurry pumped.

Coarse Particle Motion Characteristics in a Double-Stage Slurry Pump Considering Leakage Flow

Along with the pressing demand for the long-distance transportation of coarse particles in the deep-sea mining industry, evaluating the slurry pump’s passing through and erosive wear by studying the particle motion characteristics and the slurry behavior is becoming increasingly important. Research on the influence of leakage flow through the clearance and balancing devices on the motion characteristic of granular grain flow is of great significance but has been seldom studied. This study coupled the discrete element method with the CFD method to investigate the comprehensive effect of a double-stage slurry pump’s main flow and leakage flow on the motion characteristics of particles with a 10 mm diameter. Results show that the leakage flow occupation in main flow falls from 26%–27% to 8%–9% for the two stages, with the flow rate increasing from 80 m3/h to 200 m3/h. In the first stage with leakage, accumulation of coarse particles was observed at the impeller eye, which should be paid much attention to slurry pumps’ operation to eliminate the chance of blockage. In the nonleak situation, although the increment of the average kinetic energy of particles through the impeller is more significant than in the leak case, most of them dissipate primarily by more than 10% collision in the bowl diffuser. In the leak or nonleak case, the average kinetic energy of particles was more than twice through the first stage but only 1.1 times through the second stage. The selection of stages in the slurry pump design should consider the limitation of particle velocity improvement.

Frictional behaviour of wheat straw-water suspensions in vertical upward flows

The use of biofuels helps mitigate greenhouse gas emissions. Earlier studies have shown that transporting biomass in horizontal pipelines in the form of water-based slurries significantly reduces transportation costs. The frictional behaviour of water-based chopped wheat straw slurry in a vertical pipeline has not been studied and this is the focus of this study. In situ concentrations of water-based conventional solids of medium sand, glass beads, and fine sand and straw slurry flows were determined by measuring their delivered concentrations in pseudo-homogeneous regimes for prepared concentrations of 1–6% (dry volume of conventional solids) and 5–25% (saturated mass of straw), respectively. Two grades of sand and glass beads with mean particle diameters of 0.103, 0.447, and 0.5 mm, respectively, and straw with a nominal particle length of 19.2 mm were utilised. The delivered concentrations for the straw slurries and fine sand were close to their corresponding prepared concentrations and were homogeneous. There was a large discrepancy between prepared and delivered concentrations for the medium-sized sand and glass beads slurries. The pressure drop of straw slurries over the range of velocities of 0.5–4.2 m s −1 and mass concentrations of 5–25% through the vertical pipe showed a maximum drag reduction of 19% at a concentration of 25% (mass) and at a 3.5 m s −1 velocity. For concentrations of 5–20% (mass), the straw slurries showed drag-reducing capabilities in the mixed and turbulent flow regions for various velocities that were different from horizontal flows. • The pumping of aqueous slurries of chopped wheat straw was studied in a pipeline. • Friction losses in the vertical pipeline were measured over a range of variables. • The delivered and prepared concentrations for wheat straw slurries were identical. • Straw slurries in vertical upward flows behaved differently than horizontal flows. • Drag reduction appeared at even low velocities and mass concentrations of straw.

Optimization of the centrifugal slurry pump through the splitter blades position

Optimal transfer of two-phase solid-liquid flow (slurry flow) has long been a major industrial challenge. Slurry pumps are among the most common types of centrifugal pumps used to deal with this transfer issue. The approach of improving slurry pumps and consequently increasing the efficiency of a flow transmission system requires overcoming the effects of slurry flow such as the reduction in head, efficiency, and wear. This study attempts to investigate the changes in the pump head by modifying the slip factor distribution in the impeller channel. For this purpose, the effect of splitter blades on slip factor distribution to improve the pump head was investigated using numerical simulation tools and validated based on experimental test data. Next, an optimization process was used to determine the characteristics of the splitter (i.e., length, number, and environmental position of the splitter) based on a combination of experimental design methods, surface response, and genetic algorithm. The optimization results indicate that the splitters were in a relative circumferential position of 67.2% to the suction surface of the main blade. Also, the optimal number and length of splitter blades were 6 and 62.8% of the length of the main blades, respectively. Because of adding splitter blades and the reduction in the flow passage, the best efficiency point (BEP) of the slurry pump moved toward lower flow rates. The result of splitter optimization was the increase in pump head from 29.7 m to 31.7 m and the upkeep of efficiency in the initial values.