Effect Of Solid Particles Research Articles

Effect of Solid Particles in Polymer Waste Liquid on Grinding Tool Wall Erosion

Abstract With the continuous accumulation of polymer waste liquid in the third oil recovery process, the treatment of wellhead return waste liquid has become a key issue in oilfield exploitation and environmental protection. In this paper, the erosion failure of the cutter caused by sand-containing particles in the waste liquid during the shear grinding process is studied. The influence of the main structural parameters of the grinding tool and the erosion failure is studied by using the comprehensive numerical simulation method to reduce the erosion rate of the polymer flooding waste liquid on the cutter. Firstly, the flow field model of the solid-liquid fluid is established, and the erosion phenomenon on the tool wall is studied by combining the model with field experiments. In addition, the relationship between the different cutters structure and erosion rate of the grinding tool is studied, and the mathematical model is established. The optimized structural parameters are given to enhance the erosion resistance of the grinding tool in the process of polymer flooding wellhead waste liquid treatment and prolong its service life.

The effect of solid particles on the heat transfer in a slurry pipe flow

The effect of solid particles on the heat transfer in a slurry pipe flow

Spreading dynamics of a droplet upon impact with a liquid film containing solid particles.

This study examines how a deionized water droplet behaves when it centrally collides with a liquid film containing TiO2 nanoparticles at low impact velocities, aiming to understand how nanoparticles affect droplet spreading, in particular its maximum spreading diameter. Typically, we found that both the spreading velocity and dynamic contact angle of the droplet would be similarly affected by increasing TiO2 nanoparticle concentration. During retraction, the droplet's dimensionless spreading diameter oscillates, with more pronounced oscillations at higher nanoparticle concentrations. Moreover, both the droplet's maximum dimensionless rebound height and dynamic contact angle show similar trends with increasing TiO2 nanoparticle concentration. Interestingly, we proved that the influence of the solid-liquid interaction (Stokes force) on the fluid during the spreading process accounts for less than 2% of the surface energy when the droplet reaches its maximum spreading diameter, indicating a negligible effect on droplet spreading. We hypothesize that the droplet's initial energy is fully converted into surface energy and viscous dissipation at maximum spreading diameter, which involves viscous dissipation both between the fluid and the solid wall surface and the fluid and solid particle surface. Based on this, we developed a model for predicting the droplet's maximum spreading diameter that includes parameters associated with the solid particles. Compared to models in the literature that do not consider the effect of solid particles, our model aligns more closely with experimental data. The results indicate that adding solid particles leads to increased viscous dissipation, which in turn reduces the droplet's maximum spreading diameter.

Effects of solid particles with different concentrations on cavitation flow special development in the nozzle

Effects of solid particles with different concentrations on cavitation flow special development in the nozzle

An Overview of Flashing Phenomena in Pressure Hydrometallurgy

Pressure hydrometallurgy has attracted much attention for its characteristics, such as the high adaptability of raw materials and environmental friendliness. Flashing (flash boiling or flash evaporation) refers to the phase change phenomenon from liquid to gas triggered by depressurization, which is an important connection between high-pressure processes and atmospheric ones in pressure hydrometallurgy. This paper takes the flashing process in zinc leaching and alumina Bayer processes as examples, describes the flashing process in pressure hydrometallurgy in detail for the first time, and shows the importance of the flashing process in energy recovery, solution concentration, and liquid balance, as well as increasing equipment life. According to solid holdup (the volume percentage of solid), this paper proposes to divide the flashing process into solution flashing (low solid holdup) and slurry flashing (high solid holdup). A further focus is put on reviewing the state of the art of related studies. The results reveal that the research on the flashing process in pressure hydrometallurgy is scarce and often oversimplified, e.g., ignoring the BPE (boiling point elevation) and NEA (non-equilibrium allowance) in solution flashing and the effect of solid particles in slurry flashing. Computational fluid dynamic (CFD) simulation is a promising tool for investigating the flashing process. Based on the progress made in other fields, e.g., seawater desalination, nuclear safety analysis, and engine fuel atomization, we suggest that solution flashing can be studied using the CFD–PBM (population balance model) coupled two-fluid model, since a wide size range of bubbles will be generated. For slurry flashing, the effect of solid holdup on the bubble nucleation rate and mechanism as well as other bubble dynamics processes should be accounted for additionally, for which a quantitative description is still lacking. Meanwhile, data for validating the numerical method are scarce because of the harsh experimental conditions, and further research is needed. In summary, this work presents an overview of the flashing processes in pressure hydrometallurgy and some guidelines for future numerical studies.

A 3D simulation model of thermal runaway in Li-ion batteries coupled particles ejection and jet flow

A coupled simulation model of the 18650 lithium-ion batteries (LIB) thermal runaway (TR) is presented in this study, which includes TR decomposition reaction, gas generation and combustion processes, solid particles ejection and particles heat transfer process. The model considers a combination of solid heat conduction, gas convection, flame and particles radiation, which is validated to accurately capture the temperature evolution and two typical jet processes during TR. Model validation conducts with experimental measurements for the temperature of the battery surface. The simulation results show that the “ignition” time of the flammable gas mixture is delayed and the rate of flame temperature increase is slowed down when the effect of solid particles is considered. The radiation heat transfer rate and convection heat transfer rate on the adjacent battery surfaces are 80.3W and 12.76W, and are approximately 4.29 times and 1.76 times larger than the results calculated by the model without solid particles, respectively. The difference between these two can be further magnified in confined space. The model developed in this study combines the effect of the solid particles’ radiation into the TR simulation innovatively. It can provide a more accurate calculation method for the prediction of TR propagation.

Effect of solid particles on performance and erosion characteristics of a high-pressure turbine

Effect of solid particles on performance and erosion characteristics of a high-pressure turbine

A new Eulerian-Eulerian-Lagrangian solver in OpenFOAM and its application in a three-phase bubble column

Gas-liquid-solid three-phase flows (GLSTPF) have important applications in nature and industries, but they are complex and numerical simulation is challenging. In this study, a new solver coupling Eulerian-Eulerian-Lagrangian approach with population balance model (PBM) was developed in OpenFOAM to simulate GLSTPF. In the new solver, the effects of solid particles on gas-phase or liquid-phase holdups were included. Moreover, interphase forces of gas-solid and liquid-solid were calculated separately, and all the forces exerted on a solid particle were added to calculate the particle movement. Furthermore, the new solver was successfully compared with the experimental results of bubble size distribution and phase velocities in a three-phase bubble column. The introduction of PBM significantly improved the predictions of bubble rise and solid velocities (by up to 20%) and phase holdups (by up to 30%). The gas phase oscillated in the bubble column due to flow turbulence, and both the liquid and solid phases tended to circulate in the bubble column. The liquid vorticity exhibited irregular distributions, and different scales of vortex structure were observed with higher maximum radial vorticity (10 s−1) than axial vorticity (4 s−1), demonstrating the existence of swirling and oscillating flow in the column.

Effect of solid particles on the slug frequency, bubble velocity and bubble length of intermittent gas–liquid two-phase flows in horizontal pipelines

New experimental data are presented in this study for intermittent two and three-phase flows through horizontal pipelines involving air, water and polypropylene pellets of sizes ranging between 1 and 2 millimeters. Flow visualization and pressure measurements were performed and are explored in this work for intermittent flows. An automated image processing algorithm is developed to determine slug parameters of 59 flow conditions and compared with other measurements techniques. Correlations available in the literature for predicting slug frequency are tested with the new experimental data and curves of non-dimensional parameters are fitted to the data, the best fitting is obtained for the gas based Strouhal number against the input liquid or gas fraction. The influence of solid particles over the slug frequency is analyzed and reported. A decrease on the slug frequency is found when increasing solid concentrations. Finally, the influence of solid particles on the bubble length and velocity is investigated. A stronger influence of the gas flow rate on the velocity of the nose of the slug is observed for increasing solid concentration, together with more variability on the mean velocity. Also, longer bubbles are obtained with higher solid concentrations.

An Immersed Boundary Method Based Improved Divergence-Free-Condition Compensated Coupled Framework for Solving the Flow–Particle Interactions

A flow–particle interaction solver was developed in this study. For the basic flow solver, an improved divergence-free-condition compensated coupled (IDFC2) framework was employed to predict the velocity and pressure field. In order to model the effect of solid particles, the differentially interpolated direct forcing immersed boundary (DIIB) method was incorporated with the IDFC2 framework, while the equation of motion was solved to predict the displacement, rotation and velocity of the particle. The hydrodynamic force and torque which appeared in the equations of motion were directly evaluated by fluid velocity and pressure, so as to eliminate the instability problem of the density ratio close to 1. In order to effectively evaluate the drag/lift forces acting on the particle, an interpolated kernel function was introduced. The present results will be compared with the benchmark solutions to validate the present flow–particle interaction solver.

Effects of solid particles on fluid-particulate phase flow of non-Newtonian fluid through eccentric annuli having thin peristaltic walls

The current theoretical and mathematical treatments deal with the occurrence of solid particles in the peristaltic stream of Jeffrey fluid traveling in an annular region of two eccentric tubes. The influence of porous space and magnetohydrodynamics is also taken into intent. The passage is considered inside the space between two annuli having different center lines. The smaller tube is taken to be hard, and the outer annulus is having elastic walls, producing waves along its linear orientation. The flow is considered to be incompressible by the supposition of small wave number and negligible turbulence effects. The obtained flow equations for dual phases have been handled by an analytical highly convergent approach. The results achieved for basic features have been sketched against corresponding coordinates beneath the variation of some pertinent parameters. It is mainly concluded from this study that solid particles are slowing down the flow with the increase in their quantity as well as their volume and also reduce the pumping rate. It is also point of consideration that solid particles are cause of increasing peristaltic pumping. Moreover, the trapping boluses are decreasing their numbers but expand their area by increasing amount of solid particles. The flow rate can be made better by continuously reducing the size of solid particles mechanically.

STUDY OF THE PROCESS OF EROSION OF A MICRO HYDROELECTRIC POWER PLANT (HPP) TURBINES IN THE FORM OF A HYDROCYCLONE

One of the severe problems of a hydroelectric power plant (HPP) is providing a hydroelectric unit with purified water with the required pressure. Otherwise, the central working bodies - hydraulic turbines - are subjected to abrasive wear and quickly fail. Abrasive wear reduces the efficiency and life of the turbine and causes problems in operation and maintenance. This research aimed to study the degree of abrasive wear (erosion rate) of the surface of a blade hydraulic turbine of a micro HPP during water purification using a hydrocyclone and to ensure its rational layout based on the studies. Investigation of damage to the turbine surface from the dynamic impact was carried out by computer modeling of the process using the Autodesk Simulation CFD program, with different versions of the hydrocyclone body and testing of an experimental sample. Additional software SolidWorks (flow simulation) was used to check the calculations. It was found that the forms of particle hardness in water significantly affect the rate and magnitude of erosion, and a different design of the treatment body in the form of a hydrocyclone in different ways ensures the separation of the flow into phases. A rational scheme for installing a hydraulic turbine inside a hydrocyclone was selected, which provides the required power characteristic of a mini hydroelectric power station and other necessary parameters. The highest degree of water purification from solid impurities (94%) was achieved using the configuration option in a cylindrical-conical design with a rotational water inlet into the hydrocyclone. The location of the hydraulic turbine inside a hydrocyclone of a certain design and the tangential supply of water to the blades of the hydraulic turbine significantly protects the surface of the unit from the effects of solid particles. Their service life can be increased without additional investment in the restoration of the unit.

Effect of Solid Particles on Droplet Size Applying the Time-Shift Method for Spray Investigation

This study investigated the influence of solid particles on primary breakup and resulting droplet size for different process parameters. Two sets of Newtonian fluids (each consisting of one pure liquid and one suspension at the same respective viscosity) were used, for isolated investigation of solid particles on spray formation independent of liquid viscosity. The spray was recorded by a high-speed camera and a SpraySpy® system based on the time-shift effect, while a commonly used Spraytec® laser diffraction analyzer was employed for validation. An external-mixing twin-fluid atomizer was operated at different gas velocities and corresponding GLR at constant liquid mass flow. For the investigated suspensions an increased Sauter mean diameter was detected, compared to the pure liquids with identical dynamic viscosity. This effect was explained by the tensile strength stabilizing the suspension droplets.

Effect of solid particles on the volumetric gas liquid mass transfer coefficient in slurry bubble column reactors

The effect of solid particles on the volumetric gas liquid mass transfer coefficient klal in slurry bubble column reactors was investigated in the present work. klal was measured for an air-water-glass bead system using the dynamic oxygen absorption technique. Three solid concentrations and two particle diameters were used. Solid particles had a negligible effect on klal due to two opposite effects. First, a fraction of the particles tends to be located in the bulk liquid, altering its viscosity. In the heterogeneous regime, increasing the solid concentration enhances bubble coalescence, which led to an increase in size and, as a result, a decrease in the gas-liquid interfacial area al. Second, another fraction of particles moves to the bubble surface due to the collision phenomenon and tends to accumulate in the liquid film, resulting in local turbulence and an increase in the liquid-side mass transfer coefficient kl. The hydrodynamic effect mechanism was the governing mechanism of the effect of solid particles on gas-liquid mass transfer within the range of the investigated operating conditions.

Effects of solid particles with various charging states and oil aerosols on the filtration characteristics of electret media

In this study, electret media were loaded with neutralized and charged potassium chloride (KCl) to examine the effect of charged solid particles on loading behaviour. The media were then loaded with diethylhexyl sebacate (DEHS), dipropylene glycol (DPG) and glycerol to obtain a correlation between the efficiency degradation and liquid aerosol. The results indicated that the efficiency of electret media decreased from 72% to 46% under the neutralized KCl loading whilst the efficiency decreased from 96% to 82% under the positively charged KCl loading. Particle charging increased the initial efficiency and also effectively minimized the efficiency degradation. Given the increase in efficiency via chargers, the deposition morphology of the solid particles on the fibres was changed to mitigate the efficiency degradation. With respect to electret media loaded with DEHS, DPG and glycerol, the decrease in efficiency was associated with the solubility difference between the fibres and oil aerosols. Given sufficient affinity between the oil particles and fibres, oil molecules permeated the chain segments of the fibres and produced swelling that damaged the charge traps and decreased efficiency. The results of this study can guide practical electret filter operations and provide a better indoor environment.

Effect of solid particles in evaporating hot water tower on bubble movement

Effect of solid particles in evaporating hot water tower on bubble movement

Effect of solid particles on the lost circulation of drilling fluid: A numerical simulation

Lost circulation usually happens when drill through fractured formation. A clear understanding of the circulation loss mechanism is key to successful drilling operations. More attention has been paid to fracture development and lost circulation materials (LCMs) composition. Much work still needs to be done on how the solid particles affect the overall fluid loss process in rough-walled fractures. The control equations for liquid-solid multiphase flow in a 2D rough-walled stationary fracture were established based on fundamental principles of fluid mechanics. Among these equations, the drilling fluid was treated as a Bingham type non-Newtonian fluid, and the influence of solid particles on fluid flow was analyzed in detail. The finite difference method was adopted to the numerical solution of the equations, and the impact of such working parameters as fracture dimensions, bottomhole pressure differential, physical properties of both fluid and particle on the fluid loss were analyzed. The following conclusions can be drawn from the paper: (1) the presence of solid particles can lower the leakoff rate and accumulative leakoff rate to various degrees; (2) the larger the fracture dimension, the lower the leakoff rate and accumulative leakoff rate; (3) the larger the pressure differential, the higher the leakoff rate and accumulative leakoff rate; (4) the leakoff rate and accumulative leakoff rate will decrease with the increase of particle diameter and its volume concentration; (5) particle sphericity and yield stress have little influence on the leakoff rate and accumulative leakoff rate. (6) The higher the plastic viscosity of drilling fluid, the lower the leakoff rate and accumulative leakoff rate. The limitations of this study, suggested improvement and future direction of current work are also highlighted.

Numerical Analysis of Buckling of a Single Suspension Droplet

In this study, a 2D axisymmetric numerical model is developed for simulating buckling of suspension droplets for processes with a high evaporation rate. This model not only demonstrates droplet distortion during buckling but also predicts and visualizes solid particles’ behavior inside the droplet. The core element of the simulation method is the so-called D3-law predicting the droplet size and shape during different stages of the process. For improving the accuracy in the droplet shape and forces exerted on the solid particles, the effect of solid particles’ concentration on buckling process has been considered. In this method, the solid particles are modeled in Lagrangian manner and possible collision of particles during the buckling has been considered. It is shown that the role of capillary forces in the shape of agglomerated particles is significant. The numerical results also reveal that the size of agglomerated particle depends on the initial solid particle fraction and the suspension droplet size. For all cases considered, the results are in good agreement with experiment measurements reported in the literature.

Effects of solid particles and wall roughness on turbulent boundary layer in a two-phase horizontal channel flow

Particle image velocimetry (PIV) is used to study the horizontal channel flow over smooth and rough walls, and single-phase flow and particle-laden flow with two different particle diameters are analyzed. The phenomenon of the wall similarity hypothesis is verified in single-phase flow but affected by particles in particle-laden flows. The pyramidal rough elements cause a velocity defect and shorten the length scale of the vortex. The streamwise and wall-normal Reynolds stresses are enhanced by wall roughness. Two kinds of particles with different Stokes numbers are used in the experiment. The collision and dragging effect of particles in the inner region offset the influence of wall roughness on the mean velocity profile. The introduction of particles tends to increase the streamwise Reynolds stress, but makes the peak of the Reynolds stress move to a higher wall-normal position, which is contrary to the effect of wall roughness. Quadrant analysis indicates that the wall roughness and particles show a converse effect on quadrant events, but neither change the majority of second and forth quadrant events. The analysis of the spatial structure of turbulence shows that the small scale spatial structure is less affected by wall roughness compared with the large scale spatial structure. According to the statistics of the particle distribution, it was found that particles with a larger Stokes number show a more distinct prioritized deposition in the inner region, and the deposition of particles is reduced due to the existence of rough elements.

Acoustic Waves in a Liquid with Solid Particles and Gas Bubbles

The mathematical model which determines acoustic wave propagation in a mixture of liquid with gas bubbles and solid particles is proposed. A system of differential equations is written and the dispersion relation is derived. Low- and high-frequency asymptotics of the phase velocity in the mixture considered are found and illustrated. The effect of solid particles and gas bubbles on acoustic wave dispersion and dissipation is indicated. For the mixture of fluid with solid particles considered the speed of sound is compared with available experimental data.