Suspended Solid Particles Research Articles

Hydraulic, wash-off and sediment transport experiments in a full-scale urban drainage physical model

This paper presents a dataset obtained from hydraulic and sediment transport experiments performed in a full-scale urban drainage physical model of 36 m2. The study seeks to accurately measure sediment mobilization through the different parts of the model (surface, gully pots and pipe system), also obtaining a precise characterization of water flow and using realistic rainfall simulator to ensure the transferability of the results. Three different rain intensities and five sediment granulometries were tested in 6 hydraulic and 23 wash-off and sediment transport experiments. The following experimental data were produced: surface elevations and 2D runoff velocities measured by visualization techniques; surface and in-pipe water depths; flow discharges, total suspended solids concentrations and particle size distribution at the entrance of the gully pots and at the pipe system outlet; and sediment mass balances. This data is optimal for developing and validating wash-off and sediment transport formulations in urban drainage models, towards better treatment and management techniques for minimizing the impact of urban surface pollutants on the environments of towns and cities.

COMPARATIVE ANALYSIS OF EMISSIONS OF HARMFUL SUBSTANCES IN USING ALTERNATIVE TO NATURAL GAS BIOFUELS

Feature of the topic and problem statement. The paper presents for the first time a comparative characteristic of emissions of harmful substances from the combustion of traditional fuels (natural gas) and biomass in fuel furnaces of boilers and recommended for the use the most environmentally efficient fuels. Comparative characteristics of emissions of harmful substances during the combustion of various types of fuel allows to determine the optimal type of fuel in the construction and commission of a new power plants, and also adds up-to-date information that will be useful in the scientific and scientific-popular discussions that are widespread today regarding the exhaustion and replacement of non-renewable energy sources, the safety of alternative fuels and their advantages in comparison with non-renewable ones. The purpose of the work is determining of the amount of emissions of harmful substsnces entering the environment during the combustion of natural gas and solid alternative fuels - wood waste, straw, flax straw and sunflower husk, their comparison, justification of calculation of the carbon content in the fuel of a given chemical composition. Findings. During the comparative analysis, high values for the carbon dioxide emissions for all the materials were considered. It is also noted that there are no emissions of suspended solid particles and sulfur diоxide during the combustion of natural gas and it is determined that at its combustion, methane emissions will be the smallest. In as-sessing the level of safety when using unrenewable and alternative fuels, the higher content of methane, dinitrogen oxide and unmethane volatile organic compounds and the lower content of nitrogen oxide, carbon dioxide in emissions from combustion of alternative fuels compared to emissions at combustion of unrenewable fuels were determined during the calculations. When burning natural gas there is mercury in small amounts in the emissions. Originality. The paper presents for the first time a comparative characteristic of emissions of harmful substances from the combustion of traditional fuels (natural gas and fuel oil) and biomass in fuel furnaces of boilers and recommended for the use the most environmentally efficient fuels. When making calculation works the following regularities are defined. In unrenewable and alternative fuels, a higher proportion of carbon passes into carbon dioxide emission and less to carbon oxide emission, while proportion of carbon in carbon dioxide emission is higher in unrenewable fuels. In addition, in unre-newable and alternative fuels, a large proportion of nitrogen is converted into nitrogen oxide emission, and less in emission of dinitrogen oxide, while the proportion of nitrogen in the emission of nitrogen oxide is also higher in unrenewable fuels. The paper defines a formula for calculating the carbon content in natural gas from the Central Asia-Center gas pipeline. The provided calculations and the introduction of simplified formulas serve as an example for the calculation of emis-sion factors and emissions in assessing the level of safety of existing equipment and can be used in the development of permit documents of enterprises that carry out emissions of harmful substances to the environment.

Synthesis and air jet erosion wear behavior of aluminum – Al3Ti In-Situ composite

In the present study, in-situ aluminium-Al3Ti composites have been prepared by the addition of K2TiF6 inorganic salt into molten aluminium in a stir casting furnace. The in-situ composites have been formed at different holding temperatures and with varying amounts of K2TiF6. An air jet erosion set up is used according to ASTM G76 standard to conduct the erosive wear test Add see Fig. 2a. The erosion is caused by the impact of gas jet with suspended solid particle. The effects of stand-off distance and angle of erodent impingement on the erosion behavior of the composites are studied in detail.The microscopic analyses of the worn-out surfaces are carried out in a scanning electron microscope to understand the erosion mechanism, which governs the material removal. From the test results, it can be concluded that the weight loss is higher at 15° and 30° angles of impingement compared to 60° and 90° angles. Higher material loss is also observed at lower (10 mm) stand-off distance. This is because of the fact that at lower standoff distance the particles travel over smaller distance before hitting the sample surface and hence cause greater momentum transfer per second. This in turn causes higher material loss from the sample. Wear rate is also affected by the size of the Al3Ti phase. The size of this phase is in turn strongly dependent on the wt.% of K2TiF6 salt addition and the holding temperature during casting.

Effects of Flocculant, Surfactant, Coagulant, and Filter Aid on Efficiency of Filtration Processing of Copper Concentrate: Mechanism and Optimization

In the recent decades, water scarcity has become a major challenge for many reasons, especially the inadequate use of water resources. The mineral processing plant is among the most important water-consuming industries. Filtration, as one of the important processes in water recovery, is a process in which the solid-suspended particles are removed from the liquid. In the present work, the effect of the additives affecting the filtration process upon the responses including the resistance to filter cloth (R), specific cake resistance (α), moisture content, water recovery rate, and cake formation rate by the vacuum top-feed method is investigated. The experiments are performed by two methodologies: one-factor-at-a-time and statistical analysis. The additives are the flocculant, coagulant, surfactant, and filter aid. According to the one-factor-at-a-time methodology, the optimal type and dosage of the variables are as follow: flocculant A25 with a concentration of 15 g/L, perlite as the filter aid with an amount of 2.5%, surfactant cop 20-101 with a concentration of 3 cc/L, and the coagulant CaCl2.2H­2O with a concentration of 2.5 g/L. The usage of the flocculant, surfactant, and filter aid at the same time is also statistically analyzed with the aim of maximizing the cake formation rate and minimizing the moisture content of the filter cake. Under the optimal conditions and taking into account 11.68 g/t of the flocculant A25, 3.8% of perlite as the filter aid, and2.92 cc/L of the surfactant cop 20-101, the cake formation rate and the moisture content were obtained to be 0.297 mm/s and 12.7 %, respectively.

Rheometric flows of concentrated suspensions of solid particles

Publications on experimental and theoretical studies of the rheological properties of concentrated suspensions of solid particles have been analyzed. According to the currently accepted ideas, the rheology of suspensions is considered as a result of contact interaction of their constituent particles caused by the action of external forces, the formation and destruction of various types of conglomerate structures. A new rheological model of a highly concentrated suspension of solid particles in a Newtonian fluid is proposed, which describes both a continuous and discontinuous increase in the effective viscosity with a uniform increase in shear stresses. Accurate analytical formulas are obtained for the velocity profiles of suspensions in rotational viscometers “cone-plane” and “cylinder-cylinder”, as well as in a slit viscometer. The proposed model is modified to take into account the non-Newtonian properties of a dispersion medium, which exhibits pseudoplastic properties at low strain rates, and dilatant properties at large strain rates. The effective viscosity of such a suspension is presented as the sum of the contributions from the dispersion medium and the solid particles of the dispersed phase. To describe the rheology of the dispersion phase, the Ellis model was used. The velocity profiles in a pressure driven flat channel are obtained numerically by the finite element method. It is shown that, depending on the parameters of the model, the velocity profiles in a flat channel can take various complex forms.

A novel experimental study & design study on systematic designed sea water purifier machine using activated carbon

Nowadays many emerging countries have seen a substantial increase in supply for fresh water. In present scenario water comes into a drought. This paper represents converting of sea water into Drinking water processing machine. To reach the demands of the basic needs filtration and purification of water has been investigated. This paper presents on the effects of purifying water in behavior of activation carbon in comparison to conventional method. Activated carbon is used to investigate the efficiency in the water filtration mechanism Activated Carbon frequently used to extract water contaminants from tap water and salt water in water treatment. In domestic water filters, activated carbon is used because of its excellent ability of adsorption. In this research, the grades A of Activated Coal are used to analyze their efficiency in the filters. Ultraviolet radiation is used for the purification of water without abandoning hazardous chemicals. Prototype is produced through the use of a water treatment with activated carbon and ultraviolet radiation. Two activated carbons perform surface region and porosity observation. The magnified image of Granulized Activated Carbon is used for the contrast between ground structures by Scanning Electron Microscopy (SEM). Before and after water treatment, two forms of water tests investigated, the ground water and the bore-well water are evaluated. The pH test, total suspended solid particle test, biochemical oxygen requirement check, and Chemical Oxygen Demand (COD) experiment were used to evaluate the water samples. The assessment conducted is an initial effort to deal with such an issue. The maximum intensity of the radiation is 256 nm which is the most effective wavelength in inactivating bacteria. The UV-C portion is totally blocked out with prevalent bottles. A fraction of UV-C radiation exits. However, the purified water layer that implemented in larger containers. Thus, paper examines an effectiveness of technology and economics in future studies.

Seasonal variation and potential risk assessment of microcystins in the sediments of Lake Taihu, China

High concentrations of microcystins (MCs) in sediment pose a serious hazard to aquatic and terrestrial organisms. Hence, we investigated the seasonal variation of dominant MCs (MC-LR, MC-RR and MC-YR) in sediments of Lake Taihu over four seasons for the first time. Sediment MCs varied seasonally (p < 0.01) with concentrations highest in August and lowest in February. The MCs were dominated by MC-LR (61.47%) with the content ranging from 0.02 to 2.37 μg/g dry weight in sediment. The three MC congeners and their proportions were significantly correlated with latitude and longitude. Meiliang Bay in the north had the highest MCs of all sites, while the eastern part of the lake had a high level especially in August. Variation of MC-LR and MC-RR concentrations was significantly correlated (p < 0.05) with water temperature, dissolved total organic carbon, cyanobacteria density, total suspended solid particles, and total organic carbon and total nitrogen in sediment, while MC-YR was negatively correlated (p < 0.01) with nutrients in the water column and heavy metals in sediments. An ecological risk assessment suggested the MCs already pose significant adverse effects on Potamopyrgus antipodarum; although the adverse effects on humans were weak, children were at greater risk than adults.

Multiscale modeling of magnetorheological suspensions

We develop a multiscale approach to describe the behavior of a suspension of solid magnetizable particles in a viscous non-conducting fluid in the presence of an externally applied magnetic field. By upscaling the quasi-static Maxwell equations coupled with the Stokes' equations we are able to capture the magnetorheological effect. The model we obtain generalizes the one introduced by Neuringer & Rosensweig for quasistatic phenomena. We derive the macroscopic constitutive properties explicitly in terms of the solutions of local problems. The effective coefficients have a nonlinear dependence on the volume fraction when chain structures are present. The velocity profiles computed for some simple flows, exhibit an apparent yield stress and the flow profile resembles a Bingham fluid flow.

A closure model for the drag coefficient of a sphere translating in a viscoelastic fluid

In many large-scale industrial applications dealing with particle-laden viscoelastic fluids, the ensemble-averaged behavior of the mixture is of most interest. The first step to parametrize this behavior is to develop an accurate expression to rapidly evaluate the drag coefficient over a broad range of kinematic parameters. The drag coefficient of a spherical particle translating in a viscoelastic matrix is strongly affected by the viscoelasticity of the fluid. In this study, we aim to parametrize the effects of fluid elasticity, especially the relaxation and retardation times, as well as inertia on the drag coefficient of a sphere translating in a viscoelastic fluid described by the Oldroyd-B model. To this end, we employed three-dimensional direct numerical simulations of viscoelastic flow past a stationary sphere. The accuracy of the numerical formulation is thoroughly tested against a number of benchmark problems consisting of steady flow past a sphere in a bounded circular or square domain filled with either a Newtonian or viscoelastic fluid. Initially, the numerical computations for the drag coefficient over a wide range of geometric and flow parameters are validated by comparison with existing data and drag correction models from the literature. The drag coefficient correction is then evaluated for unconfined flow past a sphere at different Reynolds number, Re, over a wide range of Deborah number, De < 9, and polymer viscosity ratio, 0 < ζ < 1. For small Deborah number (De < 1), the drag coefficient decreases with respect to the Stokes drag coefficient, whereas, at large Deborah number (De > 1), the drag is enhanced due to the large elastic stresses that develop on both the surface and wake of the sphere. These canonical behaviors, observed in the inertia-less flow regime (Re ≤ 1) are amplified as the polymer viscosity ratio approaches unity. At higher Reynolds numbers (Re > 1), the drag coefficient correction arising from viscoelasticity is found to be always bigger than unity, but smaller than the enhancement calculated in the creeping flow limit. In this regime, the formation of an axisymmetric recirculating eddy expands the wake region behind the sphere, and shifts the maximum elastic stresses away from the rear stagnation point towards the flow separation points. Motivated by the self-similarity observed at Re < 1, we propose an approximate model for the viscoelastic drag coefficient based on rational functions, using the lowest possible degree of polynomial functions required to fit the computational data with 95% accuracy, for De ≤ 5 and 0 < ζ < 1. This expression is a key step towards formulating a momentum-exchange model for the flow of dilute suspensions of solid particles in a viscoelastic matrix.

Multiple nature analysis of Carreau nanomaterial flow due to shrinking geometry with heat transfer

An astonishing feature of modern research in the field of fluid flow and heat transfer is the suspension of small solid particles (nanoparticle) in the working fluid to increase the low thermal conductivity of these fluids. Because of unique chemical and physical properties, nanomaterials are being progressively utilized in almost every field of science and technology. Therefore, the intent of current manuscript is to theoretically examine the magneto-hydrodynamic flow of Carreau nanofluids along with heat transport in the presence of heat generation driven by a wedge-shaped shrinking geometry. We incorporated the revised Buongiorno’s model in which nanofluids particle fraction on the boundary is passively controlled. Mathematical modeling of assumed physical problem results in a system of non-linear partial differential equations outlining the basic conservation laws. The governing problem is made dimensionless with the assistance of non-dimensional variables and numerical solutions are computed via a built-in MATLAB solver bvp4c. The computed results showed that multiple solutions (first and second) exist for the non-dimensional velocity, temperature and concentration distributions by applying the said numerical scheme. We concluded that by enhancing the magnetic parameter the nanofluid velocity increases in case of second solution while an opposite is true for temperature. Further, the outcomes indicate that higher heat generation parameter leads to enhance the temperature distributions in both solutions.

Analysis of heat transfer mechanisms during energy storage in a vertical cylindrical unit filled with nano enhanced phase change material for free cooling applications

Abstract Research in convective heat transfer using suspensions of nano meter-sized solid particles in base liquids started only over the past decade. Recent investigations on nano fluids, such as suspensions as often called, indicate that the suspended nano particles markedly change the transport properties and heat transfer characteristics of the suspension. Several theoretical works to predict the effective thermo physical properties of the suspension, range from a homogeneous model to complex two phase flow model have been proposed. The proposed work is aimed to study the effect of nano particles (MWCNT) in liquid paraffin (RT 21), to enhance the heat transfer properties and to examine the characteristics of the Nano Enhanced PCM during the solidification process. This work is carried with two different velocities i.e., 4 m/s as Low Heat Flux (LHF) and 5 m/s as High Heat Flux (HHF). This work resulted in an improvement in heat transfer with the addition of nano particles by 20.71% and 20.94% with low heat flux and high heat flux in sensible cooling region of PCM. The improvement in heat transfer by 18.41% with high heat flux (HHF) fluid and by 11.61% with low heat flux (LHF) fluid in the remaining solidification period with corresponding decrease in solidification time.

Modelling of sprays: simple solutions of complex problems

Some new approaches to the solution of complex problems, focused on spray modelling, using relatively simple mathematical tools are briefly summarised. The following problems are considered: modelling of spray drying with pharmaceutical applications, modelling of heating and evaporation of suspended droplets with applications to water sprays for fire suppression, modelling of micro-explosions with automotive applications, and parameterisations of slow invariant manifolds with applications to spray ignition modelling. The modelling of spray drying is based on the assumption that the array of small suspended solid particles inside droplets can be treated as a non-evaporating liquid component. The modelling of the effect of a support rod on droplet heating and evaporation is based on the assumption that this heat is homogeneously distributed inside the whole volume of a droplet. In the modelling of a puffing/micro-explosion it is assumed that a water sub-droplet is located exactly at the centre of a fuel droplet and the temperature at the surface of the fuel droplet is fixed. In the presentation of slow invariant manifolds in parametric form these manifolds are found using asymptotic expansions.

Prevention of Barite Sag in Oil-Based Drilling Fluids Using a Mixture of Barite and Ilmenite as Weighting Material

Drilling high-pressure high-temperature (HPHT) wells requires a special fluid formulation that is capable of controlling the high pressure and is stable under the high downhole temperature. Barite-weighted fluids are common for such purpose because of the good properties of barite, its low cost, and its availability. However, solids settlement is a major problem encountered with this type of fluids, especially at elevated downhole temperatures. This phenomenon is known as barite sag, and it is encountered in vertical and directional wells under static or dynamic conditions leading to serious well control issues. This study aims to evaluate the use of barite-ilmenite mixture as a weighting agent to prevent solids sag in oil-based muds at elevated temperatures. Sag test was conducted under static conditions (vertical and inclined) at 350 °F and under dynamic conditions at 120 °F to determine the optimum ilmenite concentration. Afterward, a complete evaluation of the drilling fluid was performed by monitoring density, electrical stability, rheological and viscoelastic properties, and filtration performance to study the impact of adding ilmenite on drilling fluid performance. The results of this study showed that adding ilmenite reduces sag tendency, and only 40 wt.% ilmenite (from the total weighting material) was adequate to eliminate barite sag under both static and dynamic conditions with a sag factor of around 0.51. Adding ilmenite enhanced the rheological and viscoelastic properties and the suspension of solid particles in the drilling fluid, which confirmed sag test results. Adding ilmenite slightly increased the density of the drilling fluid, with a slight decrease in the electrical stability within the acceptable range of field applications. Moreover, a minor improvement in the filtration performance of the drilling fluid and filter cake sealing properties was observed with the combined weighting agent. The findings of this study provide a practical solution to the barite sag issue in oil-based fluids using a combination of barite and ilmenite powder as a weighting agent to drill HPHT oil and gas wells safely and efficiently with such type of fluids.

Wear and its Effects in Centrifugal Pumps

Wearing means the abrasion of machinery or other materials because of a lot of use and over time. Wearing can be examined under 4 different groups. These are mechanical wear, corrosion, cavitation and fatigue. Mechanical abrasion is the mechanical removal of metal by cutting or the abrasion of suspended solid particles carried in the liquid, which is a loss of material. Corrosion is the change in the physical, chemical and mechanical properties of materials as a result of the chemical and electrochemical effects of the environment they are in. Cavitation is the result of the formation of vapor bubbles in the liquid subjected to intense local pressure changes and the detonation resulting from the explosion in the high pressure zone. Wearing which occurs in machine elements under variable stresses is called fatigue. Centrifugal pumps are from the dynamic pump group and are the most widely used pump type in agricultural irrigation. They work in very difficult and critical environments. They encounter many wear-out problems throughout their lifetime. In this study, the types of wearing observed in centrifugal pumps were investigated and the effects on the centrifugal pumps were investigated.

Effect of impeller type on mixing of highly concentrated slurries of large particles

Many chemical engineering processes deal with dense suspensions of large solid particles in liquid. Behaviors of such systems are difficult to predict because the many solid particles strongly affect the hydrodynamics produced by the impeller. The main objective was to assess the performances of the PBT, A310, and PF3 impellers in agitating highly concentrated slurries of large particles. Electrical resistance tomography was used to determine the degree of homogeneity and solid particle distribution within the slurry reactor. To gain more insight into the complex behavior of the flow inside the dense suspensions, computational fluid dynamics simulations were conducted using a Eulerian‒Eulerian multiphase model. Both qualitative and quantitative analyses were performed to obtain details on the dispersed solid phase distribution and its effect on the mixing quality. We found that the PBT impeller was the most efficient in terms of consuming power and generating velocity and turbulent kinetic energy within the mixing tank.

A Review on Suspension Thermal Spray Patented Technology Evolution

Since the introduction of suspension thermal spray (STS) in 1997, the rapid evolution of this technology has resulted in a critical number of inventions justifying a comprehensive review. Today STS is one of the most important research and development topics in thermal spray. Due to the efforts of different industries, universities, and governmental institutions, STS has reached a certain maturity for implementation in different applications. STS includes any thermal spray process that is based on injection of a suspension of solid particles in a liquid carrier into the gas jet, such as suspension plasma spray, suspension high-velocity oxy-fuel, and high-velocity suspension flame spray. This review is on the state of the art of the STS technology and includes an overview of the current patent situation including the number of patents published in English language, patenting institutions and invention domains. Apparatus and methods, feedstock, and new material systems and applications were identified as the three main domains of focus for the STS inventions. The presented patents show a general perspective of the current situation and present the technology advancements in each domain. It also shows the potential of implementing this technology in new applications based on the needs of thermal spray market through further technology development.

Numerical simulation of solid-liquid mixing characteristics in a stirred tank with fractal impellers

The hydrodynamics of solid-liquid mixing process in a stirred tank with four pitched-blade impellers, fractal 1 impellers, and fractal 2 impellers were investigated using computational fluid dynamics (CFD) simulation. An Eulerian-Eulerian approach, standard k-ε turbulence model, and multiple reference frames (MRF) technique were employed to simulate the solid-liquid two-phase flow, turbulent flow, and impeller rotation, respectively. The effects of impeller speed, impeller type, impeller spacing, impeller blade tilt angle, impeller blade shape, solid particle size and initial solid particle loading on the solid particle suspension quality were investigated. Results showed that the homogenous degree of solid-liquid system increased with the increase of impeller speed. The impeller spacing of T5/6 and T and impeller blade tilt angle of 60° and 45° were appropriate for the solid-liquid suspension process. Fractal shape impeller was more efficient than jagged shape impeller in solid-liquid mixing process. Larger particle diameter and higher initial solid particle loading resulted in less homogenous distribution of solid particles. It was found that fractal impeller could improve the solid particle suspension quality compared with four pitched-blade impeller under the same power consumption, increasingly so with the fractal iteration number of fractal impeller. Moreover, fractal impeller reduced the size of impeller trailing vortex and consumed less power consumption compared with four pitched-blade impeller at the same impeller speed, and the more the number of fractal iteration, the higher the impeller energy utilization rate of fractal impeller.

Viscoelastic properties of suspensions of noncolloidal hard spheres in a molten polymer

We report an experimental study on suspensions of solid particles in a viscoelastic polymer matrix. A commercial entangled poly(ε-caprolactone) was used as the suspending fluid. Noncolloidal solid spheres (diameter = 15 μm) made of polymethylmethacrylate were dispersed in the polymer via a solvent casting method. The volume fraction of the spheres was varied from 5% to 30%, thus allowing to explore both dilute and concentrated regimes. Electron scanning microscopy demonstrated homogeneous dispersion of the spheres in the matrix. We measured the rheological properties of the suspensions both in linear and nonlinear regimes with both dynamic and transient tests. The experimental results demonstrate the reinforcement effect of the particles. Both viscous and elastic moduli increase as the concentration of the particles is increased. The results show good agreement with available theories, simulations, and previous experimental data. In particular, the second order parameter of the quadratic equation that describes the dependence of the shear viscosity of the suspension upon the volume fraction of particles is in agreement with the predicted value found by Batchelor [G. K. Batchelor and J. T. Green, “The hydrodynamic interaction of two small freely-moving spheres in a linear flow field,” J. Fluid Mech. 56, 375–400 (1972); G. K. Batchelor and J. T. Green, “The determination of the bulk stress in a suspension of spherical particles to order c2,” J. Fluid Mech. 56, 401–427 (1972); and G. K. Batchelor, “The effect of Brownian motion on the bulk stress in a suspension of spherical particles,” J. Fluid Mech. 83, 97–117 (1977)]. We probe experimentally that the linear rheological behavior of suspensions of particles in viscoelastic fluids is the same as for Newtonian fluids.

Clogging process and related pressure drops in wire-wound filters: laboratory evidence.

The present work is aimed at analyzing the performance of the commercial filters used for the mechanical filtration of suspended solid particles. In particular, it is intended to evaluate the head losses due to the presence of the filter in the plant and how these losses vary depending on the circulating flow rate, the nominal porosity of the filter, and its clogging degree. Filters with interstices of different sizes, from 1 to 50 μm, were compared for the performance analysis. The polypropylene wire, in facts, wrapped around a windowed cylinder of the same material, allows the creation of meshes with the desired degree of compactness. The experiments were carried out at the Laboratory of Environmental and Maritime Hydraulics (LIDAM) in a hydraulic circuit reproducing a domestic piping system, where different water demand scenarios were analyzed. The clogging of the cartridge was made with the aid of sand particles, attached, with the help of a natural glue, to the external surface of the filter. More than 200 measurements were carried out, which showed a clear increasing trend of the head losses at the filter as the clogging degree and the circulating flow rate increase. In all cases, the trend of the pressure drop at the filter has a more than linear trend. Also, it was observed that head losses did not exhibit a marked dependence on the nominal porosity. Best performances in terms of minor head losses were obtained by the 50-μm filter.

Experimental Investigation on Slurry Erosion Behavior of 304L Steel, Grey Cast Iron, and High Chromium White Cast Iron

The materials used for the slurry transportation system experience erosion wear due to the impact of suspended solid particles. In the present experimental investigation, a large size slurry pot tester was used to investigate the slurry erosion behavior of steel 304L, grey cast iron, and high chromium white cast iron in the velocity range of 9.0–18.5 m/s. Experiments were conducted by rotating the wear specimens in the pot tester at 1% weight concentration of Indian standard sand. The erosion behavior of the three target materials was evaluated by varying the orientation angle from 15 to 90 deg and particle size from 256 to 655 µm. The erosion rate was found to increase with velocity having power index value varying between 2 and 3, which increases with an increase in impact angle and depends on the target material. The erosion rate of the material also increases with the increase in particle size with the power index varying between 0.8 and 1.4 depending on the target material. No significant change was noticed in the mechanism of erosion of the target materials with the variation in velocity in the present range of test conditions. Empirical correlations are proposed to estimate the total erosion rate of all the three materials as a contribution of cutting and deformation wear.