Suspended Solid Particles Research Articles

Fumed Silica-Based Suspensions for Shear Thickening Applications: A Full-Scale Rheological Study.

Understanding shear thickening fluids (STFs) is critically important in a broad spectrum of fields ranging from biology to military. STFs are referred to the suspension of solid particles in an inert carrier liquid. Customizing the thickening behavior is vital for obtaining desired properties. Hence, comprehending shear thickening mechanisms is necessary to fully understand the factors affecting the shear thickening response of the STFs. Herein, we systematically investigate the effects of a wide range of parameters, from inherent properties of the constituents, including size and surface chemistry of the suspended particles, to practical conditions such as temperature and shear history, on the shear thickening behavior of fumed silica nanoparticles (NPs)-based suspensions in a polyethylene glycol (PEG) medium. Accordingly, increasing the hydrophobicity of the silica NPs or decreasing the NP size transforms the suspensions from sol to gel. The sol systems exhibit a strong shear thickening response, while shear thinning behavior is prominent in the strong gel systems. Hybridization of different silica NPs is also leveraged to tune the shear thickening behavior. In addition, we showcase the decisive role of operating temperature or shear history on the shear thickening behavior of suspensions. For instance, in terms of the shear history, above a critical value of preshear, the shear thickening behavior occurs at lower shear rates for STFs containing hydrophilic NPs. It is believed that the provided insights in this study can pave the way for developing advanced STFs with prescribed features.

Microbiological and Enzymatic Activity Modulates the Bitter Taste Reduction in Decanted Coratina Olive Oil.

Coratina monocultivar extra virgin olive oil (EVOO) is known for its level of bitterness, which, if too high, can cause consumer acceptance problems. The aim of this study was to modulate the bitter taste of freshly produced olive oil through endogenous enzymatic activity and microbiota during the decantation phase. The opalescent appearance of the newly produced EVOO was substantially reduced during the first three months of decantation due to the deposition of more than 90% of suspended material, consisting of vegetation water and suspended solid particles. The high content of biophenols and the reduction in water concentration in the oil samples negatively affected the survival of yeasts, which were absent in the oil samples at the end of the third month of decantation. The oleuropeinolytic activity was very intense during the first month of decantation, whereas the reduction in the bitter taste associated with the aglycons was consistent only in the second and third months of decantation. At the end of decantation, the sensory notes of bitterness in the Coratina EVOO were reduced by 33%, lowering the position on the value scale without altering the other qualitative parameters whose values fell within the limits of the commercial EVOO class.

Thick elastomeric coating removal using tailored infrared- and infrared-sonication hybrid technology

We report an innovative, cost-effective, and eco-friendly coating removal technology that removes thick polyurethane-based elastomeric coatings without damaging the underlying metal or glass-polymer composite substrates. The developed technology eliminates the need for chemical- or media-based treatments, thus reducing environmental problems such as releasing toxic gases or suspended solid particles in the air. This was achieved using tailored infrared and infrared-ultrasonication treatments of the coated substrates that caused bond failure at the surface coat-substrate interface by selective absorption of IR and/or impinging of the topcoat with the ultrasonication technique. The degraded interfacial adhesion strength then allowed easy removal of the specialty coating with the application of a pull at a certain angle to the substrate-coating interface. The effect of different operating parameters such as time of irradiation, surface temperature, sonication power/intensity was investigated to determine the optimal conditions for coating removal. The treated and untreated coated samples were characterized by DSC, SEM, FTIR, peel-tester, embedded thermocouple/LABVIEW, and infrared thermography techniques. The energy analysis revealed that the fracture energy component was 4× lower on the treated sample than the untreated sample indicating reduced bond strength, which can be explained based on residual thermal stress generated due to the thermal coefficient mismatch and the interfacial cell dislocation. Also, coating from the treated sample could be removed 1.75× faster than from the untreated sample. Based on the cost analysis, the operation cost for this technology is meager compared to conventional and energy-intensive technologies such as laser ablation.

Data-driven closure model for the drag coefficient of the creeping flow past a translating sphere in a shear-thinning viscoelastic fluid

A drag force closure model for particle-laden viscoelastic fluid flows is the key to describing the ensemble-averaged behavior of the mixture. The effects of fluid rheological properties on the flow dynamics of a spherical particle in viscoelastic fluids in the creeping flow regime are parameterized using the Giesekus rheological model. Direct numerical simulations are performed within a large range of Deborah number(0−10).The drag force of a sphere in unbounded Giesekus fluids decreases monotonically with the increase of Deborah number. The negative wake may occur when the viscosity ratio is larger than 0.6 in Giesekus fluids but is absent in Oldroyd-B fluids in all conditions. An explicit closure model for the drag coefficient of a sphere in Giesekus fluids is established using the backpropagation artificial neural network. The drag closure model provides a method for explicitly formulating the momentum exchange model for dilute suspensions of solid particles in shear-thinning viscoelastic fluids.

On the suspension of large and dense solid particles in turbulent stirred vessels

This work with the focus on large and dense particles aims to investigate the range of physical properties over which the 2015 Grenville, Mak, Brown correlation (referred to here as GMB) is valid for suspension of solid particles in liquid filled stirred tanks. The test particles were greater than 1000 μm in diameter (up to 10,000 μm) while the density difference ratio (ρs − ρl)/ρl between solid and liquid phase is beyond two (up to over 10). Two flat based vessels, 305 and 610 mm in diameter, were utilized, while the impellers used were a wide blade hydrofoil and a pitched blade turbine impeller with multiple diameters being tested in each scale. With the particle density and diameter represented by the Archimedes number, Ar, the results exhibit a subtle anomaly or slope change at Ar values around 104 which may be indicative of a change in the mechanism of suspending related to the ratio of particle response time to turbulence time scale. With respect to using the GMB correlation for industrial-scale agitator design, the use of exponent 0.5 on Ar looks justified. The test conditions within this study increase the range over which the GMB correlation is applicable by four orders of magnitude.

Viscous resuspension of droplets

Shear-induced migration is ubiquitous in a suspension of solid and soft particles. The contribution to particle deformability and frictional contacts between particles needs to be clarified. By measuring normal forces with viscous resuspension experiments of frictionless droplets, we show droplet deformation does not play a significant role, contrary to frictional contacts, as the normal force is much weaker for droplets than for solid particles at high volume fractions.

Clarification of regimes determining sonochemical reactions in solid particle suspensions

Although there has been extensive research on the factors that influence sonochemical reactions in solid particle suspensions, the role that solid particles play in the process remains unclear. Herein, the effect of monodisperse silica particles (10–100 μm, 0.05–10 vol%) on the sonochemical activity (20 kHz) was investigated using triiodide formation monitoring and luminol tests. The results demonstrate that, in the particle size range considered, the sonochemical yields were enhanced in dilute suspensions (0.05–1 vol%), while further particle addition in semi-dilute suspensions (1–10 vol%) decreased the yields. Two regimes, namely the site-increasing regime and sound-damping regime, are identified in respect of the enhancing and inhibiting effects of the particles, respectively, and their dependence on particle characteristics is analyzed. Both regimes are confirmed based on the cavitation erosion test results or cavitation noise analysis. The clarification of the two regimes provides a better understanding of the dominant factors controlling sonochemistry in the presence of solid particles, as well as a guide for sonochemical efficiency prediction.

Theoretical and Experimental Study of Current from Non-Disintegrable Suspended Particles at a Rotating Disk Electrode

Understanding the current response at an electrode from suspended solid particles in an electrolyte is crucial for developing materials to be used in semi-solid electrodes for energy storage applications. Here, an analytical model is proposed to predict and understand the current response from non-disintegrable solid particles at a rotating disk electrode. The current is shown to be limited by a combination of ion diffusion within the solid particle and the mean residence time of the particle at the rotating disk electrode. This results in a relationship between current and angular frequency of instead of the classical predicted by Levich theory. Specifically, the current response of Li4Ti5O12 (LTO) microparticles suspended in a non-aqueous electrolyte of lithium hexafluorophosphate (LiPF6) in ethylene carbonate: diethyl carbonate (EC:DEC) was determined experimentally and compared favorably with predictions from the proposed analytical model using fitting parameters consistent with the experimental conditions.

Variable-Fidelity Euler–Lagrange Framework for Simulating Particle-Laden High-Speed Flows

The current work presents a simulation framework for modeling high-speed flows with suspended solid particles using the point-particle discrete element method. The dispersed particle phase is treated in a Lagrangian manner, whereas the dynamics of the surrounding carrier fluid are determined by solving the compressible Navier–Stokes equations in the Eulerian frame. Additionally, a variable fidelity paradigm is adopted with the ability to model one-, two-, and four-way coupling between the dispersed and carrier phases depending on the desired levels of physical realism. Particle mesh-localization is performed using mesh-connectivity information, which also simplifies boundary conditions enforcement, parallelization, and the backcoupling of particle-induced source terms to the carrier fluid. A time-driven hard-sphere approach is employed to accelerate calculations for particle–particle collisions. The particle solution methodology in conjunction with the unstructured, finite-volume US3D flow solver is used to simulate a variety of multiphase flows. These include a series of verification tests and the first-of-its-kind numerical investigation into elevated levels of surface heat flux experienced by the Mars 2020 spacecraft if planetary entry through the Martian atmosphere were to occur during a major dust storm.

Regression analysis to estimate the response of the respiratory organs to exposure of air microtoxicants in chronic obstructive pulmonary disease

Inroduction. The assessment of the respiratory system is of particular importance in the context of increasing impact of anthropogenic factors on human health. Aim. Evaluation the response of the lung function indices to the effects of micro-suspensions and toxic metals in patients with chronic obstructive pulmonary disease (COPD), using regression models. Materials and methods. The study involved 60 patients with stable mild-to-moderate COPD and 30 healthy people (the control group). The analysis of lung function was carried out by spirometry and body plethysmography. Arterial oxygen saturation (SaO2 ) was measured by pulse oximetry. Exhaled CO2 concentration and blood carboxyhemoglobin (COHb%) concentration were assessed using a portable analyzer MicroCO Meter. The pollution of the city atmosphere was assessed by aerosol suspensions of solid particles in the areas of residence of the examined patients. Fractional composition of suspended particles (0-1, 1-10, 10-50, 50-100, 100-400, 400-700,> 700 μm; %) were analyzed in the areas of residence of the examined patients. Toxic metal (Pb, Cr, Mn, Fe, Co, Ni, Cu, Zn; μg/L) levels in the air samples were determined. The statistical module "Multiple regression" was used for assessing the response of functional parameters of the respiratory system. Results. The analysis of one-factor and multi-factor regression models made it possible to identify both trigger factors of dust and technogenic air pollution and the synergistic effect of the influence of dominant factors. It has been shown that multifactorial reactions to technogenic impact manifest as altered blood oxygen saturation and carboxyhemoglobin level and thereby contribute to the development of respiratory failure. Conclusion. Patients with COPD exhibited increased bronchial resistance to the effect of the trigger factor (Pb – 1 hazard class) associated with high motorization of the city. The response of pulmonary gas exchange (SaO2 ) to Pb in the control group indicates prolonged exposure to toxic metals can cause developing respiratory failure even in the healthy population of the city.

Numerical study of geometric parameters effects on the suspended solid particles in the oil transmission pipelines

The innovation of this paper is geometric parameters effects of the oil transmission pipelines on the suspended solid particles. This geometry has been simulated with the Lattice Boltzmann Method based on D2Q9 model for analyzing solid particle tracing, streamlines, solid particle volume fraction, and nondimensional velocity field of fluid flow. These parameters have been investigated in 9 cases of the oil transmission pipelines at two different intensity of fluid flow. The results signified that maximum and minimum ranges of fluid velocity at [Formula: see text] were in case 3 that the oil transmission pipelines with diameter of the pipeline and bending radius, D and 2D, respectively. Also, maximum volume fraction of solid particles at bending radius at [Formula: see text] was in case 3 with diameter of the pipeline and bending radius, D and 2D, respectively. Also, in case 9, solid particles in the oil transmission pipelines were almost symmetrical. Finally, with comparison between figures of solid particles tracing and volume fraction of solid particles, by increasing of the diameter of oil transmission pipelines, the sediment of solid particles was decreased, also, by increasing of the bending radius of oil transmission pipelines, the sediment of solid particles was increased.

CFD investigation of the effect of solid particles on the power consumption of a 20-inch centrifugal pump for the transportation of petroleum products

One of the main challenges in oil transmission lines and petroleum products is fluid impurities especially suspended solids. Suspended solid particles, most of which are caused by corrosion of pipe walls and equipment, have many adverse effects on the life and performance of transmission systems. One of the components most affected by solid particles is the pumps. These devices are the beating heart of oil transmission lines. Their performance has a direct impact on the performance of transmission lines. Therefore, the effect of diameter and weight percentage of solid particles on the power consumption of a sample of pumps used in one of the oil transmission lines is investigated. To this end, the pump is simulated numerically in real dimensions and the particle motion in the pump chamber is modeled using an Eulerian–Lagrangian approach. The transferred fluid is liquid gasoline with C8H18 formula and 761 kg density. The fluid flow is assumed to be incompressible, steady, and turbulent and the effect of the suspended solid particles on the pump power consumption is investigated. The results indicate that the size and amount of particle accumulation can significantly increase the pump power consumption.

Rheometric Flows of Concentrated Suspensions of Solid Particles

Rheometric Flows of Concentrated Suspensions of Solid Particles

Unsteady Convective MHD Flow and Heat Transfer of a Viscous Nanofluid across a Porous Stretching/Shrinking Surface: Existence of Multiple Solutions

The suspension of tiny solid particles inside the energy transport liquids could enhance their thermal conductivity as well as provide an efficient and inventive approach to significantly improve their properties of heat transport. Therefore, our aim is to explore the radiative two-dimensional unsteady flow of a viscous nanofluid about an aligned magnetic field that includes the joint effect of suction, velocity slip, and heat source across a porous convective stretching/shrinking surface. Initially, using non-dimensional variables, the nonlinear governing partial differential equations (PDEs) were transformed into ordinary differential equations (ODEs) which were subsequently solved with the help of bvp4c built-in package in MATLAB. The results declare that escalating the values of the unsteadiness parameter escalates the friction drag whereas it reduces with the escalation of the slip parameter. Furthermore, the heat transfer rate escalates with the escalation of radiation and concentration parameter, and the escalation of the heat source parameter causes to reduce the heat transfer rate. Finally, it is found that the rate of heat transfer and friction drag continuously improve and decline against the rising rates of stretching, respectively.

Enhancement of a Spent Irrigation Water Recycling Process: A Case Study in a Food Business

Food operations use vast amounts of water. To reduce utility costs as well as concerns regarding water depletion in ecosystems, food businesses usually try to reuse their water. However, this often needs a recycling process to ensure the water is of good quality and safe to reuse in a food environment. This paper presents a case study of a grower of beansprouts and other varieties of sprouted seeds that uses six million litres of water weekly. Approximately 60% of their spent irrigation water is recycled using both 50 µm and 20 µm drum filtration. In addition, chlorine dioxide is used as part of the recycling process as a disinfectant. Our analysis demonstrated that the size of suspended solid particles in over 90% of the cumulative sample tested was smaller than the current 20 µm filter in place, highlighting that the existing system was ineffective. We, then, explored options to enhance the water recycling system of the company. After careful analysis, it was proposed to install a membrane-filtration system with ultraviolet technology to increase the finest level of filtration from the existing 20 µm to 0.45 µm absolute and sterilize any remaining bacteria. This not only improved water quality, but also allowed for the removal of chemicals from the recycling system, delivering both financial and technical improvements.

Numerical simulation of hydro-cyclone separator used for separation of highly dense suspended particulate matter

Cyclone separators are the most cost-effective and economically gas separation devices. They are not very complex to design and offer high collection efficiency; still, their use for the waste management field, i.e., separating solid waste from the liquid, is not explored to its full extends. This paper presents a Computational Fluid Dynamics-based numerical simulation of a hydro-cyclone separator planned to separate suspended particles from the digestate of a biogas plant. The turbulent incompressible flow model is employed during the simulation. The discrete particle method is used to model and track the suspended solid particle trajectory. The fluid properties of the digestate are assigned to the fluid supplied with suspended particle sizes ranging from 10 to 100 µm during the simulation to obtain realistic flow results. The Stairmand high-efficiency hydro-cyclone geometry is redesigned by the numerical experiment method to obtain high collection efficiency for solid particles. Here the effect of inlet flow velocity and suspended solid particle diameter are simulated to understand their effects on the hydro-cyclone collection efficiency. The fluid flow dynamics are observed, and the detailed distribution of particles inside the hydro-cyclone is presented.

Shear Jamming and Fragility of Suspensions in a Continuum Model with Elastic Constraints.

Under an applied traction, highly concentrated suspensions of solid particles in fluids can turn from a state in which they flow to a state in which they counteract the traction as an elastic solid: a shear-jammed state. Remarkably, the suspension can turn back to the flowing state simply by inverting the traction. A tensorial model is presented and tested in paradigmatic cases. We show that, to reproduce the phenomenology of shear jamming in generic geometries, it is necessary to link this effect to the elastic response supported by the suspension microstructure rather than to a divergence of the viscosity.

Modeling evaluation on solid-liquid mixing characteristics in a dislocated guide impeller stirred tank

Abstract The solid-liquid mixing characteristics in a stirred tank with pitched blade impellers, dislocated impellers, and dislocated guide impellers were investigated through using CFD simulation. The effects of impeller speed, impeller type, aperture ratio, aperture length, solid particle diameter and initial solid holdup on the homogeneity degree in the solid-liquid mixing process were investigated. As expected, the solid particle suspension quality was increased with an increase in impeller speed. The dislocated impeller could reduce the accumulation of solid particles and improve the cloud height compared with pitched blade impeller under the same power consumption. The dislocated guide impeller could enhance the solid particles suspension quality on the basis of dislocated impeller, and the optimum aperture ratio and aperture length of dislocated guide impeller were 12.25% and 7 mm, respectively, in the solid-liquid mixing process. Smaller solid particle diameter and lower initial solid holdup led to higher homogeneity degree of solid-liquid mixing system. The dislocated guide impeller could increase solid particle integrated velocity and enhance turbulent intensity of solid-liquid two-phase compared with pitched blade impeller and dislocated impeller under the same power consumption.

Inovasi Pengolahan Limbah Cair Batik dengan IPAL Ekonomis di Desa Maos Kidul Cilacap

Wastewater resulted from the batik dying process is known for its environmentally hazardous substances including hazardous natural and synthetic organic matter, suspended particles, and hazardous metal. But in the micro and medium scale batik textile business, wastewater treatment is mostly not carried because it does not give benefit for the owner. Economical wastewater treatment constructions can be an alternative for the business owner for their free operational cost. Batik wastewater treatment ought to be carried out to meet government standards but most importantly to decrease hazardous pollutant’s concentrations so it does not harm the environment. This society service project aims to provide alternatively economical wastewater treatment for batik business owners by applying simples and cheapest yet effective treatment methods to reduce pollutant concentrations in wastewater. Methods applied in this project including sedimentation, filtration, and landfill-bioremediation. The laboratorium analysis result shows that sedimentation and filtration are significantly reduced total suspended solid particles in wastewater from 2450 to 100 mg/L in line with wastewater decoloring from dark blue to clear yellow.

Intensification of suspension of solid particles in non-Newtonian fluids with coaxial mixers

The coaxial mixers intensify the suspension of solids in complex fluids, which is highly desirable for process intensifications in food processing, pharmaceuticals production, and cosmetics manufacturing. The prime aim of this research work was to examine the mixing efficacy of a coaxial mixing system, comprising of a close clearance outer anchor and an inner axial impeller, in intensifying the suspension and dissemination of solid particles in carboxymethyl cellulose (CMC) solutions employing response surface methodology (RSM) and electrical resistance tomography (ERT). RSM was utilized in this research study to examine the impacts of three different numeric factors and one categoric factor on two response variables. The ERT conductivity data were utilized to generate axial as well as radial concentration profiles. The solids distribution quality in CMC solutions was assessed employing three different mixing indexes. The fluid flow patterns generated by the coaxial mixers in suspending and dispersing the solids in CMC solutions was obtained utilizing computational fluid dynamics (CFD) turbulent modeling approach. The influences of various important factors namely outer anchor speed, speed ratio, solids content, CMC concentration, average particle size, inner impeller types, and rotating mode on the slurry suspension and dispersion behaviour were comprehensively analyzed in this study.