Solid Particles Research Articles

THE EROSIVE WEAR OF GRAPHENE OXIDE REINFORCEDEPOXY POWDER COATINGS

Powder coatings are organic coatings that protect the metal substrate against corrosion and wear, and playa decorative role. The doping of paints with nanoparticles is intended to create a barrier to corrosive andchemical agents and to increase abrasion resistance. This work tested the erosion resistance of epoxy powdercoating with graphene oxide flakes and polyethylene wax covered with a layer of micro diamonds. Twomethods of testing resistance to abrasive wear were used, in which the conditions are similar to operatingconditions: solid particle impingement (sandblasting) and barrel finisher with ceramic shapes. Mass loss dueto erosion in a sandblaster using glass beads with a diameter of 200 μm for the paint with graphene was muchlower than for the reference sample. The mass loss of the samples was tested after 15, 30, and 60 seconds ofabrasive jet operation. The surface texture was analyzed during the process and after the test. The test in thebarrel finisher was carried out twice for different times: for the first series weight loss was measured after 30,90, and 210 minutes, for the second Vickers hardness at 40 g load after 90 and 210 minutes. The tests showedthat the epoxy coating with the addition of graphene oxide has a much higher resistance to erosion under theinfluence of an abrasive stream than the reference paint, and a similar resistance to erosion in a containersmoother. It was found that the paints showed a higher Vickers hardness after the wear test.

Numerical Prediction of Solid Particle Erosion in Jet Pumps Based on a Calibrated Model

Jet pumps are widely used in petrochemical processes, nuclear cooling, and wastewater treatment due to their simple structure, high reliability, and stable performance under extreme conditions. However, when transporting solid-laden two-phase flows, they face severe erosion problems, leading to reduced efficiency, malfunctions, or even failure. Therefore, optimizing jet pump performance and extending its service life is crucial. In this study, an experimental platform was established to conduct experiments on wall erosion in jet pumps. The CFD-DEM method was used to simulate the solid–liquid two-phase flow in the jet pump, comparing six erosion models for predicting erosion rates. The Grey Wolf Optimization algorithm was applied to calibrate model coefficients. The results indicate that the Neilson erosion model shows the best consistency with the experimental results. The inlet flow rate significantly influenced the erosion rates, while the flow rate ratio had a smaller effect. The particle concentration exhibited a nonlinear relationship with erosion, with diminishing impact beyond a certain threshold. As the factors varied, the erosion distribution tended to be uniform, but high erosion areas remained locally concentrated, indicating intensified localized erosion.

Synchrotron computed tomography combined with AI-based image analysis for the advanced characterization of spray dried amorphous solid dispersion particles.

Particle engineering aims to design particles with specific properties. A deeper understanding of how particle formation relates to material attributes and process conditions are critical to strengthen knowledge on powder properties and enhance modeling capabilities. New, alternative powder characterization techniques can offer novel and more accurate measures for particle properties, giving more advanced characterization information. In this context, a case study is presented in which spray dried amorphous solid dispersion powders produced by modifying process conditions were characterized by both well-established compendial methods (i.e., laser light diffraction, SEM image analysis, bulk and tapped density, and gas adsorption), as well as a new method combining synchrotron computed tomography (SyncCT) with AI-based image analysis. SyncCT was used to classify and quantify the spray dried particles as hollow spheres and solid particles, giving a more detailed quality measure of the particle shape, as they impact downstream processing differently. Moreover, hollow particle wall thicknesses, as well as internal and external particle surface areas were measured by SyncCT. Altogether, powder characterization data from SyncCT show similar trends to that obtained from compendial techniques and giving additional quality measure regarding particle shape, showing promise of this new and advanced characterization method.

Creation and research of numerical models of cyclones with inclined and horizontal inlets

The article considers the challenges of using cyclone devices for cleaning gas emissions from solid fuel combustion in power engineering and industry. With the increasing energy consumption and generation, including the use of coal, the requirements for the efficiency of cleaning emissions from small solid particles of classes PM10 and PM2.5 are also rising. One of the key tasks is to maintain high cleaning efficiency while minimizing energy costs, which is also important for reducing the environmental impact of generation and industrial production. The article considers the design features of currently used cyclones, as well as existing approaches to their classification. The main focus is on modern areas of research related to numerical modeling based on CFD (Computational fluid dynamics) aimed at optimizing the design of separators. It is shown that most studies are carried out for cyclone operating conditions in production cycles, rather than in emission cleaning systems that operate at low suspended matter loads. Using the example of creating numerical models of cyclones with inclined and horizontal inlet pipes (CN-11, SK-CN-34), the article discusses certain features of geometry creation in the SpaceClaim Direct Modeler (SCDM) environment, which ensure the correctness of grid generation and calculations in the future. The results of numerical modeling carried out using the ANSYS Fluent software are presented. The turbulence model (RANS, Reynolds Averaged Navier – Stokes), methods for closing the Navier – Stokes equations (k-ε model with near-wall functions), and methods for calculating the dispersed part of the flow (Euler – Lagrange, DPM) are selected based on the conditions relevant to the systems for cleaning emissions from coal generation. The results indicate that, with the same pressure drop, the efficiency of settling suspended matter with a concentration of 100 mg/m3 or less in an apparatus with an inlet angle of 11° to the horizontal can be higher than that of a cyclone with a horizontal inlet.

Numerical Simulation of the Melting of Solid Particles in Thermal Convection with a Modified Immersed Boundary Method

A new immersed boundary method is proposed for the numerical simulation of the melting of solid particles in its own liquid at a high temperature. The main feature of the new method is the use of the modified direct-forcing immersed boundary method for the solution of the flow field and the sharp-interface immersed boundary method for the temperature field. The accuracy of the proposed method is validated via three problems: the sedimentation of a non-melting particle, the melting of a fixed particle under mixed thermal convection, and the sedimentation of a melting particle. The method is then applied to the investigation of the effects of various parameters, the particle interactions and the particle shape on the particle melting time. A correlation for the melting time of a circular particle in forced thermal convection is established as a function of the Reynolds, Prandtl, and Stefan numbers. The melting time of a particle in mixed thermal convection first increases and then decreases, as the Grashof number increases. The effects of the particle interactions on the melting time are complicated due to the natural convection between two particles. The sufficiently strong natural convection can even render the downstream particle melt faster than the single particle. For the same particle area, the elliptic particle with the aspect ratio being around 1.4 melts most slowly.

Numerical Implementation of Electrostatic Solver Within OpenFOAM for Gas Turbine Intake Filtration

Abstract Gas turbines require filtered air to preserve operability, availability, and efficiency. Fouling, corrosion, and erosion severely affect the performance of the axial compressor and it can be in part prevented by filtering the air intake. For this reason, several stages of filters can be used in series to catch pollutant particles gradually smaller and with a high level of capturing efficiency. Traditionally, the separation is obtained using cartridges of porous material, which provide a high level of filtration but at the same time generate a pressure drop increasing over time. Another common type of filter is the inertial one, whose operating principle is based on the inertial force acting on the solid particles to separate them from the mainstream. The capturing efficiency of the inertial filter is not comparable with the porous one and for this reason, it is used upstream as a pre-filter. In recent years, another technique has been developed to filter air flows thanks to an electrostatic field, that is induced inside the flow. The electrostatic force generated is able to attract and separate metallic particles. In the present work, numerical investigations are carried out to simulate the effect of the electrostatic force for gas turbine filtering systems. The computational fluid dynamics tool used is openfoam, whose official release can simulate inertial and porous filtering media, while for electrostatic one is not possible due to the absence of a library able to simulate the electrostatic force that acts on the discrete phase. A new library was developed in order to calculate the electric field, the electric potential, and the charge density of the continuous phase. Simulation results show how the calculation of these quantities allows us to predict the electrostatic force acting on particle flows in the presence of electrostatic fields.

Micro‐nanobubbles assisted fouling reduction in membrane distillation for desalination

AbstractThe present study describes the use of micro‐nanobubbles (MNBs) as an easy‐to‐use method for delaying scaling in membrane distillation (MD) while treating highly concentrated saline feed (10 wt.%). The hydrodynamic flow conditions with MNBs are enhanced compared to the traditional gas bubbling in MD. Specifically, an air cushion is formed between the membrane surface and bulk, limiting the deposition of solid particles on the surface. Also, turbulence created by the MNBs reduces the membrane fouling. The findings of the MD performance analysis showed that, in the absence of nanobubbles, considerable membrane scaling occurred during the treatment of high‐salinity feed, which significantly decreased the distillate flux to 70% after 20 h. The one‐time incorporation of air NBs into the saline feed significantly reduced salt precipitation or fouling on the polyvinylidene fluoride (PVDF) membrane surface by delaying the start of flux drop and preventing membrane wetting, thus improving MD performance. For nanobubble‐assisted MD, the only measured flux drop after 20 h of operation was 57% under similar input concentration and operating parameters.

Lie symmetry method to discuss the optimal system of Lie subalgebras and similarity solutions for shock propagation in a perfectly conducting dusty gas with magnetic field in rotating medium

In this paper, the similarity solutions for the shock wave propagation in a perfectly conducting dusty gas under the effect of axial or azimuthal magnetic field in the case of rotating medium by using Lie symmetry method have been discussed. The optimal system of one-dimensional Lie subalgebras related to the hyperbolic system of nonlinear partial differential equations had been constructed by using general invariant function and general adjoint transformation matrix. The optimal system is the collection of inequivalent optimal classes, which provides crucial information regarding different types of the similarity solutions. On the basis of the optimal system, we have discussed all possible similarity solutions for inequivalent optimal classes individually. Also, we have found that the similarity solutions exist in two cases for power law shock path and in one case with exponential law shock path. The shock wave decay is due to an increment in the physical parameter such as shock Cowling number or non-idealness parameter or adiabatic exponent or rotational parameter. For smaller value of the ratio of density of solid particles to initial species density of the gas i.e. [Formula: see text], the shock strength decreases with an increment in the mass fraction of solid particles in the mixture [Formula: see text], but the shock strength decreases as [Formula: see text] increases for [Formula: see text]. Also, the shock strength increases with an increment in [Formula: see text] at constant [Formula: see text]. It is observed that the shock wave is stronger in the presence of axial magnetic field as compared to azimuthal magnetic field.

Physicochemical Characterization of Gasoline and Analysis of the Vulnerability and Criticality of Atmospheric Pollutants in N'Djamena

In this work we made an analysis for the physicochemical characterization of gasoline sold on the roadsides of the city of N'Djamena. For our first experience on the storage of gasoline in cans exposed to the sun, we noticed the formation of lumps and solid particles at the bottom of the cans. We then sampled a sample by district and subjected it to the analysis conditions. The analyses focused on Density at 15°C; ASTM distillation; Reid vapor pressure, Octane number; Determination of corrosion of copper blades as well as Determination of sulfur content. The results of the analyzed contraband gasolines are out of specifications under normal analysis conditions. Despite the many studies carried out on air pollution by particles, uncertainties remain. It is more or less complex to treat particulate pollution in urban areas, this is in fact due to the modifications resulting from different meteorological factors (wind, precipitation, etc.), topographical (slope, etc.) and urban morphological, which constitute limiting factors in the dispersion of these pollutants, thus, different maps have been studied according to the vulnerability and criticality of the accentuated situation relating to pollution throughout the city of N'Djamena. The results confirm the presence of particles that can affect human health. In addition to the presence of all the elements that we have been able to discover, there is on average the result of the presence of PM10 particles which is: 66.98016239 ug/m<sup>3</sup> well above the WHO guideline which recommends 50 μg/m<sup>3</sup>/day as well as the daily average for PM2.5 which is: 56.83616723 ug/m<sup>3</sup> well above the WHO guideline which recommends 25 μg/m<sup>3</sup>/day. The objective of this article is to clearly present the urgency of air pollution throughout the territory in order to take a binding decision on the current situation based on the proliferation and illicit sale of petroleum products in the city of N'Djamena, particularly gasoline.

Using medications to prevent or reduce the impact of poor air quality on health: a systematic review

Abstract Introduction Particulate matter (PM) is a mixture of tiny solid materials and liquid particles in the air that can trigger inflammatory reactions in multiple body systems, including the respiratory, cardiovascular and endocrine systems. Currently, there are no licensed pharmacological interventions to prevent or modify the effects of PM on different organs. However, several existing medications have shown promising results towards modifying or preventing the negative impact of PM. Aim To conduct a systematic review to explore pharmacological interventions that could potentially prevent, delay or treat the effects of PM on human health. Methods This systematic review complied with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework and was registered with PROSPERO database (CRD42023476448). Four databases were searched including; MEDLINE, Embase, PsycINFO and Scopus. Keywords were arranged into different relevant sets such as ‘air pollution’, ‘medication’ and ‘prevention’/’treatment’. All the resulting titles, abstracts and full-texts were screened independently by two researchers. Only peer reviewed articles published in English were included. A tailored data extraction sheet was used to collate all relevant data, including the study description (i.e. country, year), study design (i.e. prospective), medication information (i.e. type of medication, dose, indication), population (i.e. demographics and disease), effect on air pollution (i.e. treatment or prevention). Quality assessment was conducted using Newcastle Ottawa tool. Ethical approval was not required to undertake this systematic review. Results The search produced 689 articles, 676 of which were removed at the title (n=463), and abstract (n=184) and full-text (n=29) stages. Thirteen articles were included, 10 of which were rated ‘good’ quality, two ‘fair’ quality, and one ‘poor’ quality. There was a range of pharmacological interventions evaluated, including beta blockers, oral anti-diabetic agents, statins, non-steroidal anti-inflammatory drugs (NSAIDs), systematic glucocorticoids, inhalers (adrenergic, glucocorticoid and anticholinergic inhalers) and theophylline. All studies focused only on PM, with six providing information on the particle diameter (e.g., PM10, PM2.5 and PM0.1). Statins, NSAIDs and bronchodilators demonstrated the most significant impact on reducing the damage caused by PM on both the cardiovascular and respiratory systems through anti-inflammatory, vascular re-modelling, and broncho-dilating effect. These medications had already been prescribed in these study patients for other indications (e.g., diabetes or asthma). None of the included studies used a medication for the prevention or treatment of air pollution effects as an indication. Conclusion Some medications significantly prevented/treated the effects of poor air quality; however, this was inconsistent across studies. However, all studies were conducted in high to middle-high income countries; findings may have been different in low-income countries. More research is required on the effective medication dose, duration of administration, if being prescribed solely for air pollution protection, and benefits and risks for more vulnerable populations (i.e. multimorbid).

Insights into local wall erosion characteristics and prevention measures for cyclone separators

Cyclone separators are separation devices that use the principle of inertia to remove particulate matter from flue gases. The present study mainly focuses on wall erosion in cyclone separators and associated research. The main locations of erosion in gas–solid cyclone separators, including the entrance impact section, cyclone roof corner, vortex finder outer surface, spiral-type erosion strip, and lower cone section, are examined in detail. The main factors influencing wall erosion are discussed, including inlet flow velocity, solid particle properties and loading, geometrical structure, and manufacturing quality. Finally, several practically preventive measures against wall erosion are presented, including adjustment of operating conditions, the use of erosion-resistant materials, optimization of geometrical structures, and the addition of auxiliary devices, all of which are essential for ensuring operational efficiency, equipment reliability, safety, and environmental protection in various industrial applications. This paper aims to provide a basis for further research into erosion in cyclone separators as well as guidance for engineers involved in their industrial applications.

Characteristics of pollutants emitted by motor vehicles and their impact on the environment and engine operation

Gaseous and solid pollutants (dusts) of atmospheric air have been defined. Dusts have been divided according to various criteria and their properties have been given. The sources and characteristics of anthropogenic and natural pollutants of atmospheric air have been presented. It has been shown that the main sources of anthropogenic pollutants, apart from industry, are motorization, and internal combustion engines of cars are a source of gaseous pollutants and solid particles, the emission of which has been significantly reduced. The originality of the article consists in conducting an extensive literature analysis and proving that the emission of "non-engine" pollutants in the form of dust from the wear of friction linings of brakes, clutches and from the wear of tires and roads, as well as mineral dust raised from the ground, is currently a greater threat to human health and the environment than engine emissions. The impact of particulate matter emissions from road transport and mineral dust, which is the basic component of road dust, on human health, vegetation and on the operation of engine and vehicle systems is presented.

Experimental study of solid-liquid two-phase flow field in a centrifugal pump volute under multiple working conditions

In order to study the variation law of the solid-liquid two-phase flow field in the volute of centrifugal pump and the distribution law of the solid particles in the volute, based on PIV technology, the dynamic and static interference flow field of the volute under different flow conditions (30 m3/h, 40 m3/h, 50 m3/h, 60 m3/h, 70 m3/h) and different solid phase volume fractions (1 %, 1.5 %, 2 %) is studied. It is found that with the increase of the solid phase volume fraction, the head and efficiency of the centrifugal pump gradually decrease, and the addition of the solid phase has little effect on the pump head when the solid phase volume fraction is small under the condition of the large flow. The high turbulent kinetic energy area in the volute is mainly concentrated near the outer wall of the volute and the area where the tongue is located. Under the same solid phase volume fraction, the turbulent kinetic energy in the volute increases with the increase of the flow rate. The turbulent kinetic energy in the volute decreases with the increase of the solid phase volume fraction. The absolute velocity component of the flow field in the volute is significantly affected by the flow condition.

A fully coupled solid-particle microphysics scheme for stratospheric aerosol injections within the aerosol–chemistry–climate model SOCOL-AERv2

Abstract. Recent studies have suggested that injection of solid particles such as alumina and calcite particles for stratospheric aerosol injection (SAI) instead of sulfur-based injections could reduce some of the adverse side effects of SAI such as ozone depletion and stratospheric heating. Here, we present a version of the global aerosol–chemistry–climate model SOCOL-AERv2 and the Earth system model (ESM) SOCOLv4 which incorporate a solid-particle microphysics scheme for assessment of SAI of solid particles. Microphysical interactions of the solid particle with the stratospheric sulfur cycle were interactively coupled to the heterogeneous chemistry scheme and the radiative transfer code (RTC) for the first time within an ESM. Therefore, the model allows simulation of heterogeneous chemistry at the particle surface as well as feedbacks between microphysics, chemistry, radiation and climate. We show that sulfur-based SAI results in a doubling of the stratospheric aerosol burden compared to the same mass injection rate of calcite and alumina particles with a radius of 240 nm. Most of the sulfuric acid aerosol mass resulting from SO2 injection does not need to be lifted to the stratosphere but is formed after in situ oxidation and subsequent water uptake in the stratosphere. Therefore, to achieve the same radiative forcing, larger injection rates are needed for calcite and alumina particle injection than for sulfur-based SAI. The stratospheric sulfur cycle would be significantly perturbed, with a reduction in stratospheric sulfuric acid burden by 53 %, when injecting 5 Mt yr−1 (megatons per year) of alumina or calcite particles of 240 nm radius. We show that alumina particles will acquire a sulfuric acid coating equivalent to about 10 nm thickness if the sulfuric acid is equally distributed over the whole available particle surface area in the lower stratosphere. However, due to the steep contact angle of sulfuric acid on alumina particles, the sulfuric acid coating would likely not cover the entire alumina surface, which would result in available surface for heterogeneous reactions other than the ones on sulfuric acid. When applying realistic uptake coefficients of 1.0, 10−5 and 10−4 for H2SO4, HCl and HNO3, respectively, the same scenario with injections of calcite particles results in 94 % of the particle mass remaining in the form of CaCO3. This likely keeps the optical properties of the calcite particles intact but could significantly alter the heterogeneous reactions occurring on the particle surfaces. The major process uncertainties of solid-particle SAI are (1) the solid-particle microphysics in the injection plume and degree of agglomeration of solid particles on the sub-ESM grid scale, (2) the scattering properties of the resulting agglomerates, (3) heterogeneous chemistry on the particle surface, and (4) aerosol–cloud interactions. These uncertainties can only be addressed with extensive, coordinated experimental and modelling research efforts. The model presented in this work offers a useful tool for sensitivity studies and incorporating new experimental results on SAI of solid particles.

An Efficient Bifunctional Core-Shell ZIF-90@ZIF-67 Composite as a Stable Pickering Interfacial Catalyst for the Deacetalization-Knoevenagel Tandem Reaction.

Exploiting advanced solid particles is crucial to the construction of Pickering emulsions catalysis. Recently, metal-organic frameworks (MOFs) have been used as ideal emulsifiers stabilizing Pickering emulsions for interfacial catalysis. Although Pickering emulsions stabilized by core-shell MOFs have significant importance in practical studies, to date there have been very limited reports on this topic. Herein, ZIF-90@ZIF-67, a core-shell material with simultaneous acid-base bifunctionality, was synthesized by seeded epitaxial growth. It was firstly applied as an emulsifier in Pickering emulsions to catalyze the deacetalization-Knoevenagel tandem reaction, which exhibited excellent catalytic properties and achieved extremely high yields. Additionally, ZIF-90@ZIF-67 showed high stability and remained well repeatable after five cycles. This work provides a platform for the design of structurally and functionally diverse MOF-based Pickering emulsions interfacial catalysis.

Pickering Emulsion of Curcumin Stabilized by Cellulose Nanocrystals/Chitosan Oligosaccharide: Effect in Promoting Wound Healing

Background: The stabilization of droplets in Pickering emulsions using solid particles has garnered significant attention through various methods. Cellulose and chitin derivatives in nature offer a sustainable source of Pickering emulsion stabilizers. Methods: In this study, medium-chain triglycerides were used as the oil phase for the preparation of emulsion. This study explores the potential of cellulose nanocrystals (CNC) and shell oligosaccharides (COS) as effective stabilizers for achieving stable Pickering emulsions. Optical microscopy, CLSM, and Cyro-SEM were employed to analyze CNC/COS–Cur, revealing the formation of bright and uniform yellow spherical emulsions. Results: CLSM and SEM results confirmed that CNC/COS formed a continuous and compact shell at the oil–water interface layer, enabling a stable 2~3 microns Pickering emulsion with CNS/COS–Cur as an oil-in-water emulsion stabilizer. Based on FTIR, XRD, and SEM analyses of CNC/COS, along with zeta potential measurements of the emulsion, we found that CNC and COS complexed via electrostatic adsorption, forming irregular rods measuring approximately 200–300 nm in length. An evaluation of the DPPH radical-scavenging ability demonstrated that the CNC/ COS–Cur Pickering emulsion performed well in vitro. In vivo experiments involving full-thickness skin excision surgery in rats revealed that CNC/COS–Cur facilitated wound repair processes. Measurements of the MDA and SOD content in healing tissues indicated that the CNC/COS–Cur Pickering emulsion increased SOD levels and reduced MDA content, effectively countering oxidative stress-induced damage. An assessment based on wound-healing rates and histopathological examination showed that CNC/COS-Cur promoted granulation tissue formation, fibroblast proliferation, angiogenesis, and an accelerated re-epithelialization process within the wound tissue, leading to enhanced collagen deposition and facilitating rapid wound-healing capabilities. An antibacterial efficacy assessment conducted in vitro demonstrated antibacterial activity.

Edible liquid marbles stabilized with millimeter-sized spherical particles

Liquid marbles (LMs) are millimeter-sized liquid droplets in a gaseous phase coated with solid particles. The LM technology allows liquid droplets to be treated as solid particles. As an LM stabilizer, edible particles are of particular interest, especially for applications in the food industry. However and surprisingly, there are limited numbers of reports describing LMs stabilized with edible particles. In this study, we utilize silver dragees, which are millimeter-sized spherical sugar beads coated by silver overlayers used for decorating cakes and cookies, as edible particles to stabilize LMs. The silver dragees surface was modified using stearic acid to work as an effective LM stabilizer by adsorbing at the gas-liquid interface. LMs with millimeter and centimeter sizes can be fabricated. Due to high adsorption energy and jamming effect of the modified dragees at gas-liquid interface, LMs with non-equilibrium shapes including intricate ones with varying curvatures can be prepared. Developing LMs with customizable shapes is crucial for expanding their potential applications and versatility as functional systems for food applications. We therefore show how these customizable-shaped LMs can be utilized as an edible decoration material for food applications.

The impact of non-isothermal adsorption of dissolved gas on drying of acoustically levitated slurry droplet

In this study, we developed a transient convective heat and mass transfer model of an acoustically levitated slurry droplet evaporating in an atmosphere of air, water vapor, and soluble gas. The advanced model considers the effects of acoustic streaming, forced convection, non-isothermal gas absorption, and adsorption of dissolved gas on the evaporation rate of a liquid droplet containing small active solid particles. Adsorption of dissolved in a droplet soluble gas by solid particles leads to decreased dissolved gas concentration in a liquid droplet. A reduction in dissolved gas concentration in a liquid droplet causes an increase in the mass flux of active soluble gas from a gaseous phase to a slurry droplet, which causes a rise in the heating effect of absorption and an increase in evaporation rate of a droplet. The heat effect of adsorption also intensifies the evaporation rate. It is shown that the time of porous shell formation is essentially shorter when solid particles in slurry droplets are active compared to inert particles.

A New Correlation for Estimating Solid Particle Erosion in Elbows

Solid particle erosion prediction models have been developed previously based on limited data and without consideration of uncertainties involved in measurements. In this study, a new correlation is developed to estimate the maximum erosion rate caused by solid particles in standard elbow geometries. The novel development process of this correlation includes uncertainty estimation of erosion measurements. In order to estimate uncertainties in an erosion database, it is imperative to have a model that could be used to calculate accurate erosion values to have reliable references. For this purpose, a database of repeated erosion measurements for gas-sand flows at low-pressure collected by previous researchers is used that includes standard elbow geometries with 0.0762 m and 0.1016 m internal pipe diameter, sand particles with mean diameters of 75 and 300 μm. Then, the erosion values in this database are adjusted to agree with physical behaviors expected in erosion process. Finally, based on the adjusted erosion values, a new correlation is developed that accounts for important paramters such as pipe and particle diameters, and gas velocity. The results and comparison of this new model with other correlations/models in the literature show that this correlation performs very well in predicting solid-particle erosion values for elbow geometry with a RMSE value of 7.96E-02 mm/kg. The effect of superficial liquid velocity is also investigated and modeled based on a database of gas-liquid-sand erosion and the correlation is updated for predicting erosion in two-phase flow conditions. Furthermore, CFD results for higher pressure fluids and larger pipe diameters of 0.1524 m and 0.2032 m and mean particle sizes of 25, 75, 150 and 300 μm, are used to further develop and validate the correlation for larger pipe size and high-pressure fluids flows. In summary, three correlations have been developed in this research; one for low-pressure flows with application in uncertainty estimation, one for predicting erosion in two-phase flow conditions, and one for cases with larger pipe diameters or high-pressure fluids.

Investigation of slug catcher vessel degradation by hydrogen sulfide (H2S) damage

Slug catchers offer effectively multiphase flow management in the field of oil and gas industry. critical equipment required for isolates and confines liquid, gases, and solid particles in slugs under environmental conditions that observed to incoming production stream. This work examines the case study that undergoes corrosion failure in vessels of slug catcher, concentrating on (H2S) damage, hardness, and microscopic corrosion in different locations. The methodology of this study involved visual inspections, hardness, and microscopic testing in order to evaluate the level of nature corrosion. The results refer that while the failure of corrosion pits present, there were not cracks, microcracks, stress corrosion cracking (SCC), or Hydrogen Induced Cracking (HIC) recognized in the structural of vessel. The structures of ferrite and pearlite of the HIC were presented in main components, and there are no cracks or microcracks detected.