Evolution Of Particle Size Distribution Research Articles

Secondary aerosol formation alters CCN activity in the North China Plain

Abstract. Secondary aerosols (SAs, including secondary organic and inorganic aerosols, SOAs and SIAs) are predominant components of aerosol particles in the North China Plain (NCP), and their formation has significant impacts on the evolution of particle size distribution (PNSD) and hygroscopicity. Previous studies have shown that distinct SA formation mechanisms can dominate under different relative humidity (RH). This would lead to different influences of SA formation on the aerosol hygroscopicity and PNSD under different RH conditions. Based on the measurements of size-resolved particle activation ratio (SPAR), hygroscopicity distribution (GF-PDF), PM2.5 chemical composition, PNSD, meteorology and gaseous pollutants in a recent field campaign, McFAN (Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain), conducted during the autumn–winter transition period in 2018 at a polluted rural site in the NCP, the influences of SA formation on cloud condensation nuclei (CCN) activity and CCN number concentration (NCCN) calculation under different RH conditions were studied. Results suggest that during daytime, SA formation could lead to a significant increase in NCCN and a strong diurnal variation in SPAR at supersaturations lower than 0.07 %. During periods with daytime minimum RH exceeding 50 % (high RH conditions), SA formation significantly contributed to the particle mass and size changes in a broad size range of 150 to 1000 nm, leading to NCCN (0.05 %) increases within the size range of 200 to 500 nm and mass concentration growth mainly for particles larger than 300 nm. During periods with daytime minimum RH below 30 % (low RH conditions), SA formation mainly contributed to the particle mass and size and NCCN changes for particles smaller than 300 nm. As a result, under the same amount of mass increase induced by SA formation, the increase of NCCN (0.05 %) was stronger under low RH conditions and weaker under high RH conditions. Moreover, the diurnal variations of the SPAR parameter (inferred from CCN measurements) due to SA formation varied with RH conditions, which was one of the largest uncertainties within NCCN predictions. After considering the SPAR parameter (estimated through the number fraction of hygroscopic particles or mass fraction of SA), the relative deviation of NCCN (0.05 %) predictions was reduced to within 30 %. This study highlights the impact of SA formation on CCN activity and NCCN calculation and provides guidance for future improvements of CCN predictions in chemical-transport models and climate models.

Clean production of sustainable backfill material from waste gold tailings and slag

Gold tailings (GT) and slag disposed of in the landfill affect the environment. This study investigated the green process for the utilization of non-radioactive gold tailings and granulated blast furnace slag (GBFS) to synthesize a green and sustainable backfill material. The following mix design ratios of GBFS:GT were investigated; 100, 10:90, 20:80,30:70, 40:60, 50:50. Maximum dry density, optimum moisture content, and strength were studied. The elemental composition, mineralogy, micrography, and evolution of particle size distribution were studied for raw materials and developed stabilized specimens. The mix design containing 20% GBFS and 80% GT yielded the optimum strength of 0.9 MPa. Calcium magnesium carbonate and calcium sulfate dihydrate were some of the products formed. There was a significant change in the microstructure of the GBFS blended GT with the increment in GBFS content. From the evolution of the volume distribution, the generation of finer particles was evident with the stabilization of GT. There was a significant modal size change with the mix designs investigated. Particle size distribution (PSD) proved to have an impact on the strength development of GBFS modified GT. The specimen developed met the requirement for backfill bearing material, for the strength of 0.3–0.7 MPa for conventional engineering design and the strength below 1 MPa for freestanding backfilling material. The evaluation of stabilized material for environmental impact showed that the concentrations of the contaminants were within the stipulated standards. This study proved that readily available wastes were beneficiated to produce value-added construction material and solve environmental pollution challenges.

A contact model for rough crushable sand

Sand roughness is now accessible to measurement. Incorporating this parameter into sand models using the discrete element method (DEM) is known to improve bulk small strain response. In this work we explore the effect on problems where particle crushing takes place. A well-established DEM particle crushing model and a rough Hertzian contact model are here combined to incorporate both effects in a single contact model. Including contact roughness results in stronger particles whilst all other material parameters being equal. The model is then used to simulate high pressure oedometric compression tests on a strong silica sand. It is shown that including realistic values of surface roughness enables to correctly capture both load-unload behaviour and particle size distribution evolution while using realistic values of elastic bulk properties for the sand grains. Roughness is then a model refinement that may result in simpler, more objective DEM calibrations.

Coagulation of inertial particles in supersonic turbulence

Coagulation driven by supersonic turbulence is primarily an astrophysical problem because coagulation processes on Earth are normally associated with incompressible fluid flows at low Mach numbers, while dust aggregation in the interstellar medium for instance is an example of the opposite regime. We study coagulation of inertial particles in compressible turbulence using high-resolution direct and shock-capturing numerical simulations with a wide range of Mach numbers from nearly incompressible to moderately supersonic. The particle dynamics is simulated by representative particles and the effects on the size distribution and coagulation rate due to increasing Mach number is explored. We show that the time evolution of particle size distribution mainly depends on the compressibility (Mach number). We find that the average coagulation kernel ⟨Cij⟩ scales linearly with the average Mach number ℳrms multiplied by the combined size of the colliding particles, that is, 〈Cij〉∼〈(ai+aj)3〉 ℳrmsτη−1, which is qualitatively consistent with expectations from analytical estimates. A quantitative correction 〈Cij〉∼〈(ai+aj)3〉(vp,rms/cs)τη−1 is proposed and can serve as a benchmark for future studies. We argue that the coagulation rate ⟨Rc⟩ is also enhanced by compressibility-induced compaction of particles.

Understanding the relationship between particle size and ultrasonic treatment during the synthesis of metal nanoparticles

Ultrasonic treatment is an effective method for size refinement and dispersion of nanomaterials during their synthesis process. However, the quantitative relationship between ultrasonic conditions and particle size in the synthesis of metal nanoparticles has not been fully revealed. In this study, Cu nanoparticles were synthesized via the wet-chemical redox method under ultrasonic treatment, and statistical analysis on the evolution of particle size distribution was carried out. It was found that the particle size decreased exponentially with increasing ultrasonic power. A quantitative model was then proposed to describe the influence of ultrasonic power on the size distribution of metal nanoparticles from the perspective of the competition between the surface energy and the ultrasonic force. A relational expression of Rc∝γ47P-37 was revealed, and it was proved to fit well with the experimental results. Our study provides new experimental basis and theoretical method for understanding the mechanism of ultrasonic-induced size refinement of metal nanoparticles.

Role of Electrostatics in the Heterogeneous Interaction of Two-Dimensional Engineered MoS2 Nanosheets and Natural Clay Colloids: Influence of pH and Natural Organic Matter.

Few-layered molybdenum disulfide (MoS2) nanosheets are poised to be at the core of low-voltage electronic device development. Upon environmental release, these two-dimensional (2D) structures can interact with abundant natural geocolloids. This study probes the role of dimensionality in modulating the aggregation behavior of 2D MoS2 nanosheets with plate-like geocolloids (i.e., homoionized kaolinite and montmorillonite clays). MoS2 nanosheets were exfoliated using an ethanol/water mixture, and aggregation kinetics were investigated with time-resolved dynamic light scattering at low monovalent salt concentrations and at three pH levels, in the presence and absence of Suwannee River humic acid (SRHA). Results indicate that pH and particle ratios are key to modulating the stability of MoS2/clay systems. At pH 4, aggregation of MoS2 increased with increasing MoS2/clay ratios and approached maximum values of 0.09 and 0.06 nm/s in the binary systems with montmorillonite and kaolinite, respectively. Electrostatic attraction facilitates heteroaggregation at pH values of 4 and 6; differences in the clay structures (i.e., face-face or face-edge aggregates) might explain the resulting MoS2/clay aggregate configurations, which were probed via the evolution of particle size distribution. The presence of only 0.1 mg/L SRHA drastically suppresses the heteroaggregation propensity of MoS2 nanosheets with geocolloids (to less than 0.01 nm/s at all pH values tested). The high stability of these heterogeneous systems under environmentally relevant conditions can increase the likelihood for cellular uptake and long-distance transport of MoS2.

Numerical investigation of agglomeration phenomenon in fluidized beds by a combined CFD-DEM/PBM technique

PurposeThe purpose of this paper is to fundamentally develop a mathematical model for predicting the particle size distribution (PSD) in fluidized beds because their hydrodynamics depend on the PSD and its evolution during operation. To predict the gradual PSD change in a fluidized bed by using the population balance method (PBM), the kinetic parameter for agglomerate formation should be known and this parameter, in this work, is determined by the results of computational fluid dynamic–discrete element method (CFD-DEM) simulation.Design/methodology/approachMomentum and energy conservation equations and soft-sphere DEM are used to simulate the agglomeration phenomenon at high temperature in a two-dimensional air-polyethylene fluidized bed in bubbling regime. The Navier–Stokes equations for motion of gas are solved by the SIMPLE algorithm. Newton’s second law of motion is applied to describe the motion of individual particles. Collision between particles is detected by the no-binary search algorithm.FindingsA correlation is proposed for estimating the kinetic parameter for agglomerate formation based on collision frequency, collision efficiency and inlet gas temperature. Based on the corrected kinetic parameter, the PBM is able to predict the PSD evolution in the fluidized bed in a fairly good agreement with the results of the CFD-DEM.Research limitations/implicationsThe results of the agglomeration process cannot be compared quantitatively with experimental results. Because three-dimensional fluidized bed mostly contains millions of particles and simulating them takes a long computing time in DEM. As far as temperature is a dominant parameter in the agglomeration process, effects of inlet gas temperature are examined on the kinetic parameter. On the other hand, wider and deeper insights in which the effect of other parameters, such as velocity and so on will be studied, is one of the goals in the authors’ next works to compensate for the shortcomings in this work.Originality/valueThis study helps to understand the effect of the inlet gas temperature during the agglomeration process on the kinetic parameter and provides fundamental information in dealing with kinetic parameter to attain PSD in fluidized bed by the PBM.

Preparation of surfactant-free emulsions using amaranth starch modified by reactive extrusion

The use of emulsions at industrial scale involves simple, efficient and versatile applications. Currently, it is preferred the exploitation of biopolymers such as modified starch that may be used as suitable wall materials, avoiding toxic surfactants during preparation. Therefore, in this work, modified amaranth starch with improved physicochemical and morphological properties was obtained by reactive extrusion from a selected extruder outlet time. Additionally, surfactant-free emulsions based on modified starch were prepared at a registered optimal time. The evolution of particle size distributions was monitored by combining Dynamic Light Scattering (DLS) and light microscopy. For starch modification, results showed that 80 s was the best outlet time from the extruder in order to produce a homogeneous material (particle size: 553 nm; fractal dimension: 2.73). For emulsions, a thoroughly characterisation indicated that DLS and fractal analyses converged at 270 s as optimal preparation time, showing a well-dispersed and stable system (particle size: 342 nm; fractal dimension: 2.85). Thus, this contribution provides a strategy for the obtention of modified amaranth starch having appropriate hydrophobic-hydrophilic balance and Tg values for emulsions stabilisation. On the other hand, the technique applied for emulsions preparation resulted in controllable size and shape of particles. This work proposes a complete sequential process that could be helpful to overcome the challenges faced by a number of industries.

Evolution of particle size distribution for carbonate sand under impact load

The carbonate sand could encounter impact loads causing particle breakage. To study the evolution of particle size distribution (PSD) in breakage state, a series of impact load tests were conducted on carbonate sands. From the results of uniformly graded samples, it is obtained that the fractal dimension and active breakage probability, which is equal to the mass percentage of new particle groups generated from crushing, are the functions of input energy as well as initial mean diameter. An “evolution function” of PSD in breakage state for the uniformly graded sample is established according to the fractal theory, with fractal dimension and active breakage probability as parameters. Based on the evolution functions of multiple uniform graded groups, an “assembly matrix” is proposed and used to describe the PSD evolution for non-uniformly graded sample in breakage state. The test results of non-uniformly graded samples show that this method is feasible.

Magma fragmentation and particle size distributions in low intensity mafic explosions: the July/August 2015 Piton de la Fournaise eruption

Understanding magma fragmentation mechanisms in explosive eruptions is a key requirement for volcanic hazard assessment, eruption management and risk mitigation. This paper focuses on a type case small explosivity eruption (July–August 2015 eruption of Piton de la Fournaise). These eruptions, despite being often overlooked, are exceedingly frequent on local-to-global scales and constitute a significant hazard in vent-proximal areas, which are often populated by guides, tourists and, indeed, volcanologists due to their accessibility. The explosions presented here are ideal cases for the study of the dynamics of magma fragmentation and how it relates to the size distribution of scoria generated at the vent. We documented these events visually and thermally, and characterised the products through sample-return. This allowed us to describe small-scale gas bursts sending ejecta up to 30 m during intermittent lava fountains. Surface tension instabilities and inertial forces played a major role in fragmentation processes and generated particles with coarse-skewed distributions and median diameters ranging from − 8 to − 10 ϕ. However, with time distributions of particles in the most energetic fountains shifted towards more symmetrical shapes as median grains sizes became finer. Analyses of sequences of images demonstrate that the evolution of particle size distributions with time is due to instability of magma droplets and (in-flight) fragmentation.

Evolution of particle size distribution, flow behaviour and stability during mill ball refining of a white chocolate flavouring paste

The objective of this research was to study the effect of ball milling of a white chocolate anhydrous paste on its particle size, rheological and stability properties. Increasing of refining time reduced the solids particle size and resulted in an increase of paste apparent viscosity and improvement of stability. The parameters of the generalized Casson rheological model used to describe the flow curves showed a continuous increase as refining proceeded. The colloidal stability of the pastes was studied through gravimetric oil separation by both visual inspection and light backscattering acquisition along the sample height and gave comparable results with the most refined samples being the most stable.

Comparison of discrete, discrete-sectional, modal and moment models for aerosol dynamics simulations

An open source software (Aerosol and Air Quality Research Lab-Aerosol Dynamics Model, AAQRL-ADM) used for aerosol dynamics simulations is developed by including four models: discrete, discrete-sectional, method of moments, and modal. First, the mathematical description of these models as well as the effects of aerosol dynamics available in the software are reviewed, and a modal model is developed to use multiple modes to represent particle size spectrum. Second, the design of a working principle and user graphical interface (GUI) of AAQRL-ADM is described. Third, the models in AAQRL-ADM are validated by investigating the evolution of particle size distribution (PSD) in considering the effects of coagulation, condensation, and nucleation. Next, the trade-off between simulation accuracy and numerical efficiency is discussed for all of the four models, and a guide to choosing the appropriate aerosol dynamic model in practical simulation is presented. Finally, discrete-sectional, moment, and modal models are used to investigate the particle size distribution in a furnace aerosol reactor along a streamline, coupled with the velocity and temperature profiles. AAQRL-ADM is provided free of charge for the use of public researchers.Copyright © 2020 American Association for Aerosol Research

Particle breakage of uniformly graded carbonate sands in dry/wet condition subjected to compression/shear tests

The behaviour of a granular material is primarily affected by its particle size distribution (PSD), which is not necessarily a soil constant as assumed in traditional soil mechanics. The PSD may change over time due to mechanical as well as environmental actions. In this study, a series of ring shear tests and one-dimensional compression tests were completed on carbonate sand, in both dry and saturated conditions. Samples were prepared with different initial uniform gradings, to investigate: (1) the influence of the saturation state and initial grading on mechanical and deformational behaviour of carbonate sands and (2) the evolution of the PSD as a result of breakage. The ring shear tests show that the residual friction angle remains almost constant, but dilatancy reduces with increasing saturation degree. In the one-dimensional compression test, the yield stress decreases with increasing saturation degree, but the compressibility (as defined by Cc) remains almost constant, irrespective of the saturation state. Moreover, saturated samples suffer more breakage than dry samples during ring shear tests, while there is no obvious effect of saturation state on particle breakage in one-dimensional compression. A recently proposed PSD model with only two parameters (λp and κp) is employed to model the evolution of PSD, as it can more broadly capture the whole PSD throughout the breakage process than existing breakage indices. Test results demonstrate that parameter λp is linearly related to Einav’s breakage index $$ B_{\text{r}}^{*} $$ and is dependent on initial grading, but independent of test mode. Parameter κp is in power relationship with $$ B_{\text{r}}^{*} $$ and is independent of initial grading or test mode. The evolution of parameters λp and κp is related to the input work for both ring shear and compression tests, with λp being hyperbolically related to input work and κp in power relationship with input work. Using such an evolution law provides an alternative approach to capture the effects of particle breakage in constitutive models.

Theoretical analysis of particle size re-distribution due to Ostwald ripening in the fuel cell catalyst layer

AbstractThe limited durability of hydrogen fuel cells is one of the main obstacles in their wider adoption as a clean alternative technology for small scale electricity production. The Ostwald ripening of catalyst material is recognized as one of the main unavoidable degradation processes deteriorating the fuel cell performance and shortening its lifetime. The paper systematically studies how the modeling approach towards the electrochemically driven Ostwald ripening in the fuel cell catalyst differs from the classical diffusion driven models and highlights how these differences affect the resulting evolution of particle size distribution. At moderately low electric potential, root-law growth of mean particle size is observed with linear relation between mean particle size and standard deviation of particle size distribution, similar to Lifshitz-Slyozov-Wagner theory, but with broader and less skewed distribution. In case of high electric potential, rapid particle growth regime is observed and qualitatively described by redeposition of platinum from a highly oversaturated solution, revealing the deficiencies of the existing platinum degradation models at describing the Ostwald ripening in the fuel cells at high electric potentials. Several improvements to the established models of platinum degradation in fuel cell catalysts are proposed, aimed at better description of the diffusion processes involved in particle growth due to Ostwald ripening.

Modelling of particle size distribution in butyl acrylate emulsion polymerisation in a batch reactor

ABSTRACT A computer model for the development of particle size distribution in a batch reactor for the emulsion polymerisation of butyl acrylate was developed, solved and validated. Population balance model was represented by partial differential equations and these equations were solved by using the method of orthogonal collocation. The model was validated against two sets of experimental data taken from literature. The model’s reliability was demonstrated by successful simulation of the experimental data for the number of variables which included the number of particles formed at different emulsifier and initiator concentrations, the variation of conversion with time at one initiator concentration and one emulsifier concentration and number average diameter, volume average diameter at different emulsifier concentrations. The model is simpler and more accurate than the reported population balance models for this system in the literature. The simplicity is brought by studying the model in different levels of details in our earlier works.

Nanocluster Aerosol Emissions of a 3D Printer.

Many studies exist that characterize the aerosol emissions from fused filament fabrication three-dimensional (3D) printers. However, nanocluster aerosol (NCA) particles, that is particles in a size range under 3 nm, are rarely studied. The purpose of this study was to characterize the NCA emissions and the contribution of NCA to the total particle number emissions from a 3D printer. We used a particle size magnifier and a scanning mobility particle sizer to measure the time evolution of particle size distribution, which was used to calculate the average NCA emission rates during a printer operation in a chamber. The NCA emission rates ranged from 1.4 × 106 to 7.3 × 109 s-1 depending on the applied combination of filament material and nozzle temperature, showing increasing emission with increasing temperature. The NCA emissions constitute from 9 to 48% of the total emissions, that is, almost half of the particle emissions may have been previously neglected. Therefore, it is essential to include the low NCA size range in, for example, future 3D-printer-testing protocols, emission measurement standards, and risk management measures.

A coupled LES-Monte Carlo method for simulating aerosol dynamics in a turbulent planar jet

Purpose The purpose of this paper is to study the evolution and growth of aerosol particles in a turbulent planar jet by using the newly developed large eddy simulation (LES)-differentially weighted operator splitting Monte Carlo (DWOSMC) method. Design/methodology/approach The DWOSMC method is coupled with LES for the numerical simulation of aerosol dynamics in turbulent flows. Findings Firstly, the newly developed and coupled LES-DWOSMC method is verified by the results obtained from a direct numerical simulation-sectional method (DNS-SM) for coagulation occurring in a turbulent planar jet from available literature. Then, the effects of jet temperature and Reynolds number on the evolution of time-averaged mean particle diameter, normalized particle number concentration and particle size distributions (PSDs) are studied numerically on both coagulation and condensation processes. The jet temperature and Reynolds number are shown to be two important parameters that can be used to control the evolution and pattern of PSD in an aerosol reactor. Originality/value The coupling between the Monte Carlo method and turbulent flow still encounters many technical difficulties. In addition, the relationship between turbulence, particle properties and collision kernels of aerosol dynamics is not yet well understood due to the theoretical limitations and experimental difficulties. In the present study, the developed and coupled LES-DWOSMC method is capable of solving the aerosol dynamics in turbulent flows.

Turbulent Aggregation and Deposition Mechanism of Respirable Dust Pollutants under Wet Dedusting using a Two-Fluid Model with the Population Balance Method.

In this paper, a mathematical model based on the two-fluid (Euler–Euler) frame model for wet dedusting process is proposed. The model considers in detail the aggregation of particles and droplets caused by turbulence and Brownian diffusion as well as the gravitational deposition process. The population balance model (PBM) is used to describe the spatiotemporal evolution of particle size distribution (PSD) for the dust particle and the water droplet. The wet dedusting process under different conditions is simulated and compared with the detailed experimental data. The results show that the experimental data and simulation results are within the allowable range of error (about 32.3–61.2% in dedusting efficiency for respirable dust by experimental data and about 47.3–57.9% in it by simulation results). This model can be used to predict the effect of PSD of the dust particle, spray flow, and ventilation rate on dedusting efficiency of wet dedusting. The parameter analysis shows that dedusting efficiency decreases as particle size decreases. In order to ensure high capture efficiency of respirable dust, the diameter of droplets should be controlled to between 15 μm and 70 μm. The ratio of droplet volume flow to dust volume flow increases from 2.0 to 12.0, while dedusting efficiency only increases from 39.2% to 54.7%, so it is clear that for spray quantity to dedusting efficiency, larger is not necessarily better. Besides this, the speeds of both spray droplets and ventilation also have great influence on dedusting efficiency, and the related formulas are given.

Temporal evolution of submicron particles during extreme fireworks.

Evolution of submicron particles in terms of particle number concentration and mobility-equivalent diameter was measured during Diwali festival-specific intensive pyrotechnic displays in Varanasi over central Indo-Gangetic Plain (IGP). A scanning mobility particle sizer coupled with an optical particle sizer was used to fit in an overlapping size range, and particle number concentration was analyzed to have an insight into the new particle formation and subsequent evolution of particles from nucleation to accumulation mode. Further, variation in black carbon (BC) concentration and aerosol ionic composition was measured simultaneously. Frequent fluctuation in particle number concentration in and around Diwali festival was evidenced, primarily influenced by local emission sources and meteorology, with three distinct peaks in number concentrations (dN/dlogDp, 3.1-4.5 × 104 cm3) coinciding well with peak firework emission period (18:00-23:00 h). Submicron particle size distribution revealed a single peak covering a size range of 80-130 nm, and for all instances, number concentration maximum coincided with geometric mean minimum, indicating the emission primarily in the ultrafine range (< 0.1 μm). Interestingly, during peak firework emissions, besides rise in accumulation mode, an event of new particle formation was identified with increase in nucleation and small Aitken mode, before being dispersed to background aerosols. On an integral scale, a clear distinction was noted between a normal and an episodic event, with a definite shift in the formationof ultrafine particles compared with the accumulation mode. The BC diurnal profile was typical, with a prominent nocturnal peak (12.0 ± 3.9 μg m-3) corresponding to a decrease in the boundary layer height. A slight variation in maximum BC concentration(16.8 μg m-3) was noted in the night of the event coinciding well with firework emissions. An increase in some specific ionic species was also noted in combination with an increase in the overall cation to anion ratio, which was explained in terms of heterogeneous transformation of NOx and catalytic conversion of SO2. Graphical abstract Time-resolved evolution of particle size distribution during normal and episodic events.

Investigation on flow characteristics of ice slurry in horizontal 90° elbow pipe by a CFD-PBM coupled model

Elbow pipes are important components for ice slurry pipeline transport. However, the flow characteristics of ice slurry in elbow are far from fully being understood, especially the influence of ice particle kinetics on ice particle size distribution (PSD). This study is intended to provide a better understanding of the behavior of ice slurry flow in elbow pipe. A CFD-PBM coupled model is employed to investigate the flow characteristics of ice slurry in horizontal 90° elbow pipe. The quadrature method of moments is utilized to solve the population balance equations. Based on the revised model, the flow characteristics of ice slurry in the horizontal 90° elbow pipe are investigated. The simulation results show that in the range of calculations, the pressure drop of elbow pipe is increased with the increase of velocity and ice packing fraction (IPF). An adverse pressure gradient is formed due to the change in flow direction. The emergence of secondary flow is caused by the centrifugal force. It makes the ice particles gather on the outer wall of the elbow section. The ice diameter increases along the flow direction due to the aggregation. The evolution of particle size distribution (PSD) is not significant. However, aggregation and stratification cannot be ignored in the process of long distance transport of ice slurry. The results are of significance for guiding the safety design and operation of ice slurry transportation.