Article
Food Science & Technology
Mark Al-Shemmeri, Kit Windows-Yule, Estefania Lopez-Quiroga, Peter J. Fryer
Summary: The physicochemical transformation of coffee during roasting is affected by the time-temperature profile, which is in turn influenced by heat transfer mechanisms governed by particle dynamics. This study employed Positron Emission Particle Tracking (PEPT) to analyze the granular flow of coffee in a pilot-scale rotating drum roaster. The results revealed that the drum speed, batch size, and bean density significantly impact the particle dynamics within the system. These findings suggest that controlling the drum speed can modulate conductive heat transfer from the heated drum to the bean bed, thereby influencing the roasting process.
FOOD RESEARCH INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
David J. Parker, Dawid M. Hampel, Tzanka Kokalova Wheldon
Summary: The article introduces a technique called positron emission particle tracking (PEPT), developed at Birmingham University for studying fluid and granular flows. The authors compare the sensitivity and data rates obtained from three different camera systems and find that the newly constructed SuperPEPT and MicroPEPT systems have higher sensitivity and can generate data at higher rates compared to the longstanding ADAC Forte system, significantly expanding the potential for PEPT studies.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Chemical
Thomas W. Leadbeater, Jonathan P. K. Seville, David J. Parker
Summary: This article discusses the application of positron emission particle tracking (PEPT) technique in tracking the trajectories of particles in fluidized beds, and how to optimize its performance. It also explains how trajectory information can be transformed into measurements of particle movement and discusses the choices and pitfalls in data processing.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Hanqiao Che, Dominik Werner, Jonathan Seville, Tzany Kokalova Wheldon, Kit Windows-Yule
Summary: Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) is a commonly used numerical method for gas-solid flow modeling. Coarse-graining (CG) approaches can reduce the number of particles while maintaining system dynamics. This paper evaluates three typical CG methods for simulating a bubbling fluidized bed and finds that the CG simulation fails when the size ratio between the chamber and particles decreases to approximately 20. It also shows that the specific CG approach for interparticle contact parameters does not substantially affect the simulation results across a wide range of CG factors.
Article
Pharmacology & Pharmacy
O. Jones-Salkey, A. L. Nicusan, C. R. K. Windows-Yule, A. Ingram, D. Werner, S. Clifford, G. K. Reynolds
Summary: This paper introduces the application research of positron emission particle tracking (PEPT) technique, which can observe and quantify the characteristics of particle motion in real-time, and provide in-depth understanding of the behavior of powders in continuous blender systems. The results of the study indicate that increasing the RPM and hold-up mass can improve mixing conditions, and a convection-like mixing phenomenon was observed under specific conditions.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Article
Geochemistry & Geophysics
Meng Zhou, Ozan Kokkilic, Darryel Boucher, Mark Lepage, Thomas W. Leadbeater, Raymond Langlois, Kristian E. Waters
Summary: Developing dry separation methods, such as gas-solid fluidized beds, is crucial to replace water-based separation due to increasing water shortages. This study investigates particle motion in a fluidized bed using positron emission particle tracking (PEPT) technique, providing knowledge about separation mechanisms through direct visualization of the particle trajectory. The movements of different-sized beds are characterized by tracking single quartz and hematite particles, determining the separation behavior of heavy particles for different-sized fractions.
Article
Engineering, Chemical
Chloe Huckvale Bruno, Ernesto Tripodi, Dominik Werner, Christopher Windows-Yule, Fotis Spyropoulos
Summary: This study presents a novel baffled-RME setup to improve emulsion throughput and droplet microstructure. It is found that baffle addition enhances hydrodynamic conditions, resulting in higher turbulence and increased transmembrane pressure drop and drag force, which positively influence the droplet microstructure. The use of surfactant-based emulsifiers further enhances these advantages. The study lays the foundation for further optimization of bottom-up emulsification approaches, and introduces the application of PEPT analysis to such equipment.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Mechanics
D. Werner, C. R. K. Windows-Yule, Tz. Kokalova-Wheldon, J. P. K. Seville
Summary: In this study, PEPT technology was applied to a fluidized bed with gas injection through a nozzle-type distributor for the first time. Detailed three-dimensional data obtained provided direct insight into the impact of injection orifice angles on fluidization, mixing, and flow patterns within the bed. The results showed that using a nozzle with horizontal or near-horizontal outlets achieved the fastest and most consistent material recirculation (an indicator of good mixing) and the most complete fluidization.
MECHANICS RESEARCH COMMUNICATIONS
(2023)
Article
Engineering, Environmental
Hanqiao Che, Mark Al-Shemmeri, Peter J. Fryer, Estefania Lopez-Quiroga, Tzany Kokalova Wheldon, Kit Windows-Yule
Summary: Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) was used to model the dynamics of aspherical particles in a spouted bed. The CFD-DEM results were rigorously validated against experimental data acquired using Positron Emission Particle Tracking (PEPT). The study showed that the Young's modulus, Poisson's ratio, and restitution coefficient did not significantly affect the system's dynamics, and that Gidaspow's correlation using equivalent intrinsic particle density was suitable for modelling drag forces. The analysis demonstrated that the PEPT-validated CFD-DEM models accurately captured key features of the system, including particle circulation time, velocity and occupancy distributions, and residence time in different regions. The study also showed that models using simple, spherical particles could quantitatively reproduce the dynamics of highly aspherical materials.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Chemical
Diego Mesa, Katie Cole, Michael R. van Heerden, Pablo R. Brito-Parada
Summary: This study quantified the impact of different impeller designs on flotation hydrodynamics, evaluating two designs with and without a stator. The findings showed that the stator significantly modified the hydrodynamics within the flotation cell, affecting particle velocity and swirling patterns.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Chemical
C. R. Jones, A. Corona, C. Amador, P. J. Fryer
Summary: Positron emission particle tracking (PEPT) was used to study the motion of radioactively labeled tracer particles attached to fabrics and solid fabric enhancer (SFE) delivery articles in domestic clothes dryers. Different movement behaviors of fabrics and SFE delivery articles were observed within the dryer drum, with fabrics primarily exhibiting cataracting motion while SFE delivery articles tended towards centrifuging and cascading flows.
Article
Mechanics
Kun Li, Chiya Savari, Hamzah A. Sheikh, Mostafa Barigou
Summary: A novel and computationally efficient machine learning framework has been developed to construct turbulent flow fields in mechanically agitated vessels. By feeding a short-term experimental trajectory, the framework predicts flow dynamics using a supervised k-nearest neighbors regressor learning algorithm and a Gaussian process. The ML framework has shown good agreement with experimental data, making it a powerful tool for analyzing and modeling multiphase flow systems.
Article
Engineering, Chemical
Mohammadreza Ebrahimi, Amirsalar Yaraghi, Behrooz Jadidi, Farhad Ein-Mozaffari, Ali Lohi
Summary: This study investigated the mixing of bi-disperse particles in a horizontal paddle mixer using sampling experimental techniques and DEM, showing a significant influence of operating parameters on mixing quality, with r(n) having the most significant effect. The results suggest that diffusion mechanism is dominant over convection mechanism in achieving the best mixing performance.
Article
Engineering, Chemical
Jeroen Emmerink, Ahmed Hadi, Jovana Jovanova, Chris Cleven, Dingena L. Schott
Summary: In order to enhance the understanding of double shaft, batch-type paddle mixers, the discrete element method (DEM) in conjunction with a Plackett-Burman design of experiments simulation plan is utilized to determine the significance of various factors on the system's mixing performance. The effects of multiple factors, including material properties, operational conditions, and geometric parameters, are quantitatively investigated using the relative standard deviation (RSD). The results indicate that the operational conditions and geometric parameters have a more significant impact on the mixing performance compared to material properties, particularly in terms of energy consumption and sustainability.
Article
Engineering, Chemical
Zhijian Zuo, Shuguang Gong, Guilan Xie, Jianping Zhang
Summary: DEM simulations were used to study binary mixing of particles with different densities, revealing that residence time increases with particle density and mean velocity fluctuation increases with impeller speed. Moreover, trajectory radius and vertical movement in the impeller influence area also increase with impeller speed.
Article
Engineering, Chemical
Hossein Ahmadian, Mojtaba Ghadiri
Summary: A novel device has been developed to simulate granule attrition and dust formation under realistic plant conditions, subjecting granules to multiple impacts and shear deformations. Tests are conducted to determine the settings required for desired impact velocity and shear strain rate, comparing results with data obtained by more established methods.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Energy & Fuels
Mohamed Garum, Paul W. J. Glover, Piroska Lorinczi, Gilbert Scott, Ali Hassanpour
Summary: The study focuses on characterizing the pore and fracture microstructures in shale using Nano-CT and FIB-SEM techniques, revealing differences in imaging nanopore structure and shale petrophysical properties measurements between the two methods.
Article
Engineering, Chemical
David Austin, Ali Hassanpour, Timothy N. Hunter, John Robb, John L. Edwards, Stephen Sutcliffe, Jae W. Lee, David Harbottle
Summary: In the stirred wet milling of aluminum-doped TiO2, the pH shift was smaller at 8000 rpm due to a change in milling mechanism. XPS analysis showed a linear correlation between surface alumina content and particle specific surface area. TEM images revealed the presence of ultra-fines coating larger particles, which suppressed the pH shift.
Article
Engineering, Multidisciplinary
Yi He, Ali Hassanpour, Mohammadreza Alizadeh Behjani, Andrew E. Bayly
Summary: （English Summary:）
The study highlights the importance of considering sliding and rolling resistances as well as non-contact cohesive interaction when modelling cohesive fine powders, presenting a new stiffness scaling methodology that significantly improves the accuracy of simulations. The new approach preserves particle behavior and packing structure details even when stiffness is scaled down by orders of magnitude, demonstrating its applicability in various contact-dominated systems.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Mathematics, Interdisciplinary Applications
Saeid Nezamabadi, Mojtaba Ghadiri, Jean-Yves Delenne, Farhang Radjai
Summary: Soft particle materials composed of particles that can undergo large deformations under low confining pressures without rupture exhibit both rheological and textural properties governed by particle rearrangements and shape changes. Simulation techniques based on material point method coupled with contact dynamics method allow for large elasto-plastic particle deformations and contact interactions between particles. Predictive models relating stress and packing fraction fit well with simulation results, and the coordination number evolution follows a power law as a function of packing fraction beyond jamming point of hard particle packings.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Article
Chemistry, Physical
Amin Farshchi, Amin Sadeghpour, Michael Rappolt, Hossam Tantawy, Joel Caragay, Eric S. J. Robles, Ali Hassanpour, Andrew Bayly
Summary: This study investigated the molecular structure of stacked lamellae in spray-dried detergent granules using small-angle X-ray scattering. It was found that the number of lamellae decreased with increasing relative humidity, accompanied by an increase in lamellar d-spacing and a significant reduction in bilayer thickness. The decrease in the number of lamellae was attributed to an increase in the fluidity of the lamellar phases and disappearance of water-poor solid polymorphs.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Energy & Fuels
Mohamed Garum, Paul W. J. Glover, Piroska Lorinczi, Stuart Micklethwaite, Ali Hassanpour
Summary: Quantification of shale microstructures across a wide range of scales is challenging due to the complexity of the material. This study employed various techniques such as nano-CT, MIP, and nitrogen adsorption to analyze the microstructure of a gas shale sample, revealing differences in porosity and kerogen fraction measurements. The results suggest high shale gas potential based on pore size distribution, aspect ratio, and permeability assessments.
Article
Mechanics
Karrar H. Al-Dirawi, Khaled H. A. Al-Ghaithi, Thomas C. Sykes, J. Rafael Castrejon-Pita, Andrew E. Bayly
Summary: Binary droplet collisions can result in coalescence or stretching separation, with the transition between these outcomes dependent on high Weber numbers and impact parameters. The effect of viscosity on this transition is revealed in an experimental study, showing an inertial behavior over a wide range of Ohnesorge numbers. Compelling evidence is provided to show that stretching separation only occurs when the length of the coalesced droplet exceeds a critical multiple of the original droplet diameters.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Chemical
Qiang Zhao, Baoyu Cui, Dezhou Wei, Yuqing Feng, Yi He, Andrew E. Bayly
Summary: The axial velocity wave zone in hydrocyclones plays a critical role in separation sharpness, which is influenced by geometric parameters. Improving the symmetry of flow field and optimizing the spatial distribution of this zone can enhance separation sharpness.
Article
Engineering, Chemical
Mozhdeh Mehrabi, Ali Hassanpour, Andrew Bayly
Summary: The study utilized X-ray microtomography to visualize the packing behavior of two grades of Ti6Al4V powders used in AM, revealing that the packing fraction slightly decreases under the indenter for spherical powder while remaining unchanged for irregularly shaped powder, with both powders showing an increase in packing fraction from the central zone towards the wall.
Article
Engineering, Manufacturing
Rhys J. Williams, Karrar H. Al-Dirawi, Ryan Brown, Jennifer Burt, Andrew E. Bayly, Candice Majewski
Summary: High Speed Sintering (HSS) is a powder bed fusion additive manufacturing technology that utilizes inkjet printing of an infrared radiation absorbing material (RAM) onto a polymer powder bed to selectively sinter cross-sections. The distribution of RAM on parts significantly influences their properties, with different polymers showing varying levels of brightness due to differences in RAM absorption.
ADDITIVE MANUFACTURING
(2021)
Article
Chemistry, Physical
Vasileios Angelidakis, Sadegh Nadimi, Mohamed Garum, Ali Hassanpour
Summary: This study analyzes the morphology of iron pyrite particles in a shale sample using nano-computed tomography (Nano-CT) and discusses the impact of imaging resolution on the characterization of particle form.
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
(2022)
Article
Chemistry, Multidisciplinary
Wei Pin Goh, Kushal Sinha, Nandkishor K. Nere, Raimundo Ho, Shailendra Bordawekar, Ahmad Sheikh, Mojtaba Ghadiri
Summary: Agitated filter bed dryer is commonly used in the pharmaceutical industry for the isolation and drying of potent active pharmaceutical ingredients. However, the use of an impeller for homogeneous drying can cause undesired size reduction of crystal products. To evaluate the breakage propensity of crystals, a new versatile scale-down agitated filter bed dryer has been developed.
PHARMACEUTICAL RESEARCH
(2022)
Article
Chemistry, Physical
Rachel Hendrikse, Andrew Bayly, Peter Jimack
Summary: We conducted a study on the rheological properties of surfactant solutions under shear using dissipative particle dynamics. The results showed that the viscosity of micellar solutions increased with concentration, in line with experimental data. Micelles exhibited shear-thinning behavior, breaking down into smaller aggregates. Lamellar and hexagonal phases orientated under shear, with lamellar phases showing a transition between orientations as shear rate increased, resulting in lower viscosity. The choice of Schmidt number significantly affected the results, highlighting the importance of correct behavior determination via simulations.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Laura N. Elliott, David Austin, Richard A. Bourne, Ali Hassanpour, John Robb, John L. Edwards, Stephen Sutcliffe, Timothy N. Hunter
Summary: This study investigated the changes in adsorbed amount and surface structure of sodium hexametaphosphate (SHMP) in aluminum-doped TiO2 pigment during milling. It was found that sustained high-energy milling caused destructive effects on the dispersant, although there were no significant chemical changes. Relaxation NMR was proven to be an effective technique for monitoring milling processes in real-time, as long as appropriate industrial calibrations were achieved.
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.
