Article
Engineering, Chemical
Rafael R. Heilbuth, Gisele M. Souza, Dyrney A. Santos, Rodolfo J. Brandao, Marcos A. S. Barrozo, Claudio R. Duarte
Summary: A systematic investigation was conducted to study the particle mixing behavior in a flighted rotary drum using experiments and numerical simulations. The effects of the number of flights, flight height, and drum filling degree on mixing performance were analyzed. The study contributes to a better understanding of particle mixture dynamics in a flighted rotary drum.
Article
Engineering, Chemical
M. Kozakovic, J. Havlica, L. Le Guen, S. Parez, F. Huchet
Summary: This article focuses on the numerical simulation of a flighted rotary drum using Discrete Element Method (DEM), with varying number of flights (1 to 25) and a constant load of particles. The study investigates the kinematics of granular behavior in three loading conditions: under-, design-, and over-loading. The results demonstrate that the behavior of granular material during unloading from the flights determines the transitions between different regimes. The analysis of granular material distribution in different parts of the drum reveals the presence of two dense media (bed and flights) and one dilute medium (in the airborne portion). Considering the importance of the number of particles in the airborne phase for heat transport efficiency between gas and particle media, three recognition methods are proposed to detect the airborne particles and their relevance is discussed based on geometry, velocity magnitude, and minimal separation distance.
Article
Engineering, Chemical
Lanyue Zhang, Zhaochen Jiang, Jochen Mellmann, Fabian Weigler, Fabian Herz, Andreas Bueck, Evangelos Tsotsas
Summary: The number of flights has different effects on particle motion in the flighted rotating drum, with 8 and 12 flights producing a larger and more stable particle ratio of the dilute phase.
Article
Mechanics
Mingrui Dong, Zhongzheng Wang, Benjy Marks, Yu Chen, Yixiang Gan
Summary: This study investigates partially saturated granular flows in rotating drums through experiments and simulations. It explores the effects of cohesion and rotation rate on the flow patterns and flow depth. Additionally, the study reveals that stronger cohesion promotes the formation of larger clusters.
Article
Engineering, Chemical
Nicolin Govender
Summary: This paper utilizes the advances in GPU computing via the Blaze-DEM code to study the effect of particle shape on heat transfer in a rotating drum. The results show that shape irregularity has the greatest impact on heat conduction, with non-symmetric shapes exhibiting better heat transfer performance. Furthermore, there is a linear trend of system temperature with both RPM and fill level.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Meng Li, Xizhong An
Summary: This study conducted a systematic numerical investigation on the mixing characteristics and flow behaviors of Platonic solids (tetrahedra, cubes, octahedra, dodecahedra, icosahedra) in a rotating drum using the discrete element method. The research found that the rotation speed and shape of the Platonic solids have significant effects on the mixing characteristics, macroscopic properties, and microscopic properties. The mixing rate decreases and then increases with the increase of the face number of Platonic solids, and the average packing density is higher for Platonic solids with larger sphericity. The interlocking effect of cubes is not obvious, resulting in freer movement and stronger diffusive mixing in the drum.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Hongyu Chen, Milind A. Jog, Douglas E. Evans, Leonid A. Turkevich
Summary: Dustiness evaluation is crucial in estimating potential exposure to toxic, hazardous, or irritant powders. The Rotating Drum is a widely used instrument for assessing powder dustiness, but its aerodynamics during operation is not fully understood. Utilizing computational fluid dynamics to study the flow inside the Rotating Drum can aid in interpreting dustiness measurements and guiding manufacturing processes to generate less dust.
Article
Engineering, Chemical
Wenzheng Xiu, Ra Li, Quan Chen, Qicheng Sun, Vladimir Zivkovic, Hui Yang
Summary: This paper investigates particle sorting in a binary granular system composed of particles with different sizes and the same density. The segregation pattern is mainly influenced by the granular velocity and concentration in the flow layer. Experimental measurements of velocity and concentration were conducted in a quasi-two-dimensional rotating drum to establish the relationship between granular velocity and concentration, and to analyze the corresponding relationships with the segregation pattern. This research aims to improve theoretical models of segregation and provide guidance for granular segregation control in production processes.
Article
Engineering, Chemical
ZhiShuang Jing, Hui Yang, Shuaishuai Wang, Quan Chen, Ran Li
Summary: The paper corrects the speckle visibility spectroscopy (SVS) method using particle velocity to accurately measure the granular temperature. Results show acceptable differences in granular temperature compared to the discrete element method (DEM) for continuous movement of spherical particles. The corrected SVS method demonstrates superiority for engineering applications.
Article
Engineering, Chemical
A. N. Huang, T. H. Cheng, W. Y. Hsu, C. C. Huang, H. P. Kuo
Summary: DEM simulations were used to study size segregation of binary mixture in a rotating drum with inner diameter variations. The results showed that larger particle enrichment occurs in the smaller inner diameter regions. The effect of inner diameter contracting ratio (CR) on particle dynamics was further investigated, with CR of 0.9 leading to smaller particles moving towards dilated larger inner diameter regions.
Article
Engineering, Chemical
Zhijian Zuo, Jiajie Wang, Xu Wu, Shuguang Gong, Jianping Zhang, Xingfu Lu
Summary: This study explores a novel split drum to drive the size-induced axial segregation of particles. DEM simulations were conducted to investigate the particle dynamic and segregation performance, and the influence of drum speed and the speed ratio between two sub-drums was analyzed. The experimental results demonstrate that particles in the split drum exhibit faster and better axial segregation, with small particles tending to concentrate near the split.
Article
Engineering, Chemical
Ren Han, Jingyu Feng, Yufeng Zhang, Hui Yang, Vladimir Zivkovic, Ran Li
Summary: A numerical simulation was used to investigate the avalanche flow characteristic of particles in the slumping regime within a rotating drum. Results show that the growth rate of avalanching particle number follows a specific pattern over time, with the distribution and propagation velocities of particles exhibiting certain regularities.
Article
Engineering, Chemical
Andrew M. Hobbs, Jin Y. Ooi, Manogna Adepu, Heather Emady
Summary: Conductive heat transfer in granular materials plays a crucial role in many industrial processes. A particle-based model, which incorporates the effect of interstitial gases, was validated through an experiment. The model demonstrates good agreement with experimental data, indicating its effectiveness in capturing the gas contribution in dynamic systems.
ADVANCED POWDER TECHNOLOGY
(2022)
Article
Engineering, Chemical
Shengqiang Jiang, Xue Long, Yixuan Ye, Jingang Liu, Shiping Yang, Xiangwu Xiao, Sisi Liu
Summary: This study establishes a similarity criterion for the particle motion behavior in large-scale industrial drums using dimensional analysis, and finds the mapping relationship between the particle movement trajectories and the drum's size and rotational speed. The results of this study are of great significance in solving the computational challenge in industrial applications.
Article
Engineering, Chemical
Xiangwu Xiao, Yingying Li, Ruitao Peng, Jiangxiong Gao, Congfang Hu
Summary: In this study, the appropriate selection of physical and contact parameters in the mixing processes of gravel materials using the discrete element method was investigated. Physical parameters of irregular gravel were obtained through experiments, and contact parameters were determined using the response surface method. The mixing processes of gravel materials in a rotating drum with different cylindrical rod structures were simulated, and the number of contacts between particles was used to characterize the mixing uniformity. The results showed that cylindrical rods significantly improved mixing uniformity, with the best effect observed when the distance between cylindrical rods was twice the maximum particle size.
Article
Engineering, Chemical
Debashis Panda, Supriya Bhaskaran, Shubhani Paliwal, Abdolreza Kharaghani, Evangelos Tsotsas, Vikranth Kumar Surasani
Summary: In this study, the Shan Chen Lattice Boltzmann method (LBM) is used to simulate the pore-scale physics of drying porous media. The mechanisms responsible for multiphase fluid transport in drying porous media are revisited and the physical effects such as capillary valve effect and Haines jumps are described. The observed fluctuations in drying rate curves, caused by Haines jumps during gas invasion, inspire the hybrid pore-scale technique combining LBM and pore network model to track micro-macro interactions in drying porous media.
Article
Engineering, Chemical
Supriya Bhaskaran, Divyansh Pandey, Debashis Panda, Shubhani Paliwal, Nicole Vorhauer, Evangelos Tsotsas, Vikranth Kumar Surasani
Summary: The study investigates the drying phenomena of a perfectly wetting liquid in a square capillary tube, using the Shan-Chen Lattice Boltzmann method for simulation. It reveals the formation of extended corner films and surface films as the liquid develops along the internal corners of the tube.
Article
Engineering, Chemical
Jialin Men, Subash Reddy Kolan, Ali Massomi, Torsten Hoffmann, Nat Jochen Schmidt, Evangelos Tsotsas, Andreas Bueck
Summary: This study presents the formulation of nanostructured heteroaggregates using the principle of fluidization and demonstrates the feasibility of two technologies, spouted bed and opposed jet fluidized bed. Intraaggregate mixing of constituents is evaluated using SEM-EDX.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Engineering, Chemical
Yehonatan David Pour, Boris Krasovitov, Andrew Fominykh, Ziba Hashemloo, Abdolreza Kharaghani, Evangelos Tsotsas, Avi Levy
Summary: This study developed a model to investigate the convective heat and mass transfer of an acoustically levitated slurry droplet that evaporates in an atmosphere containing air, water vapor, and soluble gas. The model considered various factors such as acoustic streaming, forced convection, and non-isothermal gas absorption. The results showed that the formation time of a porous shell decreased with increasing sound pressure level (SPL) and increased with increasing frequency.
Article
Thermodynamics
Simson Julian Rodrigues, Nicole Vorhauer-Huget, Evangelos Tsotsas
Summary: This study addresses the parameterization issue of the Zehner-Bauer-Schlunder model for packed beds and provides data on the effective thermal conductivity of packed beds of cubical particles. The study investigates the effects of interparticle contact area and particle conductivity on the effective thermal conductivity of the bed under different particle-to-gas thermal conductivity ratios.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Faeez Ahmad, Marc Prat, Evangelos Tsotsas, Abdolreza Kharaghani
Summary: In this study, a two-equation non-local equilibrium continuum model of isothermal drying is evaluated by comparing it with pore network simulations. The results show that the continuum model can accurately capture the non-local equilibrium effect as well as the phase distributions and drying kinetics.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Supriya Bhaskaran, Divyansh Pandey, Vikranth Kumar Surasani, Evangelos Tsotsas, Tanja Vidakovic-Koch, Nicole Vorhauer-Huget
Summary: Based on the Shan-Chen Lattice Boltzmann Model, the invasion of oxygen in the graded porous transport layer of titanium felt is investigated. The computation domain is obtained from X-ray computed tomography. The results show that gas fingering is a common transport mechanism, and it is strongly influenced by the spatial porosity and pore size distributions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Chemical
Farooq Hussain, Kaicheng Chen, Maciej Jaskulski, Marcin Piatkowski, Evangelos Tsotsas
Summary: This study analyzed extensive experimental data to understand the dependency of product properties on operating conditions in counter-current spray drying. The results showed a strong correlation between the nozzle spray parameters, nozzle position, and the performance of the spray dryer. The moisture content of the product was found to have a strong negative correlation with the temperature of the drying medium.
Article
Pharmacology & Pharmacy
Sebastian Gruber, Maximilian Thomik, Nicole Vorhauer-Huget, Lukas Hans, Evangelos Tsotsas, Petra Foerst
Summary: This article investigates the influence of microstructural parameters (pore size, shape, and orientation) on local primary drying kinetics in freeze-drying. The results show that the orientation of pores is more important for drying kinetics in pores with a high aspect ratio, while pore size is the decisive parameter for pores with a lower aspect ratio.
Article
Engineering, Chemical
Serap Akbas, Kaicheng Chen, Torsten Hoffmann, Franziska Scheffler, Evangelos Tsotsas
Summary: In this study, an aerosol fluidized bed was used to coat particles with sodium benzoate solution droplets. The coverage of the coated particles was evaluated using scanning electron microscope pictures analyzed by MATLAB image processing. Monte Carlo simulation was employed to describe the coating process. The preferential deposition of droplets on already occupied positions was identified as the main reason for island growth on particles.
Article
Engineering, Chemical
Simson Julian Rodrigues, Nicole Vorhauer-Huget, Thomas Richter, Evangelos Tsotsas
Summary: Tortuosity, an important factor in packed beds or porous media, affects mass transport, thermal and electric conductivity. Current tortuosity models lack consideration for various particle shapes. This study proposes a new model that predicts tortuosity based on sphericity and porosity, demonstrating significant effects on thermal conductivity in different particle shapes. The new model shows superior performance in the porosity range of 0.3 to 0.4, making it an upgrade to the classical Zehner-Bauer-Schlunder (ZBS) model.
Article
Pharmacology & Pharmacy
Maximilian Thomik, Felix Faber, Sebastian Gruber, Petra Foerst, Evangelos Tsotsas, Nicole Vorhauer-Huget
Summary: This study presents a non-isothermal pore network model with quasi-steady vapor transport and transient heat transfer for primary freeze drying. The physically based model allows for the investigation of correlations between spatially distributed structure and transport conditions. The study focuses on regular pore network lattices with homogeneous and bimodal pore size distributions.
Article
Mechanics
Dasika Prabhat Sourya, Debashis Panda, Abdolreza Kharaghani, Evangelos Tsotsas, Pardha S. Gurugubelli, Vikranth Kumar Surasani
Summary: This study employs the Shan-Chen lattice Boltzmann method (LBM) to simulate the drying process of a capillary porous medium, investigating the effects of convection-diffusion conditions on drying kinetics and comparing them with purely diffusion-dominated kinetics. Additionally, the study explores the influence of a temperature gradient on the stability and instability of the drying front, extending the capabilities of the lattice Boltzmann method for simulating convection-diffusion drying.
Article
Mathematics, Interdisciplinary Applications
Rui Wang, Abhinandan Kumar Singh, Subash Reddy Kolan, Evangelos Tsotsas
Summary: This study generated a series of three-dimensional aggregates with different parameters using a tunable aggregation model. The fractal dimension of the aggregates was calculated using both the box-counting method and the power law method. The importance of the box-counting prefactor was highlighted, and correlations between the box-counting and power law methods were established.
FRACTAL AND FRACTIONAL
(2022)
Article
Engineering, Chemical
Tamara Milicic, Haashir Altaf, Nicole Vorhauer-Huget, Luka A. Zivkovic, Evangelos Tsotsas, Tanja Vidakovic-Koch
Summary: Proton exchange membrane water electrolyzers (PEMWEs) coupled with renewable energy resources play a crucial role in producing green hydrogen. However, these systems often suffer from significant voltage losses due to mass transport resistance. The main cause of these losses is considered to be the two-phase transport through the anode porous transport layer (PTL) and catalyst layer. A mathematical model was developed to study the two-phase flow and mass transport losses in PEMWEs, considering various operational factors.
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.