Article
Engineering, Chemical
Kaiwei Chu, Yanxing Chen, Li Ji, Zongqing Zhou, Aibing Yu, Jiang Chen
Summary: This study presents a numerical investigation of gas-solid flow in a gas cyclone using a coarse-grained combined Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) model. The results demonstrate that the model captures the typical flow features in a gas cyclone and highlights the importance of including the van der Waals force for accurate separation efficiency prediction.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Zeyu Li, Zhenbo Tong, Hao Zhang, Kaiwei Chu, Renjie Li, Hao Miao, Jiansong Zhao, Aibing Yu
Summary: With the increasing energy demand and environmental pollution, the utilization of hydrogen energy is gaining attention due to its high calorific value and environmentally friendly combustion products. This study investigates the behavior of solid particles in a cyclone under the extreme conditions of supercritical water (SCW) by using a combined discrete element method (DEM) and computational fluid dynamics (CFD) model. The results show that particles significantly impact the flow fields and the interaction forces between particle and wall are smaller than particle-particle interactions. The findings contribute to the understanding of SCW-cyclone mechanism and can be helpful for optimizing cyclone performance.
Article
Engineering, Multidisciplinary
Mohd Azri Mohd Nor, Shahrul Kamaruddin, Tamiru Alemu Lemma
Summary: This research investigates the effects of geometrical parameters of API plan 31 cyclone separator on pressure drop and seal flow rate. The results indicate that increasing overflow and underflow radius and length of cylinder and conical can decrease pressure drop, while increasing vortex finder length can increase pressure drop. Moreover, increasing radius overflow and length of vortex finder can increase flow rate to seal, while increasing radius underflow and length of cylinder and conical can decrease flow rate to seal. The study also highlights the importance of considering all geometrical factors in the base design of cyclone separator.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Engineering, Chemical
Chunlei Wang, Guodong Liu, Zhanhu Zhai, Xinyao Guo, Yao Wu
Summary: Models describing particle triboelectric charging and electrostatic interactions were added to the Computational Fluid Dynamic coupled Discrete Element Method (CFD-DEM) for numerical simulations. It was found that as particle size decreases, bipolar charged particles exhibit a chaining stage and an agglomerating stage, with different interactions between triboelectric charging and fluidization. The effect of the wall is positively correlated to the ratio of the particle-wall collision rate to the total particle collision rate, and the fluidization conditions of particles affect the charging process via this correlation. This work contributes to a better understanding of the interaction between triboelectric charging and particle fluidization, and helps optimize fluidized bed design and conditions.
Article
Engineering, Chemical
Honggang Yang, Nan Wang, Yingxue Cao, Xiaojing Meng, Lei Yao
Summary: This study investigated the separation performance of a cyclone separator after reshaping its cylindrical body with helical triangular fins. A numerical simulation using Fluent was used to optimize the structure of the cyclone separator. The optimal combination scheme was determined and the performances of the separator before and after optimization were compared. The results showed that the finned cyclone separator significantly increased the separation efficiency and stability of the flow field.
ADVANCED POWDER TECHNOLOGY
(2023)
Article
Engineering, Chemical
Ganghui Liu, Weibing Wang, Junzhi Yu, Xiaojun Li
Summary: This study optimized and analyzed a cyclone separator with extra inlets to reduce wall erosion and improve separation efficiency, achieving a 14.5% reduction in pressure drop and a 10% increase in total separation efficiency for the optimal cyclone.
Article
Engineering, Chemical
Ming Guo, Hao Xue, Jian Pang, Dang Khoi Le, Xun Sun, Joon Yong Yoon
Summary: By comparing the CVF and SVF_D1, SVF_D2 models of cyclone separator, the influence of SVF on the swirling turbulent flow characteristics was analyzed in detail. It was concluded that the SVF_D2 model could improve the separation efficiency and reduce the pressure drop. This study helps to clarify the impact of SVF on the mechanism of particle separation motion in cyclone separator and identify the differences between traditional cyclone separator and cyclone with SVF installation.
Article
Engineering, Chemical
B. Gopalakrishnan, G. Saravana Kumar, K. Arul Prakash
Summary: In this study, the separation of particles in an axial swirl tube cyclone separator is numerically investigated using a combination of Eulerian-Lagrangian approach and Reynolds Averaged Navier-Stokes equations with RNG K-epsilon model. The impact of four significant geometric parameters on the performance of the cyclone separator is studied through numerical analysis and multiobjective optimization. The optimization results show a trade-off between pressure drop and filtration efficiency, leading to improved overall performance compared to the conventional configuration.
ADVANCED POWDER TECHNOLOGY
(2023)
Article
Thermodynamics
Genevieve Soon, Hui Zhang, Chun Yang, Adrian Wing-Keung Law
Summary: The CD-MELT method is developed for modeling the isothermal melting of a packed bed under forced convection, allowing a high degree of representation of the melting process. It introduces a mass loss fraction for accounting for phase changes, different from other existing models. Despite using a coarse mesh, the predictions are found to be satisfactory when compared with experimental results.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Chemical
Ming Guo, Dang Khoi Le, Xun Sun, Joon Yong Yoon
Summary: This study proposed a new vortex finder and applied it in the Stairmand cyclone separator to improve its performance. The researchers used experimental design and model construction techniques to find the optimal solution, and validated its effectiveness through experiments.
Article
Engineering, Chemical
Zeyu Li, Zhenbo Tong, Aibing Yu, Hao Miao, Kaiwei Chu, Hao Zhang, Gang Guo, Jiang Chen
Summary: Hydrogen utilization is gaining attention and the supercritical water circulating fluidized bed reactor can generate hydrogen. This study uses CFD to analyze cyclone separation mechanisms under supercritical fluid, finding that changing the content of carbon dioxide and adding extra dipleg can improve cyclone performance.
Article
Engineering, Chemical
Maike S. Wullenweber, Jonathan Kottmeier, Ingo Kampen, Andreas Dietzel, Arno Kwade
Summary: Deterministic lateral displacement (DLD) is a passive microfluidic separation method used to separate micron-scale particles based on their size. This study investigates the limitations of DLD under specific conditions by varying particle volume fractions and flow rates in the microsystem. Computational simulations were performed to evaluate the separation efficiency. The results suggest that by limiting the volume fraction to a maximum of 3.6%, the flow rate and separation efficiency can be increased.
Article
Engineering, Chemical
Mostafa Sulaiman, Xiaoyu Liu, Sankaran Sundaresan
Summary: In this study, Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) simulations were conducted to investigate the behavior of air and particles in a commercial inhaler. The results showed that the interactions between air and particles significantly influenced the fine particle fraction (FPF), while the interactions between particles and the inhaler wall had a minimal effect. The study also demonstrated the benefits of loading both blisters in the inhaler, even when only a single medication needed to be delivered.
Article
Mathematics, Interdisciplinary Applications
Mahmoud A. El-Emam, Ling Zhou, Wei Dong Shi, Chen Han
Summary: The study integrated CFD and DEM codes to investigate the effect of bio-particle loading ratios on cyclone device performance. Numerical simulation successfully predicted cyclone performance under designed conditions, providing useful data for future research.
COMPUTATIONAL PARTICLE MECHANICS
(2021)
Article
Thermodynamics
Genevieve Soon, Hui Zhang, Adrian Wing-Keung Law, Chun Yang
Summary: The study extends the formulation of the CFD-DEM method, CD-MELT, to include melting in three phases (gas, liquid, and solid). The new CD-MELT method characterizes the individual phases separately, allowing for more accurate simulation of the melting process. The inclusion of latent heat and sensible heat through the introduction of a particle enthalpy variable enables the consideration of non-isothermal melting. CD-MELT provides insights into the movement of melted liquid and gas channel formations, which cannot be obtained using the current VOF approaches.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
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.