Article
Engineering, Chemical
Zachary Reinking, Kevin J. Whitty, JoAnn S. Lighty
Summary: This study proposes an alternative disengager gas-solid separator for circulating fluidized bed boilers, which allows for effective separation of ash and desirable bed material based on the entrainment velocity of particles. Compared to traditional cyclones, this disengager design can achieve higher ash removal efficiency while retaining sufficient desirable material.
Article
Engineering, Chemical
Chuanjun Han, Yang Hu, Wenying Li, Qin Bie
Summary: In this study, a 3D printed guide vane cyclone separator was designed to investigate the separation efficiency, turbulent kinetic energy, and particle movement. The results revealed that the tangential velocity played a major role in the separation process, and the bottom of the exhaust pipe was the main region for gas-solid separation and pressure drop. The separation efficiency and pressure drop were positively correlated with the inlet velocity and the particle radius of the fluid.
ADVANCED POWDER TECHNOLOGY
(2022)
Article
Energy & Fuels
Yan Xie, Xin Liu, Chaoqun Zhang, Heyang Wang
Summary: Cyclone-fired boilers have gained wide applications for burning low ash fusion temperature coals, but lack effective guidance for design and operation. This study developed a CFD model to investigate the aerodynamics and FGR optimization design of a cyclone-fired boiler, showing that adapted FGR design effectively eliminates high temperature zones.
Article
Engineering, Chemical
Hooman Abdi Chaghakaboodi, Maysam Saidi
Summary: This study analyzed the influence of different vortex finder shapes with varying hydraulic diameters on the pressure drop, flow pattern, and separation efficiency of a square cyclone separator using Computational Fluid Dynamics (CFD). The results showed that using a cylindrical vortex finder increased the pressure drop and separation efficiency. Additionally, changing the relative hydraulic diameter from 0.5 to 0.25 resulted in a ten-fold increase in pressure drop and an increase in separation efficiency from 34.2% to 83.1% under certain conditions. However, employing a square vortex finder in a cyclone separator with De/D=0.75 decreased the separation efficiency and increased the pressure drop due to dividing the inlet flow into two branches.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Engineering, Chemical
Xinxin Tang, Yuanhe Yue, Yansong Shen
Summary: This study uses the Computational Fluid Dynamics (CFD)-based Multiphase Particle-in-Cell (MP-PIC) model to describe the behavior of internal solid particles in gas cyclones under various conditions and creates an integrated simulation database for cyclone design with six geometrical factors. By comparing the Genetic Algorithm-Back Propagation Neural Network (GA-BP) model and the Response Methodology Model (RSM), it is found that the GA-BP model is more accurate in predicting separation efficiency than the RSM model. This study provides a cost-effective tool for predicting the separation efficiency of cyclones in practical industries.
Article
Engineering, Chemical
Liwang Wang, Zhanghuang Yang, Liang Ma, Chong Peng, Erwen Chen, Yangfan Li, Hualin Wang
Summary: The study found that lowering the absorption solution temperature and increasing the liquid phase velocity can enhance the removal effect of CS2, but simply increasing the mass transfer coefficient does not guarantee a higher absorption efficiency. Experimental verification showed that the highest efficiency of 94.05% was obtained at an intake air flow rate of 18 l/min. The gas cyclone-liquid jet separator has been successfully applied for the first time to remove CS2 from waste gas from the rubber industry, significantly reducing treatment costs and showing excellent application prospects.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Chemical
E. Dehdarinejad, M. Bayareh, F. Parvaz, S. H. Hosseini, G. Ahmadi
Summary: This study investigated the influence of a novel converging-diverging (CD) vortex finder and CD outlet pipe on the performance of a gas cyclone. Computational fluid dynamics (CFD) simulations were performed to compare the cutoff diameter, pressure drop, and erosion rates of the new vortex finder design with those of a conventional cyclone. The results showed that the CD outlet pipe significantly reduced the cyclone pressure drop and that the height and diameter of the converging part of the vortex finder affected the separation efficiency and turbulent intensity. Increasing the converging part's inlet diameter decreased the cyclone separation efficiency but reduced the erosion rate. The CD vortex finder with the smallest height and inlet diameter (model C1) achieved the lowest cutoff diameter, while the CD outlet pipe with the largest height and inlet diameter (model C6) achieved the greatest reduction in pressure drop.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Farzad Parvaz, Seyyed Hossein Hosseini, Ahmad Reza Bastan, Jamal Foroozesh, Nihan Uygur Babaoglu, Khairy Elsayed, Goodarz Ahmadi
Summary: The effect of gas exhaust shape on the performance, flow pattern, and erosion rate of a gas cyclone was investigated using a numerical model. The shape of the gas exhaust affects the movement of the vortex core in the gas cyclone. Different gas exhaust shapes result in changes in the axial and tangential velocities and the turbulent kinetic energy in the cyclone. The size of the Rankine vortex and the cyclone separation efficiency are influenced by the shape of the gas exhaust, with the diamond and square shapes leading to decreased vortex size and reduced separation efficiency.
KOREAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Mehdi Modabberifar, Hadi Nazaripoor, Hamed Safikhani
Summary: This paper investigates the numerical simulation of flow field in three types of standard new design cyclone separators, revealing that cyclone 2D2Dn has the highest efficiency while cyclone 1D2Dn has the lowest. Additionally, the highest pressure drop occurs in cyclone 2D2Dn.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Engineering, Chemical
Hamed Safikhani, Mohammad Rafiee, Dariush Ashtiani
Summary: This paper investigates the flow field in new design cyclones with different wall temperature profiles and finds that heating the bottom zone can improve efficiency and reduce pressure drop. Among the five temperature profiles tested, types C and E showed the most significant improvement in efficiency.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Agricultural Engineering
Mahmoud A. El-Emam, Ling Zhou, Abdelaziz I. Omara
Summary: The effects of using cyclone spiral inlets on the air flow pattern and the bioparticle separation process were investigated using computational fluid dynamics (CFD) and discrete element method (DEM). The study found that the design of the inlet plays a critical role in determining cyclone performance, affecting the pressure, velocity, and turbulence parameters of the airflow. Double axisymmetric spiral inlets demonstrated enhanced coordination and resulted in a 4%-14% increase in cyclone performance. The study concludes that the double axisymmetric spiral inlet cyclone design is the most optimized for achieving the highest performance in separating large particles.
BIOSYSTEMS ENGINEERING
(2023)
Article
Engineering, Chemical
Mathieu Morin, Ludovic Raynal, S. B. Reddy Karri, Ray Cocco
Summary: This study investigates the effect of solid loading and inlet aspect ratio on cyclone performances in a circulating fluidized bed process through experimental and numerical studies. Experimental results show that cyclone pressure drop is mainly affected by solid loading, while global solid efficiency is strongly favored by increasing the inlet aspect ratio. Numerical simulations using Barracuda VR software suggest that the most appropriate boundary condition for the cyclone dipleg outlet is a pressure BC, leading to either upward or downward gas flow.
Article
Engineering, Chemical
Salma Benzarti, Hatem Mhiri, Philippe Bournot
Summary: Fluidized beds have been crucial in processing industries for almost a century. However, their scaling up has been hindered by complex hydrodynamic behavior and diverse solids handling. This study simulated the hydrodynamic behavior of a 2D circulating fluidized bed under different superficial gas velocities and found that the gas/solid feeding configuration significantly affects the flow structure.
Article
Engineering, Chemical
A. Atxutegi, P. Kieckhefen, S. Pietsch-Braune, R. Aguado, J. Bilbao, S. Heinrich, M. Olazar
Summary: This study investigates the effect of draft tubes and fountain confiners on the gas and solids mixing behavior in conical spouted beds. The results show that these devices significantly improve the gas residence time and particle cycle time distributions, especially when high inlet gas flow rates are desired.
ADVANCED POWDER TECHNOLOGY
(2023)
Article
Engineering, Chemical
Heng Zhou, Kun Xu, Xu Tian, Mingyin Kou, Shengli Wu, Yansong Shen
Summary: The numerical study shows that burden profile has a minor effect on burden descending velocity and gas velocity in furnace. The 'W' shaped burden profile is more beneficial for the uniformity of gas-solid flow, while the 'V' shaped burden profile results in the lowest pressure drop.
Article
Construction & Building Technology
Asgar Minaei, Hamed Safikhani
Summary: A simple yet accurate transient model was developed to evaluate the thermal performance of earth to air heat exchangers (EAHEs) in this study. The analytical model was validated using experimental data and compared with numerical simulations, showing good correlation. Results also revealed thermal saturation of the soil with continuous operation, highlighting the importance of considering this factor in system performance evaluation.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Thermodynamics
Alireza Aminmahalati, Alireza Fazlali, Hamed Safikhani
Summary: In this study, the combustion chamber of a CO steam boiler is multi-objectively optimized using computational fluid dynamics and NSGA II algorithm, with the main goals of maximizing outlet gas temperature and minimizing chamber wall temperature. A step-wise increase of the mesh was used to ensure an adequate number of nodes, and simplifications were made to deal with the complexity of the steam boiler system.
Article
Green & Sustainable Science & Technology
Asgar Minaei, Zahra Talee, Hamed Safikhani, Hadi Ghaebi
Summary: A new hybrid model for transient heat transfer in Earth-Air Heat Exchangers (EAHE) based on thermal resistance capacity circuit is developed in this study, taking into account the thermal capacity of the soil around the pipe in the simulation. The results of the model show acceptable agreement with experimental and numerical ones, indicating the reliability of the model.
Article
Engineering, Chemical
Hamed Safikhani, Mohammad Rafiee, Dariush Ashtiani
Summary: This paper investigates the flow field in new design cyclones with different wall temperature profiles and finds that heating the bottom zone can improve efficiency and reduce pressure drop. Among the five temperature profiles tested, types C and E showed the most significant improvement in efficiency.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Engineering, Civil
Mostafa Yousefi, Morteza Yousefi, Hamed Safikhani, Kiao Inthavong, Keivan Bamdad
Summary: Fire safety is a major design concern for tunnel engineers, with longitudinal ventilation being a common method for dealing with smoke and hot gases. The critical velocity, key to designing the longitudinal exhaust system, was determined using an analytical solution in this study. By comparing analytical results with experimental and numerical data, the study showed that a modified Froude number can improve the accuracy of the analytical solution and save time compared to iterative methods.
FIRE SAFETY JOURNAL
(2021)
Article
Engineering, Chemical
Mehdi Modabberifar, Hadi Nazaripoor, Hamed Safikhani
Summary: This paper investigates the numerical simulation of flow field in three types of standard new design cyclone separators, revealing that cyclone 2D2Dn has the highest efficiency while cyclone 1D2Dn has the lowest. Additionally, the highest pressure drop occurs in cyclone 2D2Dn.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Thermodynamics
Alireza Aminmahalati, Alireza Fazlali, Hamed Safikhani
Summary: This study evaluated the combustion chamber performance of the CO boiler at an oil refinery using computational fluid dynamics, showing a 96% accuracy in simulation compared to experimental results. Analysis included velocity profiles, flame thermal profiles, and reaction rates of combustible compounds. The study used non-dominated sorting genetic algorithm II to determine optimal operating conditions and presented the impact of different fluid intensities on various parameters.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
C. Thianpong, K. Wongcharee, H. Safikhani, S. Chokphoemphun, A. Saysroy, S. Skullong, S. Eiamsa-ard
Summary: This study utilized a hybrid technique involving TiO2/water nanofluid and loose-fit delta-wing twisted tape to enhance heat transfer efficiency. Experimental results showed that the combined enhancement technique significantly improved heat transfer rates, mainly due to the swirling flow effect and higher thermal conductivity. Furthermore, reducing the loose-fit ratio and increasing the nanofluid concentration can also enhance heat transfer rates and thermohydraulic performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Environmental Sciences
S. A. Mostafavi, A. Dadsetan, H. Safikhani
Summary: This paper models the impact of using urban buses with outdated or modern environmental technologies on the air pollution in Arak city. The results show that the presence of EURO3 and EURO4 urban buses leads to PM2.5 pollutants concentration exceeding the standard level. The use of EURO4 urban buses can effectively reduce the number of polluted days.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
S. Eiamsa-ard, V Chuwattanakul, H. Safikhani, P. Promthaisong
Summary: In this paper, multi-objective optimization of geometric parameters of spirally-cross-corrugated (SCC) tubes is carried out using numerical methods, genetic algorithms, and artificial neural networks. The analysis reveals several important optimal design principles for heat transfer in such tubes.
THERMOPHYSICS AND AEROMECHANICS
(2022)
Article
Engineering, Multidisciplinary
A. Aminmahalati, A. Fazlali, H. Safikhani
Summary: This study re-examined the design of the combustion chamber in Imam Khomeini Oil Refinery Company using CFD and simplified the 3D simulation by applying the symmetry principle. The results showed that the temperature and velocity in the combustion chamber were within an appropriate range without thermal damage.
INTERNATIONAL JOURNAL OF ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
M. Yousefi, H. Safikhani, E. Jabbari, V. Tahmasbi
Summary: This paper utilizes CFD and RSM for optimization of drug delivery efficiency for emergency respiratory patients. Through DOE and RSM, the output efficiency and regression equation model are derived to investigate the impact of each input parameter on efficiency, and the best combination of input parameters yielding the highest efficiency is found through optimization algorithm.
INTERNATIONAL JOURNAL OF ENGINEERING
(2021)
Article
Energy & Fuels
Seyed Alireza Mostafavi, Hamed Safikhani, Siavash Salehfard
Summary: This paper develops a comprehensive model for studying air pollution in Arak city, Iran, and validates the model by comparing it with data from ambient air monitoring. The study finds that the levels of NOx, CO, and SO2 pollutants in Arak city exceed standard values, with a significant contribution from industrial sources, particularly IRALCO.
INTERNATIONAL JOURNAL OF ENERGY AND ENVIRONMENTAL ENGINEERING
(2021)
Article
Engineering, Chemical
Hamed Safikhani, Sadegh Allahdadi
ADVANCED POWDER TECHNOLOGY
(2020)
Article
Engineering, Multidisciplinary
H. Safikhani, F. Esmaeili, S. Salehfard
INTERNATIONAL JOURNAL OF ENGINEERING
(2020)
Article
Engineering, Chemical
Yongxiang Wu, Nguyen Thi Hong Nhung, Deqian Zeng, Nengneng Luo, Akira Otsuki, Gjergj Dodbiba, Toyohisa Fujita
Summary: This study proposed a novel method for synthesizing flower-like vaterite calcium carbonate using nanobubble-containing ethanol and water mixed solution as the solvent and discussed the formation mechanism of vaterite with different shapes. The synthesized vaterite has significant practical interest in the integrated treatment of wastewater contaminated by heavy metals with effective Cd(II) removal, providing a promising field for studying heavy metal and pollutant adsorption in the liquid phase.
ADVANCED POWDER TECHNOLOGY
(2024)
Article
Engineering, Chemical
Jian Gong, Lipo Cheng, Ming Liu, Jie Jiang, Xiaoduo Ou
Summary: This study investigates the effects of particle shape on the collapse of granular columns using the discrete element method. The results show that particle shape has a significant impact on deposition morphology, energy evolution, and mechanical coordination number. Sphericity and angularity are identified as the most important macroscale factors, while roughness has a weaker microscale influence.
ADVANCED POWDER TECHNOLOGY
(2024)
