Article
Engineering, Chemical
C. P. McLaren, J. P. Metzger, C. M. Boyce, C. R. Muller
Summary: Vibration can reduce both the minimum fluidization velocity (U-mf) and the minimum bubbling velocity (U-mb) in gas-solid fluidized beds. Increasing vibration frequency and amplitude decreases U-mf and U-mb, and the changes can be plotted along a single curve when compared with vibration strength. Particle density has little effect on the changes in U-mf and U-mb due to vibration, while particle diameter affects them in a non-monotonic manner.
Article
Engineering, Chemical
Krittin Korkerd, Chaiwat Soanuch, Zongyan Zhou, Pornpote Piumsomboon, Benjapon Chalermsinsuwan
Summary: This study provides detailed experimental information on the effects of solid particle size distribution (PSD), bed inventory, and bed temperature on the minimum fluidization velocity (U-mf). Silica sand with different average particle diameters and PSDs was used. The results demonstrate that wider PSDs have lower U-mf values compared to narrow cut particles with the same average particle diameter. The standard deviation (SD) and skewness of the PSD also affect the variation of U-mf. Additionally, increasing bed inventory and bed temperature lead to a decrease in U-mf. A new correlation considering these influencing factors has been proposed, which shows an average absolute deviation of 14.6% with experimental data. Furthermore, the proposed correlation has been evaluated with data from the literature, resulting in an average absolute deviation of 15.6%.
ADVANCED POWDER TECHNOLOGY
(2022)
Article
Engineering, Environmental
Shuyue Li, Yongmin Zhang, Wenjie Wang, Huan Wang
Summary: This study comprehensively evaluates the effect of particle density on hydrodynamics during the initial fluidization stage. It finds that empirical correlations for high-density particles may have significant errors in predicting the minimum fluidization velocity (Umf), and the predicted errors tend to increase with increasing particle density. Furthermore, the fluidization performance tends to deteriorate as the particle density increases.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Chemical
Mojtaba Nabipoor Hassankiadeh, Raymond J. Spiteri, Mark Berrey, Dave Jordison, Lifeng Zhang, Donald Bergstrom
Summary: Pulsed airflow was used to improve the fluidization behavior of wet potash particles in a fluidized bed by breaking agglomeration and eliminating channeling. The study investigated the effects of pulsation frequency, pulsed air to continuous flow ratio, and inlet relative humidity on bubbling behavior. The optimal condition was found to be a frequency of 1.0 Hz, an r of 0.33, and an opening time of 0.1 s, resulting in the lowest minimum fluidization velocity and generation of homogeneous bubbles. A new theoretical model considering liquid bridge force and resonant force was developed to predict the umf of wet particles in a fluidized bed, with good agreement between the predicted and experimental data.
Article
Engineering, Chemical
Anna Kohler, Diana Carolina Guio-Perez, Anna Prati, Michele Larcher, David Pallares
Summary: This study focused on the motion trajectory and drag behavior of solid particles in gas-fluidized beds, revealing the complex rheological characteristics of bed emulsions and their effects on particles. It also discovered the viscoplastic behavior of bed emulsions and their clear dependence on the size and density of tracers.
Article
Engineering, Environmental
Yanjiao Li, Chenyang Zhou, Guannan Lv, Yongxin Ren, Yuemin Zhao, Qingxia Liu, Zhonghao Rao, Liang Dong
Summary: This study proposed a novel method to predict the minimum fluidization velocity (u(mf)) in a pulsed gas-solid fluidized bed (PGFD) combined with the soft sphere model. A theoretical model of u(mf) was derived for PGFD based on experimental stress analysis of particles, showing good agreement with existing literature data.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
Chi Ma, Huibin Xu, Wenqi Zhong, Weiyu Wang, Hao Zhang
Summary: In this study, the fluidization behavior of vinegar residue in a vibrated fluidized bed was investigated by adding inert particles. The experimental results showed that stable fluidization can be achieved within a certain upper limit of vinegar residue mass concentration. The minimum fluidization velocity of the binary mixture increased with the increase of vinegar residue mass concentration and decreased with the increase of vibration intensity. The drying rate of vinegar residue increased with the increase of vibration intensity or the decrease of vinegar residue mass concentration.
ADVANCED POWDER TECHNOLOGY
(2022)
Article
Engineering, Chemical
Quanhong Zhu, Libo Zhang, Weikang Hao
Summary: This study aimed to define and determine the minimum fluidization velocity in magnetized fluidized beds (MFB) based on physics principles, resolving controversies in the field. Different methods and requirements for determining U-mf were identified for MFB with different types of particles. Experimental results showed that U-mf remained invariant in both types of MFB.
Article
Chemistry, Multidisciplinary
Jae-Rang Lee, Yong-Ha Kim, Yong Sun Won
Summary: MoO2 was produced by mixing MoS2 and MoO3 through a solid-state reaction in a fluidized bed reactor. The optimal stoichiometric ratio of MoS2 and MoO3 was found to be 1.0: 6. A conversion rate of 99% was achieved at the optimum stoichiometric ratio by varying the reaction temperature.
KOREAN JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Energy & Fuels
C. J. M. Hessels, D. W. J. Lelivelt, N. C. Stevens, Y. Tang, N. G. Deen, G. Finotello
Summary: In this study, the fluidization and reduction behavior of micron-sized iron oxide powder produced by iron combustion were investigated in a lab-scale cylindrical fluidized bed. The minimum fluidization velocity (umf) was found to stabilize above a normalized static bed height of 0.5 H/D. Experimental results deviated from the Ergun correlation at temperatures above 560 K, prompting the proposal of a new correlation that takes cohesive inter-particle solid bridge force into account. Reduction experiments revealed gradual defluidization at temperatures exceeding 800 K, with a maximum reduction degree of 61% achieved at 807 K and 100 vol% H2.
Article
Engineering, Chemical
Yaqin Huang, Hao Zhang, Xizhong An, Xinglian Ye
Summary: This paper investigates the effect of particle aspect ratio on the minimum fluidization velocity in a supercritical water fluidized bed reactor through numerical simulations. The results reveal that the minimum fluidization velocity increases with temperature but decreases with pressure, and it also increases with the particle aspect ratio.
Article
Engineering, Chemical
Huibin Xu, Weiyu Wang, Wenqi Zhong, Chi Ma, Hao Zhang
Summary: The pressurized bubbling fluidized bed is advantageous for treating municipal solid waste due to its ability to effectively capture CO2 and enhance the combustion and gasification process. This study experimentally investigated the fluidization characteristics of Geldart-D particles at elevated pressure, including flow pattern, pressure drop, and minimum fluidization gas velocity. The results showed that the fluidization behavior of Geldart-D particles changed with increasing operating pressure, indicating a transition towards the behavior of Geldart-B particles. A new correlation for predicting the minimum fluidization velocity of Geldart-D particles at elevated pressure was proposed based on the experimental data.
ADVANCED POWDER TECHNOLOGY
(2022)
Article
Engineering, Chemical
Tian Nan, Jesse Zhu
Summary: The hydrodynamics of inverse liquid-solid circulating fluidized bed were studied comprehensively, revealing specific flow patterns and solid distribution laws, influenced by factors such as particle size and flow velocity.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Michael Nelson, Saleh Srabet, Tian Nan, Dominic Pjontek, Jesse Zhu
Summary: This study compared theoretical predictions and experimental measurements of minimum fluidization velocity and found significant deviations in the predictions using common correlations for low-density particles. A modified correlation was proposed based on novel and past measurements, which improved the accuracy of predicting minimum fluidization velocity for a wider range of low-density particles.
Article
Engineering, Chemical
Hao Zhang, Yaqin Huang, Xizhong An, Aibing Yu, Jun Xie
Summary: The minimum fluidization velocity of a supercritical water fluidization bed reactor was numerically investigated using a CFD-DEM model. Different particle size distributions were studied, with Flat-type PSD showing the smallest minimum fluidization velocity and Mono-type PSD showing the largest. The correlation between Mono-type and Gaussian-type PSD velocities depends on the distribution of small particles.
Article
Thermodynamics
M. Fernandez-Torrijos, C. Marugan-Cruz, C. Sobrino, D. Santana
Summary: This study demonstrates the importance of considering water price in the analysis of the thermo economical performance of solar tower plants. By optimizing the operating parameters of dry and hybrid condensing systems, it is possible to maximize the revenue of the power plant. The cost-effective configuration depends on the water-to-electricity price ratio R.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
M. Diaz-Heras, J. F. Belmonte, J. A. Almendros-Ibanez
Summary: This study compares the influence of bed height and airflow rate on the temperature distribution over the top surface of the bed, demonstrating that the spouted bed can reduce the maximum temperature of the particles, especially in shallow beds. The spouted bed presents slightly lower homogeneous temperatures than the spout-fluid bed in deep beds, with an associated reduction of 52.28% in pumping costs. Additionally, spout-fluid temperatures strongly depend on air velocity and bed height, exhibiting a wider temperature range due to different fluidization regimes.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2022)
Article
Energy & Fuels
J. F. Belmonte, M. Diaz-Heras, J. A. Almendros-Ibanez, Luisa F. F. Cabeza
Summary: This paper reports the simulation results of two different solar-assisted heat pump systems in Madrid and analyzes the impact of integrating short-term storage tanks on system performance. The study finds that conventional thermostatic control strategies may lead to degradation in system performance, and more advanced control strategies are needed to improve system efficiency.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Green & Sustainable Science & Technology
J. F. Belmonte, F. Javier Ramirez, J. A. Almendros-Ibanez
Summary: Spanish residential buildings usually use solar thermal systems to meet building code requirements. The energy savings of these systems are significant for medium or large buildings but may not be economically feasible for small buildings. A simulation tool was used to estimate the energy savings and conduct economic feasibility assessments. Results showed that solar domestic hot-water systems are not economically feasible for small buildings with less than 5 apartments, but have a wide probability range (70-90%) of being economically feasible for buildings with more than 48 apartments.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Thermodynamics
D. Sanchez, J. A. Almendros-Ibanez, A. Molina, F. Bozzoli, L. Cattani, J. I. Corcoles
Summary: This study presents the results of a numerical simulation on the heat transfer performance of Newtonian and non-Newtonian fluids in a helical coiled tube under laminar regime. The rheological properties of the non-Newtonian fluids significantly influence the heat transfer rate, with higher heat transfer occurring in the helical section compared to the straight section. Furthermore, the mixing of the non-Newtonian fluids is improved in the coil section, leading to enhanced heat transfer.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
J. Garcia-Plaza, M. Diaz-Heras, R. Mondragon, L. Hernandez, A. Calderon, C. Barreneche, J. Canales-Vazquez, A. Fernandez, J. A. Almendros-Ibanez
Summary: This study experimentally tested the thermal performance of coated sand particles for CSP applications and found that coatings based on graphite and carbon black can enhance the thermal absorptivity of particles, leading to the absorption of more energy. These coatings showed no apparent deterioration of their thermal properties after multiple charging/discharging cycles. Extrapolation of the results indicates that coated particles can effectively increase the energy stored in the bed by 60-80% compared to raw sand.
APPLIED THERMAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
J. I. Corcoles, M. Diaz-Heras, M. Fernandez-Torrijos, J. A. Almendros-Ibanez
Summary: This study presents a numerical investigation of particle flow in a gas-particle fluidized dense suspension for CSP applications using the MP-PIC method. Two different numerical simulations were conducted, one for a cold and isothermal model and the other for a high-temperature case. The results showed the significant impact of pressure and aeration flow rate on particle mass flow, and fluctuations in heat transfer coefficients during the fluidization process.
Article
Thermodynamics
Rafael Perez-Alvarez, Carolina Marugan-Cruz, Domingo Santana, Antonio Acosta-Iborra
Summary: This study evaluates the thermal and mechanical behaviors of eccentric bayonet tubes for solar power tower plants. Results show enhanced heat transfer and reduced tube wall overheating compared to conventional tubes. Eccentric bayonet tubes can reduce pressure drop by 30.8% and increase convective heat transfer by 26.1% compared to conventional tubes under normal operating conditions.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
J. Gomez-Hernandez, R. Grimes, J. V. Briongos, C. Marugan-Cruz, D. Santana
Summary: Industry decarbonization is a crucial challenge for achieving climate neutrality. High temperature heat pumps can upgrade low temperature heat flows and achieve high performance at high temperatures through the use of new refrigerants.
Article
Thermodynamics
M. Laporte-Azcue, A. Acosta-Iborra, T. P. Otanicar, D. Santana
Summary: To analyze the thermo-mechanical properties of molten-salt solar receivers under varying solar radiation, simplified low-computational-cost analytical models are proposed. These models are compared to finite element method simulations and an analytical 2D-conduction expression. The results show that the analytical quasi-steady 1D-conduction solution for temperature-dependent thermal conductivity can accurately determine the temperature distribution and monitor damage in molten-salt receivers under transient solar flux.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
Mohamed S. Yousef, Domingo Santana
Summary: This research introduces a new and unique combined cooling and power (CCP) system utilizing nuclear power. The system's thermodynamic, exergoeconomic, and comparative aspects are analyzed, and a comprehensive parametric analysis is conducted. Results show significant improvements in energy efficiency and exergoeconomic performance.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Energy & Fuels
J. F. Belmonte, M. Diaz-Heras, J. A. Almendros-Ibanez
Summary: The integration of thermal energy storage units can increase renewable energy contribution and overall system performance, but also introduces irreversibility to the system operation. A Second-Law approach should be incorporated in the design to assess the exergy losses. This study quantifies and evaluates the entropy generated by different thermal energy storage units using a simplified and computationally efficient method. The results indicate that the temperature difference and heat losses to surroundings are the main factors contributing to entropy generation.
JOURNAL OF ENERGY STORAGE
(2023)
Proceedings Paper
Energy & Fuels
Marta Laporte-Azcue, Pedro Angel Gonzalez-Gomez, Maria De Los Reyes Rodriguez-Sanchez, Domingo Santana
Summary: This study analyzes the lifetime of various external tubular receiver configurations under design and external variations, providing guidelines for central receiver selection.
SOLARPACES 2020 - 26TH INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS
(2022)
Proceedings Paper
Energy & Fuels
Alberto Sanchez-Gonzalez, Maria Reyes Rodriguez-Sanchez, Domingo Santana
Summary: FluxSPT is a software tool that characterizes the heliostat fields and generates flux maps on central receivers. It offers a GUI-based version that can be downloaded for free with the installation of Matlab Runtime. The tool uses an optical model based on the convolution-projection method, validated by the authors. It computes symmetric flux distributions relative to the receiver midplane using either single or multi-aiming strategies, with a parameter (k aiming factor) to control the peak flux and spillage.
SOLARPACES 2020 - 26TH INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS
(2022)
Proceedings Paper
Energy & Fuels
Sebastian Taramona, Jesus Gomez-Hernandez, Javier Villa Briongos, Domingo Santana
Summary: This study proposes a design of a particle receiver based on rotating vibratory motors, which can regulate the flow rate of particles and explores the influence of different parameters on the behavior and mixing rate of particles inside the bed.
SOLARPACES 2020 - 26TH INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS
(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.
