Fluidization Behavior In A Gas- Solid Fluidized Bed With Thermally Induced Inter-Particle Forces,
2011
Ecole Polytechnique de Montreal, Canada
Fluidization Behavior In A Gas- Solid Fluidized Bed With Thermally Induced Inter-Particle Forces, Jaber Shabanian, Farzam Fotovat, Jamal Chaouki, Jonathan Bouffard
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
In this work, a new approach for increasing and controlling inter-particle forces (IPFs) was applied. This method used a spherical inert particle coated with a polymer material having a low glass transition temperature. Since IPFs depend on the temperature of the coated particles, they can be easily controlled by the temperature of the inlet air. For this reason, the temperature of the system was varied uniformly near the glass transition temperature of the polymer, between 20 – 40oC, to investigate the effect of IPFs on fluidization behavior at low and high gas velocities
Correlation Of The Minimum Spouting Velocity For The Design Of Open-Sided Draft Tube Conical Spouted Beds For The Treatment Of Fine Materials,
2011
University of the Basque Country, Spain
Correlation Of The Minimum Spouting Velocity For The Design Of Open-Sided Draft Tube Conical Spouted Beds For The Treatment Of Fine Materials, M. Olazar, Haritz Altzibar, Gartzen Lopez, I. Estiati, Javier Bilbao
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
The hydrodynamics of conical spouted beds provided with open-sided draft tubes have been studied for the treatment of fine particles. A correlation has been proposed for the calculation of the minimum spouting velocity as a function of dimensionless moduli that take into account the geometric factors of the contactor and the draft tube, particle characteristics and operating conditions.
Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanopowder,
2011
Delft University of Technology
Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanopowder, Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem, Samantha Johnson, Niels Looije
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
The fluidization of nanoparticle agglomerates can be largely improved by using downward pointing micronozzles, creating a high-velocity jet, as experimentally shown. By discrete particle simulations – treating the agglomerates as single particles – we show that the microjet strongly reduces the amount of gas in voids.
Erosion In Second Stage Cyclones: Effects Of Cyclone Length And Outlet Gas Velocity,
2011
Particulate Solid Research, Inc., USA
Erosion In Second Stage Cyclones: Effects Of Cyclone Length And Outlet Gas Velocity, S. B. Reddy Karri, Ray Cocco, Ted Knowlton
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Severe erosion in the lower cone and in the upper dipleg of second stage cyclones have been observed in commercial cyclones. The main objective of this study is to shed light on the mechanism by which this erosion takes place, and how different design and operating parameters affect the erosion. Experimental data on how parameters such as the cyclone length-to diameter ratio (L/D), inlet solids loading and gas outlet velocity affect second stage cyclone erosion are presented. The outlet gas velocity was varied by changing the size of the vortex tube diameter. The effect of a vortex stabilizer on cyclone …
Design Criteria Of Uniflow Cyclones For The Separation Of Solid Particles From Gases,
2011
MCI Management Center Innsbruck
Design Criteria Of Uniflow Cyclones For The Separation Of Solid Particles From Gases, Ulrich Muschelknautz, Paul Pattis, Michael Reinalter, Michael Kraxner
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
The main advantages of uniflow cyclones compared to standard reverse flow cyclones are their compact design and their capability of being easily integrated into pipelines. Experiments show that a 0.2m-diameter horizontal uniflow cyclone re-moves 88.6% of 2 g/m3 of fine mineral powder (d10=3m, d50=20m) from 1000 m3/h air at a pressure loss of 2510 Pa (0.364 psi).
Characteristics Of The Solid Volume Fraction Fluctuations In A Cfb,
2011
VTT Technical Research Centre of Finland, Finland
Characteristics Of The Solid Volume Fraction Fluctuations In A Cfb, Sirpa Kallio, Juho Peltola, Veikko Taivassalo
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
In the paper, the fluctuation characteristics of the solids volume fraction in a CFB are evaluated from measurements and Eulerian-Eulerian CFD simulations. In both cases, similarly large fluctuations are observed in the intermediate voidage range whereas dense and dilute suspension regions are more uniform, as expected. The frequency distributions of solids volume fraction are classified to represent three different suspension density regimes: dilute, dense and intermediate “bimodal” regimes.
Gas-Solids Hydrodynamics In A Cfb With 6 Cyclones And A Pang Leg,
2011
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou
Gas-Solids Hydrodynamics In A Cfb With 6 Cyclones And A Pang Leg, Lemigh Cheng, Xinglong Zhou, Chao Wang, Qinhui Wang, Zhongyang Luo, Kefa Cen, Li Nie, Chaogang Wu, Qi Zhou
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Solids volume fraction and particle velocity profiles were measured with a fiber optical probe in a cold circulating fluidized bed test rig with 6 parallel cyclones and a pant leg. Results in the pant leg zone, main bed zone and exit zone of the furnace are reported. The work also includes the influences of superficial gas velocity, secondary air rate and static bed height on the gas-solids hydrodynamics.
Fluidized Bed Gasification Of Mixed Plastic Wastes: A Material And A Substance Flow Analysis,
2011
Second university of Naples, Italy
Fluidized Bed Gasification Of Mixed Plastic Wastes: A Material And A Substance Flow Analysis, Maria Laura Mastellone, Umberto Arena
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Gasification as a reliable and convenient waste-to-energy process for the economic analysis of mixed-plastic waste (MPW) was investigated. To this end a pilot scale bubbling fluidized bed air gasifier was fired with two commercially available MPWs to obtain syngas composition and characterization of the bed material, cyclone collected fines and purge material from the scrubber. These results were then processed by means of Material and Substance Flow Analyses to evaluate the main process performance parameters for the two MPWs tested.
3d Cfd Simulation Of Combustion In A 150 Mwe Circulating Fluidized Bed Boiler,
2011
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences
3d Cfd Simulation Of Combustion In A 150 Mwe Circulating Fluidized Bed Boiler, Nan Zhang, Bona Lu, Wei Wang, Jinghai Li
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Eulerian granular multiphase model with meso-scale modeling of drag coefficient and mass transfer coefficient, based on the energy minimization multi-scale (EMMS) model, was presented to simulate a 150 MWe CFB boiler. The three-dimensional (3D), full-loop, time-dependent simulation results were presented in terms of the profiles of pressure, solids volume fraction and solids vertical velocity, the distributions of carbon and oxygen, as well as the temperature. The EMMS-based sub-grid modeling allows using coarse grid with proven accuracy, and hence it is suitable for simulation of such large-scale industrial reactors.
The Research Of Cfb Boiler Operation For Oxygen Enhanced Dried Lignite Combustion,
2011
Czestochowa University of Technology
The Research Of Cfb Boiler Operation For Oxygen Enhanced Dried Lignite Combustion, Wojciech Nowak, Waldemar Muskala, Jaroslaw Krzywanski, Tomasz Czakiert
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
The paper presents the research of CFB boiler operation for oxygen-enhanced dried lignite combustion. The combustion in oxygen-enhanced conditions generally leads to reducing the emissions of CO and NOx and N2O due to reduced volume of flue gas. The maximum oxygen content for oxygen-enhanced combustion in O2/N2 conditions should not exceed 60%, however, the maximum drying extent of fuel should not be higher than 50% of the initial moisture content in an examined lignite.
Dem-Cfd Modeling Of A Bubbling Fluidized Bed And A Wurster Coater,
2011
Hamburg University of Technology
Dem-Cfd Modeling Of A Bubbling Fluidized Bed And A Wurster Coater, Lennart Fries, Sergiy Antonyuk, Stefan Heinrich, Stefan Palzer
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Coupled DEM-CFD simulations were performed to study the fluid and particle dynamics of a fluidized bed granulator on the micro-scale. In a first study, wetting of the particles is estimated based on the residence time distribution inside a conical spray zone. The effect of the geometry of the apparatus on the homogeneity of wetting is analyzed in order to understand the performance and specificity of different granulator configurations. For a small simulation system, heat and mass transfer laws were resolved to calculate the moisture content of the individual particles An effective modelling tool for design of a fluidized bed spray …
Circulating Fluidized Bed Combustion-Build-Up And Validation Of A Three-Dimensional Model,
2011
Metso Power Oy
Circulating Fluidized Bed Combustion-Build-Up And Validation Of A Three-Dimensional Model, Marko Palonen, David Pallarès, Anton Larsson, Filip Johnsson, Ville Ylä-Outinen, Jukka Laine
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
This paper presents the validated simulation of a full-scale circulating fluidized bed boiler as obtained via a comprehensive three-dimensional CFB process model. The model is utilized in boiler design and scale-up as well as to study and optimize boiler performance. Feedstock characterization tests, which are also presented, are used to provide data for those parts of the process where up-to-date modeling is not fully reliable, thus enabling the model to provide accurate results.
Effect Of Temperature Field On The Coal Devolatilization In A Millisecond Downer Reactor,
2011
Tsinghua University, China
Effect Of Temperature Field On The Coal Devolatilization In A Millisecond Downer Reactor, Binhang Yan, Li Zhang, Yong Jin, Yi Cheng
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
A comprehensive CFD-DPM model was established to describe coal pyrolysis in millisecond downer reactors under high temperatures. The model predictions revealed the fact that the reactor performance is dominated by the design of the temperature field to guarantee fast, sufficient heating of coal particles in milliseconds
Experimental Study On Reforming Activity And Oxygen Transfer Of Fe- Olivine In A Dual Circulating Fluidized Bed System,
2011
Vienna University of Technology
Experimental Study On Reforming Activity And Oxygen Transfer Of Fe- Olivine In A Dual Circulating Fluidized Bed System, Stefan Koppatz, Tobias Pröll, Christoph Pfeifer, Hermann Hofbauer
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Fe-olivine was investigated in a dual circulating fluidised bed reactor system with focus on hydrocarbon reforming activity and effects of oxygen transfer. H2, CO2, CH4 and 1-methylnaphthalene were fed as a surrogate gas mixture to the reforming part. Oxygen transport was developed by solids circulation. Tar decomposition was marginally affected by partial oxidation. The overall degree of tar decomposition was found to be in the range of 70 to 80%.
Effects Of Secondary Air Injection Upon The Fluidization Characteristics Of The Lower Stage In A Two-Stage, Variable-Area Fluidized Bed Riser,
2011
West Virginia University
Effects Of Secondary Air Injection Upon The Fluidization Characteristics Of The Lower Stage In A Two-Stage, Variable-Area Fluidized Bed Riser, Eric K. Johnson, Steven L. Rowan
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
A transparent scale model of a two-stage fluidized bed coal dryer with a small diameter lower stage and a large diameter upper stage, separated by a conical transition zone with secondary air injection ports, has been constructed to study the effects of secondary air injection upon the fluidization characteristics of the lower riser stage. The superficial velocity of the lower stage of the riser was held constant within the turbulent fluidization regime while the superficial gas velocity in the upper riser stage was varied by changing the volumetric flow rates of air introduced between the upper and lower riser stages. …
Oxy-Combustion Of Different Coals In A Circulating Fluidized Bed,
2011
Sasol Technology, South Africa
Oxy-Combustion Of Different Coals In A Circulating Fluidized Bed, Adam Luckos, Monika Kosowska-Golachowska, Konrad Klos, Tomasz Musial
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
Combustion of three Polish and one South African bituminous coal particles in air versus O2/CO2 mixtures with oxygen concentrations in the range from 21% to 60% vol. was conducted at temperature of 850°C in a 12 kW bench-scale CFB combustor. Combustion in air was proceeded at ~50˚C higher centre temperatures and was slightly shorter in time compared to combustion in O2/CO2 mixture with 21% vol. O2. Larger heat capacity of CO2 compared to that of N2 also retards the ignition of volatiles in O2/CO2 mixtures with 21% O2. However, when the concentration of oxygen in O2/CO2 mixtures is larger than …
Comparison Between Measurements And Numerical Simulation Of Particle Flow And Combustion A The Cfbc Plant Duisburg,
2011
aixprocess GmbH
Comparison Between Measurements And Numerical Simulation Of Particle Flow And Combustion A The Cfbc Plant Duisburg, M. Weng, J Plackmeyer
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
The article presents the 3-dimensional numerical simulation of combustion and particle flow as an efficient engineering tool for analysis and optimization of fluidized bed combustion chambers. The comparison with measurements that were carried out within a European Research Project and with operational experience shows very good agreement and provides recommendations for future optimization.
Elutriation From Fluidized Beds: Comparison Between Experimental Measurements And 3d Simulation Results,
2011
CNRS; Federation de Recherche FERMAT, France
Elutriation From Fluidized Beds: Comparison Between Experimental Measurements And 3d Simulation Results, Renaud Ansart, Herve Neau, Olivier Simonin, Philippe Accart, Alain De Ryck
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
This paper presents comparisons between experimental measurements and unsteady threedimensional numerical simulations performed by an unstructured parallelized CFD multiphase flow code of elutriation and transport of mono-dispersed glass beads type B and A/B in a fluidized bed. These comparisons show a satisfactory agreement between experimental measurements and numerical predictions. The numerical results also show a strong dependence on the mesh size, especially for fine particles. A model accounting for influences of mesoscales structures on overall bed hydrodynamics, which are not resolved by coarse mesh simulations, is applied. Results obtained with the model show improvements for the dense fluidized bed and …
Hydrodynamics Of A Cluster Descending At The Wall Of A Cfb Riser - Numerical Study,
2011
University of British Columbia
Hydrodynamics Of A Cluster Descending At The Wall Of A Cfb Riser - Numerical Study, John R. Grace, Subhashini Vashisth
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
The incompressible hydrodynamics of a single parabolic cluster descending at the wall of a CFB riser was numerically simulated using a 2-D Eulerian-Granular model and a segregated time-dependent unsteady solver. Numerical predictions of the velocity of descent and the evolution of cluster shape are in reasonable agreement with experimental results available in the literature.
High Sulfur Lignite Fired Large Cfb Boilers-Design And Operating Experience,
2011
Bharat Heavy Electrical Limited
High Sulfur Lignite Fired Large Cfb Boilers-Design And Operating Experience, M. Lakshminarasimhan, B. Ravikumar, A. Lawrence, M. Muthukrishnan
10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10
One of the measures of the prosperity of a nation is per capita consumption of electricity. In developing countries like India the gap between supply and demand is strongly increasing. The demand for all forms of energy is expected to increase substantially in the foreseeable future and is forecasted to double by 2020. Although coal would continue to be a major energy source in India due to its availability, lignite is fast emerging as an alternate source of fuel for electricity generation. In India the total lignite potential is 4177 million tonnes. The varieties found in India (Gujarat & Rajasthan …
