Attrition Of Bed Materials And Fuel Pellets For Fluidized Bed Gasification Application,
2010
Istituto di Ricerche sulla Combustione – CNR
Attrition Of Bed Materials And Fuel Pellets For Fluidized Bed Gasification Application, P. Ammendola, R. Chirone F. Miccio, G. Ruoppolo, Fabrizio Scala
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
This paper reports on a study of the attrition/fragmentation behavior of different bed materials and fuel pellets for application in fluidized bed gasification. Three different bed materials displaying catalytic activity, namely fresh and sintered dolomite and a Ni-alumina catalyst, were tested for their resistance to fragmentation and attrition in fluidized bed. The fresh dolomite displayed extensive particle breakage upon calcination and a large production of attrited fines during fluidized bed operation. The other two materials were much more resistant to attrition and appeared to be suitable for further long-term operation testing. The attrition/fragmentation resistance of three pelletized fuels, one based …
Shear-Assisted Fluidized Bed Powder-Coating,
2010
Università degli Studi del Sannio
Shear-Assisted Fluidized Bed Powder-Coating, Piero Bareschino, Francesco Pepe, Piero Salatino
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
This study addresses a novel concept of dense-fluidized bed coating of objects where the effectiveness of coating is promoted by the intentional and controlled establishment of shear flow around the object. The fluidized powder is sheared by the controlled oscillatory motion of the object with respect to the fluidized bed. The proof-of-concept is given with experiments carried out using a commercial powder specifically manufactured for dry coating applications in fluidized bed. Systematic analysis of the effect of different levels of shear rate on particle mobility/adhesion and effectiveness of coverage was performed. A simple descriptive model has been developed to provide …
Heat Transfer To Immersed Cooling Tubes And Particles In A Fluidized Bed Reactor,
2010
Sumitomo Chemical Company
Heat Transfer To Immersed Cooling Tubes And Particles In A Fluidized Bed Reactor, Y. Kobayashi, Y. Mori, A. Goto, H.T. Bi J.R. Grace
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A simple heat transfer model is utilized to determine the heat transfer coefficients for multiple tubes immersed in an industrial fluidized bed reactor supporting an exothermic reaction. From the temperatures at their outlets, superheating occurs in some blocks of tubes, but not in others. A four-zone heat transfer model is then used to evaluate the axial and lateral temperature differences due to the existence of a bottom un-cooled entrance zone and two cooled zones, corresponding to the regions where superheating does and does not occur.
Heat Recovery From Melted Blast Furnace Slag Using Fluidized Bed,
2010
Niigata University
Heat Recovery From Melted Blast Furnace Slag Using Fluidized Bed, Tadaaki Shimizu, Daisuke Haga, Go Mikami, Takayuki Takahashi, Kenji Horinouchi
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A novel fluidized bed system is proposed to recover heat from melted blast furnace slag. The melted slag is fed into a fluidized bed of crushed solid slag particles. The heat of slag solidification is transported to immersed heat transfer surface through fluidizing particles. The solid slag clumps, which consist of solidified slag and bed material, are removed from the bottom. A part of the slag clumps are crushed and recycled into the bed as bed material. In the present article, conceptual design of arrangement of heat transfer surface was carried out. Fundamental study of heat recovery from melted wax …
Modeling Of Mass Loss Of Char Particles During Combustion And Interaction With Inert Material,
2010
Czestochowa University of Technology
Modeling Of Mass Loss Of Char Particles During Combustion And Interaction With Inert Material, Piotr Pelka, Jacek Leszczynski
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The inspiration for this research was the numerical simulation of mass loss of char particles during its combustion in a CFB boiler. The mass loss was presented as the superposition of two separate processes i.e. combustion and surface erosion. The values obtained by the model and experimental data show a good level of conformity.
Hydrodynamics Of A Spout-Fluid Bed With An Enlarged Column For Fine Particles,
2010
China University of Petroleum
Hydrodynamics Of A Spout-Fluid Bed With An Enlarged Column For Fine Particles, Jian Xu, Lei Gong, Xiaojun Bao Dr., Weisheng Wei
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
In order to improve the spoutability for fine particles, a new type of spout-fluid bed with an enlarged column section was proposed. Comparison of flow regime maps for the new design with a conventional spout-fluid bed showed that the range of stable spouting regime was extended when an enlarged column section was employed.
A Conical Spouted Bed Reactor For The Valorisation Of Waste Tires,
2010
Universidad del País Vasco
A Conical Spouted Bed Reactor For The Valorisation Of Waste Tires, Gartzen Lopez, Maider Amutio, Gorka Elordi, Maite Artetxe, Haritz Altzibar, Martin Olazar
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A pilot plant provided with a conical spouted bed reactor has been used for the valorisation of waste tires by thermal pyrolysis in continuous mode. The effect of pyrolysis temperature on product distribution and properties has been studied in the temperature range from 425 to 600 ºC. This variable has proven to have an important effect on product distribution. Thus, pyrolysis oil yield was reduced from 64.3 wt% at 425 ºC to 55.9 wt% at 600 ºC. However, the quality of carbon black was improved operating at high temperatures (increasing BET surface area values). High yields of certain interesting chemicals …
Particle Segregation In Tapered Fluidized Beds,
2010
Trinity College, Dublin
Particle Segregation In Tapered Fluidized Beds, T. M. Gernon, Mark A. Gilbertson, R.S.J. Sparks
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
In practical situations, a bed of particles often has a wide range of sizes or is a mixture of differently sized components, and this allows a number of different segregation structures to form depending on local flow conditions. These vary systematically in tapered beds. This paper is an experimental investigation of the interaction between size segregation and the effects on local flows in a tapered bed.
Numerical And Experimental Steady State Flow And Heat Transfer In A Continuous Spouted Bed,
2010
Federal University of São Carlos, Rod.
Numerical And Experimental Steady State Flow And Heat Transfer In A Continuous Spouted Bed, Cezar A. Rosa, José T. Freire, Hamid Arastoopour
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Experimental measurements on heat transfer and flow properties and CFD simulations based on the two-fluid model (Eulerian-Eulerian approach) were performed in a draft tube continuous spouted bed system. The simulated results on the gas-particle flow patterns and the temperature distribution in the bed agreed well with our experimental data.
Numerical Study Of Bubbling Fluidized Beds: Influence Of Immersed Tubes, Extraction Methods And Averaging Periods,
2010
Brandenburg University of Technology Cottbus
Numerical Study Of Bubbling Fluidized Beds: Influence Of Immersed Tubes, Extraction Methods And Averaging Periods, Matthias Schreiber, Teklay Weldeabzgi Asegehegn, Hans Joachim Krautz
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Numerical simulations using the Two Fluid Model were performed for 2D gas-solid fluidized beds with and without immersed horizontal tubes. The results were compared with experimental data available in the literature. Different techniques of extracting the time-averaged values of pressure drop and bed expansion and the influence of averaging time were investigated. Furthermore, the influence of tubes on the solids motion and distribution were studied.
Basic Study For Coal Moisture Control Integrating Pneumatic Classification Technique,
2010
Chinese Academy of Sciences
Basic Study For Coal Moisture Control Integrating Pneumatic Classification Technique, Zhou-En Liu, Yin Wang, Yajun Tian, Yimin Xie, Wenfeng Ji, Guangwen Xu
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A technique of coal moisture control integrating pneumatic classification with flue gas as heating medium was put forward. With this technique, refined coal moisture control can be realized accompanying classification in one process, and considerable high-quality energy can be saved in coking and milling procedure. In this paper, coal classification and moisture control behaviors was investigated at different conditions. Based on experimental results, the basic parameters for the technique were worked out accordingly.
Numerical Study Of Bubble Hydrodynamics For Gas-Solid Fluidized Beds With And Without Horizontal Tubes,
2010
Brandenburg University of Technology Cottbus
Numerical Study Of Bubble Hydrodynamics For Gas-Solid Fluidized Beds With And Without Horizontal Tubes, Teklay W. Asegehegn, Hans Joachim Krautz
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The paper deals with numerical simulations using the Eulerian-Eulerian Two Fluid Model (TFM) of 2D gas-solid bubbling fluidized beds with and without immersed horizontal tubes. The bubble diameters and rise velocities obtained from the simulations presented good agreement when compared with experiments and correlations available in the literature. The presence of horizontal tubes inside the bed was found to be the main cause of bubble breakup, which eventually reduce the bubble diameter and rise velocity.
Biomass Gasification In Rotating Fluidized Bed,
2010
Ecole Polytecnique Montreal
Biomass Gasification In Rotating Fluidized Bed, Mania Abdollahi, Christophe Guy, Jamal Chaouki
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A steady-state mathematical model is developed for a rotating fluidized bed gasifier. Integrating reactor hydrodynamics with devolatilization kinetics, char gasification and combustion of both char and gas species; the model is used to present the gas-solid phenomena in novel reactor and investigates the reactor application in gasification processes. Model outputs are compared with experimental and simulation results of existing fluidized bed gasifier. It is observed that for the same equivalence ratio, the gasification process in RFB-SG is improved as a result of improved heat and mass transfer and gas-solid contact.
Direct Numerical Simulation Of Fluidized Bed With Immersed Boundary Method,
2010
Okayama University of Science
Direct Numerical Simulation Of Fluidized Bed With Immersed Boundary Method, Kenya Kuwagi, H. Utsunomiya, Y. Shimoyama, H. Hirano, T. Takami
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The applicability of the immersed boundary (IB) method, which is one of direct numerical simulations (DNS) for multiphase flow analyses, has been examined to simulate a fluidized bed. The volumetric-force type IB method developed by Kajishima et al. (2001) has been applied in the present work. While particle-fluid interaction force is calculated with the surface integral of fluid stress at the interface between particle and fluid in the standard IB method, the volume integral of interaction force is used in the volumetric-force type IB method. In order to validate the present simulation code, drag force and lift force firstly were …
Time-Averaged Modelling Of Cfbs – Analysis Of The Terms In The Momentum Equations,
2010
VTT, Finland
Time-Averaged Modelling Of Cfbs – Analysis Of The Terms In The Momentum Equations, Sirpa Kallio, Maiju Seppälä, Veikko Taivassalo
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The features of the terms in the time-averaged momentum equation for the solid phase are examined for three CFB units ranging from a laboratory-scale unit to a small CFB boiler. The CFD simulations were based on the Eulerian granular model of the Fluent software. The time-averaged terms calculated during the time dependent simulations are analysed and conclusions on their relative importance are drawn. An analysis of the terms in the vertical solids momentum equation in the central region of a CFB is presented.
Cfd Simulation Of The Reacting Flow Process Of Coal Pyrolysis To Acetylene In Hydrogen Plasma Downer Reactors,
2010
Tsinghua University
Cfd Simulation Of The Reacting Flow Process Of Coal Pyrolysis To Acetylene In Hydrogen Plasma Downer Reactors, Binhang Yan, Yi Cheng, Yong Jin, Yi Cheng
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A comprehensive computational fluid dynamics (CFD) model was established to describe the reacting flow of coal pyrolysis in hydrogen plasma downer reactors. The model predictions showed good accordance with the experimental results of the 2-MW and 5-MW pilot-plant reactors. The operating conditions were optimized to improve the 5-MW reactor performance.
Cfd-Dem Simulation Of Syngas-To-Methane Process In A Fluidized-Bed Reactor,
2010
Tsinghua University
Cfd-Dem Simulation Of Syngas-To-Methane Process In A Fluidized-Bed Reactor, Changning Wu, Dayong Tian, Yi Cheng
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The CFD-DEM coupled approach was used to simulate the gas-solid reacting flows in a lab-scale fluidized-bed reactor for syngas-to-methane (STM) process. The simulation results captured the major features of the reactor performance including unwanted defluidization. The fluidized-bed reactor showed good performances, such as in preventing the catalyst particles from overheating and sintering.
Cfd Simulation Of A Liquid-Fluidized Bed Of Binary Particles,
2010
University of British Columbia
Cfd Simulation Of A Liquid-Fluidized Bed Of Binary Particles, Long Fan, John Grace, Norman Epstein
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The ability of computational fluid dynamics to predict the expansion and segregation of a binary solids mixture in a liquid-solid fluidized bed is investigated. Unsteady laminar flow is simulated by a modified two-dimensional Eulerian-Eulerian model in Fluent 6.3. The predictions are compared with experimental results for binary particles in the same narrow (1.00-1.18 mm) size range, but with different densities, 1600 and 1900 kg/m3, fluidized by water (1). The voidages and heights of two layers which form, each dominated by one particle species, were found to be sensitive to small changes in particle properties (diameter, density, sphericity), as well as …
Fluidization Technology For Stable Startup Of Commercial Fcc Unit,
2010
SK energy Institute of Technology
Fluidization Technology For Stable Startup Of Commercial Fcc Unit, Sung Won Kim, Gyung Rok Kim, Jae Wook Shin, Ik Sang Yoo, Hun Sik Kang, Sang Hoon Park
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Conditions for maintaining good fluidization in the start-up of FCC have been determined. Catalyst defluidization and consequent catalyst losses from reactor cyclone are mainly affected by catalyst properties and stripper operating condition based on previous commercial startup experiences. Effect of fine catalyst contents on bed fluidity was determined. Bed fluidity in stripper was analyzed with slip velocity. Finally new startup guide was proposed and it was successfully applied to commercial FCC process of SK energy, Korea.
Performance Comparison Of Syngas Methanation On Fluidized And Fixed Bed Reactors,
2010
Chinese Academy of Sciences
Performance Comparison Of Syngas Methanation On Fluidized And Fixed Bed Reactors, Yingli Wang, Jiao Liu, Qiang Li, Jian Yu, Fabing Su, Guangwen Xu
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The performance was compared on Syngas Completely Methanation at atmospheric pressure on fluidized and fixed bed reactors. From space-time yield of CH4, coke content and hot spots of bed temperature, fluidized bed technology was demonstrated to be more applicable to Syngas Completely Methanation. Characterization results showed that different carbon deposition forms were presented on the two operation modes.
