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Full-Text Articles in Engineering
Improved Gas-Solid Mixing And Mass Transfer In A Pulsed Fluidized Bed Of Biomass With Tapered Bottom, Dening Jia, C. Jim Lim, Xiaotao Bi, Shahab Sokhansanj, Atsushi Tsutsumi
Improved Gas-Solid Mixing And Mass Transfer In A Pulsed Fluidized Bed Of Biomass With Tapered Bottom, Dening Jia, C. Jim Lim, Xiaotao Bi, Shahab Sokhansanj, Atsushi Tsutsumi
Fluidization XV
To improve fluidization quality and mass transfer rate of biomass fluidized beds with pulsed gas flow, an existing fluidized bed with rectangular cross-section area was modified with the insertion of a tapered bottom section such that dead zones observed in the original design could be eliminated. Batch drying tests were performed as an indirect indicator of gas-solid contact efficiency and mass transfer performance. Compared to the original design, biomass particles could be fluidized at a wider range of gas pulsation frequencies with significantly reduced channeling and gas bypassing in the new tapered design. Faster drying and thus improved mass transfer …
Investigation Of The Effect Of Fluidization Time On Electrostatic Charge Generation In Gas-Solid Fluidized Beds, Amanda Giffin, Andrew Sowinski, Poupak Mehrani
Investigation Of The Effect Of Fluidization Time On Electrostatic Charge Generation In Gas-Solid Fluidized Beds, Amanda Giffin, Andrew Sowinski, Poupak Mehrani
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
This work focused on determining the effect of the fluidization time on particle charging. Charge equilibrium was reached on the bed particles after 60 minutes. The wall particle layer was built with negative and positive charges. Similar sized particles migrated to each region of the bed regardless of fluidization time.
Study Of Solids Entrainment Into Attrition Jets In Fluidized Beds, Feng Li, Cedric Briens, Franco Berruti, Jennifer Mcmillan
Study Of Solids Entrainment Into Attrition Jets In Fluidized Beds, Feng Li, Cedric Briens, Franco Berruti, Jennifer Mcmillan
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Supersonic nozzles are applied to various fluidized bed processes, such as the production of pharmaceutical powders, fluid catalytic cracking, and fluid coking. In applications such as jet milling, it is essential to entrain a maximum flow-rate of solids from the fluidized bed into the jet cavity. Studies of solid entrainment rate into gas jets have been mostly conducted with subsonic jets and none with convergent-divergent nozzles. The purpose of this research is to study solids entrainment into jets issuing from supersonic convergent-divergent nozzles, and particularly the effects of nozzle size, nozzle mass flow-rate, injection gas properties and fluidization velocity. A …
Effects Of Particle Size And Fluidizing Velocity On The Charge Density Of Entrained Fines, Xiaotao T. Bi, John Grace, Kwang Seok Choi, Muammar Omar
Effects Of Particle Size And Fluidizing Velocity On The Charge Density Of Entrained Fines, Xiaotao T. Bi, John Grace, Kwang Seok Choi, Muammar Omar
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A previously-developed Faraday cup fluidized bed unit was modified to facilitate the in-situ monitoring of the transient entrainment rate and net charge of entrained fine powders. This enabled the determination of the transient charge density as a function of particle size and residence time of entrained fine particles. The results showed that the charge density increased significantly with increasing size of entrained fines, but was not very sensitive to the residence time and the fluidizing gas velocity for the finest entrained particles at gas velocities of 0.24 and 0.36 m/s. At Ug=0.48 m/s, the charge density of larger particles increased …
Development Of A Continuous Nanoparticle Coating With Electrospraying, N. Ellis, J. Ruud Van Ommen, C.U. Yurteri
Development Of A Continuous Nanoparticle Coating With Electrospraying, N. Ellis, J. Ruud Van Ommen, C.U. Yurteri
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Coating of micron-sized particles (host particles) with nanoparticles can result in modifying the surface properties of host particles leading to various applications. This work presents a novel concept of combining the electrospraying of nanoparticles onto the charged particles entrained out of the fluidized bed for developing a continuous coating process. By controlling the processes to effectively charge and contact particles using electric forces, we are able to fine-tune the properties of the obtained nano-coated particles.
Experimental And Computational Study On The Bubble Behavior In A 3-D Fluidized Bed With A Vertical-Axis, Rotating Distributor, Antonio Acosta Iborra, F. Hernández-Jiménez, C. Sobrino, M. De Vega
Experimental And Computational Study On The Bubble Behavior In A 3-D Fluidized Bed With A Vertical-Axis, Rotating Distributor, Antonio Acosta Iborra, F. Hernández-Jiménez, C. Sobrino, M. De Vega
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
This work presents experimental measurements in a three-dimensional fluidized bed equipped with a novel vertical-axis, rotating distributor, together with two-fluid (Eulerian-Eulerian) CFD simulation results. The influence of the distributor rotation on the behavior of the bubbles in the experiments and in the CFD results is compared and critically analyzed.
The Influence Of Particle Attrition On Sorbent Inventory And Particle Size Distribution In Air-Blown Circulating Fluidized Bed Combustors, Piero Salatino, Fabio Montagnaro, Fabrizio Scala, Massimo Urciuolo
The Influence Of Particle Attrition On Sorbent Inventory And Particle Size Distribution In Air-Blown Circulating Fluidized Bed Combustors, Piero Salatino, Fabio Montagnaro, Fabrizio Scala, Massimo Urciuolo
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
This paper presents a population balance model aiming at the prediction of sorbent inventory and particle size distribution establishing at steady state in the bed of an air-blown circulating fluidized bed combustor fuelled with a sulphur-bearing solid fuel. The core of the model is represented by population balance equations on sorbent particles which embody terms expressing the extent/rate of sorbent attrition/fragmentation. The effect of the progress of sulphation on attrition and fragmentation is taken into account by selection of appropriate constitutive equations. Model results are presented and discussed with the aim of clarifying the influence of particle attrition/fragmentation on sorbent …
Design Of New Fluidized Bed Reactors For Cvd - Processes, T. Strer, M. Schober, K.-E. Wirth
Design Of New Fluidized Bed Reactors For Cvd - Processes, T. Strer, M. Schober, K.-E. Wirth
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A new concept of fluidized bed will be shown which can be used for various gas-tosolids reactions (e.g. chemical vapour deposition (CVD) reactions) with high throughput like the production of new materials. For the design and scale-up of the new bubbling fluidized bed with vertically aligned vertical nozzles the fluid dynamics of the fluidized beds have to be determined and analysed, especially the flow around the gas nozzles. A jet region around a single centrally arranged injector lance in a bubbling fluidized bed reactor is characterized by different parameters like solids concentration and jet gas distribution. It can be shown …
Challenges With The Coupling Of Fluidized Beds For Chemical Looping Combustion, Marvin Kramp, Andreas Thon, Ernst-Ulrich Hartge, Stefan Heinrich, Joachim Werther
Challenges With The Coupling Of Fluidized Beds For Chemical Looping Combustion, Marvin Kramp, Andreas Thon, Ernst-Ulrich Hartge, Stefan Heinrich, Joachim Werther
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
In the present work the system of interconnected fluidized bed reactors of a Chemical Looping Combustion (CLC) process is simulated in pilot plant scale and 100 MWth scale. Attrition models, derived from small scale laboratory experiments, are employed to predict the behavior of a large scale CLC process in terms of attrition and oxygen carrier (OC) losses. Realistic circulation mass flows of OC are calculated and the sources of the losses are further investigated. Different arrangements of cyclones are evaluated for their potential to improve the solids recovery. For example the introduction of a second-stage cyclone separation for the air …
Co-Gasification Of Coal And Wood In A Dual Fluidized Bed Gasifier Variation Of Fluidization Conditions And Load Ratio, Christoph Pfeifer, Isabella Aigner, Hermann Hofbauer
Co-Gasification Of Coal And Wood In A Dual Fluidized Bed Gasifier Variation Of Fluidization Conditions And Load Ratio, Christoph Pfeifer, Isabella Aigner, Hermann Hofbauer
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Within this work the use of coal has been tested in a dual fluidized bed 100 kW - steam blown- gasifier originally designed for wood. With adjustments like fluidization conditions and fuel load, it is possible to gasify coal in load-ratios from 0 % to 100 % with this technology.
Steam Gasification Of Low Rank Coal Chars In A Thermobalance Reactor And A Fluidized Bed Reactor, Byungho Song, Xueyan Zhu, Woongsig Moon, Won Yang
Steam Gasification Of Low Rank Coal Chars In A Thermobalance Reactor And A Fluidized Bed Reactor, Byungho Song, Xueyan Zhu, Woongsig Moon, Won Yang
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The six chars of low rank coals have been gasified with steam in a thermobalance reactor and one lignite in a fluidized bed to obtain the kinetic information needed for a design of coal gasifier. The gas-solid reaction models have been compared for their prediction ability of the gasification reaction behavior. The apparent reaction rate equations have been presented.
Novel Two-Interconnected Fluidized Bed System For Selective Solid Circulation, Ho-Jung Ryu, Jaehyeon Park, Dowon Shun, Seung-Yong Lee
Novel Two-Interconnected Fluidized Bed System For Selective Solid Circulation, Ho-Jung Ryu, Jaehyeon Park, Dowon Shun, Seung-Yong Lee
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A novel two-interconnected fluidized bed system was developed to separate fine and coarse particles by means of particle size difference. Coarse (212~300 μm) and fine (63~106 μm) particles were separated perfectly using the solid separator. The effects of the fluidizing velocity, solid injection velocity, diameter of solid injection nozzle, and solid height on the solid separation rate were investigated. Moreover, continuous solid separation and circulation test up to 20 hours was performed to check feasibility of stable operation.
Attrition Of Bed Materials And Fuel Pellets For Fluidized Bed Gasification Application, P. Ammendola, R. Chirone F. Miccio, G. Ruoppolo, Fabrizio Scala
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, Piero Bareschino, Francesco Pepe, Piero Salatino
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 Recovery From Melted Blast Furnace Slag Using Fluidized Bed, Tadaaki Shimizu, Daisuke Haga, Go Mikami, Takayuki Takahashi, Kenji Horinouchi
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 …
Particle Segregation In Tapered Fluidized Beds, T. M. Gernon, Mark A. Gilbertson, R.S.J. Sparks
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.
Fluidized Bed Combustion Of C1-C4 N-Alkanes, Jean-Philippe Laviolette, Gregory S. Patience, Jamal Chaouki
Fluidized Bed Combustion Of C1-C4 N-Alkanes, Jean-Philippe Laviolette, Gregory S. Patience, Jamal Chaouki
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The non-premixed combustion of C1 to C4 n-alkanes was investigated inside a bubbling fluidized bed of inert sand particles at intermediate temperatures: 923 K (650oC) ≤ TB ≤ 1123 K (850oC). Lower (T1) and upper (T2) critical transition bed temperatures were measured for ethane, propane and n-butane as 923 K (650oC) and 1073 K (800oC), respectively. The values for methane were significantly higher with T1 = 1023 K (750oC) and T2 > 1123 K (850oC). Alkane conversion was accurately modeled with first-order kinetics and C2 to C4 n-alkanes combustion rates were characterized by a uniform Arrhenius expression: (. The reaction rate …
Penetration Of High Velocity Horizontal Gas Jets Into A Fluidized Bed At High Temperature, Cedric Briens, Feng Li, Franco Berruti, Jennifer Mcmillan
Penetration Of High Velocity Horizontal Gas Jets Into A Fluidized Bed At High Temperature, Cedric Briens, Feng Li, Franco Berruti, Jennifer Mcmillan
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
High velocity horizontal gas jets are applied to various industrial processes. In this work, a new thermal technique has been developed to measure the penetration length of horizontal gas jets. Experiments were conducted in a fluidized bed with a height of 1.23m and a rectangular cross section of 0.10m × 0.50m. The fluidized bed particles, which were either petroleum coke or sand, were heated by an in-bed electrical heater to temperatures between 300°C and 500°C. Cold gases, such as helium, nitrogen, carbon dioxide, were injected into the hot fluidized bed via a horizontal nozzle operating over a range of velocities. …
Evaluation Of Fluid Dynamics In A Hot And A Cold System Of Interconnecting Fluidised Beds, Fredrik Lind, Martin Seemann, Henrik Thunman
Evaluation Of Fluid Dynamics In A Hot And A Cold System Of Interconnecting Fluidised Beds, Fredrik Lind, Martin Seemann, Henrik Thunman
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Operation controllability and fluid dynamics were evaluated in a system of interconnecting fluidised beds. Results indicate that the solid circulation is controllable and possible to determine from pressure measurements. Sufficient gas tightness of the loop-seals and flexibility in controlling of solid fluxes was indicated.
Modeling Of An Interconnected Fluidized Bed Reactor For Chemical Looping Combustion, Min Xu, Naoko Ellis, Ho-Jung Ryu , C. Jim Lim
Modeling Of An Interconnected Fluidized Bed Reactor For Chemical Looping Combustion, Min Xu, Naoko Ellis, Ho-Jung Ryu , C. Jim Lim
The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering
Chemical Looping Combustion (CLC) is comprised of two reactors, in which direct contact between air and fuel is avoided. A metal oxide, as oxygen carrier, transports oxygen from the air reactor to the fuel reactor while circulating between them. Based on the hydrodynamics coupled with reaction kinetics of oxygen carrier from the literature, a model for an interconnected fluidized bed reactor has been developed to optimize the design and operation of the reactor system. The model considers the chemical reaction of a single particle and a particle population balance for the calculation of bed particle conversion. The core-annulus and two-phase …
Combustion Studies Of Sawdust In A Bubbling Fluidized Bed, K.V.N. Srinivasa Rao
Combustion Studies Of Sawdust In A Bubbling Fluidized Bed, K.V.N. Srinivasa Rao
The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering
Biomass fuels are difficult to handle due to high moisture and fines content. In the present work, the effect of secondary air injection on combustion efficiency of sawdust in the fluidized bed combustor has been discussed. An enlarged disengagement section is provided to improve combustion of fines. The maximum possible combustion efficiency with saw dust is 99.2 % and is observed at 65 % excess air.
A Discrete Particle Simulation Study Of Solids Mixing In A Pressurized Fluidized Bed, Willem Godlieb, Niels G. Deen, J.A.M. Kuipers
A Discrete Particle Simulation Study Of Solids Mixing In A Pressurized Fluidized Bed, Willem Godlieb, Niels G. Deen, J.A.M. Kuipers
The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering
A fluidized bed containing polymeric particles is investigated using a state-of-the-art soft-sphere discrete particle model (DPM). The pressure dependency of particle mixing, flow patterns and bubble behaviour are analysed. It is found that with increasing pressure a less distinct bubble-emulsion structure and improved solids mixing can be observed.