Measurement of Particle Phase Stresses in Fast Fluidized Beds

Polashenski, William; Chen, John C.

doi:10.1021/ie980354n

Cited by 36 publications

(17 citation statements)

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“…Figure 13 shows the granular temperatures in this study compared to the measurements of granular temperature of large particles reported in literature 23, 28, 29, 30, 31, 32, 33, 34. Preliminary data were presented earlier at the 2004 Nanoscale Science and Engineering Grantee Conference Poster Session 27.…”

Section: Discussionmentioning

confidence: 81%

Wave propagation and granular temperature in fluidized beds of nanoparticles

Driscoll

Gidaspow

2007

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).The speeds of motion of compression waves through a fluidized bed of 10 nm silica particles were determined by measuring the times of arrival of compression zones using a light probe. A correlation for the modulus of elasticity was determined as a function of void fraction. Using a kinetic theory type equation of state for particles, this experimentally determined modulus gives a value for the granular temperature for 10 nm particles of approximately one (meter per second) squared. This value is close to that obtained by assuming the motion of the 10 nm particles to be due to collision with air molecules with no energy dissipation. The values of the granular temperature were also determined in a two-dimensional (2-D) fluidized bed by measuring the volume fraction distributions of 10 nm silica particles. Granular temperatures were deduced from a one-dimensional particle momentum balance using an ideal equation of state for particles, which is similar to the barometric formula for gases. These granular temperatures agreed with the measurements obtained from wave propagation experiments.

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Section: Discussionmentioning

confidence: 81%

Wave propagation and granular temperature in fluidized beds of nanoparticles

Driscoll

Gidaspow

2007

AIChE Journal

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“…Comparison of the computed total granular temperatures with literature based experimental data for CFB (Chalermsinsuwana et al 2011;Gidaspow and Mostofi 2003;Polashenski and Chen 1999) is shown in Fig. 16.…”

Section: Particles Granular Temperaturesmentioning

confidence: 99%

Hydrodynamic Study of Gas–Solid Internally Circulating Fluidized Bed Using Multiphase CFD Model

Gujjula

Mangadoddy

2015

Particulate Science and Technology

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Hydrodynamic study of gas and solid flow in an internally circulating fluidized bed (ICFB) is made in this study using the CFD multi-phase model. 2D and 3D computational meshes were used to represent physical ICFB geometries of 0.186 m and 0.3 m diameter columns. The model approach uses the two-fluid Eulerian model with kinetic theory of granular flow options to account particle-particle and particle-wall interactions. The model also uses the various drag laws to account the gas-solid phase interactions. The 2D simulation results by various drag laws show that the Arastoopour and Gibilaro drag models predict the fluidization dynamics in terms of flow patterns, void fractions and axial velocity fields in close agreement with the Ahuja et al (2008) experimental data. 3D simulations were also carried out for a large scale ICFB. The effect of superficial gas velocity and the presence of draft tube on solid hold-up distribution, solid circulation pattern, and gas bypassing dynamics for the 3D ICFB investigated extensively. The mechanism governing the solid circulation and the pressure losses in an ICFB has been explained based on gas and solid dynamics obtained from these simulations. Predicted total granular temperature distributions in 3D ICFB draft tube and the annular zone are qualitatively in agreement with the experimental data. The total Downloaded by [University of Colorado -Health Science Library] at 13:48 30 March 2015 2 granular temperature tends to increase with increasing solids concentrations and decrease with an increase of solids concentration.

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“…A relation was established by Ruckenstein (1966) based on equation (4.19) for non-homogeneous fluidization. Huilin(1996) 75µm FCC Polasenski andChen(1999) 94µm FCC Cody et al(1996) 70µm FCC Polasenski and 94µm FCC Jung (2003) 42µm 63µm Mehmet and Gidaspow (2003) 530µm Campbell and Wang(1991) 500µm Cody et al(1996) 420µm Polasenski and Chen(1997) 283µm Cody et al(1996) 297µm Jung (2003) 530µm 4.21) where, ϕ is the volume fraction of the fluidized bed occupied by the bubble and U B is the bubble rise velocity. Shi and Fan (1985) derived a similar relation.…”

Section: Dispersion Coefficients and Granular Temperature In Fluidizementioning

confidence: 99%

University/NETL Student Partnership Program

Holder¹

2003

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2 methane on the coal surfaces that may otherwise stay adsorbed in the coal matrix by decreasing the partial pressure of methane in the gas mixture. In addition, experimental work conducted on enhanced coalbed methane recovery by CO 2 injection [Reznik et al, 1984] shows that CO 2 is more adsorbing on coal than methane thereby giving it the potential to efficiently displace CBM and remain sequestered in the coal-seam. Thus coal-seams are considered to offer a very attractive option for CO 2 sequestration.In this work, focus is on the final part of the sequestration process -storage. The effects of various coal properties as well as operational scenarios on the injection and storage of CO 2 into a given coal-seam are analyzed. The analyses are based on results obtained from PSU-COALCOMP, a compositional coalbed methane numerical reservoir simulator capable of modeling the primary and enhanced recovery of coalbed methane.The operational design parameters considered in this study include the type, length and orientation of the injectors/producers while the coal-seam properties studied include coal porosity, coal permeability, cleat spacing, sorption capacity, and the initial conditions of the coal-seam -the reservoir pressure, adsorbed gas composition, amount of CO 2 initially adsorbed, water saturation and free-gas composition.Based on the data, results and analyses obtained, a CO 2 sequestration performance predictor tool is developed using artificial neural network (ANN) technology. The developed network will be able to predict the values of the performance indicators of the CO 2 sequestration process for a wide range of coal-seams and various production schemes. The developed ANN would also enhance our understanding of CO 2 sequestration process. 3 CHAPTER 2 LITERATURE REVIEW Carbon Dioxide SequestrationThe amount of carbon dioxide (CO 2 ) in the atmosphere has risen from preindustrial levels and most of this increase has been in recent years as shown in the data presented graphically in Figure 2-1. The corresponding increase in temperature as CO 2 levels increase raises environmental concerns such as global warming and its effects.This increase in CO 2 levels is attributed widely to the burning of fossil fuels, and if current trends in resource utilization continue, anthropogenic CO 2 emissions will increase rapidly during the 21 st century. Figure 2-2 shows the sharp increase in global CO 2 emissions over the last 100 years.The term "CO 2 sequestration" refers to the removal of CO 2 from either manmade emissions or the atmosphere and the safe, essentially permanent storage of this CO 2 .There are two main types of sequestration: direct sequestration, where CO 2 is removed from energy systems, and indirect sequestration, where CO 2 is removed from the ambient atmosphe re by enhanced natural processes. Sequestration is one of the three options for stabilizing CO 2 concentrations in the atmosphere and until the late 1990's, was not yet in the scientific lexicon. It is less familiar to the public at large than...

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Measurement of Particle Phase Stresses in Fast Fluidized Beds

Cited by 36 publications

References 30 publications

Wave propagation and granular temperature in fluidized beds of nanoparticles

Wave propagation and granular temperature in fluidized beds of nanoparticles

Hydrodynamic Study of Gas–Solid Internally Circulating Fluidized Bed Using Multiphase CFD Model

University/NETL Student Partnership Program

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