Hostname: page-component-76fb5796d-r6qrq Total loading time: 0 Render date: 2024-04-26T17:44:31.978Z Has data issue: false hasContentIssue false
  • English
  • Français

Report of a Symposium on Mechanics of Fluidized Beds

Published online by Cambridge University Press:  26 April 2006

G. M. Homsy ,
R. Jackson  and
J. R. Grace
G. M. Homsy
Affiliation:
Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
R. Jackson
Affiliation:
Department of Chemical Engineering, Princeton University, Princeton, NJ 08544, USA
J. R. Grace
Affiliation:
Department of Chemical Engineering, University of British Columbia, Vancouver V6T 1Z1, Canada
Get access Rights & Permissions [Opens in a new window]

Abstract

Fluidized beds are widely used in industry for carrying out a variety of chemical reactions and physical processes. Applications are frequently impeded by a lack of fundamental understanding of the mechanical behaviour of fluidized beds. Despite intensive experimental and theoretical study over the last four decades, there are still many aspects of fluidized beds and related fluid—particle systems that remain obscure. Further work is needed to understand interactions between the particles, influence of particle physical properties, development of non-obtrusive experimental techniques, and study of high-velocity beds and of novel-geometry beds in which particulate solids interact with interstitial fluid.

An international symposium was held at Stanford University on 1–4 July 1991 to discuss recent developments and the current state of knowledge and understanding of the mechanical behaviour of fluidized beds and related fluid—particle systems. The symposium was sponsored by the International Union of Theoretical and Applied Mechanics, and co-funded by the US Department of Energy, National Science Foundation and Electric Power Research Institute. The symposium was attended by 58 specialists representing academic institutions, industry and government research organizations in 11 countries. The diversity of background, coupled with differences in approach, ranging from purely theoretical to fully experimental, led to interesting exchanges where participants were often groping to understand the viewpoint of those involved. The result was frequently rewarding, occasionally perplexing, but certainly stimulating of thought and encouraging for further meetings of this nature.

The scientific committee for the Symposium were G. K. Batchelor (Cambridge University), J. J. H. Brouwers (Trent University), J. Gibilaro (University College London), J. R. Grace (University of British Columbia), G. M. Homsy (Stanford University) (Chairman), R. Jackson (Princeton University), R. I. Nigmatulin (Moscow University) and W. Schneider (Techische Universität Wien).

Each session began with an invited talk for one hour. This was followed by a series of 20-minute presentations. Participants were able at the end of each session to give brief (5 minute) unscheduled mini-presentations. Except for the latter, abstracts were submitted for the presentations, compiled by the organizers and distributed to participants. The meeting also included an informal workshop and a series of video and cinephotographic presentations not reported here. No formal proceedings of the meeting are being published; instead, this report is intended to summarize key findings and areas of discussion.

The titles of all formal presentations are identified with asterisks in the list of References. The report is organized around common themes, and the sequence of presentations may not be that in which they were given. The authors have endeavoured to interpret and extract the essence of the presentations, and apologize if any of the presentations have been misinterpreted or overlooked.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 236 , March 1992 , pp. 477 - 495
Copyright
© 1992 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

*Agarwal, P. K., Khakhar, D. V., Gururajan, V. S. & Lim, K. S. Raining of particles from an emulsion-gas interface in a fluidized bed. Also, submitted to Chem. Engng Sci.
Bashir, Y. M. & Goddard, J. D. 1991 A novel simulation method for the quasi-static mechanics of granular assemblages. J. Rheol. 35, 849–885.Google Scholar
Basu, P. (Ed.) 1986 Circulating Fluidized Bed Technology. Pergamon.
Batchelor, G. K. 1988 A new theory of the instability of a uniform fluidized bed. J. Fluid Mech. 193, 75–110.Google Scholar
*Batchelor, G. K. Hydrodynamic interaction of particles and its consequences.
Baxter, G. W., Behringer, R. P., Fagert, T. & Johnson, G. A. 1989 Pattern formation in flowing sand. Phys. Rev. Lett. 62, 2825–2829.Google Scholar
Baxter, G. W., Leone, R. & Behringer, R. P. 1991 Time-dependence and pattern formation in flowing sand. Eur. J. Mech. B 10, 181–186.Google Scholar
Baxter, G. W., Leone, R. & Behringer, R. P. 1992 Experimental determinations of time-scales in flowing sand. Phys. Rev. Lett. (submitted).Google Scholar
*Behringer, R. P., Baxter, G. W., Leone, R. & Johnson, G. A. Time-dependence, scaling and pattern formation in flowing sand.
*Brouwers, J. J. H. Coal combustion in a fluidized bed.
*Buggisch, H. Wall effects in granular flow.
*Buyevich, Y. A. Fluctuations and dispersion in fluidized beds.
Campbell, C. S. & Wang, D. G. 1990 A particle pressure transducer suitable for use in gasfluidized beds. Measurement Sci. Technol. 1, 1275–1279.Google Scholar
*Campbell, C. S. Particle pressures in gas-fluidized beds.
Campbell, C. S. & Wang, D. G. 1991 Particle pressures in gas-fluidized beds. J. Fluid Mech. 227, 495–508.Google Scholar
*Caram, H. S. & Pierrat, P. 1992 Bubble formation and gas leakage in beds at minimum fluidization conditions. Also, submitted to Fluidization VII Conf.Google Scholar
*Chen, M. M., Sun, J. G. & Hoang, T. Radioactive particle tracking measurements of particle dynamics in gas fluidized beds.
*Clift, R. Forces on horizontal tubes in fluidized beds.
*Dankworth, D. C. & Sundaresan, S. Time-dependant flow patterns arising from the instability of uniform fluidization.
Davidson, J. F. 1991 The two phase theory of fluidization: successes and opportunities. AIChE Symp. Series, vol. 87, No. 281, pp. 1–12.
Davidson, J. F. & Harrison, D. 1963 Fluidized Particles. Cambridge University Press.
Davis, R. H. & Hassen, M. A. 1988 Spreading of the interface at the top of a slightly polydisperse sedimenting suspension. J. Fluid Mech. 196, 107–134.Google Scholar
Epstein, N. & Grace, J. R. 1984 Spouting of particulate solids. In Handbook of Powder Science and Technology (ed. L. Otten & M. Fayed), chap. Ii. Van Nostrand-Reinhold.
*Felderhof, B. U. Virtual mass in two-phase flow.
*Felderhof, B. U. 1991 Virtual mass and drag in two-phase flow. J. Fluid Mech. 225, 177–196.Google Scholar
*Felice, R. di A pseudo-fluid model to describe the behaviour of binary-solid suspensions.
*Filla, M., Massimilla, L., Musmarra, D. & Vaccaro, S. Propagation velocities of disturbances originated by gas jets in fluidized beds. Also, submitted to Intl J. Multiphase Flow.
Foscolo, P. U. & Gibilaro, L. G. 1984 A fully predictive criterion for the transition between aggregative and particulate fluidization. Chem. Engng Sci. 39, 1667–1675.Google Scholar
Goddard, J. D. 1990 Nonlinear elasticity and pressure-dependent wave speeds in granular media. Proc. R. Soc. Lond. A 430, 105–131.Google Scholar
*Goddard, J. D. Reynolds dilatancy, microstructural breakdown and seismic liquefaction in granular media.
*Goez, M. F. Bifurcation analysis of fluidized bed equations.
Goez, M. 1990 Instabilities and bifurcations in a two-dimensional bed model. Z. Angew Math. Mech. 70, 386–388.Google Scholar
Goez, M. 1992 On the origin of wave patterns in fluidized beds. J. Fluid Mech. (submitted).Google Scholar
*Grace, J. R. Influence of particle size distribution on the behaviour and performance of fluidized beds.
Grace, J. R. & Sun, G. 1991 Influence of particle size distribution on the performance of fluidized bed reactors. Can. J. Chem. Engng 69, 1126–1134.Google Scholar
Haff, P. K. 1983 Grain flow as a fluid mechanical phenomenon. J. Fluid Mech. 138, 401–430.Google Scholar
Ham, J. M. & Homsy, G. M. 1988 Hindered settling and hydrodynamic dispersion in quiescent sedimenting suspensions. Intl J. Multiphase Flow 14, 533–546.Google Scholar
Ham, J. M., Thomas, S., Guazzelli, E., Homsy, G. M. & Anselmet, M.-C. 1990 An experimental study of the stability of liquid-fluidized beds. Intl J. Multiphase Flow 16, 171–185.Google Scholar
*Hanes, D. M. The thickness of a collisional, granular, shear flow in a half-space with gravity.
Hanes, D. M. & Inman, D. L. 1985a Observations of rapidly flowing granular-fluid materials. J. Fluid Mech. 150, 357–380.Google Scholar
Hanes, D. M. & Inman, D. L. 1985b A dynamic yield criterion for granular materials. J. Geophys. Res. 90, 3670–3674.Google Scholar
*Honing, G. van der Bubble initiated turbulent mixing above fluidized beds.
Honing, G. van der 1991 Volatile and char combustion in large scale fluidised bed coal combustors, Ph.D. thesis. Twente University.
Hopkins, M. A. & Louge, M. Y. 1991 Inelastic microstructure in rapid granular flow of smooth disks. Phys. Fluids A 3, 47–57.Google Scholar
Hui, K., Haff, P. K., Ungar, J. E. & Jackson, R. 1984 Boundary conditions for high-shear grain flows. J. Fluid Mech. 145, 223–233.Google Scholar
*Jackson, R. The elusive fluidized bed: does it really exist?
*Jansen, G. H. & Romate, J. E. Modelling of two-phase riser flow.
*Jenkins, J. T. Viscous fluctuations and the fluidization of concentrated suspensions.
Koch, D. L. 1992 Anomalous diffusion of momentum in a dilute gas—solid suspension. Phys. Fluids (submitted).Google Scholar
*Koch, D. L. & Kumaran, V. Kinetic theory for gas—solid suspensions.
*Kok, J. B. W. Propagation velocity and rate of attenuation of surface waves on a homogeneously fluidized bed. Also, submitted to Intl J. Multiphase Flow.
*Kuipers, J. A. M., Prins, W. & Swaaij, W. P. M. van Theoretical and experimental bubble formation at a single orifice in a two-dimensional gas-fluidized bed. Chem. Engng Sci. 46, 2881–2894 (1991).
*Ladd, A. J. C. Dissipative and fluctuating hydrodynamic interactions via lattice-gas cellular automata.
Lin, J. S., Chen, M. M. & Chao, B. T. 1985 A novel radioactive tracking facility for measurement of solids motion in straight and tapered fluidized beds. AIChE J. 10, 924–929.Google Scholar
Louge, M., Mastorakos, E. & Jenkins, J. T. 1991 The role of particle collisions in pneumatic transport. J. Fluid Mech. 231, 345–359.Google Scholar
*Louge, M., Yusof, J. M., Jenkins, J. T. & Mastorakos, E. Heat transfer in the pneumatic transport of massive particles. Also, submitted to Intl J. Heat Mass Transfer.
Lu, L.-J. & Schaeffer, D. 1991 The flutter instability in granular flow. J. Mech. Phys. Solids (in press).Google Scholar
Lun, C. K. K., Savage, S. B., Jeffrey, D. J. & Chepurniy, N. 1984 Kinetic theories for granular flow: inelastic particles in Couette flow and slightly inelastic particles in a general flow. J. Fluid Mech. 140, 223–256.Google Scholar
*Milne, B. J., Berruti, F. & Behie, L. A. Gas and particle flow characteristics in the entrainment region of spouted and spout-fluid beds with draft tubes.
Muir, J., Berruti, F. & Behie, L. A. 1990 Solids circulation in spouted and spout-fluid beds with draft tubes. Chem. Engng Commun. 88, 153–171.Google Scholar
Needham, D. J. 1984 Surface waves on a homogeneously fluidized bed. J. Engng Maths 18, 259–271.Google Scholar
*Nigmatulin, R. I. Continua mechanics and averaging theory for monodisperse gas-particle suspension with a random motion and collision of dispersed particles.
Richman, M. W. & Chou, C. S. 1988 Boundary effects on granular shear flows of smooth disks. Z. Angew. Math. Phys. 39, 885–901.Google Scholar
*Salatino, P., Poletto, M. & Massimilla, L. Stability of uniform gas fluidized beds operated with CO2 in ranges of pressure and temperature between ambient and nearly critical conditions.
*Sangani, A. S. & Didwania, A. K. Dynamic simulation of bubbly flows at large Reynolds numbers.
*Savage, S. B. Diffusion. stability and segregation in granular shear flows.
Savage, S. B. 1992 Instability of an unbounded uniform granular shear flow. J. Fluid Mech. (in press).Google Scholar
*Schaeffer, D. G. The flutter instability in granular flow.
Schofield, A. & Wroth, P. 1968 Critical State Soil Mechanics. McGraw-Hill.
Schugerl, K., Merz, M. & Fetting, F. 1961 Rheologische Eigenschaften von gasdurchströmten Fliessbet systemen. Chem. Engng Sci. 5, 1–38.Google Scholar
*Singh, P. & Joseph, D. D. Finite size effects in fluidized beds.
Singh, P. & Joseph, D. D. 1992 Dynamics of fluidized suspensions of spheres of finite size. J. Fluid Mech. (submitted).Google Scholar
Spalding, D. B. 1971 Concentration fluctuations in a round turbulent free jet. Chem. Engng Sci. 26, 95–107.Google Scholar
Stocker, R. K., Eng, J. H. & Behie, L. A. 1990 Hydrodynamic and thermal modelling of a high temperature spouted bed reactor with a draft tube. Can. J. Chem. Engng 68, 302–311.Google Scholar
Tchen, C. M. 1947 The motion of small particles suspended in a turbulent flow. Ph.D. thesis, Delft University of Technology, The Hague.
*Thornton, C., Kafui, D. K. & Yin, K. K. Computer simulated agglomerate collisions.
Tsuji, Y., Morikawa, Y. & Shiomi, H. 1984 LDV measurements of an air—solid two-phase flow in a vertical pipe. J. Fluid Mech. 139, 417–434.Google Scholar
Van Bruegel, J. W., Stein, J. J. M. & de Vries, R. J. 1969 Isokinetic sampling in a dense gas—solids stream. Proc. Inst. Mech. Engrs 184, 18–23.Google Scholar
*Wallis, G. B. Decompression waves in fluidized beds.
*Walton, O. Computer simulation of inclined chute flow.
*Werther, J. Particle motion and dispersion of gas in circulating fluidized beds.
*Wirth, K. E. Fluid mechanics of circulating fluidized beds.
Wirth, K. E. 1991 Fluid mechanics of circulating fluidized beds. Chem. Engng Technol. 14, 29–38.Google Scholar
*Zenz, F. A. 1971 Regimes of fluidized behaviour. In Fluidization (ed. J. F. Davidson & D. Harrison), pp. 1–23. Academic.
*Zierfuss, R. & Schneider, W. Jet-like flows in fluidized and packed beds.
*Zierfuss, R. & Schneider, W. 1992 Jet flows in fluidized beds. Z. Angew Math. Mech. (in press).Google Scholar