Skip to main content
SpringerLink
Log in

Experimental Research of Flow Structure in a Gas-Solid Circulating Fluidized Bed Riser by PIV

  • Published:
Journal of Hydrodynamics Aims and scope Submit manuscript

Abstract

Particle Imaging Velocimetry (PIV) techniques were applied to investigate the particle motion and cluster properties in a gas-solid two-phase flow in a circulating fluidized bed riser. Visual images and micro-structure of various clusters were captured. After the boundary of clusters was determined by the gray level threshold method, clusters were classified by the distance between particles and the shape and position of clusters. In addition, the process of clusters forming and breaking up was described, and the sizes of clusters were also obtained. With the Minimum Quadric Difference (MQD) cross-correlation algorithm suitable for high-density particles, the axial velocities of the particles were obtained in the dilute phase section. The features of particle motion were revealed by investigating statistically the magnitude and distribution of particle axial velocity in the radial direction. At most radial cross-sections, there exists a parabola-shaped distribution of upward axial velocity of particles, namely, the magnitude of axial velocity in the core region is higher than that near the wall region of the riser.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

Cfg :

Coefficient of cross-correlation

dp :

Average diameter of bed material

h1 :

Height of bed materials

N, M:

Number of pixels

W:

Distance from the center to the wall

X:

Distance from the cross-section to the wall in the x direction

Y:

Distance from the cross-section to the wall, in the y direction

fij, gij :

Pixels’ gray ijg

f(x,y):

Gray level distribution function

g(x,y):

Gray level distribution function

Gs :

Solid circulation flux

h:

Height of the cross-section above the distributor

t:

time

Δt:

Internal of the time

Ug :

Fluidization velocity

α:

Mass fraction

U:

Average for the velocity of particles

References

  1. LIU Ying-zheng, CAO Zhao-min. Recent progress on particle image velocimetry in China[J]. Journal of Hydrodynamics, Ser. B, 2006, 18(1): 11–19.

    Google Scholar 

  2. ZHANG Wei, Daichin. Experimental research of flow structure behind a circular cylinder with wave surface by PIV[J]. Journal of Hydrodynamics, Ser. B, 2006, 18(1): 97–103.

    MathSciNet  Google Scholar 

  3. SHI Hui-xian, WANG Qin-hui and LUO Zhong-yang et al. The application of PIV in gas-solid multiphase flow[J]. Power Engineering, 2002, 22(1): 1589–1593 (in Chinese).

    Google Scholar 

  4. SHI Hui-xian, WANG Qin-hui and WANG Can-xing et al. PIV measurement of the gas-solid flow pattern in a CFB riser[J]. Journal of Hydrodynamics, Ser. B, 2003, 15(6): 39–44.

    Google Scholar 

  5. HORIO M., KUROKI H. Three-dimensional flow visualization of dilute dispersed solids in bubbling and circulating fluidized beds [J]. Chem. Eng. Sci., 1993, 49: 2413–2421.

    Article  Google Scholar 

  6. KUROKI H., HORIO M. The flow structure of a three-dimensional circulating fluidized bed observed by the laser sheet technique[C]. Proc. 4th International conf. on circulating fluidized beds. New York, USA, 1994, 77–84.

    Google Scholar 

  7. WERTHER J. Measurement techniques in fluidized beds[J]. Powder Technology, 1999, 102(1): 15–36.

    Article  Google Scholar 

  8. LACKERMEIER U., RUDNICK C. and WERTHER J. et al. Visualization of flow structures inside a circulating fluidized bed by means of laser sheet and image processing[J]. Powder Technology, 2001, 114(1–3): 71–83.

    Article  Google Scholar 

  9. QU Jian-wu, MURAI Yui-chi and YAMAMOTO Fujio. Simultaneous PIV/PTV measurements of bubble and particle phase in gas-liquid two-phase flow based on image separation and reconstruction[J]. Journal of Hydrodynamics, Ser. B, 2004, 16(6): 756–766.

    Google Scholar 

  10. ADRIAN R. Particle-imaging techniques for experimental fluid mechanism[J]. Annu. Rev. Fluid Mech., 1991, 23: 261–304

    Article  Google Scholar 

  11. HARTMAN J., KOHLER J. and STOLZ W. et al. Evaluation of instationary flow fields using cross-correlation in image sequences[J]. Exp. in Fluids, 1997, 20: 210–217.

    Article  Google Scholar 

  12. WANG Can-xing, LIN Jin-zhong and YAMAMOTO Fujio. An algorithm for two-dimensional PIV image [J]. Journal of Hydrodynamics, Ser. A, 2001, 16(4): 399–404 (in Chinese).

    Google Scholar 

  13. WANG Can-xing, LIN Jin-zhong and YAMAMOTO Fujio. An algorithm for three-dimensional PIV based on the cross-correlation [J]. Journal of Hydrodynamics, Ser. A, 2002, 17(2): 162–173 (in Chinese).

    Google Scholar 

  14. MANYELE S.V., PÄRSSINEN J. H. and ZHU J. X. Characterizing particle aggregates in a high-density and high-flux CFB riser[J]. Chemical Engineering Journal, 2002, 88: 151–161.

    Article  Google Scholar 

  15. BI H. T., ZHU J. X. and JIN Y. et al. Forms of particles aggregations in CFB[C]. Proc. 6th Chinese Conf. on Fluidization. Wuhan, 1993, 162–167.

    Google Scholar 

  16. LIM K. S., ZHU J. X. and GRACE J. R. Hydrodynamics of gas-solid fluidization[J]. Int. J. multiphase Flow, 1995, 21: 141–193.

    Article  Google Scholar 

  17. LI J., TUNG Y. and KWAUK M. Method of energy minimization in multi-scale modeling of particle-fluid two-phase flow[C]. Proc. 2th International conf. on circulating fluidized beds. Toronto, Canada, 1988, 89–103.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Modern Agricultural Science and Engineering Institute, Tongji University, Shanghai, 200092, China

    Hui-xian Shi

Authors
  1. Hui-xian Shi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Hui-xian Shi.

Additional information

Biography: SHI Hui-xian (1969-), Female, Ph. D., Associate Professor

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shi, Hx. Experimental Research of Flow Structure in a Gas-Solid Circulating Fluidized Bed Riser by PIV. J Hydrodyn 19, 712–719 (2007). https://doi.org/10.1016/S1001-6058(08)60008-6

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1016/S1001-6058(08)60008-6

Key words

Search

Navigation