Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Characteristics of Minimum Fluidization Velocity and Pressure Fluctuations in Annular Fluidized Beds

Annular 유동층 반응기에서 최소유동화 속도 및 압력요동 특성

  • Son, Sung-Mo (School of Chemical Engineering, Chungnam National University) ;
  • Kim, Uk-Yeong (School of Chemical Engineering, Chungnam National University) ;
  • Shin, Ik-Sang (School of Chemical Engineering, Chungnam National University) ;
  • Kang, Yong (School of Chemical Engineering, Chungnam National University) ;
  • Choi, Myung-Jae (Advanced Chemical Technology Division, Korea Research Institute of Chemical Technology)
  • 손성모 (충남대학교 화학공학과) ;
  • 김욱영 (충남대학교 화학공학과) ;
  • 신익상 (충남대학교 화학공학과) ;
  • 강용 (충남대학교 화학공학과) ;
  • 최명재 (한국화학연구원, 신화학연구단)
  • Received : 2008.04.08
  • Accepted : 2008.05.07
  • Published : 2008.08.31
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Abstract

Characteristics of minimum fluidization velocity and pressure fluctuations were investigated in an annular fluidized bed whose diameter was 0.102 m and 2.0 m in height. Effects of gas velocity, particle size and bed temperature on the minimum fluidization velocity and pressure fluctuations were examined. The values of minimum fluidization velocity obtained by means of three different methods were very similar each other. The correlation dimension could be a quantitative parameter for expression the resultant complex behavior of gas and solid mixture in the annular fluidized bed. The value of correlation dimension increased with increasing gas velocity, fluidized particle size and temperature in the bed. The minimum fluidization velocity could be determined by means of correlation dimension of pressure fluctuations as well as pressure drop in the bed and standard deviation of pressure fluctuations. The minimum fluidization velocity increased with increasing particle size but decreased with increasing bed temperature in annular fluidized beds. The minimum fluidization velocity was well correlated in therms of correlation dimension as well as operating variables within experimented conditions of this study.

직경이 0.102 m이고 높이가 2.0 m인 annular 유동층에서 최소유동화 속도 및 압력 요동 특성을 고찰하였다. 기체유속($U_G$), 고체 입자의 크기($d_p$) 그리고 유동층 온도가 최소유동화 속도 및 압력 요동 특성에 미치는 영향을 검토하였다. 본 연구 결과, annular 유동층 내의 압력 요동 자료로부터 구한 상관차원을 유동층 내부의 기체 및 유동 입자의 복합적인 거동을 정량적으로 나타내는 파라미터로 쓸 수 있었으며, 이 상관차원의 값은 기체의 유속, 유동 입자의 크기 그리고 반응기의 온도가 증가함에 따라 증가하였다. 유동층에서 유동입자의 최소유동화 속도를 유동층에서 압력 강하 및 압력 요동자료의 표준 편차를 사용하는 방법뿐만 아니라 압력 요동 자료의 상관차원을 이용하여서도 구할 수 있었으며 이들 각기 다른 방법으로 구한 최소 유동화 속도 값은 서로 매우 유사하였다. Annular 유동층에서 유동 입자의 최소유동화 속도는 유동 입자의 크기가 증가할수록 증가하였으나 유동층의 온도가 증가함에 따라 감소하였다. 본 연구의 범위내에서 annular 유동층에서 최소 유동화 속도를 압력 요동 자료의 상관 차원과 무차원군의 함수로 나타낼 수 있었다.

Keywords

Acknowledgement

Supported by : 한국화학연구원, 자원 재활용 사업단

References

  1. Sasse, F. and Emig, G., "Chemical Recycling of Polymer Materials," Chem. Eng. Technol., 21(10), 777-789(1998) https://doi.org/10.1002/(SICI)1521-4125(199810)21:10<777::AID-CEAT777>3.0.CO;2-L
  2. Lim, K. Y., Jun, H. C., Lee, H. P., Kim, H. T. and Yoo, K. O., "Recovery of Styrene Monomer from Polystyrene Using Carbon Black from Pyrolysis of Waste Tire," J. Korean Ind. Eng. Chem., 11(8), 952-958(2000)
  3. Hirose, T., Takai, Y., Azuma, N., Morioka, Y. and Ueno, A., "Polystyrene Foams with Dispersed Catalyst for a Design of Recyclable Plastics," J Mater. Res., 13(1), 77-80(1998) https://doi.org/10.1557/JMR.1998.0011
  4. Sakata, Y., Uddin, A. and Muto, A., "Degradation of Polyethylene and Polypropylene into Fuel oil by using So1id Acid and Non-acid Catalysts," J. Anal. Appl. Pyrolysis, 51(1-2), 135-155(1999) https://doi.org/10.1016/S0165-2370(99)00013-3
  5. Mertin, J., Kirsten, A., Predel, M. and Kaminsky, W., "Cracking Catalysts used as Fluidized Bed Materia1 in the Hamburg Pyrolysis Process," J. Anal. Appl. Pyrolysis, 49(1-2), 87-95(1999) https://doi.org/10.1016/S0165-2370(98)00103-X
  6. Lee, C. G., Kim, J. S., Song, P. S., Cho, Y. J., Kang, Y. and Choi, M. J., "Effects of Catalyst on the Pyrolysis of Polystyrene Wastes in a Fluidized Bed Catalytic Reactor," HWAHAK KONGHAK, 40(4), 445-449(2002)
  7. Lee, C. G., Kang, S. H., Kim, J. S., Yun, J. S., Kang, Y. and Choi, M. J., "Characteristics of Catalytic Pyrolysis of Polystyrene," J. Korean Ind. Eng. Chem., 15(2), 188-193(2004)
  8. Son, S. M., Kim, U. K., Shin, I. S., Kang, Y., Kang, S. H., Yoon, B. T. and Choi, M. J., "Analysis of gas flow behavior in an annular fluidized bed reactor for PS waste treatment," The 4th International Symposium on Feedstock Recycling of Plastics and Other Polymeric Materials, September, Jeju(2007)
  9. Shin, I. S., Son, S. M., Kim, U. Y. and Kang, Y., "Gas Mixing and Characteristics of RTD in an Annular Fluidized Bed Reactor," The 20th Symposium on Chemical Engineering Daejeon/Chungnam- Kyushu, December, Daejeon(2007)
  10. van den Bleek, C. M., Coppens, M. O. and Schouten, J. C., "Applications of Chaos Analysis to Multiphase Reactors," Chem. Eng. Sci., 57(22-23), 4763-4778(2002) https://doi.org/10.1016/S0009-2509(02)00288-9
  11. Kang, S. H., Lee, C. G., Song, P. S., Kang, Y., Kim, S. D. and Kim, S. J., "Radial Liquid Dispersion and Chaotic Behavior of Liquid-Solid Flow in Liquid-Solid Circulating Fluidized Beds," Korean Chem. Eng. Res., 42(2), 241-247(2004)
  12. Karamavruc, A. I., Clark, N. N. and Halow, J. S., "Application of Mutual Information Theory to the Fluid Bed Temperature and Differential Pressure Signal Analysis," Powder Technol., 84(3), 247-257(1995) https://doi.org/10.1016/0032-5910(95)02986-C
  13. Schouten, J. C., and van den Bleek, C. M., "Chaotic Hydrodynamics of Fluidization Consequences for Scaling and Modeling of Fluid bed Reactors," AIChE Symp. Series, 88(289), 70-84(1992)
  14. Daw, C. S. and Halow, J. S., "Characterization of Voidage and Pressure Signals from Fluidized Beds Using Deterministic Chaos Theory," Proc. 11th International Con. on Fluidized Bed Combustion, Montreal, April, 777-786(1991)
  15. Kunii, D. and Levenspiel, O. Fluidization Engineering, Butterworth-Heinemann (1991)
  16. Chitester, D. C., Kornosky, R. M., Fan, L. S. and Danko, J. P., "Characteristics of Fluidization at High Pressure," Chem. Eng. Sci., 39(2), 253-261(1984) https://doi.org/10.1016/0009-2509(84)80025-1
  17. Kang, S. H., Kang, Y. Han, K. H. and Jin, G. T., "Effects of Pressure on the Minimum Fluidization Velocity and Bubble Properties in a Gas-solid Fluidized Bed," 10(3), 330-336(2004)
  18. Ergun, S., "Fluid Flow through Packed Columns," Chem. Engr. Prog., 48(2), 89-94(1952)
  19. Wen, C. Y. and Yu, Y. H., "A generalized Method for Predicting the Minimum Fluidization Velocity," AIChE J., 12(3), 610-612(1966) https://doi.org/10.1002/aic.690120343