화학공학소재연구정보센터
Journal of the Korean Industrial and Engineering Chemistry, Vol.15, No.1, 120-124, February, 2004
삼상 순환유동층의 상승관에서 연속 액상의 축방향 혼합특성
Characteristics of Axial Dispersion of Continuous Liquid Phase in the Riser of Three-Phase Circulating Fluidized Beds
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초록
직경이 0.102 m이고 높이가 3.5 m인 기체-액체-고체 순환유동층의 상승관에서 액상의 축방향 혼합특성을 고찰하였다. 기체유속(0.01 ~ 0.07 m/s), 액체유속(0.25 ~ 0.31 m/s) 그리고 고체순환속도(2 ~ 8 kg/m2s)를 실험변수로 선정하였으며 이들 변수들이 액상의 축방향 분산계수에 미치는 영향을 고찰하였다. 축방향의 추적자 농도분포로부터 분산모델을 사용하여 액상의 축방향 분산계수를 구하였다. 액상의 축방향 분산계수는 기체유속과 고체순환속도가 증가함에 따라서 증가하였으나 액체의 유속의 증가에 따라서는 약간 감소하였다. 또한, 액상의 축방향 분산계수는 등방성 난류 모델을 적용한 무차원군으로 표현되는 상관식으로 나타낼 수 있었다.
Characteristics of liquid dispersion in the axial direction were investigated in the riser of a three-phase circulating fluidized bed whose diameter is 0.102 m and 3.5 m inheight. Effects of gas (0.01 ~ 0.07 m/s) and liquid (0.25 ~ 0.31 m/s) velocities and the circulation rate of solids (2 ~ 8 kg/m2s) on the dispersion coefficient of the continuous liquid phase in the axial direction were determined. A dispersion model was employed to obtain the axial dispersion coefficient of the liquid phase from the radial concentration profiles of tracer with variations of axial position. The axial dispersion coefficient of the liquid phase increased with increasing gas velocity or solid circulation rate, however, decreased slightly with increasing liquid velocity in the riser bed. The axial dispersion coefficient of the liquid phase was well correlated in terms of dimensionless groups based on the isotropic turbulence theory.
  1. Fan LS, Gas-Liquid-Solid Fluidization Enigneering, Butterworths, Stonehair, MA (1989)
  2. Kim SD, Kang Y, Chem. Eng. Sci., 52(21-22), 3639 (1997) 
  3. Kang Y, Cho YJ, Lee CG, Song PS, Kim SD, Can. J. Chem. Eng., 81, 1621 (2003)
  4. Cho YJ, Song PS, Kim SH, Kang Y, Kim SD, J. Chem. Eng. Jpn., 34(2), 254 (2001) 
  5. Kang TG, Han HD, Cho YJ, Choi HS, Kang Y, Kim SD, HWAHAK KONGHAK, 40(4), 450 (2002)
  6. Cho YJ, Kim SJ, Nam SH, Kang Y, Kim SD, Chem. Eng. Sci., 56(21-22), 6107 (2001) 
  7. Shin KS, Cho YJ, Kang Y, Kim SD, HWAHAK KONGHAK, 39(1), 91 (2001)
  8. Zhu JX, Zheng Y, Karamanev DG, Bassi AS, Can. J. Chem. Eng., 78(1), 82 (2000)
  9. Yang WG, Wang JF, Zhou LM, Jin Y, Chem. Eng. Sci., 54(22), 5523 (1999) 
  10. Zheng Y, Zhu JX, Powder Technol., 114(1-3), 244 (2001) 
  11. El-Temtamy S, El-Sharnoubi YO, El-Halwagi MM, Chem. Eng. J., 18, 161 (1979) 
  12. Han S, Zhou J, Jin Y, Loh KC, Wang Z, Chem. Eng. J., 70(1), 9 (1998) 
  13. Kim SD, Kim HS, Han JH, Chem. Eng. Sci., 47, 3419 (1992) 
  14. Kim SD, Kim CH, J. Chem. Eng. Jpn., 16, 172 (1983)
  15. Kim SW, Kim HT, Song PS, Kang Y, Kim SD, Can. J. Chem. Eng., 81, 621 (2003)
  16. Cho YJ, Ph.D. Thesis, Chungnam National University, Korea (2002)
  17. Kang Y, Kim SD, Ind. Eng. Chem. Process Des. Dev., 25, 717 (1986)