Articles & Issues

Language: korean

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

All issues

삼상 순환유동층에서 기포특성

Bubble Characteristics in Three-Phase Circulating Fluidized Beds

남석희 조용준 강용^† 최호석 김상돈¹

Seok-Hee Nam Yong-Jun Cho Yong Kang^† Ho Suk Choi Sang-Done Kim¹

충남대학교 화학공학과, 대전 305-764 ¹한국과학기술원 화학공학과, 대전 305-701

Department of Chemical Engineering, Chungnam National University, Teajon 305-764, Korea ¹Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, Teajon 305-701, Korea

HWAHAK KONGHAK, December 2000, 38(6), 859-863(5), NONE

Download PDF

Abstract

직경이 0.102m, 높이 3.5m인 삼상 순환유동층에서 기체-액체-고체 흐름 거동에 따른 기포특성을 고찰하였다. 기체유속(0.01-0.07 m/s), 액체유속(0-0.31 m/s) 그리고 고체순환속도(2-8 kg/m²s) 등을 변수로 선정하였으며, 이들 변수들이 삼상 순환유동층의 상승관에서 기포의 상승속도와 수직길이 그리고 빈도수에 미치는 영향을 검토하였고 각 실험조건에서 기포 크기의 분포를 비교함으로써 비순환영역과 순환영역 흐름에서 기포특성을 비교하였다. 본 연구의 실험결과 삼상 순환유동층의 상승관에서 기포의 상승속도와 빈도수는 기체와 액체유속이 증가함에 따라 증가하는 경향을 나타내었다. 고체 순환속도가 증가함에 따라서는 기포상승속도는 약간 감소하고 빈도수는 약간 증가하는 경향을 나타내었다. 기포의 수직길이는 기체유속의 증가에 따라 증가하는 경향을 나타내었으며, 액체유속과 고체의 순환속도가 증가하면 감소하였다. 기포의 크기분포는 고체입자의 비순환영역에 비해서 순환영역에서 균일도가 상당히 증가하였으며, 기포의 평균크기도 크게 감소하였다. 본 연구의 실험범위에서 기포의 상승속도와 수직길이 그리고 빈도수를 실험변수의 상관식으로 나타낼 수 있었다.

Bubble characteristics have been investigated in a three-phase circulating fluidized bed of 0.102 m I.D. and 3.5 m height. Effects of gas(0.01-0.07 m/s) and liquid velocities(0-0.31 m/s) and solid circulating rates(2-8 kg/m(2)s) on the bubble characteristics such as rising velocity, chord length and frequency have been determined. Probability density of bubble chord length has been examined with the variations of experimental conditions to analyze the bubble characteristics in the solid circulating regime. As a result of this study, The bubble rising velocity and frequency have increased with increasing gas and liquid velocities, but the former has decreased while the latter has increased slightly, with increasing solid circulating rates. The bubble chord length has increased with increasing gas velocity but it has decreased with liquid velocity and solid circulating rate in the riser of three-phase circulating fluidized beds. The probability density of bubble chord length becomes more narrow representing more uniform bubble size distribution with increasing liquid velocity as well as solid circulating rate in the beds. The rising velocity, chord length and frequency of bubbles have been well correlated in terms of operating variables.

Keywords

Three-Phase Circulating Fluidized Bed Bubble Characteristics Bubble Size Distribution

References

Kang Y, Woo KJ, Ko MH, Kim SD, Chem. Eng. Sci., 52(21-22), 3723 (1997)
Kang Y, Woo KJ, Ko MH, Kim SD, HWAHAK KONGHAK, 34(4), 429 (1996)
Kim SD, Kang Y, Chem. Eng. Sci., 52(21-22), 3639 (1997)
Matsuura A, Fan LS, AIChE J., 30, 894 (1984)
Kang Y, Woo KJ, Ko MH, Cho YJ, Kim SD, Korean J. Chem. Eng., 16(6), 784 (1999)
Han S, Zhou J, Jin Y, Loh KC, Wang Z, Chem. Eng. J., 70(1), 9 (1998)
Liang W, Wu Q, Yu Z, Jin Y, Wang Z, Can. J. Chem. Eng., 73(5), 656 (1995)
Liang WG, Wu QW, Yu ZQ, Jin Y, Bi HT, AIChE J., 41(2), 267 (1995)
Kim SH, Cho YJ, Song PS, Kang Y, Kim SD, HWAHAK KONGHAK, 37(6), 916 (1999)
Cho YJ, Song PS, Kim SH, Kang Y, Kim SD, J. Chem. Eng. Jpn., 34(2), 254 (2001)
Wang T, Lin ZT, Zhu CM, Liu DC, Saxena SC, AIChE J., 39, 1406 (1993)
Kang Y, Cho YJ, Woo KJ, Kim KI, Kim SD, Chem. Eng. Sci., 55(2), 411 (2000)
Kwon HW, Kang Y, Kim SD, Yashima M, Fan LT, Ind. Eng. Chem. Res., 33(7), 1852 (1994)
Yu HY, Kim SD, Chem. Eng. Sci., 46, 313 (1991)