기체-고체 유동층에서 유동입자의 분산 거동 해석

강석환; 김준식; 김사중; 강용; Suk Hwan Kang; Jun Sik Kim; Sa Jung Kim; Yong Kang

Journal of the Korean Industrial and Engineering Chemistry, Vol.12, No.5, 584-589, August, 2001

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기체-고체 유동층에서 유동입자의 분산 거동 해석

Analysis of Dispersion Behavior of Fluidized Particles in Gas-Solid Fluidized Beds

강석환 , 김준식 , 김사중, 강용 ^†

충남대학교 화학공학과, 대전 305-764

Suk Hwan Kang , Jun Sik Kim , Sa Jung Kim, and Yong Kang^†

Department of Chemical Engineering, Chungnam National University, Daeduck Science Town, Taejon 305-764, Korea

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초록

직격이 0.105 m이고, 높이가 2.5 m인 기체-고체 유동층에서 입자의 분산 거동을 고찰하였다. 유동층에서 입자의 bulk 흐름은 매우 불규칙적이기 때문에 입자의 분산 흐름 거동을 해석하는데 확률론적(stochastic), 무작위적(random) 그리고 chaos 해석방법을 사용하였다. 압력강하 및 요동(fluctuations)의 변동은 계단함수로서 기체의 유속을 변화한 후 시간의 흐름에 따라 압력변동을 측정하여 결정하였다. 입자의 분산거동은 유동층이 최초정상상태에서 기체유속이 단계함수로 변하며, 최종 정상상태에 도달할 때까지 불균일과 균일 팽창 상태의 두 가지 상태로 분류할 수 있었다. 입자의 흐름 거동은 기체-고체 유동층에서 압력강하변동 신호자료의 위상공간투영과 상관차원의 해석으로 감지할 수 있었다. 유동층 내부의 일정시험영역에서 입자의 분산계수, 요동빈도수 그리고 시험영역을 빠져나가는 유동입자의 분율 등은 유동층내에서 입자의 분산 거동에 대한 해석으로부터 얻을 수 있었다.

The dispersion behavior of particles has been investigated in a gas-solid fluidized bed of 0.105 m ID and 2.5 m in height. Since the bulk flow of particles in the fluidied bed is highly irregular, stochastic and random, a chaos analysis has been employed to analyze behavior of dispersion flow. More specifically, pressure drop fluctuations have been measured and analyzed with the variation of time after introd the gas flow rate as a step function. It has been found that the dispersion behavior of particles can be classified into two states, heterogeneous and homogeneous expansion states, before it finally reached a new steady state. Particle flow behavior has been betected from the analyses of the phase space portraits and correlation dimension of pressure drop fluctuations in gas-solid fluidized beds. Dispersion coefficient, fluctuating frequency and exiting rate of particles from the test section have been obtainend from the analyses of dispersion behavior in the fluidized beds.

Keywords:fluidized bed;particle dispersion;stochastic method;chaos theory;unsteady state

[References]

Horio N, Nonaka A, AIChE J., 33, 1865 (1987)
Glicksman LR, Lord WK, Sakagami M, Chem. Eng. Sci., 42, 479 (1987)
Fan LT, Ho TC, Hiraska S, Walawender WP, AIChE J., 27, 388 (1981)
Avidan A, Yerushalmi J, AIChE J., 31, 835 (1985)
Kunni D, Levenspiel O, "Fluidization Engineering", 2, 211, Butterworth-Heinemann, Stoneham, MA (1991)
Lee GS, Kim SD, Chem. Eng. J., 44, 1 (1990)
Thiel WJ, Potter OE, AIChE J., 24, 561 (1978)
Kobayashi N, Yamazaki R, Mori S, Powder Technol., 113(3), 327 (2000)
Mostoufi N, Chaouki J, Powder Technol., 114(1-3), 23 (2001)
Shen LH, Zhang MY, Powder Technol., 97(2), 170 (1998)
Govan AH, Int. J. Multiph. Flow, 15, 287 (1989)
Kang Y, Ko MH, Kim SD, Yashima M, Fan LT, AIChE J., 42(4), 1164 (1996)
Kang Y, Woo KJ, Ko MH, Kim SD, Chem. Eng. Sci., 52(21-22), 3723 (1997)
Kang Y, Nah JB, Min BT, Kim SD, Chem. Eng. Commun., 97, 197 (1990)
Yutani N, Ototake N, Too JR, Fan LT, Chem. Eng. Sci., 37, 1079 (1982)
Kang Y, Kim SD, Chem. Ind. Technol., 13(1), 27 (1995)
Fan LT, Kang Y, Nieogi D, Yashima M, AIChE J., 39, 513 (1993)
Fan LS, Zhu C, "Principles of Gas-Solid Flows", Cambridge University Press, Cambrige, UK (1998)
Shrikhande KY, J. Sci. Ind. Res., 14B, 457 (1955)
Lewis WK, Gilliland ER, Girouard H, Chem. Eng. Prog. Symp. Ser., 38, 87 (1962)
de Groot JH, "Scaling Up of Fluidized Bed Reactors", Proc. Intern. Symp. Fluidization, 348, Netherlands Univ. Press., Eindhoven (1967)
Hutchinson P, Hewitt GF, Dukler AE, Chem. Eng. Sci., 26, 419 (1971)

[Referenced By]

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[1] Horio N, Nonaka A, AIChE J., 33, 1865 (1987)

[2] Glicksman LR, Lord WK, Sakagami M, Chem. Eng. Sci., 42, 479 (1987)

[3] Fan LT, Ho TC, Hiraska S, Walawender WP, AIChE J., 27, 388 (1981)

[4] Avidan A, Yerushalmi J, AIChE J., 31, 835 (1985)

[5] Kunni D, Levenspiel O, "Fluidization Engineering", 2, 211, Butterworth-Heinemann, Stoneham, MA (1991)

[6] Lee GS, Kim SD, Chem. Eng. J., 44, 1 (1990)

[7] Thiel WJ, Potter OE, AIChE J., 24, 561 (1978)

[8] Kobayashi N, Yamazaki R, Mori S, Powder Technol., 113(3), 327 (2000)

[9] Mostoufi N, Chaouki J, Powder Technol., 114(1-3), 23 (2001)

[10] Shen LH, Zhang MY, Powder Technol., 97(2), 170 (1998)

[11] Govan AH, Int. J. Multiph. Flow, 15, 287 (1989)

[12] Kang Y, Ko MH, Kim SD, Yashima M, Fan LT, AIChE J., 42(4), 1164 (1996)

[13] Kang Y, Woo KJ, Ko MH, Kim SD, Chem. Eng. Sci., 52(21-22), 3723 (1997)

[14] Kang Y, Nah JB, Min BT, Kim SD, Chem. Eng. Commun., 97, 197 (1990)

[15] Yutani N, Ototake N, Too JR, Fan LT, Chem. Eng. Sci., 37, 1079 (1982)

[16] Kang Y, Kim SD, Chem. Ind. Technol., 13(1), 27 (1995)

[17] Fan LT, Kang Y, Nieogi D, Yashima M, AIChE J., 39, 513 (1993)

[18] Fan LS, Zhu C, "Principles of Gas-Solid Flows", Cambridge University Press, Cambrige, UK (1998)

[19] Shrikhande KY, J. Sci. Ind. Res., 14B, 457 (1955)

[20] Lewis WK, Gilliland ER, Girouard H, Chem. Eng. Prog. Symp. Ser., 38, 87 (1962)

[21] de Groot JH, "Scaling Up of Fluidized Bed Reactors", Proc. Intern. Symp. Fluidization, 348, Netherlands Univ. Press., Eindhoven (1967)

[22] Hutchinson P, Hewitt GF, Dukler AE, Chem. Eng. Sci., 26, 419 (1971)