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삼상순화유동층에서 상체류량 특성

Phase Holdup Characteristics in Three-Phase Circulating Fluidized Beds

김성훈 조용준 송평섭 강용 김상동

Kim SH Cho YJ Song PS Kang Y Kim SD

HWAHAK KONGHAK, December 1999, 37(6), 916-920(5), NONE

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Abstract

기체-액체-고체 삼상순환유동층(직경 0.1.2m×높이 3.5m)에서 각 상들의 체류량 특성을 고찰하였다. 분산상인 기체상과 연속상인 액체상의 유속 그리고 고체 순환속도의 변화가 기체, 액체, 고체 각 상들의 체류량의 변화 및 축방향 체류량 분포에 미치는 영향을 검토하였다. 분산상인 기체로는 건조공기를, 연속상인 액상으로는 물을, 그리고 고체 입자로는 2.1mm 의 유리구를 사용하였다. 분산상인 기체의 체류량은 분산상의 유속이 증가함에 따라 증가하지만 액체의 유속과 고체 순화속도에는 큰 영향을 받지 않았으며 연속상인 액체의 체류량은 액체유속이 증가하면 증가하였으나 기체 유속 및 고체 순환속도가 증가함에 따라 감소하는 경향을 나타내었다. 한편, 고체 체류량은 기체 유속이 증가함에 따라 약간 증가하나 액체 유속의 증가에 따라서는 감소하는 경향을 나타내었고 고체순환속도의 증가에 따라서는 증가하였다. 축방향 고체체류량은 액체 유속이 증가함에 따라 그 분포가 점점 균일해졌다. 기체의 체류량과 층공극률은 조작변수인 액체 및 기체 유속 그리고 고체 순환속도들과의 상관식으로 나타낼 수 있었다.

Phase holdup characteristics have been investigated in a gas-liquid-solid circulating fluidized bed(0.102m I.D×3.5 m in height). Effects of velocities of dispersed gas and continuous liquid phases and solid circulation rate on the individual phase holdup and its axial distribution in the bed have been determined. Compressed air and water have been used as a dispersed gas and a continuos liquid phase, respectively, while glass beads with the diameter of 2.1 mm have been used as a fluidized solid phase. It has been found that the gas holdup has increased with increasing dispersed gas velocity, but liquid velocity and solid circulation rate have little effect on the gas holdup. The liquid holdup has increased with increasing liquid velocity, however, it has decreased with increasing gas velocity and solid circulation rate. The solid holdup has increased with increasing solid circulation rate and gas velocity, whereas, it has decreased with increasing liquid velocity. The axial distribution of solid holdup has become uniform with increasing liquid velocity. The gas holdup and bed porosity have been well correlated in terms of operating variables such as gas and liquid velocities and solid circulation rate.

Keywords

Gas-Liquid-Soild Fluidized Bed Solid Circulation Rate Phase Holdup Characteristics Bed Porosity

References

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)
Liang WG, Zhang SL, Zhu JX, Jin Y, Yu ZQ, Wang ZW, Powder Technol., 90(2), 95 (1997)
Kim SD, Bakeer CGJ, Bergougnou MA, Can. J. Chem. Eng., 53, 134 (1975)
Kim SD, Kang Y, "Mixed Flow Hydrodynamics, Advances in Engineering Fluid Mechanics Series," Gulf Pub. Co., Houston, 845 (1996)
Kim SD, Kang Y, Chem. Eng. Sci., 52(21-22), 3639 (1997)
Kang Y, Kim SD, Ind. Eng. Chem. Process Des. Dev., 25, 717 (1986)
Kumar S, Fan LS, AIChE J., 40(5), 745 (1994)
Kang Y, Woo KJ, Ko MH, Kim SD, Chem. Eng. Sci., 52(21-22), 3723 (1997)
Kang Y, Suh IS, Kim SD, Chem. Eng. Commun., 34, 1 (1985)
Han S, Zhou J, Jin Y, Loh KC, Wang Z, Chem. Eng. J., 70(1), 9 (1998)
Yerushalmi J, turner DH, Squires AM, Ind. Eng. Chem. Process Des. Dev., 15, 47 (1976)
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)
Schnitzlein MG, Weinstein H, Chem. Eng. Sci., 43, 2605 (1988)