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Language: korean

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

Publication history: Received February 10, 2020
Accepted February 21, 2020
Available online May 4, 2020

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.

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대기압 이하에서 운전하는 유동층 반응기의 유동 특성

Fluidization Characteristics in Fluidized Bed Reactors Operated in Subatmospheric Pressur

박성희^†

Sounghee Park^†

우석대학교 에너지공학과, 27841 충청북도 진천군 진천읍 대학로 66

Department of Energy Engineering, Woosuk University, 66, Daehak-ro, Jincheon-eup, Jincheon-gun, Chungcheongbuk-do, 27841, Korea

drpark@woosuk.ac.kr

Korean Chemical Engineering Research, May 2020, 58(2), 307-312(6)
https://doi.org/10.9713/kcer.2020.58.2.307

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Abstract

최근 대기압이하 진공 압력 상태에서 운전되는 유동층 반응기는 진공건조 공정이나 플라즈마 화학증착과 같이 감압 유동화가 요구되기에 관심이 증대되어 왔다. 그러나 대기압 이하에서 운전되는 유동층의 수력학적 특성 연구는 많이 연구되지 않았다. 본 연구에서는 대기압 이하에서 운전하는 유동층의 압력강하를 층내 압력을 1.33 에서101.3kPa 까지 변화시키며 측정하였다. 유동층의 운전 압력이 진공인 상태에서는 최소유동화속도가 압력이 감소함에 따라 증가하며, 이는 기체 밀도와 평균 자유경로 변화와 같은 slip 흐름에 의한 변화이다. 또한 기존의 상압 상태에서 운전되는 유동층의 최소유동화속도 상관식과 비교함으로써 압력 감소에 따른 slip 흐름의 영향 뚜렷하게 나타남을 가리키는 임계Knudsen 수를 결정하였다. 이로부터 slip 흐름이 주도하기 시작하는 임계 압력을 실험적으로 결정하였다.

Fluidized bed reactors operated in subatmospheric pressure has been focused because several industrial applications such as vacuum drying and plasma cvd requires reduced pressure fludization. However, the hydrodynamics of fluidized beds in subatmospheric pressure has not been extensively investigated. The pressure drop in the fluidized bed has been measured with variation of downstream pressures from 1.33 to 101.3 kPa in the shallow and deep fluidized beds under the sub-atmospheric pressures. The obtained minimum fluidization velocity of powders is a function of pressure due to the changes of gas density and mean free path. We can experimentally determine the critical Knudsen number and the critical pressure to define the slip regime significantly to influence the hydrodynamics of fluidized beds.

Keywords

Fluidized Bed Subatmospheric Vacuum Minimum Fluidization Velocity Slip Flow

References

Kunii D, Levenspiel O, Fludization Engineering, 2nd ed., Elsevier Inc., New York, NY(1991).
Chitester DC, Kornosky RM, Fan LS, Danko JP, Chem. Eng. Sci., 39(2), 256 (1984)
Kozanoglu BU, Vichez JA, Casal J, Arnaldos J, The Canadian J. of Chem. Eng., 80(3), 376-385(2002).
Weerasiri LD, Das S, Fabijanic D, Yang W, International Scholarly and Science Research & Innovation, 13, 656-660(2019).
Rogers T, Morin TJ, Plasma Chemistry and Plasma Processing, 11, 203-228(1991).
Park SH, Kim SD, Polym. Bull., 33(2), 249 (1994)
Park SH, Kim SD, Colloids Surf. A: Physicochem. Eng. Asp., 133, 33 (1998)
Song LH, Park SH, Jung SH, Kim SD, Park SB, Korean J. Chem. Eng., 28(2), 627 (2011)
Kawamura S, Suezawa Y, Kagaku Kogaku, 25, 524 (1961)
Germain B, Claudel B, Powder Technol., 13, 115 (1975)
Fletcher JV, Deo MD, Hanson FV, Powder Technol., 76, 141 (1993)
Roth A, “Vacuum Technology,” North-Holland, Amsterdam (1976).
Kusakabe S, Kuriyama T, Morooka S, Powder Technol., 58, 125 (1989)
Llop MF, Madrid F, Arnaldos J, Casal J, Chem. Eng. Sci., 51(23), 5149 (1996)
Zarekar S, Buck A, Jacob M, Tsotsas E, Powder Technol., 287, 169 (2016)
Kozanoglu BU, Chanes JW, Cuautle DG, Jean JPS, Powder Technol., 125(1), 55 (2002)
Wraith AE, Harris R, Minerals Engineering, 5, 993 (1992)