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Korean Chemical Engineering Research,
Vol.57, No.1, 105-110, 2019
유동층 반응기 프리보드 내 높이에 따른 CNT 응집체 형상 변화
Effect of Height on CNT Aggregates Size and Shape in Freeboard Region of a Fluidized Bed
CNT 유동층 반응기(내경 0.15 m, 높이 2.6 m) 프리보드 내 미세 CNT 입자(평균입도 46 μm, 벌크밀도 93.2 kg/m3)의 높이 별 거동을 확인하기 위해 레이저 슬릿광 형상 측정법을 이용하여, CNT 응집체의 크기 및 형태를 측정하였다. 기체 유속 증가에 대해, 비산되는 CNT 응집체의 Feret 직경과 Heywood 직경이 증가하였다. 프리보드 내 높이가 증가할 수록 평균 직경은 작아졌고, 응집체 내 CNT 입자수가 감소하였다. 기체 유속 증가에 대해, 응집체의 종횡비는 농후상에 가까울수록 증가하였으나, 높은 높이에서는 감소하였다. 그러나, 견고도는 큰 변화를 보이지 않았다. 응집체의 형상 분석 정보에 기반하여, 높이 별 CNT 입자의 응집과정이 서로 다름을 확인하였다. 유동층 프리보드 내 CNT 응집체의 Heywood 직경을 예측할 수 있는 상관관계식을 제안하였다.
Effect of height on the size and shape of carbon nanotube (CNT) aggregates in the freeboard region of a bubbling fluidized bed (0.15 m i.d. × 2.6 m high) has been determined. Feret diameter and Heywood diameter of the CNT aggregates in the freeboard region of fluidized bed increased with increasing gas velocity. The average aggregate diameters and CNT particle number in the aggregates decreased with increasing of height in the freeboard. Aspect ratio increased as the location was closer to the surface of the dense phase, but decreased at the highest location. Solidity did not show any significant changes with height. The results showed the aggregates formation process is affected by the height in the freeboard. A correlation was proposed to predict the Heywood diameter of the CNT aggregates.
[References]
  1. Wang Y, Wei F, Luo GH, Yu H, Gu GS, Chem. Phys. Lett., 364(5-6), 568, 2002
  2. Kim SW, Korean Chem. Eng. Res., 55(5), 646, 2017
  3. Jeong SW, Lee JH, Kim J, Lee DH, J. Ind. Eng. Chem., 35, 217, 2016
  4. Son SY, Lee DH, Kim SD, Sung SW, Park YS, Han JH, Korean J. Chem. Eng., 23(5), 838, 2006
  5. Park SH, Kim SW, Int. J. Eng. Technol., 7(3.34), 534, 2018
  6. Kim SW, Processes, 6, 121, 2018
  7. Yu H, Zhang QF, Gu GS, Wang Y, Luo GH, Wei F, AIChE J., 52(12), 4110, 2006
  8. Hakim LF, Portman JL, Casper MD, Weimer AW, Powder Technol., 160(3), 149, 2005
  9. Jeong SW, Lee DH, Adv. Powder Technol., 28(10), 2706, 2017
  10. Kim SW, Ahn JY, Kim SD, Lee DH, Int. J. Heat Mass Transf., 46(3), 399, 2003
  11. Kim SW, Lee JW, Koh JS, Kim GR, Choi S, Yoo IS, Ind. Eng. Chem. Res., 51(43), 14279, 2012
  12. Rasband WW, ImageJ US, National Institute of Health, Bethesda, Maryland, US.(1997) (http://rsb.info.nih.gov/ij/).
  13. Wang XS, Palero V, Soria J, Rhodes MJ, Chem. Eng. Sci., 61(16), 5476, 2006
  14. Arai Y, Chemistry of Powder Production, Springer Science & Business Media, US., 215-217(2012).
  15. Kim SW, Kim SD, Processes, 6, 80, 2018
  16. de Luna MS, Pellaegrino L, Daghetta M, Mazzocchia CV, Acierno D, Filippone G, Compos. Sci. Technol., 85, 17, 2013