Korean Chemical Engineering Research

  • 제55권5호
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  • Pages.646-651
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  • 2017
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  • 0304-128X(pISSN)
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  • 2233-9558(eISSN)
한국화학공학회 (The Korean Institute of Chemical Engineers)
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유동층 반응기 희박상 내 탄소나노튜브 응집체의 크기 및 형상 측정

Measurement of Carbon Nanotube Agglomerates Size and Shape in Dilute Phase of a Fluidized Bed

  • 김성원 (한국교통대학교 화공신소재고분자공학부)
  • Kim, Sung Won (School of Chemical and Material Engineering, Korea National University of Transportation)
  • 투고 : 2017.06.02
  • 심사 : 2017.07.18
  • 발행 : 2017.10.01
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초록

CNT 유동층 반응기(내경 0.15 m, 높이 2.6 m) 희박상 내 CNT 입자(평균입도 $291{\mu}m$, 벌크밀도 $72.9kg/m^3$)의 거동을 확인하기 위해 레이저 슬릿광 형상 측정법을 이용하여, CNT 응집체의 크기 및 형태를 측정하였다. 기포유동층 조건에서 CNT 반응기 내 축방향 고체체류량 분포는 하부 농후상과 상부 희박상을 갖는 S자 형태를 보였다. 기체 유속이 증가할수록 비산되는 CNT 응집체의 Heywood 직경과 Feret 직경이 증가하였고, 응집체 내 CNT 입자수가 증가하였다. 또한, 기체의 유속이 증가할수록 CNT 응집체의 종횡비는 증가하고, 원형도는 감소하였다. CNT 응집체의 원마도와 견고도는 기체의 유속이 증가할수록 감소하였다. 응집체의 형상 분석 정보에 기반한 희박상 내 응집체 형성 원인을 제안하였다.

Size and shape of carbon nanotube (CNT) agglomerates in the dilute phase of a bubbling fluidized bed ($0.15m\;i.d{\times}2.6m\;high$) have been determined by the laser sheet technique. Axial solid holdup distribution of the CNT particles showed S curve with dense phase and dilute phase in bubbling fluidization regime. Heywood diameter and Feret diameter of the CNT agglomerates in the dilute phase of bubbling fluidized bed increased with increasing gas velocity. The CNT particle number in the agglomerates increased with increasing of gas velocity. Aspect ratio increased and circularity, roundness and solidity decreased with increasing of gas velocity. A possible mechanism of agglomerates formation was proposed based on the obtained information.

키워드

참고문헌

  1. Iijima, S., "Helical Microtubules of Graphitic Carbon," Nature, 354, 56-58(1991). https://doi.org/10.1038/354056a0
  2. Lyu, S. C., Sok, J. H. and Han, J. H., "Technical Trends of Carbon Nanotubes Growth Method," KIC News, 12(4), 1-12(2009).
  3. Jung, S. W., "Hydrodynamic Characteristics and Synthesis of Multi-walled Carbon Nanotubes in Fluidized Beds, Ph.D. Dissertation (2016).
  4. Wang, Y., Wei, F., Luo, G., Yu, H., Gu, G., "The Large-scale Production of Carbon Nanotubes in a Nano-agglomerate Fluidizedbed Reactor," Chem. Physics Letters, 364, 568-572(2002). https://doi.org/10.1016/S0009-2614(02)01384-2
  5. Son, S. Y., Lee, D. H., Kim, S. D., Sung, S. W., Park, Y. S., Han, J. H., "Synthesis of Multi-walled Carbon Nanotube in a Gas-solid Fluidized Bed," Korean J. Chem. Eng., 23(5), 838-841(2006). https://doi.org/10.1007/BF02705937
  6. Jeong, S. W., Lee, J. H., Kim, J. and Lee, D. H., "Fluidization Behaviors of Different Types of Multi-walled Carbon Nanotubes in Gassolid Fluidized Beds," J. Ind. Eng. Chem., 35, 217-223(2016). https://doi.org/10.1016/j.jiec.2015.12.035
  7. Yu, H., Zhang, Q., Gu, G., Wang, Y., Luo, G. and Wei, F., "Hydrodynamics and Gas Mixing in a Carbon Nanotube Agglomerate Fluidized Bed," AIChE J., 52(12), 4110-4123(2006). https://doi.org/10.1002/aic.11031
  8. Wang, X. S., Palero, V., Soria, J. and Rhodes, M. J., "Laser-based Planar Imaging of Nano-particle Fluidization: Part I-Determination of Aggregate Size and Shape," Chem. Eng. Sci., 61, 5476-5486(2006). https://doi.org/10.1016/j.ces.2006.04.012
  9. Rasband, W. W. and Image, J., U.S. National Institute of Health, Bethesda, Maryland, US.(1997) (http://rsb.info.nih.gov/ij/).
  10. Hakim, L. F., Portman, J. L., Casper, M. D. and Weimer, A. W., "Aggregation Behavior of Nanoparticles in Fluidized Beds," Powder Technol., 160, 149-160(2005). https://doi.org/10.1016/j.powtec.2005.08.019
  11. Arai, Y., Chemistry of Powder Production, Springer Science & Business Media, US., 215-217(2012).
  12. Jeong, S. W., "Hydrodynamic Characteristics and Synthesis of Multi-walled Carbon Nanotubes in Fluidized Beds," PhD Dissertation (2015).
  13. Kim, S., Park, S., Kwon, J. and Ha, K., "Preparation of Electrically Conductive Composites Filled with Nickel Powder and MWCNT Fillers," Korean Chem. Eng. Res., 54(3), 410-418(2016). https://doi.org/10.9713/kcer.2016.54.3.410
  14. Kim, D. W. and Kim, J. S., "Mechanical Properties of Carbon Nanotube/Polyurethane Nanocomposites via PPG Dispersion with MWCNTs," Korean Chem. Eng. Res., 53(6), 703-708(2015). https://doi.org/10.9713/kcer.2015.53.6.703
  15. Bokobza, L., "Multiwall Carbon Nanotube Elastomeric Composites: A Review," Polymer, 48(17), 4907-4920(2007). https://doi.org/10.1016/j.polymer.2007.06.046
  16. Horio, M. and Kuroki, H., "Three-dimensional Flow Visualization of Dilutely Dispersed Solids in Bubbling and Circulating Fluidized Beds," Chem. Eng. Sci., 49, 2413-2421(1994). https://doi.org/10.1016/0009-2509(94)E0071-W
  17. Kim, S. W., Ahn, J. Y., Kim, S. D. and Lee, D. H., "Heat Transfer and Bubble Characteristics in a Fluidized Bed Heat Exchanger," Int. J. Heat Mass Transfer, 46(3), 399-409(2003). https://doi.org/10.1016/S0017-9310(02)00296-X