Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Mixed Flow and Oxygen Transfer Characteristics of Vertical Orifice Ejector

수직 오리피스 이젝터의 혼합유동 및 산소전달 특성

  • Kim, Dong Jun (Dept. of Automotive System Engineering, Chonnam Nat'l Univ.) ;
  • Park, Sang Kyoo (School of Mechanical Design Engineering, Chonnam Nat'l Univ.) ;
  • Yang, Hei Cheon (School of Mechanical Design Engineering, Chonnam Nat'l Univ.)
  • 김동준 (전남대학교 자동차시스템공학과) ;
  • 박상규 (전남대학교 기계설계공학부) ;
  • 양희천 (전남대학교 기계설계공학부)
  • Received : 2014.07.16
  • Accepted : 2014.10.17
  • Published : 2015.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

The objective of this study is to experimentally investigate the mixed flow behaviors and oxygen transfer characteristics of a vertical orifice ejector. The experimental apparatus consisted of an electric motor-pump, an orifice ejector, a circulation water tank, an air compressor, a high speed camera unit and control or measurement accessories. The mass ratio was calculated using the measured primary flow rate and suction air flow rate with experimental parameters. The visualization images of vertically injected mixed jet issuing from the orifice ejector were qualitatively analyzed. The volumetric oxygen transfer coefficient was calculated using the measured dissolved oxygen concentration. At a constant primary flow rate, the mass ratio and oxygen transfer coefficient increase with the air pressure of compressor. At a constant air pressure of the compressor, the mass ratio decreases and the oxygen transfer coefficient increases as the primary flow rate increases. The residence time and dispersion of fine air bubbles and the penetration of mixed flow were found to be important parameters for the oxygen transfer rate owing to the contact area and time of two phases.

본 논문은 수직 오리피스 이젝터의 혼합유동 및 산소전달 특성에 대한 실험적 연구를 목적으로 한다. 실험장치는 전동 모터-펌프, 오리피스 이젝터, 순환 수조, 공기압축기, 고속 카메라 시스템 그리고 제어 및 측정기기로 구성하였다. 측정된 구동유체 및 유입공기의 유량을 이용하여 유량비를 도출하였다. 이적터에서 분출된 혼합유동의 가시화를 통해 정성적 거동을 고찰하였으며, 용존산소 농도를 측정하여 총괄 산소전달계수를 도출하였다. 구동유체의 유량이 일정하고 압축기의 공기압이 높아지면 유량비와 산소전달계수는 증가하며, 압축기의 공기압이 일정하고 구동유체의 유량이 증가하면 유량비는 감소하지만 산소전달계수는 증가하였다. 기포의 크기에 따른 체류시간 및 확산도와 수직 혼합유동의 도달거리는 2 상의 접촉면적과 시간에 크게 영향을 미치기 때문에 산소전달율의 중요한 변수임을 유추할 수 있다.

Keywords

References

  1. Rodrigues, R. T. and Rubio, J., 2007, "DAF-Dissolved Air Flotation: Potential Applications in the Mining and Mineral Processing Industry," Int. J. Mineral Processing, Vol. 82, No. 1, pp. 1-13. https://doi.org/10.1016/j.minpro.2006.07.019
  2. Takahashi, M., Kawamura, T., Yamamoto, Y., Ohnari, H., Himuro, S., Shakutsui, H., 2003, "Effect of Shrinking Microbubble on Gas Hydrate Formation," J. Physical Chemistry, Vol. 107, No. 10, pp. 2171-2173. https://doi.org/10.1021/jp022210z
  3. Marui, T., 2013, "An Introduction to Micro/Nano-Bubbles and Their Applications," Systemics, Cybernetics and Informatics, Vol. 11, No. 4, pp. 68-73.
  4. Kim, D. J., Du, H., Jang, D. H. and Yang, H. C., 2013, "Experimental Investigation on Air Bubble Behavior for Development of Cleaning Technology," Proceedings of the KSME 2013 Fall Annual Meeting, pp. 4188-4193.
  5. Ushikubo, F. Y., Furukawa, T., Nakagawa, R., Enari, M., Makino, Y., Kawagoe, Y., Shiina, T. and Oshita, S., 2010, "Evidence of the Existence and the Stability of Nano-Bubbles in Water," Colloids and Surfaces A: Physicochemical Engineering Aspects, Vol. 361, pp. 31-37. https://doi.org/10.1016/j.colsurfa.2010.03.005
  6. Kawahara, A., Sadatomi, M., Matsuyama, F., Matsuura, H., Tominaga, M. and Noguchi, M., 2009, "Prediction of Micro-Bubble Dissolution Characteristics in Water and Seawater," Experimental Thermal and Fluid Science, Vol. 33, pp. 883-894. https://doi.org/10.1016/j.expthermflusci.2009.03.004
  7. Liu, S., Wang, Q., Ma, H., Huang, P., Li. J. and Kikuchi, T., 2010, "Effect of Micro-Bubble on Coagulation Flotation Process of Dyeing Wastewater," Separation and Purification Technology, Vol. 71, pp. 337-346. https://doi.org/10.1016/j.seppur.2009.12.021
  8. Tsai, J. C., Kumar, M., Chen, S. Y. and Lin, J. G., 2010, "Nano-Bubble Flotation Technology with Coagulation Process for the Cost-Effective Treatment of Chemical Mechanical Polishing Wastewater," Separation and Purification Technology, Vol. 58, pp. 61-67.
  9. Reuter, F., Mettin, R., Lippert, A., Holsteyns, F. and Okorn-Schmidt, H., 2013, "Single Bubble Cleaning and Vortex Flow," Solid State Phenomena, Vol. 195, pp. 165-168.
  10. Song, W. D., Hong, M. H., Lukyanchuk, B. and Chong, T. C., 2004, "Laser-Induced Cavitation Bubbles for Cleaning of Solid Surface," J. Applied Physics, Vol. 95, No. 6, pp. 2952-2956. https://doi.org/10.1063/1.1650531
  11. Meakhail, T. A. and Teaima, I. R., 2013, "A Study of the Effect of Nozzle Spacing and Driving Pressure on the Water Jet Pump Performance," Int. J. Engineering Science and Innovative Technology, Vol. 2, No. 5, pp. 373-382.
  12. Prabkeao, C. and Aoki, K., 2005, "Study on the Optimum Mixing Throat Length for Drive Nozzle Position of the Central Jet Pump," J. Visualization, Vol. 8, No. 4, pp. 347-355. https://doi.org/10.1007/BF03181554
  13. Kim, K., Kim, E., Kang, S., Lee, J. and Rho, B., 2008, "Effect of Primary Nozzle Configuration on the Flow and Transfer Characteristics in an Ejector System for Pellet Transfer," Trans. KSAE, Vol. 16, No. 5, pp. 49-59.
  14. Kim, D. J., Peng, L., Park, S. K. and Yang, H. C., 2014, "Mixed Flow and Oxygen Transfer Characteristics of Orifice Ejector," Proceedings of the KSME Fluid Engineering Division 2014 Spring Conference, pp. 317-318.
  15. Park, S. K. and Yang, H. C., 2013, "Flow and Oxygen Transfer Characteristics in an Aeration System Using an Annular Nozzle Ejectors," Industrial & Engineering Chemistry Research, Vol. 52, pp. 1756-1763. https://doi.org/10.1021/ie302208e
  16. Park, S. K. and Yang, H. C., 2013, "Mixed Flow Characteristics of Aeration Process for Recirculation Aquaculture System Using Ejector," Trans. Korean Soc. Mech. Eng. B, Vol. 37, No. 9, pp. 847-854. https://doi.org/10.3795/KSME-B.2013.37.9.847
  17. 2013, Phantom Camera Control Software (Version 2.2.737.0), Vision Research.
  18. 2010, iworks FX User Guide, Nahwoo Trading Co.
  19. Klein-Douwel, R. J. H., Frijters, P. J. M., Somers, L. M. T., de Boer, W. A. and Baert, R. S. G., 2007, "Macroscopic Diesel Fuel Spray Shadowgraphy Using High Speed Digital Imaging in a High Pressure Cell," Fuel, Vol. 86, pp. 1994-2007 https://doi.org/10.1016/j.fuel.2006.11.039
  20. Du, H., Jang, D. H., Kim, D. J. and Yang, H. C., 2012, "Experimental Study of Oxygen Transfer Characteristics in an Aeration System Using an Annular Nozzle Ejectors," Proceedings of the KSME 2012 Fall Annual Meeting, pp. 2926-2931.
  21. Chern, J.M. and Yang, S.P., 2003, "Oxygen Transfer Rate in a Coarse-Bubble Diffused Aeration System," Industrial & Engineering Chemistry Research, Vol. 42, pp. 6653-6660. https://doi.org/10.1021/ie030396y
  22. EL-Ghandour, M., EL-Sawaf, I. A. and EL-Ottla, F. M., 2001, "Solid-Materials-Handling Central-Type Jet Pump," 6th Int. Water Technology Conference, IWTC 2001, pp. 328-340
  23. Garcia-Ochoa, F. and Gomez, E., 2009, "Bioreactor Scale-Up and Oxygen Transfer Rate in a Microbial Process: An Overview," Biotechnology Advances, Vol. 27, pp. 153-176. https://doi.org/10.1016/j.biotechadv.2008.10.006

Cited by

  1. Mass Transfer Characteristics of Vertical Two-Phase Flows with Orifice Nozzle vol.39, pp.10, 2015, https://doi.org/10.3795/KSME-B.2015.39.10.817
  2. Improving oxygen dissolution and distribution in a bioreactor with enhanced simultaneous COD and nitrogen removal by simply introducing micro-pressure and swirl vol.99, pp.20, 2015, https://doi.org/10.1007/s00253-015-6714-y
  3. Effect of Orifice Nozzle Design and Input Power on Two-Phase Flow and Mass Transfer Characteristics vol.40, pp.4, 2016, https://doi.org/10.3795/KSME-B.2016.40.4.237