DOI QR코드

DOI QR Code

Prediction of Micro-Bubble Releasing Concentration with the Retention Time of a Micro-Bubble Generating Pump

미세기포 발생펌프 내 체류시간에 따른 미세기포의 발생 농도 예측

  • Received : 2016.03.21
  • Accepted : 2016.04.11
  • Published : 2016.06.30

Abstract

The mechanism of micro-bubble generation with a pump is not clarified yet, so the design of water treatment systems with a micro-bubble generating pump is based on trial and error methods. This study tried to explain clearly quantitative relationships of experimental micro-bubble concentration ($C_{air}$) of continuous operation tests with a micro-bubble generating pump and theoretical air solubility. Operation parameters for the tests were discharge pressure ($P_g$), water ($Q_{w0}$) and air ($q_0$) flow rates, orifice diameter ($D_o$), and retention time (t). The experimental micro-bubble concentrations ($C_{air}$) at 4.8 atm of discharge pressure ($P_g$) were in the range of 21.04 to 25.29 mL/L. When the retention time (t) by changing the pipe line length ($L_p$) increased from 1.22 to 6.77s, the experimental micro-bubble concentrations ($C_{air}$) increased from 25.86 to 30.78 mL air/L water linearly. The dissolved and dispersed micro-bubble concentrations ($C_{air}$) are approximately 4 times more than the theoretical air solubility.

Keywords

References

  1. Adeney, W. E., Becker, H. G., 1919, The Determination of the rate of solution of atmospheric nitrogen and oxygen by water Part I, Philo. Maga. Series 6, 38, 317-337.
  2. An, D. M., Lee, C. H., Choi, Y. C., Cho, S. H., Ahn, K. H., Kim, S. S., 2002, Bubble concentration and flotation efficiency in domestic DAF pump, Theor. App. Chem. Eng., 8, 1553-1556.
  3. Bahadori, A., Zahedi, G., Zendehboudi, S., Bahadori, M., 2013, Estimation of air concentration in dissolved flotation(DAF) systems using a simple predictive tool, Chem. Eng. Res. Design, 91, 184-190. https://doi.org/10.1016/j.cherd.2012.07.004
  4. Fujiwara, A., 2006, Microbubble generation using venturi tube, ECO Industry, 11, 27-30.
  5. Fukushi, K., Tambo, N., Matsui, Y., 1995, A Kinetic model for dissolved air flotation in water and wastewater treatment, Wat. Sci. Tech., 31, 37-47.
  6. Lee, C. H., Ahn, K. H., 2009, Effect of chemical conditioning on flotation and thicken properties of sludge using a microbubble generating pump, KSEE, 31, 641-648.
  7. Lee, C. H., Park, J. W., Ahn, K. H., 2014, Micro-bubble generating properties on gas/liquid flow rate ratio with the sludge flotation/thickening apparatus, J. Environ. Sci. int., 23, 97-104. https://doi.org/10.5322/JESI.2014.23.1.97
  8. Letcher, T. M., 2007, Developments and applications in solubility (1st ed.), Royal Society of Chemistry, RSC Publishing Inc., Dorset, 66-77.
  9. Muroyama, K., Imai, K., Oka, Y., Hayashi, J., 2013, Mass transfer properties in a bubble column associated with micro-bubble dispersions, Chem. Eng. Sci., 100, 464-473. https://doi.org/10.1016/j.ces.2013.03.043
  10. Okamoto, R., Takeda, T., Shakutsui, H., Ohnari, H., 2005, Performance of micro-bubble generators, Japanese Society for Multiphase Flow Annual Meeting, Tokyo, Japan, August.
  11. Ohnari, H., 2000, Swirling type micro-bubble generation system, Japan Patent, WO0069550.
  12. Ohnari, H., Saga, T., Watanabe, K., Maeda, K., Matsuo, 1999, High functional charateristics of micro-bubbles and water purification, Resour. Pros., 46, 238-244. https://doi.org/10.4144/rpsj1986.46.238
  13. Perez-Garibay, R., Martinez-Ramos, E., Rubio, J., 2012, Gas dispersion measurements in microbubble flotation systems, Miner. Eng., 26, 34-40. https://doi.org/10.1016/j.mineng.2011.10.006
  14. Sadatomi, M., Kawahara, A., Matsuura, H., Shikatani, 2012, Micro-bubble generation and bubble dissolution rate into water by a simple multi-fluid mixer with orifice and porous tube, Exp. Therm. Fluid Sci., 41, 23-30. https://doi.org/10.1016/j.expthermflusci.2012.03.002
  15. Smith, F. L., Harvey, A. H., 2007, Avoid common pitfalls when using Henry's law, Chem. Eng. Prog., Sept., 33-39.