냉각법 및 영상 처리기법을 이용한 서브마이크론 정전분무 액적의 크기분포 측정

DOI QR코드

DOI QR Code

구본기;김상수;김유동;이상용
Gu, Bon-Gi;Kim, Sang-Su;Kim, Yu-Dong;Lee, Sang-Yong

  • 발행 : 2001.10.01

초록

The size distributions of electrospray droplets from the Taylor cone in cone-jet mode are directly measured by using a freezing method and a transmission electron microscope (TEM) image processing technique. These results are compared with the data obtained by an aerodynamic size spectrometer (TSI Aerosizer DSP). The use of glycerol seeded with NaI and a freezing method make it possible to sample droplets with their original sizes preserved. Since pictures of droplets are taken with TEM with very low vapor pressure of the solution, evaporation is suppressed by freezing. For liquid flow rates below 1 nl/sec, the measured droplet diameters by the TEM image processing technique and the aerosizer are in the range of 0.25 to 0.32 m add 0.3B to 0.40m, respectively. Comparing the TEM data with the aerosizer measurements, it has been revealed that the TEM image processing technique can afford more accurate values of droplet size distributions in the submicron range of 0.1 to 0.4m.

키워드

정전분무;냉각법;영상 처리 기법

참고문헌

  1. Hartman, R. P. A., Brunner, D. J., Camelot, D. M. A. Marijnissen, J. C. M. and Scarlett, B., 2000, 'Jet Break-up in Electrohydrodynamic Atomization in the Coneojet Mode,' J. Aerosol Sci., Vol. 31, No.1, pp. 65-95 https://doi.org/10.1016/S0021-8502(99)00034-8
  2. Huberman, M. N., 1970, 'Measurement of the Energy Dissipated in the Electrostatic Spraying process' J. Appl. Phys., Vol. 4C No.2, pp. 578-584 https://doi.org/10.1063/1.1658716
  3. Riqdick,. J. A. and Bunger, W. B., 1970, Organic Solvents: Physical Properties and Methods of Purification, 3rd Ed., John Wiley and Sons, New York
  4. Fetnandez de la Mora, J. and Loscertales, J. G., 1994, 'The Current Emitted by Highly Conducting Taylor Cones,' J. Fluid Mech., Vol. 260, pp. 155-184 https://doi.org/10.1017/S0022112094003472
  5. Saville, D. A., 1971, 'Stability of Electrically Charged Viscous Cylinders,' Phys. Fluids, Vol. 14, No. 6, pp. 1095-1099 https://doi.org/10.1063/1.1693569
  6. Kim, Y. D. and Lee, S. Y., 2000, 'Improvement of Image Processing Algorithm for Particle Size Measurement Using Hough Transformation,' the fifth conference of ILASS-Asia, Tsukuba, pp. 99-104
  7. Gonzalez, R. C. and Woods, R. E., 1993, Digital Image Processing, Addison-Wesley, New York
  8. Kidd, P. W., 1968, 'Parametric Studies with a Singlec-Needle Colloid Thruster,' J. Spacecraft and Rockets, Vol. 5,No. 9, pp. 1034-1039
  9. Gomez, A. and Tang, K., 1994, 'Charge and Fission of Droplets in Electrostatic Sprays,' Phys. Fluids, Vol. 6, No.1, pp. 404-414 https://doi.org/10.1063/1.868037
  10. Rao, K. V. L., 1978, 'Liquid Nitrogen Cooled Sampling Probe for the Measurement of Spray. Drop Size Distribution in Moving Liquid-Air Sprays,' Proc. ICLASS-78, Tokyo, pp. 293-300
  11. Karasawa, T.,Shiga, S. and Kurabayashi, T., 1991; 'Measurement of Droplet Sizes by Liquid Nitrogen Freezing Method,' Proc. ICIASS-91, Gaithe-sburg, pp. 637-644
  12. Tang, K. and Gomez, A., 1994, 'On the Structure of an Electrostatic Spray of Monodisperse Droplets,' Phys. Fluids, Vol. 6, No.7, pp. 2317-2332 https://doi.org/10.1063/1.868182
  13. Naqwi, A., 1994, 'In situ measurement of submicron droplets in electro sprays using a planar phase Doppler system,' J. Aerosol Sci., Vol. 25, No.6, pp. 1201-1211 https://doi.org/10.1016/0021-8502(94)90209-7
  14. Rosell-Llompart, J. and Fernandez de la Mora, J., 1994, 'Generation of Monodisperse Droplets 0.3 to 4${\mu}$m in Diameter from Electrified Cone-jets of Highly Conducting and Viscous Liquids,' J. Aerosol Sci., Vol. 25, No.6, pp. 1093-1119 https://doi.org/10.1016/0021-8502(94)90204-6
  15. Chen, D. R., Pui, D. Y. H. and Kaufman, S. L., 1995, 'Electrospraying of Conducting Liquids for Monodisperse Aerosol Generation in the 4 nm to 1.8 ${\mu}$m Diameter Range,' J. Aerosol Sci., Vol. 26, No. 6, pp. 963-77 https://doi.org/10.1016/0021-8502(95)00027-A
  16. Cloupeau, M. and Prunet-Foch, B., 1989, 'Electrostatic Spraying of Liquids in Cone-jet Mode,' J. Electrostatics, Vol. 22, pp. 135-159 https://doi.org/10.1016/0304-3886(89)90081-8