Film Fraction and Droplet Size inside of a Rectangular Venturi Scrubber

Abstract:

The Venturi scrubber, equipment frequently used in the removal of particles from gases, is constituted basically by a duct with a convergent section followed by a constriction, or throat, and a divergent section. A liquid, usually injected in the throat, is atomized by the flowing air at high speed. The formed droplets act as collectors of particles from the gas. The process of droplet formation from an injected liquid can be described as follows: the liquid enters the gas stream in the form of a jet, perpendicular to the gas flow. As the jet penetrates the gas stream, it is bent by the gas drag. After a given penetration distance, a burst occurs, and the remaining jet is disintegrated as a droplet cloud. Depending on the liquid and gas flow rates, the penetration on the jet into the gas stream may reach the walls of the equipment, and a fraction of liquid deposits in the form of a film. This film contributes little for the removal of particles from the dust laden gas. Few studies have analyzed the formation of film at the scrubber walls and its influence in the droplet size inside the Venturi scrubber. For this reason, the present study is focused on the experimental measurement of the deposition of the liquid film on the walls of a rectangular Venturi scrubber and, simultaneously, the estimation of the droplet size measured in the Venturi throat. The experiments were carried out varying the liquid flow rate, the gas velocity and the number of orifices of liquid injection. A correlation, using a dimensionless number, was proposed to quantify the influence of each experimental condition. The results indicate that film fraction has a significant influence in the droplet size measured inside of Venturi scrubber.

• Periodical: Materials Science Forum (Volumes 660-661)
• Pages: 549-554
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.660-661.549
• Online since: October 2010
• Authors: Vádila Giovana Guerra, M.A.F. Daher, José Antônio Silveira Gonçalves, José Renato Coury
• Keywords: Droplet Size, Film Fraction, Venturi Scrubber

References

[1] S. Viswanathan, C.C. ST. Pierre and A.W. Gnyp: Canadian Journal of Chemical Engineering Vol. 61 (1983), p.504.

[2] M.A.F. Daher, V.G. Guerra, J.A.S. Gonçalves, J.R. Coury: submitted to Int. J. Environment and Waste Management (2008).

[3] S. Nukiyama and Y. Tanasawa: Transactions of the Society of Mechanical Engineers Vol. 4 (1938), p.86.

[4] R.H. Boll, L.S. Flais, P.W. Maurer and W.L. Thompson: Journal of the Air Pollution Control Assocition Vol. 24 (1974), p.934.

[5] A. H Lefebvre: Atomization and Sprays (Hemisphere Publishing Corporation, New York 1989).

[6] H.F. Liu, W.F. Li, X. Gong, X.K. Cao, J.L. Xu, X.L. Chen, Y.F. Wang, G.S. Yu, F.C. Wang and Z.H. Yu: Chemical Engineering and Processing Vol. 45 (2006), p.240.

[7] V.G. Guerra, M.A.F. Daher, M.V. Rodrigues, J.A.S. Gonçalves and J.R. Coury: Mater. Sci. Fórum Vols. 591-593 (2008), p.896.

[8] V. Cleary, P. Bowen and H. Witlox: Journal of Hazardous Materials Vol. 142 (2007) p.786.

[9] K. Krishna, T.K. Kim, K.D. Kihm, W.J. Rogers and M.S. Mannan: Journal of Loss Prevention in the Process Industries Vol. 16 (2003), p.1.

[10] K.D. Kihm, G.M. Lyn and S.Y. Son: Atomization and Sprays Vol. 5 (1995), p.417.

[11] B.K. Park, J.S. Lee and K.D. Kihm: Atomization and Sprays Vol. 6 (1996), p.285.

[12] K.D. Kihm and N. Chigier: Atomization and Sprays Vol. 1 (1991), p.113.

[13] K.J. Hay, Zi-Chao Liu and T.J. Hanratty: International Journal of Multiphase Flow Vol. 22 (1996), p.829.

[14] L. Bayvel and Z. Orzechowski: Liquid Atomization (Taylor & Francis, Washington D. C 1993).