Performance of Twin-Fluid Atomizers for Atomization of Viscous Solutions

¹ Brno University of Technology, Faculty of mechanical engineering, Department of the thermodynamics and environmental engineering, Technická 2896/2, 616 69 Brno, Czech Republic
² Karlsruhe Institute of Technology, Institute of Process Engineering in Life Sciences, Section I: Food Process Engineering, Kaiserstraße 12, 76131 Karlsruhe, Germany

^a Corresponding author: mlkvik@fme.vutbr.cz

Published online: 6 May 2015

Abstract

Presented paper deals with a comparison of two internally mixing twin fluid atomizers. The well - known Y- jet atomizer and so called outside-in-liquid effervescent atomizer (OUIL) were investigated. The working regimes were defined by the pressure drop (Δp) and the gas to the liquid ratio (GLR). The internal and the external two-phase flows of both atomizers were studied. The influence of the mixing mechanism on the internal flow was evaluated by the gas to the liquid momentum ratio (Φ). In advance, the stability of the separated flow (liquid film) was examined in term of the critical wavelength of the surface disturbances (λ_c). The external flow was observed by the high – speed camera. The influence of the basic forces on the deformation of the liquid was determined by a dimensionless criterion w·μ / σ. The values of Φ < 1 for the OUIL atomizer indicates that the internal flow of this atomizer was annular. The internal flow Y- jet atomizer was more complicated, because the momentum ratio varies from Φ < 1, where the gas momentum is dominant, p to Φ > 3, where the liquid momentum overcomes the gas momentum. The values of w·μ / σ> 20 for both atomizers indicates the dominant influence of the viscosity and the drag force on the breakup process.