Characterizing the Two-Phase, Air/Liquid Spray Profile Using a Phase- Doppler-Particle-Analyzer

The droplet break-up mechanism of a two-phase gas/liquid ( TPGL ) spray is an intricate process. In this study, radial and axial spray profiles were measured using a Phase-Doppler-Particle-Analyzer ( PDPA ) system. In the first study, the TPGL spray atomization behavior was examined with the values of β (gas-to- liquid ratio by mass ) of 0.37%, 1.41%, 2.04%, and 3.33% at a constant pressure of 482 kPa and a fixed axial distance downstream of 60 D n (Dn represents nozzle diameter of 3.10 mm). In the second study, the TPGL spray atomization behavior was examined at axial distances ( x of 30D n, 60D n, 120D n) and radial distances ( r) at a constant β of 1% and a Pm of 428 kPa. The length and diameter of the feeding conduit ( FC ) was 36.8 cm and 6.35 mm, respectively. It was observed that around the center of the spray ( r/R =0-0.25) the droplets response time was much higher than the continuous phase (air) response time, which was characterized by the droplet Stokes number (St ). However, at the outer region of the spray, the droplets response time follow the continuous phase (air) response time. A higher critical aerodynamic Weber number (We g) at 30D n downstream compared to 120D n downstream of the spray indicates that more droplets will undergo a secondary atomization ( SA ) at 30D n. The fundamental knowledge of the TPGL flow/atomization process in nozzles is important for many industrial and chemical reactions. The outcome of this research will assist in the optimization of commercial process conditions and will provide a comprehensive means of improving the design conditions of the TPGL flow/atomization process.