Conventional spray nozzles diversely use in various applications such as combustion system, coating process and cleaning particles. Damage-free sensitive device is becoming more critical in some industries like semiconductor and Organic Light Emitting Diodes (OLED) because a pattern of wafer is becoming smaller and weaker as companies are trying to improve the performance of their own products further. Consequently, an influence of submicron sized contaminated particles is increasing, so the importance of cleaning process has increased. It required new approaches and technologies in order to meet high particle removal efficiency (PRE) without damage to wafer substrate. And dealing with nanometer-sized particulate contamination without physically damaging sensitive wafer patterns is still one of the major challenges as the number of critical processing steps increases. Pressure-swirl type atomizer nozzle accelerates the liquid through nozzles known as swirl ports into a central swirl chamber and is usually used in physical cleaning process steps. It can essentially remove smaller particles due to greater impact of droplets without any material loss and added chemicals. However, the spray at a high flow rate can easily cause damage to fragile structures on patterned wafer surfaces. Two-fluid atomizer based on the air-blast atomizer that involves impacting a bulk liquid with high velocity gas is used because maintenance of one-fluid nozzle is so expensive in fine orifice processing and high- pressure pump. But droplet size distribution and velocity from two-fluid atomizer should maintain within a certain range to prevent wafer pattern collapse. In this paper, two-fluid atomizer as the external mixing nozzle is numerically studied according to various geometrical parameters to confirm the effect on the atomizer performance. The working fluids are nitrogen (N~2~) and deionized water (DIW) with constant properties. The inlet values are 0.3 MPa for gas and 0.06 L/min (LPM) for liquid, respectively. To predict the size and velocity of droplets, a commercial code, ANSYS FLUENT 2019 R03 Ver., is used with Taylor Analogy Breakup (TAB) model in Discrete Phase Method (DPM) assuming droplet diameter is the most probable droplet size of a Rosin-Rammler distribution with a spread parameter. Turbulence model used in this study is Shear Stress Transport (SST) based on *k*-*ω* model. And the thermodynamics, heat transfer and collision are neglected in the present study. The simulation is conducted to define its characteristics like Sauter Mean Diameter (SMD) and Weber number that have used as the crucial factor to determine nozzle performance. In addition, since the fluid drag force generated by continuous fluid velocity is the main mechanism of particle removal, the drag coefficient is also determined as the one of characteristics. The results as Gaussian distribution are graphically depicted and comparted with experiment data estimated by Phase Doppler Particle Analyzer (PDPA).


Numerical Analysis on Performance of Spiral Two-Fluid Atomizer Using Dpm Method

Division / Sponsors: 
Heat Transfer Division (HTD), Fluids Engineering Division (FED)

Heat Transfer Summer Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/HT/HT2020/volume/83709

18th International Conference on Nanochannels, Microchannels, and Minichannels
Paper Proceedings: https://asmedigitalcollection.asme.org/ICNMM/ICNMM2020/volume/83693

Fluids Engineering Division Summer Meeting
Paper Proceedings: https://asmedigitalcollection.asme.org/FEDSM/FEDSM2020/volume/83716

HT-ICNMM2020 - Virtual Conference, SHTC - Virtual Conference, FEDSM2020 - Virtual Conference

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