Atomization and Sprays, Vol.18, No.6, 511-522, 2008
Flow-adapted design option for free-fall atomizers
Free-fall gas atomizers are often used for liquid solution and melt atomization in the area of powder production and spray forming applications. This external mixing atomizer often uses two separate gas nozzle systems, namely, a primary gas nozzle (for prevention of major gas recirculation flow in the atomization area) and a secondary gas nozzle (for atomization), both concentrically surrounding the central liquid jet. Due to this specific arrangement, the atomization area is separated from the atomizer body, however the primary and secondary gas pressures need to be carefully adjusted. To improve the free-fall atomizer construction and operating conditions, the gas flow field of a conventional free-fall atomizer was investigated by numerical simulations. Aim of the investigation was to economize the primary gas application, while safely operating the atomizer without recirculations. Advantages of the derived flow-adapted atomizer design are a reduction in gas consumption, as well as the potential of generation of smaller particles. This effect was proven by atomization of a viscous melt.