A Study of Liquid Metal Atomization Using Close-Coupled Nozzles, Part I: Gas Dynamic Behavior

Published

January 24, 2005

Author(s)

Steven P. Mates, G S. Settles

Abstract

Experiments are conducted to examine the gas dynamic and atomization behavior of a convergent and a converging-divering (c-d) close-coupled nozzle used to fabricate fine metal powders by gas atomization. Part 1 of this paper concentrates on the gas dynamic behavior of the two nozzles, while Part 2 focuses on their atomization behavior. In Part 1, the schlieren technique is used to visualize the gas flow patterns produced at overall pressure ratios between 15 and 55. Pitot pressure surveys are performed to quantitatively compare the nozzle flows at a low, medium and high pressure ratio spanning this range. In Part 2, a high-speed schlieren technique is used to visualize melt breakup behavior simultaneously with the compressible flow field in which it occurs. Post-experiment particle size analysis is used to determine the effect of pressure ratio and nozzle geometry on atomization performance. The process observations, gas flow measurements and particle size data present a more complex physical picture of this atomization process than currently exists, including the existence of an extended active atomization zone. In addition, the c-d nozzle was not superior to the convergent nozzle in either gas dynamic behavior or atomization performance over most of the range examined.

Citation

Journal of Atomization and Sprays

Volume

15

Pub Type

Journals

Keywords

gas atomization, gas dynamics, metal powder, power metallurgy

Citation

Mates, S. and Settles, G. (2005), A Study of Liquid Metal Atomization Using Close-Coupled Nozzles, Part I: Gas Dynamic Behavior, Journal of Atomization and Sprays (Accessed May 18, 2024)