Nozzle clogging in vacuum induction melting gas atomisation: influence of gas pressure and melt orifice diameter coupling

ABSTRACT

The clogging problem of close-coupled nozzles in the vacuum induction melting gas atomisation (VIGA) process is studied by numerical simulation and industrial experiments. To understand the factors affecting lick back on the nozzle, volume of fluid (VOF) multiphase flow model simulation was adopted to visualise the motion of alloy melt around the outer wall of the delivery tube in the primary atomisation process. When the melt orifice diameter is 4 mm and the atomisation pressure is close to 3.5 MPa, the atomisation process is continuous, the powder particle size is fine, and the atomiser can be reused. When the orifice diameter is 5 mm, and the atomisation pressure is greater than 2.5 MPa, the risk of nozzle clogging is avoided, the powder size is relatively coarse. In the case of using the same atomiser structure, this study explains the mechanism of lick-back and the resulting nozzle damage in VIGA units.

KEYWORDS:

• Lick back
• gas atomisation
• nozzle performance
• delivery tube

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This research work was supported by Fundamental Research Funds for the Central Universities (FRF-GF-19-0058).