Box-Type / Launder-Type Online Degassing Unit

Main Application

The box-type or launder-type unit continuously treats molten aluminum before casting. Inert gas and a rotating rotor reduce hydrogen content and carry out some non-metallic inclusions. Equipment type and capacity are matched to metal flow, alloy grade, hydrogen target and available launder space.

Overseas Project Support

For export projects, Lanyu can configure the online degassing unit around local fuel or power conditions, plant layout, automation level, operator workflow and environmental requirements. The equipment should be matched to molten aluminum flow rate, casting process, hydrogen removal target and available space in the launder system.

For a faster technical proposal and quotation, please share:

• Molten aluminum flow rate, alloy grade and casting process
• Required hydrogen removal target and inclusion control target
• Box-type or launder-type preference and available installation space
• Argon or nitrogen supply conditions and filtration requirements
• Destination voltage, frequency and local safety requirements

Working Principle

This equipment uses inert-gas degassing based on hydrogen diffusion. A rotating graphite rotor disperses a measured flow of high-purity argon or nitrogen into fine bubbles throughout the molten aluminum. Because the hydrogen partial pressure inside newly formed bubbles is initially low, dissolved hydrogen diffuses into them while some non-metallic inclusions attach to their surfaces. The bubbles then rise to the melt surface carrying hydrogen and inclusions.

Smaller, more evenly dispersed bubbles improve hydrogen removal. Fine inclusions can be carried to the surface during degassing, while larger inclusions require a dedicated filter box. Rotor speed, inert-gas flow, treatment time and filtration are selected according to melt flow, alloy grade and the required hydrogen and inclusion targets.

Degassing Effect

Under the following conditions:

• Aluminum melt temperature range: 690°C to 730°C
• Use high-purity inert gas (Ar or N₂, purity ≥ 99.996%) without high magnesium alloy.

Hydrogen content treatment effect:

• When the hydrogen content of incoming molten metal is ≤ 0.30 ml/100g-Al,
• The degassing result is ≤ 0.14 ml/100g-Al

Oxygen content treatment efficiency:

• When the oxygen content of incoming molten metal is ≥ 0.30 ml/100g-Al,
• Degassing efficiency is ≥ 50%