company news about aluminium degassing machine

In aluminium casting industry, dissolved hydrogen and inclusions porosity have long been one of the major quality threats. Reducing the mechanical strength of casting directly, they increase scrap rates and even pose safety issues in extreme applications like automotive and aerospace. Aluminium degassing equipment becomes the key solution to this problem, as an unavoidable instrument of purification in modern aluminium processing lines.

An aluminium degassing machine is a piece of equipment used to degas dissolved hydrogen and non-metallic inclusions from molten aluminium. Unlike conventional manual degassing methods, the machine offers efficient purification with mechanized control. It is situated between the melting furnace and casting machine to ensure molten aluminium is free of defects before solidification. Hydrogen, the primary object of purification, dissolves in molten aluminium 50 times quicker than in solid aluminium—adsorbed from water in raw materials, wet air, or degrading lubricants. The aluminium degassing machine eliminates this hydrogen and traps impurities, effectively curing porosity and inclusion defects.

Most industrial aluminum degassing facilities employ the gas flotation process, an established technology with proven effectiveness. The process follows in four basic steps:

1. First, inert gas injection. The apparatus uses high-purity inert gas (99.996% nitrogen or argon, dried and dehydrated) in an effort to avoid the addition of new impurities.
2. Second, microbubble formation: A silicon nitride rotor, under controlled rotation, shears the gas into very fine bubbles, which spread out evenly in molten aluminium. Material and rotor velocity both affect bubble size—smallest bubbles have greatest surface areas to carry out purification.
3. Third, diffusion and adsorption of gas. Due to zero hydrogen pressure in bubbles and highest partial pressure in molten aluminum, hydrogen permeably diffuses into bubbles. Simultaneously, non-metallic inclusions adhere to bubble surfaces.
4. Finally, separation and removal: Hydrogen and impurity-containing bubbles rise to the top and solidify into slag, which is separated by a filter box and removed by a slag skimmer. This closed-loop degassing system keeps degassing efficiency constant at around 60%.

Aluminium degassing machines are differentiated by structure and technology for use against diverse production needs:

• Box-type degassers: With fully sealed box bodies and ports for melting, these machines prevent secondary oxidation and are ideally suited to high-purity uses (e.g., aerospace materials). Their multi-rotor design (single, double, or triple) allows for variation in efficiency requirements.
• Launder-type degassers: Incorporated into continuous casting lines, they process molten aluminium as it flows through launders. This type suits high-volume production involving fast alloy switching and low maintenance .
• Vacuum degassers: Using lower pressure to reduce the solubility of hydrogen, they deliver ultra-low gas content but require more energy input, which is suitable for precision parts.
• Ultrasonic degassers: A literature technology that exploits the influence of cavitation, they do away with inert gas consumption and ensure strict environmental compliance—ideal for SMEs seeking green alternatives .

The appropriate aluminium degassing machine depends on balancing production needs and cost, with six key factors :

• Degassing requirements: Purity-high applications (e.g., aerospace) require box-type machines with ≥60% efficiency, while general castings can do with launder-type models with 40%+ efficiency.
• Capacity for production: Size the machine to your volume of melt—large-scale lines (1000kg/h+) need continuous launder-type units, but small runs accommodate portable models.
• Technology and operations: Use machines with automatic controls (e.g., Siemens touch screens) for remote monitoring, reducing operation errors .
• Efficiency in energy: Select units featuring high-quality insulation (e.g., nano-boards) and energy-efficient heaters to minimize energy wastage.
• Reliability and after-sales: Choose renowned brands with durable parts (e.g., silicon nitride rotors with a shelf life of 3+ months) and comprehensive after-sales support .
• Compliance: Ensure the machine is compliant with safety and environmental regulations, especially if using chlorine-based degassing chemicals .

The aluminium degassing unit delivers genuine value in-line. It reduces scrap by taking out porosity—cutting defect rates from 8% to below 3% in car castings. For high-end product like capacitor foil, it boosts yield by 8% by pulling out micro-inclusions.

Apart from improving quality, aluminium degassing machine enhances operational efficiency. Its automation reduces labor costs and reduces efficient gas consumption by 30% compared to manual operations. Environmentally, sophisticated machines pre-empt toxic chemicals (used in the process of chlorine to inert gases) and adhere to EU emissions regulations.

With lightweighting and quality upgrading being the current trends, the aluminium degassing machine is now a necessary rather than a discretionary investment. It guarantees aluminium products to meet stringent specifications of the automotive, aerospace, and packaging sectors to fuel competitiveness in an era of quality-centricity.