company news about aluminium degassing machine

In the aluminum casting industry, the quiet foe of product quality is generally dissolved hydrogen and inclusions of non-metallic particles in molten aluminum. These impurities lead to porosity, shrinkage, and reduced mechanical strength in finished parts, raising scrap rates and reducing safety in such critical applications as engine components for cars or aircraft parts. The aluminum degassing machine appears as the first line of protection against this issue, pairing automation and precision in cleaning molten aluminum efficiently.

An aluminium degassing machine is a piece of specialized equipment designed to extract dissolved hydrogen and entrained non-metallic inclusions from molten aluminium prior to casting. In contrast to traditional manual degassing techniques, this machine eliminates the need for manual purging, providing consistency and efficiency. Liquid aluminium possesses a built-in affinity for hydrogen—picking up on it from damp raw materials, humid atmosphere, or broken-down lubricants—and its solubility crashes as the metal cools, creating ruinous bubbles. The aluminium degassing machine corrects this by providing controlled conditions for gas extraction, making it an indispensable fixture between melting furnaces and casting lines in contemporary foundries.

The common mechanism in most aluminium degassing equipment relies on the inert gas flotation technique, optimized by advanced engineering:

First, high-purity inert gas (typically 99.996% nitrogen or argon, dried to avoid contamination) is introduced into the molten aluminium.

Then, a rotating rotor—a highly commonly corrosion-resistant silicon nitride (Si₃N₄)—breaks up the gas into minute bubbles, which distribute homogeneously through the melt. They act as "sponges": hydrogen penetrates through them due to pressure differences (hydrogen partial pressure in bubbles is near zero), whereas non-metallic inclusions are bound to their surfaces by surface tension. While rising to the surface, bubbles carry impurities with them and form slag subsequently removed, with an average efficiency of 60% for degassing. More recent aluminium degassing equipment now incorporates ultrasonic technology, which removes gas without inert gas usage. Mass production developed for the process utilizes cavitation effects to discharge entrapped hydrogen, providing a cost-saving, safer alternative for SMEs.

Aluminium degassing machines are split based on operation mode to cater to varied production requirements:

• Continuous degassing machines: Fitted directly into continuous cast lines, these treat large amounts (up to 65 mt/h) in multi-rotor setups (1B1R to 3B3R designs). Their box-like enclosed design—lined with high-silicon molten metal—prevents secondary oxidation and has a 2-3 year lifespan.
• Batch degassing machines: For small batch or special alloy production, these use hydraulic-lifted graphite rotors for easy maintenance and purifying to set points.
• Ultrasonic degassing machines: Gas-free equipment designed for high-pressure die casting, minimizing porosity and complying with stringent environmental laws.

The efficiency of an aluminium degassing machine relies on its accuracy-crafted components:

• Rotors: Silicon nitride rotors (60mm shaft diameter, 200mm head diameter) provide 2-5 years of use, resisting corrosion and heat shock in breaking the gas into even bubbles at 450-550 RPM.
• Box structure: Carbon steel composite-insulated shells of (aluminium silicate fibre + calcium silicate board) minimize heat loss, and high-aluminium castable working layers avoid aluminium adhesion.
• Controls: Automatic control of rotor speed, gas flow, and temperature, and proper molten aluminium conditions are maintained by heaters (Si₃N₄-sleeved).

Selecting an aluminium degassing machine includes specification to production objectives matching:

1. Scale of production: Online models are for big volume lines (e.g., 35 mt/h for car casting), whereas small quantities are for mobile batch machines.
2. Purity levels: Aerospace alloys need Si₃N₄-rotor machines with ≤0.09 cc/100g hydrogen level, whereas general castings are for standard graphite-rotor units.
3. Maintenance cost: Highlight long-life components—silicon nitride rotors and linings reduce downtime in relation to traditional graphite components.
4. Environmental considerations: Ultrasonic or inert gas-exclusive machines avoid chlorine-based products, complying with EU emissions regulations.

The aluminium degassing plant adds real value along production lines: it decreases casting scrap levels by 50% by eliminating porosity, enhances tensile strength by removing inclusions, and decreases inert gas usage by controlling bubbles effectively. On high-grade uses like capacitor foils, it raises yield by 8% by preventing pinholes. Besides quality, automation cuts labour costs, and energy-efficient insulation lowers operating costs.

During a period of lightweighting and stringent quality demands, the aluminium degassing machine is no longer a want but a competitive necessity for the production of aluminium. From its application in recycled aluminium ingot to aerospace aluminum alloys, it provides molten aluminium for today's industry requirements.