Uneven Composition of Molten Aluminum Impairs Billet Mechanical Properties: In-line Degassing Unit for Simultaneous Melt Homogenization and Refining

In continuous aluminum melting and casting lines, mixing of old and new melt, local thermal gradients, and impurity segregation lead to uneven distribution of molten aluminum composition. Composition fluctuations alter mechanical indicators including tensile strength and elongation, causing property dispersion within the same batch of aluminum billets.

Under 25–35 t/h casting throughput, melt residence time is limited. Furnace stirring alone cannot eliminate micro-segregation. Inhomogeneity carries over into extrusion and forging processes, raising dispersion in mechanical tests and unstable batch quality risks.

The FDUII‑30 box-type dual-rotor in-line degassing unit stirs molten aluminum through rotating dual rotors. It performs hydrogen removal while promoting melt mixing. Controlled fluid disturbance generated by the rotors reduces local composition gradients and mitigates elemental segregation. The sealed chamber limits secondary oxidation and foreign impurities that disrupt melt composition. Installed in series within the melting-casting workflow, flowing aluminum passes continuously through the refining chamber for concurrent degassing and homogenization.

Source: Document “Dual‑rotor In‑line Degassing Parameter Sheet”

• Symmetric dual rotors create a directional circulating flow field that combines mixing and bubble dispersion.
• Submerged inlet and outlet ports reduce splashing and prevent air entrainment and oxide inclusions.
• Lining made of CV8 refractory castable resists aluminum erosion and will not leach foreign elements to contaminate the melt.
• Variable frequency drive adjusts rotor speed according to melt flow rate to match homogenization requirements at different throughputs, avoiding violent surface turbulence from excessive agitation.

• Batch sampling for chemical composition and mechanical property inspection is recommended during production.
• Regular rotor wear inspection preserves a stable flow field and consistent homogenization performance.