LARS® Aluminum Refining System

LARS® (Liquid Aluminum Refining System) is a degassing and purification treatment equipment which cleans metal by removing physical (hydrogen gas inclusions), chemicals (alkali metals) & metallurgical (alkali salts & sludge inter-metallic) impurities. The LARS® system operation is based on the proven principle of high-energy diffusion and chemically driven mass transfer. Although systems utilizing rotating gas sparging device have been available in the industry for years, only LARS® offers patented gas preheating and other sophisticated features for optimal molten aluminum refining.

With over 1 billion lbs. of hard alloy processed over the past 10 years, LARS® has a proven track record of making the following contributions to the bottom line of a casthouse:

Metallurgical Sophistication:
In-situ process gas preheating gives superior degassing and inclusion capture. Gas preheating is achieved by making the gas flow through the passageway formed by the helical groove (which is machined on the outer diameter of the graphite shaft) and the inner wall of the graphite cylinder. The gas then captures heat from the graphite cylinder, which is immersed in the molten aluminum. Accordingly, the gas flow path is extended 30 times its original straight flow path length. Preheating of gas help retain fine bubble size by preventing the undesirable growth in the bubble after the gas comes into contact with the molten aluminum.

Attrition (intense) mixing of the melt and gas bubbles controls vortexing and reduces “carry-over”. Vortexing is controlled by generating cross and reverse velocity vectors in the melt. Through specialized design of the reaction vessel and placement of the gas dispersing mechanisms, the velocity vectors have no vortexing tendency. The benefit of this design is that vortexing prevents reentry of dross into the upper layer of the melt and reduces bubble carryover at the lower exit end of the reactor.

Each reactor’s shape and internal slope prevents bubble agglomeration and improves efficiency. Additionally, the reactor volume is increased from the bottom to the top in a controlled manner to accommodate increase in the gas bubble’s volume (which results from reduced metallostatic pressure). This prevents bubble coalescence and keeps gas surface area higher for a longer duration of the gas’ total residence time in the reactor.

Thermal Stabilization:

• Heater Surface Area: Multiple 1.2 kw individual heaters are located into large surface area graphite heating blocks; providing rapid temperature equalization

• Intelligent PLC assisted thermal control with 4 thermocouples per reaction chamber

• System sized for flow rate between 2 tons per hour and 75 tons per hour

 Operational Ease:

• Unitized lift

• Rotor change over time: Less than 12 minutes

• Dross Ports: Horizontal Skimming at the metal level line (no access through roof is required)

Longevity and Life:

• Nitrogen Shrouding over Tiles and Heater Junction Boxes

• Silicon Carbide covered graphite heating tiles

 Total Quality Assurance in Metal Treatment:

• Mass flow alarms

• Differential temperature alarms

• Rotor RPM alarms

Environmental Safety:

• Noiseless & cool atmosphere maintained around the reactor

• PLC & Mass flow meter assisted halogen control

• Chlorine sensing alarms & no environmental toxic gas release to atmosphere

Custom Configuration of Foot Print:

• Hexagonal Reaction Chambers allow for multiple configurations of entry and exit ports to increase installation options

Guaranteed Technological Superiority:

• 75% Degassing efficiency

• Inclusion removal to pass 60 ppi Ceramic Foam Filter (CFF)

• Alkali removal- Na, Ca, Li <1 ppm output

• Alkali salt removal- to pass sonic Mil 2154 AA testing

Rapid return on investment:

• Typical payback period of under 1 year

Elimination of furnace fluxing requirement:

• Many of our customers (including hard-alloy manufactures) do not use a holding furnaces at all after installation of LARS® degassing system.  Pretreatment in the melter is not often not required either.

Almex LARS® is patent protected in the United States and other countries. Refer to Almex’s Patents Page for further information.