Freedom Shaft Melter^®

Freedom Shaft Melter reduces holding bath dross cleaning without special treatment

Freedom Shaft Melter has a low-oxidation design that ensures months of operation without requiring holding bath cleaning, even after 7 months of production.

Foundries benefit from lower energy consumption, low metal loss from oxidation, cleaner metal, and less scrap from inclusions. What’s more, the Freedom Shaft Melter offers remarkably long holding bath cleaning cycles that translate to longer uptimes and less metal-rich drag out during daily bath cleaning.

Freedom Shaft Melter

• Shaft melting principles for continuous operation.
• Flat flame holding burner (no impingement).
• Independent combustion systems.
• Separate sealed holding bath for reduced oxide formation.
• Separate melt chamber with submerged metal flow.
• High K-Mold results (B – AA).
• Small footprint for “in cell” use.
• Automatic charging elevator.
• Longer cleaning cycles for holding chamber!

Independent melting and holding burners allow for more precise control

• Adoption of high efficiency burner(s) in the melting chamber ensures that oxidation loss is drastically reduced.
• Melting burners have separate combustion fans and quick release fittings for easier maintenance.
• The holding burner recuperates the heat from the separate exhaust system to further improve efficiency.

Freedom Shaft Melter Benefits

• Reduce cleaning time for holding bath
• Less cleaning will reduce flux usage
• Flat flame burner avoids surface impingement.
• Sealed bath zone restricts air ingress and reduces surface oxidation.
• Average 6-month intervals.
• Metal loss reduction.
  • <0.004% in holding bath through reduced oxidation.
• Energy savings for holding energy.
  • Sealed holding chamber reduces heat loss.
  • Exhaust recuperator for holding burner.
  • Ceramic fiber upper wall and roof insulation.
  • lower internal temperature and heat loss.
• Metal quality.
  • Reduced oxide contamination of melt.
  • No flame impingement, no air ingress = lower gas levels.
• Holding temperature stability.

Seeing is Believing: The Ingenuity of the Freedom^® Furnace.

We consider ourselves fortunate to offer the North American casting industry the ingenuity behind the melting furnaces developed by Nippon Crucible Corporation. It all began several years ago with the introduction of the Jet Melter® furnace, followed by the subsequent evolution into the Freedom Furnace. 

What’s so innovative? Ask a furnace operator. The Freedom Furnace has reduced holding chamber cleaning frequencies from once per shift to once every 6 months. In one case seen by the author this was extended to an 18-month period to verify the technology of a new furnace.

Cleaning the dross from melting and holding furnaces is a necessary part of the overall maintenance regime required to ensure the best quality metal and the longest possible life for an expensive asset. Cleaning the holding chamber is a tough and uncomfortable task for furnace operators and anything that makes this task easier and less frequent has significant effects on both operator and furnace efficiency as well as overall operating and energy costs.

Extending the cleaning cycle from every shift to every six months may seem too good to be true, but in fact, is made possible by world-class engineering of the holding chamber and burner design. The resulting outcome:

• Removes or reduces the amount of oxygen present in the holding chamber by separating the melting, holding and pocket chambers to avoid air ingress.
• Avoids surface impingement on the metal bath by strategically locating burners.
• Runs burners as close to stoichiometric as possible.
• Avoids air flow into the chamber when burners are off or idling on low fire.

This patented development has created significant savings in energy, operator time and effort and very importantly, metal loss and metal quality and consequent cost savings for the foundry by: 

• Reducing operator time to clean the holding bath.
• Avoiding excessive production downtime for cleaning
• Improving metal quality through reduced inclusions from cleaning
• Reduced metal loss from oxidation (dross) removed during cleaning.
• Better energy efficiency from closed holding chamber
• Reduced flux usage in cleaning the holding bath.

The below series of images documents that the amount of dross produced during continuous aluminum melting remained virtually the same over the course of 18 months.