Breaking the mold

The process of die casting aluminum is energy intensive. Thermal energy is required to melt solid aluminum inventory and distribute molten aluminum to casting machines and maintain a supply of molten aluminum at each machine. The current aluminum melt shop at Empire Die Casting Co. Inc., a manufacturer of high pressure zinc and die castings, is not energy-efficient. CEO Richard Rogel knew something had to change to make the process better.

The current system at Empire uses natural gas to help maintain temperature throughout the process. Even under no melt flow conditions, the system requires a constant energy input. The energy requirement is in excess of 32 billion BTU a year and the combined melting, metal distribution and holding systems consume an estimated 51.5 billion BTU a year for every 3 million pounds of aluminum produced.

Empire melts predominantly on-grade aluminum charge using two gas-fired melters. Molten metal is batch transferred from these melters by gravity into metal delivery ladles of roughly 800 pounds capacity. These ladles are heated by direct flame impingement using 400,000 BTU an hour burners. This method is extremely undesirable because of low thermal efficiency, a ladle high temperature decay rate, and high metal loss due to oxidation from direct burner flame contact.

Thermal efficiency improvements have been incremental over many decades. The new technology being implemented by Empire is not incremental, but a quantum shift in process capability and performance. Empire will replace two natural gas fired batch melters, two of the transfer ladles used for metal delivery and five gas fired holding furnaces with the proposed new showcase systems as a package under the Melt Shop Modernization Comparative Showcase project.

The new systems for Empire are all electric, lead the market in efficiency and will position Empire as precedent setting in the industry. The new systems replace inefficient equipment, eliminate in-plant greenhouse gas emissions, improve the work environment, create a technology benchmark for other die casting operations and give insight into the advantages of electric versus gas processes all while saving money, too.

HOW TO REACH: Empire Die Casting Co. Inc., (330) 467-0750 or www.empiredie.com

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