Furnaces Designed for Fuel Efficiency

The purpose of this paper is to enlighten you about the various designs of aluminum melting and holding furnaces and how they relate to energy efficiency. The word efficiency is thrown around with little regard to its true meaning. There are three types of efficiencies in every furnace. There are burner efficiencies, furnace efficiencies and melting and holding efficiencies. They are not the same and cannot be looked at as individual items when making a decision on a new furnace, they are equally important. The first one that should be looked at is furnace efficiency. It is the only one we will talk about today. Does the furnace design make sense from an overall melting and holding standpoint? You can buy four different radiant roof melting furnaces and end up with three different actual BTU’s/# of metal melted. Does it take more net BTU’s in one gas fired furnace than the other to melt a pound of aluminum? No! But the amount of Gross BTU’s required to maintain that net BTU’s has to do with furnace efficiency. Adding pre heat hearths and circulation to the furnace will increase BTU’s/# melted efficiencies but not combustion efficiencies. In breaking these down one by one we can better understand the importance of each type of efficiency.