Waste Heat Recovery – Submerged Arc Furnaces (SAF)

Abstract

Submerged Arc Furnaces are used to produce high temperature alloys. These furnaces typically run at 3000°F using high voltage electricity along with metallurgical carbon to reduce metal oxides to pure elemental form. The process as currently designed consumes power and fuel that yields an energy efficiency of approximately 40% (Total Btu’s required to reduce to elemental form/ Btu Input). The vast majority of heat is lost to the atmosphere or cooling water system.

The furnaces can be modified to recover this heat and convert it to power. The system will then reduce the amount of purchased power by approximately 25% without any additional use of fuel. The cost of this power is virtually unchanged over the life of the project because of the use of capital to displace fuel consumed from the purchased power source.