Substantial Energy Savings for Steel Mills

With melting points in excess of 2,000°F, steel mills have many processes requiring tremendous amounts of heat. Although every effort is made to capture excess heat for various purposes, exhaust streams often contain megawatts of useful power. AirClean’s engineering experience and knowledge of the steel industry make us well-suited to assess your opportunities to capture that energy and distribute it for use in your mill – whether as electricity or heat.

Two common opportunities which AirClean has encountered are Basic Oxygen Furnace heat recovery and Steel Reheat Furnace heat recovery. These two opportunities are described in additional detail below.

AirClean will perform assessments of your heat recovery opportunity at no cost to you. We will estimate the benefit and cost of implementation for your company. Please contact us if you would like to learn more.

  • Substantial Energy Savings for Integrated Steel Mills
  • AirClean Energy Patented Technology

The basic oxygen furnaces used in integrated steel mills produce a significant amount of waste heat in the form of exhaust gas, which is normally vented to the atmosphere. Rather than venting, this waste heat can be used for the benefit of the facility. In addition to the heat, the exhaust gas contains a substantial percentage of carbon monoxide, which can be used as a fuel rather than wasted. However, taking advantage of this waste can be difficult due to the cyclical nature of the system. Cycling over large temperature ranges makes heat recovery difficult because the recovered energy is highly variable, and the equipment must be equipped to handle the thermal variation. Additionally, the large volume of particulate entrained in the hot exhaust gas can coat heat transfer surfaces, reducing efficiency and causing mechanical failures.

AirClean Energy has developed a patented process for effective basic oxygen furnace heat recovery. The system takes advantage of the wasted carbon monoxide by combusting it in the airstream. This is coupled with a buffering chamber with heat sinking surfaces to moderate the temperature variation and keep the heat load more constant for heat recovery equipment. In addition, a refractory lined cyclone may also be added to remove most of the entrained particulate. The clean, hot exhaust gas can then be used to generate steam.  The steam is typically used for onsite processes (offsetting natural gas consumption) or to turn steam turbine generators and produce power. These systems typically provide a five-year simple payback on investment.