A well-known fact about the operation of the electric arc furnace is that the water-cooled panels take away a considerable amount of the heat produced during melting cycle resulting in a reduced efficiency. Currently it is known that having a good slag cover will help reduce energy loss, damage to the pipes on the panels and increase life to a certain extent.

However, the slag is not enough to keep the heat inside the furnace and so water continues to remove heat through convection. Typically, the water inside the pressurized panels has a ?T of about 6 to 8°C this ensures that the panels are cool enough to operate safely but also means that the removed heat is essentially wasted energy from the process perspective, since that heat is not being used to melt steel. It is also known that these panels get damaged by arcing, fatigue and burner flame rebound, which could create a leak of pressurized water that, could result in an explosion.

Recently, Melter started working closely with Emisshield® a US, company that creates high-emissivity coatings for industrial applications, to create MINT a new product line for its Melt Shop division that takes advantage of the high-emissivity and corrosion resistance capabilities of these coatings resulting in longer life, more efficient pressurized panels that reduce or eliminate the problems typically found in traditional panels used in the EAF.

These advantages include:

• Increased emissivity which reduces energy loss through cooling water
• Increased temperature uniformity which reduces hot spots
• Increased electrical resistance which reduces arcing
• Increased service life which reduces maintenance costs

Coated MINT roof panels show a ?T of 1 to 3°C, which is 60% reduction of temperature change which translates into less energy loss through the water which will translate into energy savings of varying amounts depending on the specific operation. They will also have a longer life thanks to a reduced risk of arcing and general reduction of thermal fatigue issues.

Melter is also introducing this solution to other components such as:

• Dry deltas
• Water cooled deltas
• Fourth hole elbows
• Ducts
• Electrode arms

Alberto Rivera – Research + Development