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Molten Splash Protection for EAF Power Cables
When a water cooled power cable is used in severe environments such as powering an EAF (electric arc furnace) in a steel mill, there is an enormous potential for heat, flames, ash or molten splash to damage the electrical cables (or series of cables) thus crippling the melting operation. This damage translates into unscheduled maintenance and lost production time. In some instances these costs have been estimated as high as $100,000 per hour, depending on the size of the operation and production schedules.
Water-cooled power cables provide a flexible source of power to permit movement of the electrode arms up and down, and to allow swinging the electrode arms and roof back and forth when charging the furnace. A low temperature rubber jacket allows cooling water to flow around the outside of the cable assembly.
Given the large diameter of the rubber jackets surrounding the power cables and proximity to the EAF, there is a significant landing area for sparks, molten metal splash, etc. In many applications the cables are left completely unprotected, exposed to severe high temperature environments. In other cases the rubber cooling water hose is wrapped with inexpensive fiberglass tape that offers minimal protection against possible hazards.
The danger is that molten metal splash caused by “wet charges”, flame impingement, or extreme heat will damage the power cables. This can cause a chain reaction of catastrophic events, including loss in water cooling resulting in overheating or shorting of the electrical power cables and halting the melting process.
The Solution
Wrapping a new or existing water cooled power cable assembly with a severe duty protective molten splash sleeve is the way to prevent damage from heat, flame, ash and large intermittent exposure to molten metal splash. A product manufactured and designed with 100% non-conductive materials specifically for safe non-arcing use in close proximity to AC or DC EAF’s will serve the purpose more successfully than ineffective fibreglass tape, or rubber jackets alone.
A thick silicone coating on a high temperature fiberglass substrate sheds large, random, but potentially hazardous amounts of 3000˚F molten metal splash by virtue of its hydrophobic, low surface energy, non-stick properties. Such a coating helps maintain the integrity of the water cooled power cable until the next scheduled maintenance period. Equipped with a hook and loop self gripping closure, the molten splash away sleeve is easily field installed (or removed for maintenance) without cable disconnection, but also ensures the closure doesn’t separate during severe bouncing and bumping of cables during furnace arc and cold starts.
Depending on the application, the cost to procure and install a high temperature jacketing system could be as low as $30 per foot. Relative to the enormous costs associated with unscheduled maintenance and lost production time, this capital investment could pay for itself several times over with the prevention of a single unscheduled maintenance event.
