Ladle preheating

Electric ladle preheating solutions leave no carbon footprint, provided the electricity they use is generated from a renewable energy source. Even when the source is a fossil-based power plant, the reduced energy consumption of an electric heater leads to better resource efficiency overall. Electric ladle heaters have the potential to cut energy use by as much as 70 percent, depending on the process in which they are used.

Ladle preheating is used first to dry out the refractory and prevent explosions in the event of any remaining water vapor being exposed to liquid metal, and second to heat up the refractory material to reduce the risk of thermal shock when it is filled with molten metal, thus preventing cracks and damage to the lining.

Olivier Tanguy explains that ladles have traditionally been preheated using open-flame gas or oil burners, but these days, he says, electrical solutions are on the rise.

“Real change is happening and companies everywhere are looking to reduce their carbon footprint,” he says. As businesses invest in new equipment, more decision-makers than ever are seeking climate-positive long-term solutions, he adds.

NO MORE GUESSWORK

Caption Olivier Tanguy, Business Development Manager with Kanthal.Electric heaters do not emit any excess heat, harmful nitrous oxides or poisonous carbon monoxide. While gas burners are extremely noisy and polluting, electric solutions are quieter, safer and cleaner than any gas-driven alternative.

They are also more precise. “Whereas gas systems blow heat against the ladle, allowing a lot of energy to escape out of the exhaust, an electric heater is a closed system,” Tanguy explains.

In other words, the heat is concentrated in the place where it is needed, making the heating process more controlled and far more uniform. Moreover, refractory lifetime is extended by as much as 20 percent, since the lining of the ladle is less likely to crack from local overheating or thermal shock.

“Whereas temperature control with a gas heater is mainly guesswork, an electric heater ensures a reliable outcome by heating the ladle to a uniform, measurable temperature,” Tanguy says.

ADAPTED FOR ALL TEMPERATURE RANGES

As to what that number is, it very much depends on the application. Whereas aluminum processing requires preheating to around 650 degrees Celsius (1,200 degrees Fahrenheit), steel processing requires significantly higher temperatures of up to 1,400 Celsius (2,550 Fahrenheit). Bronze, zinc and copper require something between the two extremes.

While there is a common misconception that electric heaters are not equipped to deliver the higher temperatures, Kanthal’s electric heating systems can be adapted for all temperature ranges, delivering heating and preheating up to ladle temperatures of 1,500 degrees Celsius (2,730 degrees Fahrenheit).

Safer, cleaner, more sustainable and more efficient, electric ladle preheating is the future-proof solution for aluminum and steel producers everywhere.

Five reasons to electrify your ladle preheating process

Electric ladle preheating is safer, cleaner, more efficient and more sustainable. Here are the top five reasons to electrify your ladle heating process.

Zero emissions

For companies seeking to reduce their carbon footprint, converting to electric is a no-brainer. Electric ladle heating solutions produce zero carbon emissions, provided the electricity is generated from a renewable energy source. When using electricity from a fossil-based power plant, the enhanced efficiency of an electric heater can still produce fewer carbon emissions overall.

Thermal efficiency of up to 95 percent

Whereas gas heaters allow significant amounts of energy to escape into the ambient air, an electric heater focuses the power where it needs to be. The average net efficiency of an electric ladle preheating system is up to 95 percent, compared with only 20 percent for a gas heater. This can result in an energy saving of up to 70 percent when converting from gas to electric.

Enhanced working environment

An electric ladle heater contributes to a safer, cleaner working environment. Whereas gas burners are noisy and polluting, Kanthal’s electric solutions are quiet, safe and clean. In addition to eliminating the obvious safety risks posed by gas in the working environment, electric heaters produce no excess heat, harmful nitrous oxides or poisonous carbon monoxide.

Precise temperature control

A ladle that is too hot or too cold can cause all sorts of problems in the casting process. While gas heaters are not able to measure ladle temperature, electric systems are equipped with thermal controls, enabling you to get the temperature just right every time. The result is greater uniformity and reliability in the production process.

Extended product lifespan

When a ladle has not been sufficiently preheated, the extreme heat of the molten metal may damage the refractory material. By always heating the ladle to the required temperature, electric ladle heaters reduce the risk of thermal shock, thus extending the life of the ladle lining by an average of 20 percent.