Key benefits of electric preheating of billets in walking beam furnaces
The preheating of billets is an essential step in steel production for achieving a high-quality end product. However, the fossil-fuel-based heating typically used in walking beam furnaces is inefficient, consuming large amounts of energy and emitting high volumes of CO2.
By electrifying the heating process through Kanthal’s Globar® and Kanthal® Super heating elements, steel producers can achieve much higher thermal efficiency and potentially reduce CO2 emissions to zero. Globar® can achieve temperatures as high as 1,625 degrees Celsius (2,960 degrees Fahrenheit), and Kanthal® Super can reach as high as 1,850 Celsius (3,360 Fahrenheit).
Here are four good reasons to choose Kanthal’s heating elements.
Thermal efficiency of more than 90 percent
When using conventional gas-heated industrial burners in walking beam furnaces, only 30 to 60 percent of the heat generated is actually used to heat the billets. Most of the remaining heat is lost through the flue gases that are released into the atmosphere. In contrast, because electric heaters do not generate flue gases, the thermal efficiency can be higher than 90 percent. This means a significant reduction in energy consumption and a substantial reduction in costs.
Industrial burners that use fossil fuels also produce a high level of CO2 emissions. However, using electric heating can substantially eliminate this problem. In fact, if the electricity derives from a renewable source, the heating can be completely emission free.
Precise temperature control
Both Globar® and Kanthal® Super enable precise temperature control in the furnace and in turn in the billets. This improves the overall quality of the final steel and reduces costs by minimizing the number of rejections in downstream operations.
Less oxide scale
Since electric heating has greater flexibility to operate in controlled atmospheres that do not contain high levels of oxygen, there is significantly less oxide scale forming on the surface of billets compared with fuel-fired heating. This reduces time and costs in downstream operations and increases the overall yield.