This great idea became a golden egg for Celsa

"The Thermos," as the project manager and inventor Tim Ivan Bredesen calls it, is the official name of the Hot Charging system. Ten years ago, Celsa's owners in Spain wanted to save energy on the production of reinforcing steel. The challenge was that the steel bars lost temperature during transport from the steel plant to the rolling mill. When they arrived at the rolling mill, they had to be reheated to almost the same temperature as when they left the steel plant to be rolled into reinforcing steel. These few hundred meters became a huge energy loss project for Celsa Armeringsstål. But a brilliant idea, combined with a culture of promoting innovation within the company, yielded valuable returns. 

"I think it's fun to create something and I really enjoy finding solutions to problems," says Bredesen. 

Inspired by a magazine 

Over the years at Celsa Armeringsstål, in collaboration with good partners in the industrial park, he has repeatedly shown his skills in finding solutions to challenges in the company. Also, this time his creative and solution-oriented talent was awakened. After a few rounds in the Sketch Up drawing program on his computer, which he had learned on his own time out of interest, Bredesen came up with what turned out to be a golden idea. Through the drawing program, he illustrated and explained to his leaders how he envisioned the construction and functionality. 

"The construction is actually inspired by how a magazine for the AG3 rifle works," says Bredesen, who is familiar with the weapon from his time in the Home Guard. 

Essential Enova support 

This is how Celsa Armeringsstål`s development of the Hot Charging thermobox began. The project also received Enova support, an important contributing factor that helped trigger the project. When Celsa Armeringsstål applied for Enova support in June 2014, a reduction in energy consumption in the oven of 57 kWh/tonne was assumed. The result in 2022 shows a reduced energy consumption from around 262 kWh/tonne in the years before 2014 to 195 kWh/tonne. This is a reduction of 67 kWh/tonne. 

Holds up to 900 degrees 

Now, the golden egg of an idea has taken the form of a box that is over nine meters long. It is made of steel and insulation and consists of one chamber that is "charged" with five steel beams each time, which are stacked on top of each other. There is room for ten layers in total. They are fed in glowing red, and with the help of the box's insulation and the heat from each other, they arrive at the rolling mill with a temperature of up to 900 degrees. Then they are almost ready for further processing in the rolling mill, a process that requires the steel bars to be at 1170 degrees. 

"To illustrate how well the thermo boxes work, it's like going from 1 liter of gasoline per mile in your car to 0.2 liters per mile. We save large amounts of energy," says Bredesen. 

"Always good support" 

The first version of Hot Charging was put into use in 2015. Today, they use version 2.0 of the box, which has been improved and modified, with the help of the local company Imtas. Celsa Armeringsstål has a total of six Hot Charging boxes to maintain steady production. 

"It's fun to see when it works. I've always enjoyed creating things and I receive good support from the company for my ideas," says Tim Ivan Bredesen at Celsa Armeringsstål."