“I am a physicist too. But I did not believe in the energy revolution that many people predicted the 1986 discovery would lead to,” says SINTEF scientist Magne Runde.
A lot of energy is required for cooling, although of course minus 200 degrees is not as cold as minus 273.
“What you gain through loss-free transport of current can easily be lost again unless you can find applications in which energy losses are particularly large. For example, electrical cables and transformers have very low energy losses in the first place, often less than one percent of the current that passes through them,” says Runde.
Identified a need
In the course of a SINTEF project in 1996, the senior scientist became involved with a branch of the aluminium industry that produces profiles. He learned that the traditional induction kilns used by the sector have energy losses of about 50 percent!
That was what got him to start the snowball rolling.
Aluminium in focus
In 2001 he was joined by Niklas Magnusson as post-doctoral research fellow in the SINTEF team. According to Runde, his arrival got the ball rolling even faster.
After some preliminary work that was funded by SINTEF, in 2003 the two drew up a patent application that described a new type of induction kiln that relied on superconductors and would be used in the production of aluminium profiles.
Factories with huge "icing syringes"
The induction kiln patented by the SINTEF duo - with its superconductors incorporated – is used in metal extrusion plants. Such plants operate a sort of giant "icing syringe", in which the “icing " consists of copper or aluminium alloys, cast in the form of massive cylindrical billets.
Products for our everyday life
Through the extrusion die at the end of the "syringe" emerge profiles of all shapes and sizes that are almost everywhere around us. We find aluminium that has passed through the die in an extrusion plant in the light fittings above our heads, the front panel of our radio and in window-frames.
But before it is transformed in the press, the aluminium has to be heated to 450-500 degrees in order to make it malleable.
This is where the induction kiln comes in. SINTEF’s solution has laid the foundations of a new, more energy-efficient generation of these kilns. And all thanks to the use of superconductors.