“OTTO JUNKER can easily combine gas-fired and electrical resistance heated technologies with highest power electrical Induction Heating technology,” Klaus Schmitz, Vice President Sales, Thermoprocessing Plants for Aluminium and Copper at Otto Junker

Klaus Schmitz is serving Otto Junker as Vice President Sales, Thermoprocessing Plants for Aluminium and Copper since 2017. He started working with Otto Junker in 1996 as a Project engineer for Thermoprocessing of Plants, and then he was promoted to Project Manager, Leader of Product Group, and Division Manager Thermoprocessing plants for Copper-alloys. By qualification, he has a master's degree in Mechanical engineering from RWTH Aachen University.

AL Circle: Can you briefly overview Otto Junker's history and contributions to heat treatment in the aluminium industry?

Klaus Schmitz: Otto Junker Company was founded by Mr. Otto Junker in 1924, so we will celebrate our 100 anniversary next year. The company was first established near Aachen, Germany, where the headquarters and primary operations are still located. The start of OTTO JUNKER Company was with furnaces and casting equipment for the brass industry. However, in 1934, with the general increase of aluminium applications, OTTO JUNKER supplied any kind of furnaces for the aluminium industry, such as melting furnaces, pre-heating furnaces, and heat treatment furnaces. OTTO JUNKER has been part of the aluminium industry since the beginning.

AL Circle: How does Otto Junker differentiate itself from other companies in the field of furnaces and plants for aluminium and aluminium-based alloys?
 

Klaus Schmitz: OTTO JUNKER’s technical expertise is based on two quite different technological pillars related to heating technology: High-Convection heating/Jet heating and Hand Induction Heating. High-convection heating is based on the heavy circulation of air or gas inside a furnace. Compared with Radiation Heating, the heat transfer of High-convection is much better in the temperature range up to approx. 900°C. Consequently, our technology is advantageous for those metals treated with up to 900°C, i.e. in practice, aluminium and minor amount of copper alloys. Many competitors are experts in Radiation Heating, which is applied for steel at more than 1,000°C. Aluminium and high-convection is only minor topic for them. For us, with our base in High-Convection Technology, aluminium is our core business since nearly 90 years.

AL Circle:  Could you elaborate on the role of heat treatment in enhancing the properties of aluminium and aluminium alloys for various industrial applications?
 

Klaus Schmitz: Lightweight applications are a highly relevant topic of today’s engineering applications, not only for aerospace but also for automobiles, electrical vehicles (EVs), and trains. Due to its corrosion resistance, aluminium is also very much used for civil construction. OTTO JUNKER’s pre-heating and recrystallisation furnaces are used in the rolling and extrusion plants. In the aforementioned applications, the tensile strength of the material is mandatory. For this reason, OTTO JUNKER’s T4/T5/T6 treatment furnaces with HiPreQ®-Quench systems for strip, sheet, plate, castings and forgings are the key for aluminium alloys to ensure the required strength.

 However, another property of aluminium is getting relevant more and more: Recyclability. The recycling yield of aluminium is very high, so aluminium applications for daily demand are increasing significantly, like for packaging, beverage cans, foil and others. In this field, OTTO JUNKER recycling and melting furnaces are applied.
 

AL Circle:  Otto Junker is known for its innovative technologies. Could you highlight some of the latest advancements in processes and equipment explicitly tailored for aluminium?
 

Klaus Schmitz: At our headquarters, located near Aachen, Germany, our R&D department operates the OTTO JUNKER Technology Centre with a wide range of pilot lines. In parallel, we have a long-term close cooperation with RWTH Aachen Technical University. Mr Junker was awarded an honorary doctor of RWTH Aachen University in 1962. Our HiPreQ®-Quench system for smooth quenching of auto-body sheets, for example, is installed as a pilot line in our Technology Centre. At present, we are focussing on recycling technologies and heat recovery. A rotary kiln for pre-treatment of aluminium scrap was started in our Technology Centre in 2022.
 

AL Circle:  How does Otto Junker incorporate energy-efficient and sustainable practices into its furnace and plant designs for aluminium heat treatment?
 

Klaus Schmitz: Here we see many advantages for our customers as OTTO JUNKER can easily combine gas-fired and electrical resistance heated technologies with highest power electrical Induction Heating technology - our second pillar. OTTO JUNKER already has supplied induction furnaces with 40MW, controlled by our own IGBT controllers.
 

AL Circle:  What are some key industrial applications where Otto Junker's heat treatment solutions have significantly impacted aluminium products' quality and performance?
 

Klaus Schmitz: Just to give two examples: Our HiPreQ® Quench system for auto-body sheet improved the distortion of the thin gauge strip material significantly, so that our customers are enabled the supply much better quality. Our Induction Melting furnaces can generate a controlled high turbulence in the melt by magnetic field, this ensures highest metal yield for our customers when melting small pieces like milling chips.
 

AL Circle:  Could you share any insights into the company's vision for advancing sustainable practices within the aluminium downstream industry?
 

Klaus Schmitz: For the heat treatment applications we see the electrification and operation of the furnaces with green power as the highest reasonable route for the aluminium downstream industry. Here green power is directly converted into the required heat. OTTO JUNKER supplies electrically heated furnaces in parallel to others since its foundation in 1924. Hydrogen heating is also followed up, but looks less reasonable for our applications. That is mainly due the huge efficiency impact from green power to hydrogen and finally to heat, in comparison to “green power direct into heat”. For direct gas fired furnaces, the substitution with resistance heating is much more complicated. However, for these applications, OTTO JUNKER recently has developed special heating elements with increased  power density. For melting and recycling applications, we prepared combinations with electrical induction heating and testing already together with some of our customers.
 

AL Circle: Hydrogen can be stored more easily, whereas direct electrical power may  be more volatile in future due to high portion of solar and wind power. How does OTTO JUNKER overcome this topic?
 

Klaus Schmitz: Together with project partners in Germany, OTTO JUNKER has developed a Power to Heat PtH storage system capable of up to 1.000°C. In times of high power generation by solar and/or wind, the excess power is stored as heat in this system. And at night, for example, when the sun is not shining, the heat from this storage is used to operate the furnaces. This system has also already found interest in other heat applications as well as for usage in combination with reverse power generation. The pure storage part can also be used for the heat recovery between different furnaces in heating and cooling operations.
 

AL Circle: In what ways does Otto Junker invest in research and development to stay at the forefront of innovation and provide solutions that meet evolving industry needs?

Klaus Schmitz: OTTO JUNKER continuously invests in research and development in order to improve the process quality and efficiency of our furnaces. One relevant part not yet mentioned are our mathematical models/digital twins online simulating and optimizing the process performance. The downtime during Covid-19 was used to increase R&D activities and strengthen the cooperation with RWTH Aachen University. Our Technology Centre with several pilot lines just this summer 2023 was moved into a bigger workshop within our premises in order to have more possibilities. Of course, most important drive for our activities is the targets and demands of our customers. Close discussions and contact with our customers and their feedback are always highly appreciated.