SIS Injector

The SIS injector is a component installed in electric arc furnaces. For melting steel and scrap a burner capacity of 300 kilowatts is provided. To this end, oxygen is accelerated via a Laval nozzle, mixed with fuel gas and ignited.

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Conventional design

The conventional design of the SIS injector is based on a welded assembly comprising several components of different materials. The weight of the structure is approx. 18 kilograms. With a size of 573 x 288 x 210 millimeters, the welded assembly is difficult to install in the available space. For this reason, the reduction of the component dimensions offers the potential to facilitate installation.

Optimization potential

  • Increased ignition reliability and operational safety
  • Lower number of parts
  • Perfect media feeding associated with an ideal mixing ratio

Additive Manufacturing design

A new design was developed to reduce the number of parts and to change the size of the SIS injector. The AM design consists of just one monolithic part. Previously, the component was welded together from 18 individual parts. Using the additive manufacturing technology, it was possible to reduce the installation space required for the SIS injector by 50 percent. A flow-optimized channel routing and near-contour cooling are benefits thanks to the layer-based structure. Another advantage is that the individual media can be fed in an ideal way. During the buildup process to the laser-based powder bed fusion method, the geometry is self-supporting and does not require supporting structures within the component while production is going on.


  • Installation space reduced by 50 percent
  • Reduced number of parts
  • Flow-optimized channel routing
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