Using vault structure steels to improve the lifetime of radiant tubes

In the field of industrial furnace construction, the radiant tubes used for heating are critical components. The radiant tubes, which contain a gas burner, are used for separating the oxidizing gas from the furnace atmosphere. An industrial furnace used e.g. for heat treatment of steel strip consists of several hundreds of radiant tubes. Mechanical stresses reduce the lifetime of radiant tubes considerably. For profitable use, a long lifetime is crucial. Therefore, an expanded lifetime of radiant tubes is one of the most decisive parameters in the design of industrial furnaces. This work deals with the capability of radiant tubes made of structured steel sheets. The objectives are a significant increase in lifetime as well as material savings. In addition, further advantages such as an increase in radiant surface are aimed at. The tubes were deformed in a Zwick/Roell testing machine. A vault structured tube and tube without surface structuring were compared with respect to force compensation effects and creep strength. The experimental results were supported by FEM simulation. The compensation of the maximum stresses and deformation is verified by simulation, which explains the effect of structuring on the lifetime of radiant tubes.ISSN:2351-978