Research group “Industrial Furnace Technology”

Contact person Furnace mechanics: Wolfgang Lenz
Contact person combustion: Christian Schwotzer

Areas of research

The core of the activities in this research group is formed by process optimization and process development in the sector of the metal-working industry. To improve the energy and resource efficiency of thermotechnical plants like industrial furnaces, a profound understanding of flow and heat transfer phenomena is essential. The processes are investigated using physical and numerical models. To do this, a number of hot and cold test stands are available and equipped with extensive measurement instrumentation. Apart from that, empirical and analytical modeling as well as simulations based on Computational Fluid Dynamics (CFD) are used. The combination of experimental and numerical investigations allows for a comprehensive representation of the physical phenomena. The research is focused on the following areas:

Industrial furnaces aerodynamics:

  • Hot gas ventilators for high temperature applications
  • Heat introduction into industrial furnaces, direct (gas fired) or indirect heating (gas or electrically heated radiant tubes)
  • Conditions of heat and mass transfer on constructional elements of industrial furnaces
  • Nozzle assemblies for furnaces with high convective heat transfer (chamber furnaces, strip flotation furnaces, etc.)
RWTH-FB5-029
Physical modell of a strip cooling line ( photographer: Martin Braun)

Process gas furnaces:

  • Optimization of gas exchange strategies
  • Control of process gas exchange
  • Development of metal oxide sensors

Combustion:

  • Construction and optimization of burners
  • Direct Flame Impingement (DFI)
  • Flameless combustion (FLOX)
  • Combustion under oxygen deficiency conditions to reduce oxidation of copper and steel
  • Combustion diagnostics using OH* visualization and laser induced fluorescence (LIF)

Modelling and simulation:

  • Recrystallization and grain growth of copper and brass
  • Fluid-Structur-Interaction: effects of fluid flow and thermotechnical phenomena on load and furnace housing
  • Combustion in different applications

Another still emerging research topic are hybrid heating concepts. Most of the industrial furnaces are using fossile fuels, especially natural gas, oil or coal. Against the background of the so called “Energiewende” (energy transition) conventional fuels shall be substituted more and more by electrical power from renewable sources and therefore contribute to the stability of the electrical grid (power to heat). To implement these changes, systematic research and development of new innovative concepts for thermotechnical plants and industrial furnaces is needed.

Ongoing research projects

Renewable residential heating with fast pyrolysis bio-oil – Residue2Heat (EU H2020)

Development of a recuperator for the hybrid combustion air pre-heating in industrial furnaces (AiF ZIM)

Influence of heat transfer on the process stability of continuous strip treatment plants (AiF IGF)

Influence of thermal load changes on the service life of highly stressed furnace components made from metallic high temperature materials (AiF IGF)

Development of energy efficient burners for heat treatment plants with reducing protective gas atmosphere (AiF ZIM)

Development of cross-flow fans for the use in thermoprocess plants (AiF IGF)

Completed research projects

  • Device for the measurement of high volume flows at high temperatures in industrial furnaces (AiF IGF)
  • Expansion of the limitations of use of the FLOW technology for low and high burner powers (BMWi)
  • Improvement of service life of metallic recirculating radiant heating tubes for industrial furnaces by reducing thermal stresses (AiF IGF)
  • Process developemtn for non-scaling reheating of metallic semi-finished products (AiF IGF)
  • Stability considerations for metallic strips under the influence of nozzle fields (AiF IGF)
  • Development of a multilayered chamber furnace for the press hardening of tailored blanks for automotive engineering to improve cost effectiveness (AiF ZIM)
  • Device for volume flow measurement during high convective heat treatment (AiF IGF)
  • Improvement of the service life of metallic components in industrial furnace engineering (AiF IGF)
  • Development of metal oxide sensors for gas analysis for the control of gas atmospheres in industrial furnaces (AiF IGF)
  • Improvement of product quality and economy of industrial furnaces with protective gas atmosphere by optimization of the change of furnace atmosphere (AiF IGF)