During the production of ferro-alloys like Ferro Manganese (FeMn), Silicon Manganese (SiMn) and Ferrochrome (FeCr) as well as Pig Iron, Calcium Carbide and Titanium Oxide slag in closed electric furnaces, a large volume of process gas, with a high calorific, is generated.

Process gas characteristics and hazards

  • Extremely high temperatures, up to 1.800°C
  • High dust loading (SPM), up to 500 g/Nm3
  • High levels of carbon monoxide (CO; 60 to 90 vol.-% dry) and hydrogen (H2; 5 to 40 vol.-% dry)
  • Toxic as well as self-combustible / potentially explosive gas mixture

With these characteristics, the reduction process requires a downstream Gas Cleaning Plant to exhaust the gas from the furnace and for gas cooling, scrubbing and conditioning. This high energy gas is then fed into a gas network or is flared.

Overview of the THEISEN Gas Cleaning Plant

  • High level of operational safety, reliability and availability
  • Excellent cleaning efficiency of SPM from gas (Residual SPM < 5 mg/Nm3)
  • Integrated pressure boosting (up to 10 kPa)
  • Flexibility in operating gas volume and volume variability (up to 140.000 m3/h)
  • Safety relevant component of the production facility

Advantages of the THEISEN wet gas cleaning system

  • Technically superior method to extract, cool, de-dust and condition the off-gases from closed electric reduction furnaces
  • Can be employed for greenfield projects as well as retrofitted to existing plants for production upgrade or efficiency projects
  • Reduction of environmentally harmful emissions and full compliance with environmental emission legislation
  • Incorporates the furnace pressure control system
  • Conditioning of the off-gas to be suitable to utilise the thermal and calorific energy