PHOENICS Application: Metallurgical Waste-Heat Boilers

DETAILS :

• Two industrial waste-heat boilers (WHBs) for the Outokumpu Copper Flash Smelting Process
• Three-Dimensional, gas flow and heat transfer in participating media (high SO2 + dust)
• BFC and Cartesian grids
• k-epsilon models for turbulence
• Composite flux model for thermal radiation
• Numerical tracer experiments: RTD analysis
• CFD models used to predict gas flow pattern, temperature distribution, heat flux distributions, and overall cooling efficiency

NOTES :

• The horizontal WHB consists of a radiation section and a convection section
• Hot dust-laden off-gas at 1350 C entering WHB from the flash smelting furnace
• Off-gases cools by over 600 - 700 C in the radiation section, and by about 400 C in the convection section
• Two boilers were studied: (1) old WHB operated before May 1995 (2) modified (new) WHB after May 1995 at Outokumpu Harjavalta Metals Oy
• Simulation results provide useful information for boiler modifications
• CFD simulation proves to be a convenient tool for more aerodynamic design and optimisation for metallurgical waste-heat boilers

RESULT EXAMPLES :

• Illustration of the waste-heat boilers used in the Outokumpu Copper Flash Smelting Process
• Example of the computational grid for the new boiler
• Gas flow pattern for the old boiler
• Gas flow pattern for the new boiler
• Gas flow pattern for the new boiler: effect of circulating off-gas
• Predicted temperature distribution for the old boiler
• Predicted temperature distribution for the new boiler: radiation section model
• Predicted temperature distribution for the new boiler: effect of off-gas circulation
• Predicted energy distribution in the new boiler
• Comparison of predicted temperature profile with on-line measurement, in the radiation section of the old boiler
• Comparison of predicted temperature profile with on-line measurement, in the radiation section of the new boiler
• Typical residence-time distribution (RTD) curves: radiation section models
  

REFERENCES :

• Y. Yang, Computer simulation of gas flow and heat transfer in waste-heat boilers of the Outokumpu copper flash smelting process. Acta Polytechnica Scandinavica, Chemical Technology Series No.242, Helsinki 1996, 135 pp (PhD thesis).
• Y.Yang, A. Jokilaakso et al., Gas flow and cooling in waste-heat boilers in the Outokumpu flash smelting process, PHOENICS Journal, Vol. 11 No. 3, 1998, pp 332-347.

For further information, please contact :

• Yongxiang Yang, Faculty of Applied Earth Sciences, Delft University of Technology, Mijnbouwstraat 120, 2628 RX Delft, the Netherlands. Phone: +31-15-278 2542; Fax: +31-15-278 2836; e-mail: Y.Yang@ta.tudelft.nl