An Improved Model for Char Combustion in Blast Furnace Pulverized Coal Injection

An improved char combustion model has been presented, taking additional consideration of the influence of the finite‐rate heterogeneous reduction and oxidation. Explicit algebraic expressions for the overall rate of combustion, the surface temperature of the particle, and the gas temperature at the flame sheet are given in the model. The transition between various limiting combustion conditions was analysed using the improved model. A Fourier Transform Infrared spectroscopy (FTIR) system was established to measure the particle temperatures. Rational agreement was achieved between the predictions and the data from the present work and the literatures. Compared with the single‐film model, the predictions of particle temperature by the improved model were in much better agreement with those predicted by the rigid continuous‐film model, while the calculation time for the improved model is 100,000 times faster than that using the continuous‐film model. It is shown that the present model could not only be integrated easily into comprehensive computing codes for industrial pulverized coal flame, but also considers most of the physico‐chemical processes involved and is then accurate enough for engineering applications.