Abstract
A comparison of experimental data for the final moisture content and gas temperature profile for a pressurised entrained flash drier to a one-dimensional mathematical model developed previously for the brown coal mill process is discussed. A combustor fired with diesel and air was used to produce a flue gas at 800°C and 10 bara to flash dry Yallourn lignite at a nominal feed rate of 750 kg/hr. The comparison between model predictions and measured temperature profiles for the flue gas and final moisture content of the dried coal product showed excellent agreement. A new coal feeder arrangement was developed which provides a simple positive feeding device for feeding against a back pressure. The feeder takes as an input coal which is nominally < 50 mm and discharges it as a finely divided product with a mean particle size of approximately 1.0 mm. Coal moisture was reduced from 67 wt % to between 30 and 40 wt %.
