A lab-scale cold flow model reactor to investigate near-wall particle segregation relevant to entrained-flow slagging coal gasifiers

The particle deposition rate at the wall and the partitioning of wax droplets between the lean-dispersed phase and the wall liquid layer have been assessed under a range of operating conditions. Temperatures of the atomized wax, of the mainstream air and of the reactor wall have been set in a range of values (120-155 °C) at which the wax was fluid. Experiments with wax feeding rate of 0.2 g s−1 and flow rate of atomizing air in the order of 0.30 m3 h−1 demonstrated that the fractional mass of wax in the dispersed phase decreased from 91% to 12% as the reactor length increased from 0.03 m to 0.27 m. The velocity of the descending wall liquid layer, whose thickness was in the order of 0.2 mm, ranged between 3 mm s−1 and 6 mm s−1. The effects of the flow rate of atomization air and of the nozzle temperature were limited.