Gas-particle flow and combustion in the near-burner zone of the swirl-stabilized pulverized coal burner

In an air-particle test facility, a three-dimensional particle-dynamics anemometer was used to measure air particle flows in the near-burner region of the radial bias combustion burner. With the increase of nonswirling secondary air (SA) ratio, the air and the particle divergent angles greatly decrease. Both the diameter and the length of the central recirculation zone decrease and the peak value of particle volume flux near the burner axis increases. The reacting flow experiment shows that oxygen concentration decreases while CO and NO_x concentrations increase in the burner central zone when the nonswirling SA ratio increases. The application of the nonswirling jet of the secondary combustion air results in a substantial reduction in carbon-in-ash content.