Influence of secondary air mass flow rates on gas/particle flow characteristics near the swirl burner region

In a gas/particle two-phase testing facility with the use of a three-component particle-dynamics anemometer, we determine the influence of secondary air mass flow rates on gas/particle flow characteristics in the near-burner region of a centrally fuel-rich swirl coal combustion burner. Velocities, particle volume flux profiles and normalized particle number concentrations were obtained. The peaks of axial, radial, and tangential mean velocities and root mean square velocities increase as the secondary air mass flow rate increases. Simultaneously, the recirculation zone enlarges accompanied by an increase in swirl number. The peak particle volume flux near the chamber axis, between axial distance x/d = 0.1–0.7, increases with secondary air mass flow rate although its peak value decreases and the attenuation rate falls faster than other mass flow rates.