Effect of primary air flow types on particle distributions in the near swirl burner region

In this study, 3-component particle-dynamics anemometry is used to measure, in the near-burner region, the characteristics of gas-particle 2-phase flows with 2 swirl burners with different primary air flow types, on a gas-particle 2 phase test facility. The first burner is of the radial bias combustion swirl type whose primary air is non-swirl and the second whose primary air is swirl. With the first, particle volume fluxes, fractions and concentrations are greater near the edge of the central circulation zone, and volume fractions and concentrations are also greater within the central recirculation zone. With the 2nd burner, the particle volume fluxes and concentrations are less near the edge of the central recirculation zone but are greater in the wall zone. The influence of gas-particle flow characteristics on combustion have been analysed, and the theory of air-surrounding-coal combustion is given. (Original abstract - amended)