Experimental study on the characteristics of the gas-particle fields in furnace with a PDA system

The phase-Doppler technique has become one of the most important instruments in two phase flow research in recent years because of its capability to simultaneously measure diameter and velocity of spherical particles. The basic measurement principle of phase-Doppler particle dynamic analyzer (PDA) is presented. A test model is set up based on the 600MW unit of a tangentially-fired boiler to predict the characteristics of the gas-particle two phase flow fields for the micronized coal reburning technology demonstration. With the stoichiometric-ratio α = 0.9 in main combustion zone, gas-particle velocity fields, particle size and concentration in reburing zone are measured and analyzed. The velocity fields and the gas-particle mixing characteristics indicate that an effective reductive field can be formed in the reburning zone.