Detonation burning of anthracite and lignite particles in a flow-type radial combustor

Regimes of continuous spin detonation of anthracite and lignite particles in an air flow in a radial vortex combustor 500 mm in diameter with a constant (along the radius) cross-sectional area are studied. Ground coal with a particle size of 1-12 mu m is used. For transporting coal into the combustor and promoting the chemical reaction on the surface of solid particles, hydrogen or syngas is added in the ratio CO/H-2 = 1/1, 1/2, or 1/3. Continuous spin detonation of two-phase mixtures of fine anthracite and lignite particles and air with addition of hydrogen up to 4% of the coal consumption rate is obtained for the first time. The amount of syngas added to coal increases with decreasing fraction of hydrogen in the syngas: 14, 21, and 27% for anthracite and 11, 20, and 29% for lignite at CO/H-2 = 1/3, 1/2, and 1/1, respectively. The structure of detonation waves and the flow in their vicinity are not principally different from those observed previously for long-flame bituminous coal and charcoal. Higher detonation velocities are observed for more energy-intensive coal (anthracite). A higher pressure is obtained near the cylindrical wall of the combustor in cold runs as compared to detonation in the case with identical flow rates of the coal-air mixtures.