Gas mixing in circulating fluidised-bed risers

摘要: Abstract Steady-state tracer-gas measurements were carried out in a circulating fluidised-bed (CFB) boiler and cold experimental unit. The main focus was on the radial spread of gas core region transport zone under different operating conditions. Helium (He) used as tracer gas, local He-concentration determined by mass spectrometer. fluidisation velocity ranged from 1.2 to 4.3 m/s 1 6 m/s bed material silica sand with an average particle diameter 0.32 mm both units. Measurements also bottom splash for comparison those zone. In unit, greater range conditions could be covered than what possible boiler, including case without solids. there is no backmixing horizontal mixing injected characterised axi-symmetric around centre line injection. gas-mixing rate quantified dispersion coefficient, which above 0.01 m 2 /s 0.005 m difference coefficients unit due size. present results compared literature data obtained solids CFB risers.