Flame chars at different burnout degrees from tunnel furnace tests

Five different series of flame chars from four different coals normally used in Danish power stations have been produced in the Risø 1.3 MW tunnel test furnace. Each series consists of chars with burnout degrees from about 40% to 90%. The tests were performed at the standard operational condition of the furnace with a fuel/air ratio corresponding to about 3.5% O_2 in the flue gas.

In a single test an increased fuel/air ratio was used, corresponding to about 2% O_2 in the flue gas. The operational conditions were determined by local cooled-probe measurements of temperature and gas composition in the flame region. Chars were sampled by a cooled suction probe, using approximately isokinetic suction, along the main flow path in the furnace.

The burnout degrees were subsequently determined by TGA analysis. (au) 20 tabs., 51 ills., 3 refs..