Two colour pyrometer technique for coal particle temperature measurements in pressurised pulverised coal flame

AbstractThe present paper describes the development and application of two modifications of a two colour pyrometer for the measurement of coal particle temperatures in a pressurised pulverised coal combustor operating at a maximal thermal power of 400 kW and pressures up to 10 bars. The mean diameter of coal particles ranged from 40 to 100 μm. Slag tap and dry dust firing modes were used. The first system for slag tap firing conditions consists of an achromatic lens system arranged outside the combustor and it is coupled to the pyrometer by an optical fibre. The second system preferably for dry dust firing is a probe configuration and consists of an achromatic lens which is integrated into a water cooled radially movable probe with a cooled background to exclude the effect of the combustion wall radiation. Several series of measurements at a pressure of 3 bars for different coal types were carried out at the pressurised pulverised coal combustion test facility of RWTH Aachen University.