Remediation of ash problems in fluidised-bed combustors

摘要: Abstract The paper reports the control methods for mitigating particle agglomeration and bed defluidisation during fluidised-bed combustion of low-rank coals. A laboratory scale spouted-bed system is used to study effectiveness several including use alternative materials, mineral additives, pretreatment coal blending. Sillimanite, bauxite, calcite magnesite were as materials whereas additives viz. clay, kaosil bauxite injected into while burning South Australian at 800°C. Samples same subjected water-washing, Al Ca are also tested in combustor. In addition, experiments conducted with blends prepared ratios 50:50 90:10 from two lignites one sub-bituminous coal. Experiments showed that all effective different extents reducing ash problems resulted extended operation. Tests trouble free-operation longer periods (7–12 h 800°C) than sand runs temperature. Wet blending found be operation (9–12 h 800°C). Chemical analyses indicated formation low temperature eutectics was suppressed by Al/Ca/Mg-rich phases coating particles. This identified main mechanism prevention observed pretreated coals blends.