| 论文简介 |
Deposits on the surface, upstream, and downstream of bag filters in a 12MWbiomass-fired grate furnace
in China were collected, sampled, and analyzed by X-ray fluorescence (XRF) and X-ray powder
diffractometry (XRD). Major elements in the surface and upstream deposits were Si, Ca, K, Cl, S, and
Na; the share of Al, P, Mg, and Fe was relatively poor. In comparison to the upstream deposits, the high
concentrations of K, Na, Cl, and S in the surface deposits were indicative of the formation of sub-
micrometer particles in the boiler, which were subsequently captured on the bag filters. However, high
concentrations of Si, Al, and Ca in the upstream deposits could trap chloride via the formation of
aluminosilicate and calcium chloride. In addition, the relatively lower contents of K, Na, Cl, and S in the
upstream deposits went against the formation of sub-micrometer particles and led to upstream deposits
that were more like an aggregate of fly ash and unlike the surface deposits, which were as hard as stone and
adhered to the surface of bag filters when flue gas passed through the bag filters. XRD analysis further
proved the above results. The intensity of sylvine and halite phases in surface deposits were significantly
higher than those in the upstream deposits, and the intensitise of quartz and berlinite phases in the surface
deposits were obviously lower than those in the upstream deposits. Higher contents of sylvine and halite as
well as lower contents of quartz and berlinite in the surface were indicative of the formation of sintered ash
in the boiler. Then, it adhered to the surface of the bag filters. At the exit of bag filters, a mysterious
substance evinced asNH4Cl byXRDwas generated by the recombination reaction ofNH3 (g) and HCl(g) at
23 the outlet temperature of bag filters. The purity of NH4Cl was almost 100% |
(创新港)
