Abstract
In order to predict the deposit formation in the recovery boiler, advanced modelling tools are required. Current models for the deposit formation need experimental data on the coarse fly ash particles (diameter >3 µm), since no validated formation model has been reported for them. On the other hand, a formation model for the fine fume particles (diameter <3 µm) has been established and validated. In this work, the characteristics of recovery boiler flue gas particles were studied experimentally in the furnace. The particles were extracted from the flue gas with a quench probe and subsequently collected on a planar filter or size classified with a Berner type low pressure impactor. In addition, individual particles were collected with a settling probe and a cooled grid sampler. The particle characterization was carried out by analyzing the samples with ion chromatography, X-ray absorption of free structure, and a scanning electron microscope along with an energy dispersive X-ray analysis system. The fine particles in the furnace of typical Finnish boilers are mainly Na2SO4, double sulphate of Na and K, and NaCl. No KCl was detected. The chemical composition of the coarse particles in the furnace suggests that they are unburned particle residues or originate from impurities in black liquor. The coarse particles deposit along the flue gas passage and they are not detected at the ESP inlet. Nevertheless, as reported earlier, the particle size distribution is bimodal at the ESP inlet. At this site, the coarse particles are not unburned residues, but mostly large agglomerates of fine particles re-entrained from the heat exchangers.
Original language | English |
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Title of host publication | 1998 International Chemical Recovery Conference Proceedings |
Publisher | TAPPI Press |
Pages | 983-987 |
Volume | 3 |
Publication status | Published - 1998 |
MoE publication type | B3 Non-refereed article in conference proceedings |
Event | 1998 TAPPI International Chemical Recovery Conference - Tampa, United States Duration: 1 Jun 1998 → 4 Jun 1998 |
Conference
Conference | 1998 TAPPI International Chemical Recovery Conference |
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Country/Territory | United States |
City | Tampa |
Period | 1/06/98 → 4/06/98 |