Extending Recovery Boiler Runtime Through the Temperation of Stem at the Soot Blower, 1998 Engineering Conference Proceedings

Recent advances in soot blower nozzle design have enabled doubling of the jet Peak Impact Pressure (PIP) while maintaining the same blowing pressure in the soot blower. Two main factors that determine the removal of brittle deposits are the PIP of the jet and the strength of the deposit. Due to the flue gas path and geometry of the generating bank it is not unusual to see localized deposit accumulation in this section of the boiler. Left unchecked these deposits sinter to form a strong brittle deposit. During the sintering process these deposits gain strength, and in some instances can even render improved nozzles ineffective. This happens to be the case reported here, where severe localized plugging was detected 167 days into a run cycle. At this time the addition of full expansion nozzles in the vicinity of the deposit did not reduce the pressure differential in the generating bank. A water wash looked imminent. Specific soot blowers were retrofitted to accept a water spray at the soot blower in order to increase the density of the blowing medium. Following this course of action the boiler was able to run the full cycle without having to be taken off line for a water wash. No adverse effect was seen on the boiler tubes.