Soot blowers can be a root cause for
deterioration if they are not operating properly. Therefore, soot-blower parts
should be inspected for proper alignment, position, and operability. If soot
blowers are out of position or misaligned, the blower blast could impinge on
tubes which will eventually cause tube failure due to erosion. Soot blowers can
also be a source of liquid water that can promote dew point corrosion of tubes,
casing and the blowers themselves. The shut-off valve to the blowers should be
checked to ensure it does not leak while in service. Condensate can form in the
system when the blower is out of service and if it leaks into the firebox can
cause dew point corrosion.
The blower, supporting hangers, and brackets
should be examined visually for soundness and for excessive thinning from
oxidation. Soot blowers for the high-temperature part of the boiler are
sometimes composed of high-chromium alloys that embrittle in service and so
they should be handled/inspected appropriately to avoid fracture. Connection
welds of supporting elements should be inspected for cracks. If the welds look
cracked, a magnetic-particle inspection should be made. Packing glands and all
operating parts of the rotating and retracting types of soot blowers should be
examined for good working condition. Because of the potential difficulty of
repacking soot blowers in service, repacking should be done during down periods
if there is any evidence that repacking might be required.
No comments:
Post a Comment