How to deal with scaling problems in economizers and superheaters
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This post was last edited by large ** Protect me on 2014-1-8 at 14:59. When chemicals are added to the boiler, they go directly into the drum; they can reach the downcomers and water wall, but not the economizer or superheater. So how is scale in the economizer and superheater removed?
First, ensure the quality of the feed water; next, ensure that the steam-water separation elements inside the drum are in good condition. During operation, the water level in the drum should not be too high to prevent steam from carrying water with it. With these maintenance and operational safeguards in place, the superheater system can be backwashed regularly – generally once every six months to a year. An indication that the backwashing was successful is that the salt content in the wastewater discharged from the backwashing process is within acceptable limits. For the economizer, under good operating conditions, scaling is mainly caused by high feedwater hardness and iron ion levels; this should be avoided. If pipe cutting inspections reveal scaling to such an extent that acid cleaning is necessary, acid cleaning can be used to resolve the issue. The superheater system cannot be pickled