Compressed Air Cleaning of Main Steam Piping

<<This paper presents a summary of long-term and short-term experience that demonstrates compressed  air-blow results are "at least as good, and often better than steam-blows." Compressed airblows  have been used effectively on applications for supercritical boilers, drum-type boilers, and heat recovery steam generators for preoperational  cleaning of main steam lines at power
plants with ratings from 35 to 700 MW.
Cleaning of the main steam piping is required to minimize the possibility of damage to the turbine  by removing weld bead deposits, pipe slag, and other foreign material which might otherwise  be carried over into the turbine. Any particles  that would be dislodged while operating must be dislodged during the cleaning process, and any particles that are or become loose must be removed from the system. Thus, the momentum  or cleaning force must exceed the force that occurs during the maximum flow operation.  This requirement is satisfied by selecting the initial pressure level so that the momentum or cleaning force ratio is greater than one. The procedure is similar to a steam blowdown except that compressed air is used as the cleaning  medium. The system is pressurized using rented compressors or site equipment and depressurized by rapidly opening the temporary valve. The cycle is repeated until the cleanliness criteria have been satisfied.>>

http://www.gepower.com/prod_serv/products/tech_docs/en/downloads/ger3636a.pdf Received on Thu Jul 19 23:34:00 2007