Hi all,
In my plant we have 90m S type once through type steam generator (Tube side: Feed water) with inlet/outlet temp of 180/440 Deg. C feeding to turbine. We maintaining the water chemistry by a online condensate polishing unit and the silica content inlet/outlet of SG and rest of the steam water system is <20 ppb. But in the last two weeks, silica started increasing gradually and gone more than 50ppb from the SG outlet. Hence, we pulled out the turbine.
As suggested by our cheif chemist, we are doing flushing with more amount of feed water (mechanical cleaning) to remove the silica formed in the SG. So far, two weeks gone, the silica content out from the SG outlet is more than 200ppb.
Here we cannot use manual cleaning as we can do in condenser. Since, its a enclosed steam generator.
My question is, whether this mechanical cleaning is the easiest way to reduce the silica carry over or any chemical cleaning is required?
#Samayaraj
Edited by samayaraj, 02 December 2014 - 01:04 PM.