Reason For Silica Deposition In Turbine
Silica Deposition in Turbine How is silica coming to turbine? There are two types silica : 1. Colloidal Silica: SiO2-O-SiO2- More prevalent in water from surface source pH>7,, this is insoluble and mainly removed by UF, Coagulation, Nano filtration. 2. Reactive Silica: (OH)3Si-O- This is soluble and removed by EDI (Electro deionisation), RO. But Silica is coming in turbine through steam from Boiler. Silica in steam should be less than 0.02ppm . It can be increased due to following reason: 1. High silica level in steam drum: : Silica in drum should be less than 2ppm upto 100ata drum pr ref fig below (drum pr vs silica level and pH) .If it increases above this value, blow down (IBD and CBD ) should be operated to control the silica level. Secondly it can be seen when boiler is not properly cleaned during commissioning time. It can also be seen due to lower steam separator efficiency in boiler drum. 2. ...