Multi-stage water treatment technique enhances online turbine washing
Gas Turbine Efficiency (GTE) has expanded its range of turbine cleaning systems with a water purification technique for use with online turbine washing. The first of these new systems will be delivered shortly to an offshore customer as part of a turbine washing package.
According to industrial sales manager Per Andersson, GTE is the only turbine wash technology specialist to supply this equipment as part of its package. For offshore applications, the water purifier comes in a fully certified EEx version.
There can be no compromise in water quality during online washing, Andersson explains, because as the water evaporates, there is a risk of fouling downstream of the gas path. Compressor washing should be performed ideally once a day, with a high water quality.
GTE’s water purifier de-ionizes the water, thereby removing all contaminates and ensuring a neutral pH. Water quality is monitored continuously and water below 10 MOhm resistivity is not used. The system does this by putting the water through five stages of treatment. The standard system produces up to 5,500 liters/d of high purity water, which can also be used elsewhere on the platform for duties such as boiler feed, amine make-up, battery filling, and instrument rinsing.
The GTE 400iEX, the latest version of GTE’s turbine wash unit for hazardous areas.
Regular online washing - just three minutes a day - significantly extends the intervals at which the turbine needs to be taken out of service for an offline wash, typically from 1,500 to 4-5,000 hrs, Andersson claims.
Closed loop technique
During offline washing, because the turbine is not in operation, the water does not evaporate, and therefore there is no problem in using regular water. On the other hand, it leaves a lot of dirty water - up to 400 liters - to be dealt with after the wash.
GTE has therefore developed a patented closed loop water collection and treatment system. Once treated, the water is returned for re-use in the washing process. The system offers clear benefits for offshore users obliged to comply with regulations restricting or prohibiting the discharge of dirty water into the sea.•
For more information contact Per Andersson, Gas Turbine Efficiency. Tel +46 8546 10 507, fax +46 8546 10 501. [email protected], www.gtefficiency.com.
