Bespoke and cost-effective gas turbine compressor cleaning solutions

At Rochem, we believe in understanding our customers’ situations, challenges, and goals in order to provide bespoke and effective solutions.

Over the , we’ve discovered this is the way to deliver the best and most cost-effective results.

A great example of our approach is the following case study, in which a gas turbine-powered plant manager approached us for help with a list of specific issues…

The power plant

Rochem were asked to help at a site with two gas turbines, operating 7000 hours annually. Until they contacted us, they had been following the original directions from the OEM (original equipment manufacturer) regarding cleaning equipment and procedures but believed there was scope for improvement.

The problems

The team had identified numerous issues and challenges with the existing situation and procedures:

Offline washing

• Took a long time (4 hours) during which an engineer had to be present at all times.
• Complex wash procedure with 4 wash cycles and 20+ rinse cycles.
• Due to the site’s geographic position, the air is dirtier in the summer than the arctic air that blows in over winter.
• Offline washes have to be performed before the ambient temp. drops below 40F. Although offline washes are possible below this temp, glycol must be added to the wash solution which increases costs (300 gallons of glycol are required to wash both machines) plus the costs of its disposal post clean
• Contaminated rinse water: the existing piping allowed for soap to be sucked into the rinse tank as the system transitioned from wash to rinse. This meant the tank needed to be decontaminated before a rinse cycle could start.
• Excessive water consumption leading to excessive, expensive hazardous waste disposal of effluent.
• Environmental challenges: the plant is surrounded by pine trees meaning pine pitch enters the system through the air inlet and adheres to the bellmouth, inlet guide vanes, and other compressor parts.
• Ineffective detergent: the original water-soluble detergent recommended was not the best choice for the site and was ineffective at tackling the contaminants specific to the area. The water-soluble detergent was unable to effectively remove the pine pitch.

Online washing

• Only possible when ambient temp. is 50F+ i.e. June-Oct. (during these months the compressors are washed daily).
• Erosion: washes were restricted to 10 minutes because of erosion caused by large droplets produced by the OEM spray nozzles.

The goals

The team at the power plant believed their site could perform much better and already had an idea of what they wanted to achieve. This included better producing smaller droplets and better coverage; better detergent, preferably ‘green’ to allow for on-site disposal of effluent rather than expensive offsite disposal; reduced waste; and an end to rinse tank contamination by modifying the equipment.

The solution

When Rochem were approached for help, we were confident we could offer solutions to meet the goals identified. Backed by years of specific industry experience, this is exactly the kind of project in which we specialize.

The ultimate plan was split into two phases:

1. Trying at least one alternative and detergent to improve offline washing.
2. To improve .

Like all shrewd businesses, the power plant were keen to monitor and compare results to ensure they were making a smart investment. We were happy to oblige: equipment (, , and a service engineer to oversee installation) and detergent ( – low foam, natural solvent-based) from Rochem were selected and provided on a trial basis to compare with the existing setup.

A side-by-side comparison was made possible by the two gas turbines onsite and were installed in both turbines to monitor progress. The Rochem equipment was retrofitted to GT2 while GT1 retained its original setup.

The results

A comparison test was conducted approximately six months after the last offline wash, with impressive results. The report from the plant manager concluded that:

• The Rochem procedure was easier to implement, took less time, and required less operator intervention.
• It cut 70mins off the 4hrs for offline cleaning.
• GT2 (with the new Rochem products and procedure) gained 300kW more than GT1 after the washing and correcting numbers to allow fair comparison.
• The smaller droplet size and better coverage achieved by Rochem’s nozzles on GT2 was more effective and reduced the waste stream by more than 1100 gal (1846 gal for GT1 vs 736 gal for GT2).

The future for the happy customer

Now into phase two of the testing (for online washing), the team at the power plant are extremely impressed by the results achieved with Rochem products. They found for offline cleaning easy to change and the results were certainly impressive. While the Rochem skid is currently integrated into the GT2 system, GT1 will be retrofitted soon.

The teams at Rochem and the power plant are thrilled with the results and look forward to working together in the future.

Bespoke solutions

Rather than giving a one-size-fits-all solution, we tailor our approach to our customer’s specific requirements. In this case, we evaluated how the power plant is run and the specific environmental challenges, keeping in mind the customer’s goals and budget. We draw upon decades of experience and unmatched industry knowledge to come up with unique, carefully considered solutions.

We are proud to have helped this customer find a simple-to-implement yet highly effective gas turbine cleaning solution for their site and look forward to the results from the next phase.

Get in touch

If you want to improve the gas turbine cleaning equipment, detergents, and/or procedures at your gas turbine site, we’re here to help. Please with our friendly, knowledgeable team to discuss the possibilities.