Are you overlooking blade coverage and spray distribution in compressor cleaning effectiveness?

You may carry out regular gas turbine compressor washes. You may have selected the most appropriate cleaning chemicals possible. You may reasonably presume your washes are effective at removing foulants... However, have you considered that your detergent isn’t even touching parts of the compressor, leaving it dirty and compromising overall performance?

Blade coverage and spray distribution are critical to ensuring the most effective gas turbine compressor cleaning possible. But why are these factors so important, and how can you improve them? Let’s find out…

What happens during gas turbine compressor cleaning?

During a gas turbine compressor cleaning cycle, atomised water/cleaning chemicals are sprayed directly into the compressor. This washes the internal surfaces via a combination of:

• physically dislodging deposited fouling
• specialist chemicals breaking down and/or dissolving foulants.

Foulants removed, the process is followed by thorough rinsing until conductivity levels are achieved.

Why full coverage is essential

It’s simple: a cleaning solution can only clean the surfaces it contacts. Any areas that are missed will remain fouled, undermining your efforts. Even if you use the correct detergent, poor spray distribution results in uneven cleaning, increased rinse requirements and avoidable overall performance loss.

Where are some systems falling short?

Observations on some GE units during on-line washing showed visible “streaking” patterns across the bellmouth and compressor blades. In several cases:

• blade tips appeared cleaner than root sections
• some areas showed evidence of water contact while others remained visibly fouled
• spray coverage appeared uneven across the compressor face

These observations suggested that airflow and nozzle positioning were significantly affecting spray distribution and cleaning coverage.

Does full coverage matter with water-only washes?

Some operators choose to conduct water-only online cleaning programs. In these cases, you may think spray distribution is less important. However, field observations showed that on some GE 7FA units operating with water-only online washing:

• water appeared to be pushed toward the bellmouth during operation
• centre/root sections of blades appeared less effectively treated
• airflow appeared to influence where the water travelled

Whether you opt for water-only washes or introduce specialist cleaning chemicals, ensuring full blade coverage and even spray distribution should be a priority to get the most from your efforts.

What makes Rochem different?

Rochem FYREWASH® nozzles are designed to inject atomised spray into the airflow zone ahead of the compressor face to improve overall blade coverage.

The three fundamental factors that impact how effectively a cleaning solution reaches all the areas within a compressor are:

• Nozzle positioning
• Atomisation
• Spray trajectory

Understanding these factors allowed us to develop superior nozzle technology, enabling customers to achieve more complete blade coverage with water/their chosen cleaning solution.

Cleaning nozzle evolution

We’ve spent decades in this specialist area, and our technology has evolved with greater research and understanding. When we conducted a site visit in Lake Charles, our own 1990s nozzle designs produced:

• visible gaps between spray zones
• “scalloping” effects between nozzle placements
• uneven coverage areas

Since then, our designs have evolved through field experience, testing and continued development work. We’re dedicated to staying at the forefront of the industry, always striving to deliver superior results for our customers. Our latest nozzle designs are a testament to this dedication.

Comparison of OEM nozzle configuration vs Rochem FYREWASH® design

Our cleaning nozzles are installed at sites around the globe, each one having been made from high-quality materials and tested in-house at our workshop in the UK.

Some operators of GE 7FA/ EA units noted several observations following nozzle changes:

Our customers are overwhelmingly pleased with the results our nozzles and technology achieve.

Find out more

Nozzle positioning, atomisation, and spray trajectory are critical to enabling cleaning solution full reach within a gas turbine compressor. If you compromise on your nozzle technology and setup, you waste opportunities during cleaning cycles and suffer uneven cleaning, increased rinse requirements and performance loss.

If you’re interested in upgrading your gas turbine compressor cleaning nozzles, we’d love to hear from you. Visit our cleaning nozzles page for more information or get in touch to discuss how we can help.