The document discusses the FrothFlushTM process for cleaning combined cycle plant components such as condensate lines, HRSG watersides, superheaters, reheaters, and condensers. It explains that FrothFlushTM uses high velocity slugs of compressed air and water to generate full turbulence that scrubs surfaces, removing particles and salts. Test results show FrothFlushTM achieves much cleaner results than other methods, with conductivity below 50 uS/cm and solids below 0.05 mg/L. FrothFlushTM is also effective for cleaning preheat and economizer coils in HRSGs.

1. Combined Cycle Plant Applications
FrothFlush™ Condensate and Feedwater
Results:
•Targets
SigmaClean™ HRSG Watersides •Steam Chemistry
•Water Cycle Chemistry
•Stabile Operation
Superheaters/Reheaters/MS piping,
SigmaBlow™ Condenser

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3. Why FrothFlush TM?
• Very high Reynolds numbers and complete turbulence using
small quantities of water return the fastest, highest quality
and most consistent flushing of pipe circuits
• Cleaning to this level prevents contaminates from entering
the steam generation equipment.
• Improves water chemistry in the HRSG which in turn
improves the ability to achieve steam purity.
• Current cleaning requirements result in minimal feedwater
and condensate suction strainer fouling.

4. Froth Former Setup

5. FrothFlush™
6 inch pipe, 1,000 feet in length
40 feet per second
“Froth” (compressible) Air / Water “slug”
The FrothFlush™ process utilizes short two phase (air/water) frothed slugs
displaced at velocities of 15 20 meters/sec generating Reynolds numbers of
4 5 million to remove both particulate and non particulate contamination
from the metal surfaces.

6. FrothFlush™
Full Turbulence
Effectiveness of FrothFlush™ is due to generation of full turbulence that
scrubs particles and salts from pipe & tube surfaces

7. Improved
Cleanliness
• The FrothFlush™ effectiveness in removal of particulate contamination is
monitored by means of Millipore filters. Samples of the flush effluent water
are taken and filters using fine Millipore filters.
• Millipore filters are so fine that the water sample will not flow through the filter
without the aid of a vacuum to draw the sample water through the filter.
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• The effectiveness of the FrothFlush™ process in removal of salts from the
metal surfaces is monitored by measurement of the conductivity of the
effluent flush water.
• VGB Guideline for acceptable solids in flush water is < 5 mg/l.
FrothFlush™ will typically achieve cleanliness of < 0.05 mg/l.
• The VGB Guideline for acceptable flush water conductivity is < 1,000 S/cm.
The FrothFlush™ process typically achieves flush water effluent < 50 S/cm.
VGB(ISO-3166-1, British Virgin Islands)

8. Typical
FrothFlush™
Results
First FrothFlush™ 11th Froth FrothFlush™ Final Effluent on
20th FrothFlush™
The above sequence of photographs show the typical
results of a FrothFlush™ of a piping system

9. Millipore®
0.45 Micron Patch Test
First FrothFlush™ (500ML) 11th FrothFlush™ (500ml) Final Acceptable at 20th Pass
600 S/cm 60 S/cm FrothFlush™ (500ml)
15 S/cm
System cleanliness far exceeds criteria specified in VGB
BES&T Millipore™ Test
Apparatus Guideline and all other water flush methods.

10. FrothFlush™
Preheat & Economizer
Coil Flushing
• Contamination is proportional to system metal surface area.
• Contamination is proportional to amount fabrication to build a HRSG coils.
Cutting, grinding, welding and PWHT generates more contamination.
• Piping typically contributes less contamination than HRSG coils to the
steam cycle as piping has less metal surface and less fabrication.
• The FrothFlush™ process effectively flushes contamination from HRSG
preheat and economizer coil sections at high velocity and high turbulence.
• Effective removal of particulate and non-particulate contamination prior to
gas turbine first fire minimizes fouling of BFW pump and attemperator
strainers and sensitive control valve trim.
• Removal of imbedded salts from metal surfaces of the pre-boiler piping and
coils reduces the tine required to achieve steam cycle purity.