HRSG Cleaning Services: Restoring Backpressure and Heat Rate
A practical guide to HRSG dry ice cleaning — what fouls, what it costs the plant, and how outage crews restore performance without water or chemistry.
Heat Recovery Steam Generators silently bleed megawatts as iron oxide, ammonium bisulfate, and combustion residue accumulate on finned tubes and catalyst faces. By the time backpressure shows up on the trend, the plant has already paid for it in fuel, MW, and emissions margin.
What dry ice cleaning targets inside an HRSG
- Finned tube bundles — external fouling that restricts gas flow
- SCR catalyst faces — masking that reduces NOx conversion
- CO catalyst faces — surface deposits that hurt CO oxidation
- Ammonia injection grids — uneven spray patterns driving slip
- Duct burners and transition ducts
- Inlet houses and filter plenums
Why dry ice instead of water or grit
HRSG internals do not tolerate water well — carbon steel fins corrode, catalysts can be damaged, and the outage extends until everything is dry. Grit gets trapped in bundles and migrates downstream. Dry ice sublimates on contact, so the only thing left behind is the fouling itself, ready for vacuum recovery.
What plants typically see after a full cleaning
- 1–3 inches of water column of backpressure recovery
- Measurable heat-rate improvement
- NOx, CO, and ammonia slip back inside margin
- Extended catalyst service life
- A dry, ready-to-fire unit on restart
Outage planning notes
Most HRSG scopes complete in 2–5 days depending on access, unit size, and parallel work. We mobilize 24/7 for planned and forced outages, bring our own diesel air, and staff shift rotations so blasting stays continuous.
Frequently Asked Questions
Will dry ice damage finned tubes or catalyst beds?+
No. Dry ice is non-abrasive and sublimates on contact. Operated at correct pressures by trained HRSG technicians, it cleans aluminized fins, SCR, and CO catalysts without bending fins or eroding washcoat.
How long does an HRSG cleaning take?+
Typical scopes run 2–5 days. Triple-pressure units with SCR and CO layers and tight access take longer; smaller single-pressure HRSGs can complete in 48 hours.
Do you need plant water, drains, or chemistry?+
No water and no chemical drainage. We bring air, ice, vacuum recovery, and containment. The only waste stream is the loosened fouling.
Can you support forced outages?+
Yes. We mobilize crews on 24-hour notice for forced outages when capacity allows.
See the full scope and request a quote on our HRSG Cleaning Services page.
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