Project

Induced Draft Fan Blade Erosion Protection

Eroded ID fan blades and housing rebuilt cold and coated to resist ash-laden gas and extend the run between rebuilds.

The challenge

What was failing

An induced draft fan pulls ash-laden flue gas across its blades and housing, and the suspended particulate wears the metal away wherever it strikes hardest. The leading edges of the blades lose profile first, the housing thins behind them, and the loss throws the rotor out of balance. As that wear spreads, the fan vibrates, moves less gas, and runs the risk of an unplanned trip. Left untreated, the blades and housing keep degrading until the fan has to come out for a full rebuild far sooner than the plant can afford.

Erosion-resistant coating applied to a high-velocity wear surface by AAS
Our approach

How AAS approaches it

We take the rotor and housing where the metal has been carried away by the gas stream and bring it back. We blast the worn surfaces to clean, profiled steel, then rebuild the lost leading edges and the thinned housing with Belzona 1000 Series composites, working cold so the blades see no heat distortion that would warp the profile or shift the balance. Once the metal is back to shape, we apply an erosion-resistant coating over the blades and the high-wear paths so the new surface takes the particulate instead of the steel. The coating gives the gas a sacrificial face that is easy to renew at the next outage, which is what stretches the run between rebuilds.

Assess and map

We inspect the rotor and housing to locate where the ash-laden gas has eaten the leading edges and thinned the metal, and confirm the wear paths through the fan.

Surface preparation

We grit-blast the worn blades and housing back to clean, profiled steel so both the rebuild and the coating bond properly.

Cold rebuild leading edges

We rebuild the lost leading edges and thinned housing with Belzona 1000 Series composites, working cold so the blades take no heat distortion.

Apply erosion-resistant coating

We coat the blades and high-wear paths with an erosion-resistant system that gives the gas stream a sacrificial face instead of bare steel.

Cure and return to service

We confirm cure and check the finished profile, then hand the fan back ready to run within the outage window.

What you get back

The result

Eroded leading edges and housing rebuilt in place without replacing the rotor
Blades returned to profile cold, with no heat distortion to the balance
Erosion-resistant coating gives the ash-laden gas a sacrificial face that renews at outages
Longer run between fan rebuilds, delivered by factory-trained and factory-certified Belzona applicators
In the field

From the job

Repair and protection work of this kind, performed by AAS crews across Louisiana.

Capabilities used here

Where this work happens

24-hour on-call service

Have equipment that needs to stay in service?

Tell us what is failing. We respond quickly, and we offer 24-hour on-call service.

Call (225) 751-1930