Blower Housing and Impeller Erosion Lining

The challenge

A process blower handled a dust-laden stream that slowly wore its parts down. The impeller vanes lost profile and the housing scroll grooved out where the dust scoured it, so the flow path turned rough and the running clearances opened up. As that geometry went, the blower moved less air for the same input, and the plant felt it as lost airflow on the process it served. Left alone, the wear keeps eating into the metal until the impeller and the scroll have to be replaced, which is costly and pulls the unit out of service.

The Belzona approach

The blower comes down for a look at where the dust has taken the metal, both on the impeller and along the scroll. The housing and the impeller are stripped to clean metal so the repair bonds, then the worn vanes and the grooved scroll are rebuilt back to profile with a cold-applied composite. From there an erosion-resistant coating lines the whole flow path, so the rebuilt geometry is sitting under a surface that takes the dust instead of being ground out again. The line is finished smooth so the air moves the way it should, then the unit is balanced and returned.

1. Assess the wearThe impeller and the housing scroll are inspected to map where the dust-laden stream has worn the vanes and grooved the flow path.
2. Strip to clean metalBlasting takes the housing and the impeller back to a clean, profiled surface so both the rebuild composite and the lining bond to bare metal.
3. Rebuild vanes and scrollA cold-applied composite rebuilds the worn impeller vanes and the grooved scroll back to profile, working cold so the parts see no heat distortion.
4. Line the flow pathAn erosion-resistant coating lines the rebuilt impeller and scroll, and the surface is finished smooth so the air moves cleanly through the unit.
5. Balance and return to serviceThe rebuilt impeller is balanced, the finished lining is checked, and the blower goes back over to the plant.