Turbocharger Failure Sulzer RTA58

[tomatge]

We recently encountered a new and interesting failure on a Sulzer 9RTA-58 engine. The initial symptom was surging of the turbocharger, requiring an investigatory strip down.

What we found was some quite severe damage to the nozzle ring and some blade tip damage on the tubine itself. We also found some unusually large pieces of metal (up to 75x50mm) within the gas inlet, which could not be attributed to any damage within the turbocharger itself.

As the strip down progressed, we eventually found the source of the problem. The engine exhaust gas reciever has an expansion joint midway along the engine. The metal heat shield for this joint had disintegrated, the exhuast flow had carried pieces through the turbocharger gas inlet casing, breaking through a heavy duty metal gid in the process. This is what caused the nozzle ring damage.

Fortunately, the larger pieces did not make in though the nozzle ring, and the turbine itself suffered only minor damage. Nonetheless, and expensive repair.

Thought you may be interested !

 

[Paramagurubaran]

Hi tomatge,
I,ve had the same experience, the failed Turbo Charger (Of MAN B&W make) was fitted onto a medium speed Diesel Engine of Mitsubishi MAN B&W make, of the 52/55v Type & developing 20,000 BHP. We were not as fortunate as you were. In our case the stainless steel heat shield of the expansion joint had found its way through the nozzle ring & had fouled the turbine blades damaging them resulting in heavy repairs.
Paramagurubaran

 

[Wheeler]

Do you have any idea about how many hours were on that expansion joint?

 

[tomatge]

It was the original expansion joint from new, so it will have run about 54,000 hours over 10 years.

It may be relevant, that the plant duty has recently changed. For the first 8 years the machine ran base load, however recently has been relegated to intermittent operation. We've noticed a few problems creeping in since, but no others quite so damaging as this one.