dear all

i have a turbine rotor of 10 mw , 6000 rpm weighing approx 3 tons for high speed balancing and this rotor operational speed is 6000 and the first critical is arround 2100. my problem is this rotor does not have provision for adding weight. but we can remove the weight by grinding. we have a provison at no of places( multi plane). i have a experience in flexible rotor balancing by adding weight. can anyone tell me how to do the high speed flexible rotor balancing by removal method.

ur imm help in this matter will be highly appreciated .

my email id is
knsvel2000@gmail.com

There aren't ports to add set-screws? Are you sure a experienced consultant or OEM reps isn't the best route or approach to take? Without the 100% confidence factor maybe you should hire a consultant and ask for training to remove your liability. Not a good unit to practice on!

Sam is getting to the point. Usually, one can find a way to add weights to such a machine. Grinding on a turbine could be messy, lengthy, and very ugly. Additionally, where one grinds or otherwise removes weights would need careful review.

Besides Sam's suggestion of using a consultant (experienced) try contacting the OEM.

Are you doing this in the field, or in a high speed balance bunker?

It is not unusual to grind compressor rotors as they rarely have provision for weight add.. I have also seen it done on turbines occasionally..

Typically the balance procedure is carried out by using putty in a groove or for compressors on an impeller eye. Once the balance is complete, enough metal is ground away opposite the putty to equal the weight add of the putty.

I agree with Sam and Bill, if this not something you are familiar with, take care.. I have seen compressor rotors come out with grind marks and drill holes all over them from a balancer who was not doing things right... It was an air compressor rotor, and we ended up scrapping the rotor...

May we add weights in the form of nuts (other than the main nut) on coupling bolts?