Atomizing air pressure is somewhat 0.3 kg/sq cm less than CPD.
We are not in a position to shut the unit. The gas turbine is running without atomizing air since last 15 days.

How long it may run without fail...? presently all other parameters are fine like wheelspace etc. The fuel here is straight run naptha.

PLz enlighten.

 

>PLz enlighten.

You've posted this question here before, though you did not indicate what fuel you were burning at that time.

What part of the previous responses were you not clear about or were unhappy with?

And you were asked why you felt the Main Atomizing Air Compressor had failed and you didn't respond. That compressor runs at tens of thousands of RPM, so one would think if the compressor failed there would be a lot of visible damage or noise (at least there would have been some noise for a little while).

If I recall correctly the coupling between the Main Atomizing Air Compressor and the Accessory Gear drive shaft is designed to shear in the event of a high torque requirement. Many of these types of couplings have failed before the Compressor.

It was said before: If you gotta run you make that decision and live with the consequences. It would seem that the straight naphtha being burned doesn't require the same amount of Atomizing Air that distillate fuel does. One of my concerns would be that the AA piping may not be being properly purged.

Best of luck with your problem.

 

I was out of track since my last post that's why i missed to reply u.
pardon me sir.

There is no way to determine whether atomising AA compressor is decoupled or not.

The things we observed
1. AA air pr 0.3 kg less than the CPD.

2. high pressure air leaking from AA comp gear box i.e. comp seal is damaged and air is coming to gear box.

3. AA pr is showing that there is probably reverse flow of air from combustion chamber to AA comp.

I again repeat we r not in a condition to shut the unit.
And the system is running under precise watch.
lets c what happens.

 

> I was out of track since my last post
>that's why i missed to reply u.

control.com has a 'Search' feature in the far right corner of the Menu bar at the top of every control.com page. And, if you can remember the day of your posts you can use the 'calendar search' feature on the left. You can also subscribe to a thread (once it's posted) by clicking on the email envelope icon on the right of the thread title and supplying the appropriate information.

So, there are many ways to go back and see if anyone has responded to a previous thread without posting the same question again.

And, this is not a mobile phone text message, either. We use complete words and sentences in engineering circles. Avoids misunderstandings and just makes for clearer communications.

Best of luck with your issue.

 

I saw exactly the same many years ago, this was a sheared AA compressor drive shaft. First indication was a "High Turbine Compt. temp" Fortunately nobody opened the compartment door or there would have been a fatality. After shut-down it was found that three AA pigtails had melted through and bits of them were lying in the compartment floor.
I don't know what your constraints are about not shutting down but I would not go anywhere near while running and advise your management that they have a very dangerous situation developing.

 

Exactly. Backflows through the AA pigtails/manifold can be very destructive. I've seen tips of fuel nozzles liberated and go downstream because of lack of cooling (which is one of the things Atomizing Air does to the nozzle tips).

 

thanks for your kind information