hi all, i am new here.

i am confused about the sealing air for the bearing. how does it seal? and also why sealing is it for oil not to go out or for other reason?

can you help me with pictures for that or any manual i could use??

and thank you all

 

s. buqain,

If you're working at the plant where the turbine is located you should have access to the manuals supplied with the turbine which would have the best documentation for that turbine.

If the turbine was packaged and supplied by GE, then in Vol. I of the manuals you should find a section ("Tab") for each and every one of the systems on the turbine (Lube Oil; Hydraulic Oil; Trip Oil; Cooling Water; Starting Means; etc.). While some of these System Descriptions, as they are called, are not very detailed they do provide a good basis for a basic understanding of the system, it's components and how they are intended to work.

One use of Cooling and Sealing Air is indeed to provide a source of air at a higher pressure than exists inside bearing enclosures. Applied to the shaft seals, this helps to keep oil and oil vapors from leaking out along the shaft and into places where they are not wanted and could cause fire or explosion.

Depending on the age of your turbine, the Cooling and Sealing Air Schematic Piping Diagram (P&ID), usually found in Vol. III of GE-supplied turbine manuals, may have a lot of information not normally found on newer turbine Cooling & Sealing Air P&IDs. (In other words, older is better in this case.)

Again, please refer to the documentation in the manuals provided with the turbine at your site for the best information about the systems on the turbine at your site.

While this many apply directly to your situation, s. buqain, I realize that at some sites the equipment manuals are not readily available for operators or even technicians. That is a shameful practice in this day and age that hopefully doesn't exist at your site. It is the rare supervisor (though they do exist) that prevents access to the manuals for people seeking to better understand the equipment they are working on. In most cases, it benefits everyone when more people are better informed and more knowledgeable. The key is to share that information in a non-threatening way with managers who, when preventing or limiting access to manuals, are generally seeking to protect their job by ensuring no one else can have a better understanding of the equipment than they do.

 

S.Buquain,

In our Fr-9E machine sealing and cooling air is taken from 5th stage of compressor.

The reason for sealing air already explained well by CSA.

FYI, in our Fr-6B sealing and cooling was taken from 11th and 5th stage. Initially it'll use 11th stage air, once sufficient pressure established at 5th stage, it use 5th stage air. The above operation was controlled by 3 way valve.

Take care
G.Rajesh

 

In our Frame-9E with DLN 1.0 equipped unit sealing and cooling air is taken from 11th and 5th stage.

Initially it'll use 11th stage air, once sufficient pressure established at 5th stage, it use 5th stage air. The above operation is controlled by 3 way valve.

Regards