Dear Expert, Vacuum thrust

[vrl3]

Dear Expert,

A steam duct of Dia 2800mm is subjected to full vaccum. The duct starts from the turbine exhaust and goes to the air cooled condenser. From the turbine the duct drops for a height of 4M and takes a right angle turn, where it is supported to the ground.

We are connecting a simple axial bellow/Expansion joint after the turbine.
1.what is the amount of vacuum thrust tat wil be acting?

2.Where this will be acting?

3.The fondation should be designed for what load?

4. Will the vacuum load act on the joint of the turbine nozzle and bellow.

Your replies required urgently.

Regards

 

[budt]

I am not sure exactly what you are asking but the action of vacuum is the same as air pressure in reverse. The negative pressure inside the pipe allows atmospheric pressure to try to crush it and also to move it toward any place backed up by atmospheric pressure. Atmospheric air is trying to fill the void but is stopped by the wall of the container.

Fortuantely the most pressure difference possible is one atmosphere at sea level on an average day, approximately 14.7 PSI. Doesn't sound like much until you get a lot of square inches.

Bud Trinkel Bud Trinkel
Certified Fluid Power Engineer
HYDRA-PNEU CONSULTING, INC.
812-853-32344
fluidpower1@hotmail.com