Calculating Blower Flow in CFM - Required Data & Equation

[Eng.Ayed]

dears;
happy new year...
I would like to ask you about how can I calculate the blower flow in CFM.
what are the required data that must be available. Also I need the equation that calculate the flow.

 

[russ_watters]

Welcome to PF!

You're going to have to give us a lot more information if we are to help you. What is the purpose of this blower? Do you need to select it or do you have it and want to find out what it can do? Typically, people calculate what flow they need, then select the blower out of a catalog or with selection software to math their needs. No calculation required.

 

[Eng.Ayed]

Dear Sir;

First of all, we have Gas Turbine and it has a lube oil mist separator blower. It is designed to exhaust air from the oil reservoirs and remove the oil mist entrained in that air via vent line pipe. Before we did not face any problem but we did some modification which was the extended of the vent line pipe after this modification we faced some problem and the most of it was the tank almost pressurized it must be vacuum because of blower. Now we are looking for how can we calculate the flow then we can see it in the performance curve. Finally after this clarification I hope you understand my issue.
please note down all the information may need during the flow's calculation.

your help is highly appreciated

 

[Eng.Ayed]

Welcome to PF!

You're going to have to give us a lot more information if we are to help you. What is the purpose of this blower? Do you need to select it or do you have it and want to find out what it can do? Typically, people calculate what flow they need, then select the blower out of a catalog or with selection software to math their needs. No calculation required.

First of all, we have Gas Turbine and it has a lube oil mist separator blower. It is designed to exhaust air from the oil reservoirs and remove the oil mist entrained in that air via vent line pipe. Before we did not face any problem but we did some modification which was the extended of the vent line pipe after this modification we faced some problem and the most of it was the tank almost pressurized it must be vacuum because of blower. Now we are looking for how can we calculate the flow then we can see it in the performance curve. Finally after this clarification I hope you understand my issue.
please note down all the information may need during the flow's calculation

 

[Danger]

Welcome to PF, Eng.
Russ is certainly the guy to listen to on this subject, and Fred Garvin if he's still around.
Since I know nothing about the matter, I'll just chirp up with my normal "outsider" viewpoint. This reminds me very much of the pan-evac systems that we used on our cars back in the day, wherein pipes ran from the valve covers to the headers to eliminate pressure (if good enough, create vacuum) in the crankcase.
Since yours is a closed system, you don't want to lose your oil. Might I suggest, therefore, that you introduce some sort of diffuser that will lower the return to atmospheric pressure before it gets to the return reservoir? (Or is there no return reservoir, and it has to go directly back to the main tank?)