3 replies to this topic

[gunjan]

Dear all,

I am working in a steel industry. well we are having an multistage compressor. with interstage cooler.
I need to calculate the compressor power requirement for both adiabatic condition and isothermal condition. so can any one of u suggest me some equations to do so or any links where can i get this information.......

Regards,

Gunjan

[Art Montemayor]

Gunjan:

In order for us to give you specific equations, you have to give us specific basic data.

What kind (type) of compressor are you talking about? Recip or centrifugal - or perhaps screw?
What gas are you compressing?
What are your suction and discharge conditions - pressure and temperature?
How many stages are you talking about?
What kind of intercoolers are you employing - water cooled or air cooled?
What kind of driver are you using? steam turbine, electric motor, gas turbine, etc., etc.?

Why in the world would you want to calculate such an impractical (& unachievable ) process as isothermal compression? It doesn't exist in real life. It only exists in the minds of academic, theoretical engineering professors who have never operated a compressor. This is the Industrial Professional Forum and not the Student Forum, so I assume you're dealing with real life and not academia.

Await your reply.

[gunjan]

Thanks Art for your reply...


Well we are compressing the gas mixture mainly containing CO2, CO, H2O, H2 and trace amount of O2, CH4, and N2......Well we are using here an lobe compressor and that two in two stage in first stage we have three compressor and in second stage we have two compressor.

We are increaing the pressure from 0.5 barg to 2.5 barg in two stage with water cooled intercooler.

The inlet temperature of compressor is around 50 C.....

So, here is all the details you want.... so tell me How should i proceed for the power calculation for this....

And also we are planning to remove the lobe compressor by centrifugal compressor. so, for that also i need to calculate the power...so let me know about that also...

THanks Art its really gud that we have find a mentor like u...

Regards,

Gunjan

[engware]

Gunjan:

It is me again.

Here are two URLs for free HTML and XLS files that can also help you with the isentropic compression calculations:
http://members.aol.com/engware/calc4.htm
http://members.aol.com/engware/modeling-11.xls

The engineering equations related to the isentropic compression are provided with the HTML file.

Thanks,

Gordan