Calulate the RPM of the pump 1

Hello!

I need to calulcate the RPM of the pump with the following given data:

Flow rate: given in Gallons per minute
Velocity of gas : meters per second
System pressure : 100 psi

Please let me know at myjollygroup@yahoo.com

Regards,
Parimal

 

[MortenA]

That seems quite impossible

1) You dont pump gas
2) The speed required would ultimately be dependant on impellar diameter.
3) You dont mention pressure increase

If you knew the impellar diameter, efficieny of the pum (without motor and bearing) and dP you probaly could calculate the speed.

Best Regards

Morten Andersen

 

[tstead]

The most accurate way that you can determine the speed of a direct drive pump is via the following process:

1. Run the pump at full speed
2. Record the discharge pressure
3. Record the suction pressure
4. Measure the difference in height between the pressure gauges, make sure you convert this to mmHg.
5. Take the square root of the sum of the squares of the pressure ratings
6. Multiply the result obtained in step 5 by the cubed root of pi. Add the difference in height of the pressure gauges.
7. Record the flowrate and convert it to m^3/min.
8. Close the discharge valve.
9. Repeat steps 1-7
10. Open the valve
11. Look at the motor nameplate, record all the motor data.
12. Call the motor manufacturer and ask them what the full load speed of the motor is.
13. Throw out everything you recorded in steps 1-10 because quite frankly, I wouldn't know what it would tell you even if you did those steps correctly.
14. Quit posting homework problems to this forum.

 

[Jonkatz]

Tstead,
You're killin' me,.. for a second..I thought that was a real method
-j. katz

 

[tstead]

heheeh

Actually, I guess the best way to measure the speed is to measure it directly with a strobe - not back into it from perf. curves and mfg. data.

Of course, if you were working a homework problem, you wouldn't have the luxury of simply looking at a nameplate or measuring the speed with a strobe, would you?

Tim