fan flow calculation

[nasir]

please may anybody can help me , how can i calculate the flow of air in CFM if i have the following information
fan dia = 1000 mm
fan speed= 1500 RPM
pich angle= 17(Deg)
No of Blades= 10
Motor= 18.5 KW

[TRASH101]

Hello

The info you gave is a bit sparse
is it a plate fan , direct drive, what resistance you working against ???

if it is a centrifugal try contacting NICOTRA fans, as they supply a lot of vent. manufacturers

If it is a plate/ axial /bifurcated you could try ELTA fans

[Rayin]

Hi Nasir,
As you may know, flow rate (in cfm) = Cross sectional area (in sq. ft) * Velocity (ft/minute). You have to find out the velocity. Then only, I think, you can calculate flow rate.

[US Iceman]

Or you can contact the fan manufacturer and ask for a fan curve. This curve represents the fan performance at various speeds and static pressure.

[nh3simman]

fan dia = 1000 mm
fan speed= 1500 RPM
pich angle= 17(Deg)
No of Blades= 10
Motor= 18.5 KW

If I understand your question, you have certain limited information and need to make an estimate of the airflow.

There is always a way to make a good guess.

Motor Power = 1.15 x dp x Q / e

dp is the total pressure drop, say 500Pa
e is efficiency, say 65%
the 1.15 is a number used by some manufacturers to prevent overload.


18.5 = 1.15 x 0.5 x Q / 0.65
Q = airflow in cms

[Lc_shi]

Very good!
It bases on the basic physical principle of

Power = Pressure diff x flow volume

Make sense