Flow conversion....

[Lynx]

Hello,
I am having to convert several different flow rates for construction.
I have feet per sec and I am having to convert to standard cubic feet per sec.
Can someone post an easy conversion please.
Thanks

 

[mbeychok]

Lynx:

Feet per second (ft/s) is a linear velocity. Cubic feet per sec (ft[sup]3[/sup]/s) is a volumemetric flow. They are related as per:

Volumetric flow = (linear velocity)(flow area)

For example, let's take a linear velocity of 8 ft/s in a pipe with an inside diameter of 4 inches:

(1) flow area = (Pi)(diameter)[sup]2[/sup]/4 = (3.14)(4)[sup]2[/sup]/4 = 12.57 in[sup]2[/sup]= 0.087 ft[sup]2[/sup]

(2) Volumetric flow = (8)(0.087) = 0.7 ft[sup]3[/sup]/s


Milton Beychok
(Contact me at www.air-dispersion.com)
.

 

[Lynx]

Thank You

 

[Mech85]

Lynx:

Download a free copy of the units conversion program "CONVERT 4.1" from the web page

http://www.joshmadison.com/software/convert/

It is an easy to use unit conversion program that will convert the most popular units of distance, temperature, volume, time, speed, mass, etc

 

[Lynx]

Milton,
I was just looking over your book "Fundamentals of Stack Gas Dispersion". We are currently building a Flare Gas Recovery unit to eliminate enviromental polution (H2S, etc..)

Thanks again y'all & Perth I downloaded the Convert tool

 

[vzeos]

I concur with mbeychok but note to convert to standard cubic feet per sec (Q[sub]s[/sub]), you need to correct the flowing temperature(T[sub]a[/sub]) and pressure (P[sub]a[/sub]) conditions to standard T - P conditions using the combined gas laws:

P[sub]a[/sub]Q[sub]a[/sub]/T[sub]a[/sub]=P[sub]s[/sub]Q[sub]s[/sub]/T[sub]s[/sub]

where the subscript a refers to actual conditions and the subscript s refers to standard conditions

Also, you may need to correct for compressibility depending on your operating pressure and your working fluid.