grams/second to square CC/min at STP

sean-keys
sean-keys used Ask the Experts™
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Hi,
I'm trying to hunt down a formula to convert air in grams per second, to standard cubic centimetres per minute.  By standard I'm referring to the standard-temperature-pressure.

I was able to find some info on converting SCFM to pounds per hour.  Any input would be appreciated.
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Business Consultant (Owner)
Most Valuable Expert 2012
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Commented:
Grams is a measure of mass, cubic feet is a measure of volume.

1 cubic foot per minute is 28.317 litres per minute. See:

http://www.convertunits.com/from/litres+per+minute/to/cubic+foot/minute

So 1 cfm = 472 millilitres per second.

Look then on this page to convert ml to grams at a density you want.

http://www.ehow.com/how_4869894_convert-gram-liters.html

.... Thinkpads_User
What do you mean by
SCFM?
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
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Commented:
SCFM is Standard Cubic Feet of air per Minute. My air wrench uses 6 or 7 SCFM of air and a compressor needs to deliver that much to run it.

.... Thinkpads_User
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Commented:
Grams is a measure of mass, cubic feet is a measure of volume.
Standard cubic feet is a measure of mass too. Let me look up those links....
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Commented:
Cubic feet is a measure of volume, not mass.

A cubic foot of sand is the same size as a cubic foot of steel, but the mass is very, very different.

In any event, the links I gave you will get you the conversion you need.

.... Thinkpads_User
ozo
Most Valuable Expert 2014
Top Expert 2015
Commented:
Looks like SCF it can be either of two different quantities, depending whether 1 atm or 30 inHg is used in the standard
http://en.wikipedia.org/wiki/Standard_cubic_foot
Neither of which is STP, which is at 0 °C, not 60 °F
But to convert to mass, you would need the molecular weight of the gas in question,
http://www.engineeringtoolbox.com/gas-density-d_158.html
What you have to know for the conversion is the volume of one gram of air at STP! You will then be able to convert the VOLUME of one gram of air to cubic feet!
ozo
Most Valuable Expert 2014
Top Expert 2015

Commented:
At STP, a mole of any ideal gas will have a volume of 22.414 l
SCF conditions are not quite STP, but that's an easy adjustment, if know which SCF you are using
The gasses composing air are
http://en.wikipedia.org/wiki/Gas_composition
Obviously, in real life, you also have to take into consideration the amount of water vapor in the air (i.e. the relative humidity)! STP or Standard conditions for temperature and pressure
grams divided by 454 will give you pounds
minutes divided by 360 will give you seconds
-
so air in grams/sec divided by 454 and 360 will give you the air in pounds per hour
- as has been pointed out you have to be sure that all the assumptions on temperature, water vapor and pressure are met.
JohnBusiness Consultant (Owner)
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Commented:
@sean-keys - Thank you, and I was happy to help you with this. It brought back my university days and my CRC tables.  ... Thinkpads_User

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