Re: Nm3/hr to m3/hr

›› Re: Nm3/hr to m3/hr   (09/06/2008, 12:52 AM)

Nm3/hr - Normal Metres Cubed per Hour
This is at a Temp of 0 deg C and 1013mbarA

Sm3/hr - Standard Metres cubed per hour
This is an old throw back from SCFM and based on 60 Deg F and Atmospheric pressure..............i.e. 1013 mbarA and 15.6 Deg C

Am3/hr - Actual Metres cubed per hour
As it says "Actual" at the temperature and pressure conditions stated.

To convert Nm3/hr to Sm3/hr it's a ratio of the absolute temperatures -
(The difference between 0 and 15.5 deg C)

10 Nm3/hr *(15.6+273)/ (0+273) = 10.57 Sm3/hr

Where -273 is absolute zero on the temperature scale.

To convert either of the above to Am3/hr or m3/hr (as normally written)
you need to convert both the temperature and pressure ratios

10 Nm3/hr ..... To Am3/hr at 20 deg C and +2 bar G (Two bar above atmospheric)


10 Nm3/hr *(20+273)/ (0+273)*(1013/1013+2000) = 3.6 Am3/hr

A way to think of the above is:
You heated the volume to start with to 20 degC .... It therefore it got bigger.....Then you squeezed it at a higher pressure...It shrank