Conversion

Please check earlier threads

http://cr4.globalspec.com/thread/25018

And the interesting part is the title of the thread is

Nm3/hr to M3/hr

A normal google search too would have landed you into this as well as a few others.

We were not able to understand the search results in google. If you know please give details with basis of calculation

The gas equations are

PV = nzRT

or PV/nzT = R = Const.

So

P₁V₁/ n₁z₁T₁ = P₂V₂/ n₂z₂T₂

or

P_actV_act/ n_actz_actT_act = P_nV_n/ n_nz_nT_n

n = number of moles and z is the compressibility factor.

or

V_act= P_nV_nn_actz_actT_act / n_nz_nT_nP_act

V_act = (n_act/n_n) (z_act/ z_n) (P_n/ P_act) (T_act/T_n) V_n

or if yoy want to talk in terms of Volume, convert the V (volume) into Q (Volume Flow rate) and then

Q_act = (n_act/n_n) (z_act/ z_n) (P_n/ P_act) (T_act/T_n) Q_n

For the lower pressure and temperature range, for air, we can safely take

z_act= z_n and n_act = n_n

so we have almost the ideal gas equation

Q_act = (P_n/ P_act) (T_act/T_n) Q_n

P_n = 1 bar = 101.3 Kpa

T_n = 20 deg C = 293 Deg K

Q_act = (1/ P_act) (T_act/293) Q_n

here P_act = 210 +101.3 = 311.3 Kpa

T_act = 293 - 317 Deg K

so

Q_act (m³/hr) = (101.3/ 311.3) (293~317/293) Q_n (Nm³/Hr)

= 0.3520 Q_n

or Q_n = 2.84~3.07 Q_act

(Hope my calculations are correct )

Dear Guru,

Thank you for your detailed calculation.

If we are converting from 10 Nm3 to Am3= 3.6 Am3 is coming, for 10 Nm3 to Sm3= 11.57 Sm3 is coming as per our temperature and pressure conditions. So what we have to consider,Am3 or Sm3 ?.

The capacity of the compressor (cfm or m³/Hr) if I am not wrong are expressed as

The amount of Air or gas the compressor can compressed at one atmosphere sea level, and 20 deg C

This almost fall in the STP region and not NTP region.

Check this link where different rating types are provided.

http://www.engineeringtoolbox.com/rating-air-compressors-d_848.html

Dear Sir,

I tried calculating your way but my answer comes negative.......if you can please check

Qact (m3/hr) = (101.3/311.3) (293-317/293) Qn (Nm3/hr)

i get

Qact = -0.0267 Qn

Can you please check and correct me if am wrong.