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7 comments
Guest

Conversion

06/27/2009 5:47 AM

We need Nm3 to m3 conversion for 10 Nm3/Min, Pressure 2.1 bar.

Barometric pressure is 98 Kpa

Temperature Minimum:20 deg. C, maximum:44 deg.C

Medium: Compressor air

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Guru

Join Date: Mar 2007
Location: India
Posts: 2593
Good Answers: 102
#1

Re: Conversion

06/27/2009 6:03 AM

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.

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Fantastic ideas for a Fantastic World, I make the illogical logical.They put me in cars,they put me in yer tv.They put me in stereos and those little radios you stick in your ears.They even put me in watches, they have teeny gremlins for your watches
Guest
#2
In reply to #1

Re: Conversion

06/27/2009 6:43 AM

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

Guru

Join Date: Mar 2007
Location: India
Posts: 2593
Good Answers: 102
#3

Re: Conversion

06/27/2009 9:22 AM

The gas equations are

PV = nzRT

or PV/nzT = R = Const.

So

P1V1/ n1z1T1 = P2V2/ n2z2T2

or

PactVact/ nactzactTact = PnVn/ nnznTn

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

or

Vact= PnVnnactzactTact / nnznTnPact

Vact = (nact/nn) (zact/ zn) (Pn/ Pact) (Tact/Tn) Vn

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

Qact = (nact/nn) (zact/ zn) (Pn/ Pact) (Tact/Tn) Qn

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

zact= zn and nact = nn

so we have almost the ideal gas equation

Qact = (Pn/ Pact) (Tact/Tn) Qn

Pn = 1 bar = 101.3 Kpa

Tn = 20 deg C = 293 Deg K

Qact = (1/ Pact) (Tact/293) Qn

here Pact = 210 +101.3 = 311.3 Kpa

Tact = 293 - 317 Deg K

so

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

= 0.3520 Qn

or Qn = 2.84~3.07 Qact

(Hope my calculations are correct )

__________________
Fantastic ideas for a Fantastic World, I make the illogical logical.They put me in cars,they put me in yer tv.They put me in stereos and those little radios you stick in your ears.They even put me in watches, they have teeny gremlins for your watches
Guest
#5
In reply to #3

Re: Conversion

06/29/2009 7:40 AM

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 ?.

Guru

Join Date: Mar 2007
Location: India
Posts: 2593
Good Answers: 102
#7
In reply to #5

Re: Conversion

06/29/2009 8:22 AM

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

__________________
Fantastic ideas for a Fantastic World, I make the illogical logical.They put me in cars,they put me in yer tv.They put me in stereos and those little radios you stick in your ears.They even put me in watches, they have teeny gremlins for your watches
Guest
#4

Re: Conversion

06/29/2009 2:28 AM

Your need of conversion can be due to following factors.

1. You are considering procuring compressed air system. or

2. You are an young engineer would like to learn the design procedure. Or

3. You are an Owner ( Non Technical ) and has to give your approval. Or

4. You are an approving authority and does not trust your Team design work.

Can you throw more light from above so that we understand your need.

Off Topic (Score 5)
Guest
#6
In reply to #4

Re: Conversion

06/29/2009 7:45 AM

We are planning to procure compressor and want to know technical details

Off Topic (Score 5)
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