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chemeng
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Air Leakage Conversion

03/09/2011 8:01 AM

Does any one know how to convert air leakage from litres/second to kg/hr taking the pressure of air at atmospheric????

I know that 1 litre per second = 1 millibar litres

What do i do from there???

I need this to find out how much air evacuation is required for our vacuum system. the current ejector system is designed for 60 kg/h and the new vacuum system consisting o condenser 2 stage booster ejectors and liquid ring pumps. the condenser is only designed for 10kg/h air evacuation.

I have had leak testing done but the results have come back as litres/second or cc/second.

please advise

Chemeng

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#1

Re: Air Leakage Conversion

03/09/2011 8:22 AM

Density of air[1] ≈ 1.2 kgm-3 = 1.2 g/L

1 L/sec ≈ 1.2 g/sec = 4320 g/hr = 4.32 kg/hr

[1] Dry air at 1 atm, 20 °C

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chemeng
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#2
In reply to #1

Re: Air Leakage Conversion

03/09/2011 9:04 AM

how did you get 1 L/sec ~ 1.2 g/Sec???

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JohnDG
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#3
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Re: Air Leakage Conversion

03/09/2011 9:12 AM

Density of air is approx. 1.2 kg/m3.

1 kg = 1000 g and 1 m3 = 1000 L,

so density of air ≈ 1.2 g/L.

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#4
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Re: Air Leakage Conversion

03/09/2011 9:38 AM

Not certain where to place your GA... I will put it here for proving your proof.

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chemeng
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#5
In reply to #4

Re: Air Leakage Conversion

03/09/2011 10:08 AM

Thanks , im loosing my mind will all these calcualtions, making me forget the basics.

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#8
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Re: Air Leakage Conversion

03/09/2011 11:27 AM

Definitely, by rule of the thumb that is 1kg of air= 1 cu. meter air so as 1kg of water =1 liter water. Both is at 1 atm pressure

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chemeng
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#6
In reply to #4

Re: Air Leakage Conversion

03/09/2011 10:09 AM

your GA??

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Doorman
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#7
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Re: Air Leakage Conversion

03/09/2011 10:24 AM

In my comment #4, in the top right hand corner it says #4, in reply to #3. That tells us I was replying to JohnDG. I awarded him a GA, which is a 'Good Answer' vote for providing a complete and accurate response for you.

You can do this as well, if you feel his answer helped to solve your question. In the bottom left hand corner of a comment, hit the 'Rate' button and vote accordingly.

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#9

Re: Air Leakage Conversion

03/09/2011 11:32 PM

Density Unit is mass/volume Kg/m3 Mass flow rate is Kg/hr Volume flow rate is Density/Mass flow rate = m3/hr or m3 /sec.
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#10

Re: Air Leakage Conversion

03/10/2011 11:33 AM

PV=nRT

solve for n and then use the average molecular weight of air to determine the weight. This will then need to be converted from seconds to hours.

or

there are engineering table galor for air flow, particularly at STP.
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#11

Re: Air Leakage Conversion

03/11/2011 8:56 AM
  • Mayhew & Rogers, "Thermodynamic Properties of Fluids", any edition.
  • Kempe's Engineers' Yearbook, any edition.
  • Perry, "The Chemical Engineer's Handbook", any edition.
  • Etc.
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