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Associate

Join Date: Jan 2010
Posts: 52

### Compressed Air Consumption Calculation

09/18/2012 2:56 AM

I am designing a compressed air system of 60 bar pressure.In the system there are some pneumatic valves and other miscellaneous pneumatic equipments to be operated by compressed air.How can i calculate air consumption? and on the basis of this consumption i can define storage capacity of air receiver/storage cylinder (storage pressure is 60bar)?How can i calculate pressure in air receiver if some pneumatic equipments are in use?
Thanks

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Guru

Join Date: Oct 2007
Location: India
Posts: 1272
#1

### Re: Compressed air consumption calculation

09/18/2012 4:10 AM

''How can i calculate air consumption?''

Total the air consumption of all air consuming equipments/units, to get the total air consumption.

''How can i calculate pressure in air receiver if some pneumatic equipments are in use?''
I always thought, calculations are made on paper. Anyway, shutdown all equipments for the duration of your calculation.

Guru

Join Date: Jan 2007
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#2

### Re: Compressed air consumption calculation

09/18/2012 4:53 AM

Storage capacity isn't related to consumption. Storage capacity is there to increase the time between individual switch-on-events on the compressor. Remember the distribution pipework is part of the storage system.

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Guru

Join Date: Jan 2007
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Posts: 19628
#3

### Re: Compressed air consumption calculation

09/18/2012 6:12 AM

60bar is a bit high for many pneumatic components by a factor of 10 or so. Is 60bar correct?

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Guru

Join Date: Oct 2007
Location: India
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#4

### Re: Compressed air consumption calculation

09/18/2012 6:46 AM

That's a very good & valid question. Wonder how we, all the rest missed it.

Guru

Join Date: Jan 2007
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#12

### Re: Compressed air consumption calculation

09/19/2012 5:42 AM

Because "we" doesn't exist.

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Guru

Join Date: Oct 2007
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#13

### Re: Compressed air consumption calculation

09/19/2012 6:18 AM

A slip. To err is human. Thanks for pointing out. Indeed, "we" does not exist. Your edict, with humility, accepted.

Guru

Join Date: Apr 2006
Location: Cincinnati, Ohio, USA
Posts: 619
#8

### Re: Compressed air consumption calculation

09/18/2012 11:35 PM

THAT was my first question and was scrolling down to see if anyone else asked first.

Good catch.

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Guru

Join Date: Mar 2007
Location: Rosedale, Maryland USA
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#5

### Re: Compressed Air Consumption Calculation

09/18/2012 7:57 AM

Each piece of equipment has spec for how many CFM it takes to operate. If not listed on the name plate call the manufacture and ask. Or each device may have some listed capacity. For a cylinder it has volume. Maximum strokes a min times that volume.

Knowing what air consumption(CFM) is gives you the info to choose a compressor. You should not design the system to depend on the volume in the receiver.

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Guru

Join Date: Dec 2008
Location: Cd. Juarez, Chihuahua, Mexico.
Posts: 654
#6

### Re: Compressed Air Consumption Calculation

09/18/2012 8:54 AM

Multiply the air volume of all cylinders of every machine by the number of cycles per minute of that machine; add all the machines. Take into account that some cylinders consume air while extending and when retracting too.

Determine the proper tank and air dryer capacity.

You don't need to calculate air pressure when equipment is in use, meassure it, use a manometer.

And last but not least, make sure you're not confusing pressure units, or show us some of you pnematic wonder tools that whitstand 870 Psig. and how you manage to muffle air exhausts to silence such a tremendous expasion into atmosphere.

Regards

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Guru

Join Date: Oct 2008
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#7

### Re: Compressed Air Consumption Calculation

09/18/2012 5:35 PM

Good luck finding any pneumatic Equipment rated to 870 PSI, I don't know of anything readily available.

I'm curious what equipment you plan to use...

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Associate

Join Date: Jan 2010
Posts: 52
#9

### Re: Compressed Air Consumption Calculation

09/19/2012 12:36 AM

Thanks Guys,

I forgot to mention that i am using 2 diesel engines which are air started at 24bar pressure.

Power-User

Join Date: Aug 2010
Location: Wales, UK
Posts: 243
#10

### Re: Compressed Air Consumption Calculation

09/19/2012 3:44 AM

OOPS! only a "little" thing you forgot then. I think that "little" fact puts a whole new complexion on things. 60 Bar is still high as you "only" need 24 Bar. It will cost a lot of money raising that sort of pressure.

Best regards,

John

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Participant

Join Date: Sep 2007
Location: Pune, India
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#11

### Re: Compressed Air Consumption Calculation

09/19/2012 4:48 AM

Look for number of starts recommended per engine. All engine manufacturer specify air consumption for starting engine. Work out pressure drop, based on distance between engine and receiver. You can arrive on capacity and pipe diameter. Of course 60 bar is too high. General guide line is 27 -31 bar. You should not use this air other than engine starting and engine controls.

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