# how to reduce power consumption of the compressor??



## bemegopi (Mar 19, 2014)

I have using 604 CFM air compressor.It also have the VFD.
Motor-90 KW
outlet air pressure 6.7

I am doing power reduction project for air compressor.

Initially I arrested all the air leakages.

What are the other ways to reduce the power consumption of the compressor.?

If any one want additional details i am pleasure to share


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## corey872 (Jan 10, 2010)

Beyond arresting / stopping the leaks and using only enough air pressure to do the job, that is about all you can do physically. Basically the 'waste' is generated when you dump high pressure air to atmosphere, so by using only enough pressure to move the object, you dump as little 'excess' pressure as possible.

At 604 CFM/90KW, this sounds like a huge industrial compressor? So you may also look at how the air is used. If the stream is continuous, but the need is intermittent, you might add a solenoid to shut the air off when not needed. Also, how the air is delivered/used can play a big part. If you're using high pressure air for an application which might be better served with a low pressure blower, or fan, that could be a point for savings. Even things like the shape and size of a nozzle can help. Do you need a 'sheet' of air which might be more efficiently delivered by a flat nozzle or 'air knife' vs a row of drilled holes, etc.


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## bfjou812 (Aug 15, 2008)

I would contact the manufacturer of both the compressor and the VFD. I would bet that they have info of power ratings @ different loads, no load, and idle conditions. Usually an industrial environment is a different animal than what is done here.


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## fontgeek (Jul 24, 2006)

Set your output pressure to as low as you can get away with, that and shut the compressor off when you don't actually need it.


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## bemegopi (Mar 19, 2014)

*reducing the output pressure*

if i reduced my output pressure i.e 6 bar to 5 bar. how power consumption will be reduced. any theoritical method is there?


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## bfjou812 (Aug 15, 2008)

What type of compressor is this, and what are you trying to accomplish with it? If that is known you might be able to get better answers. The reduction of pressure should reduce the time run under load, if it is a conventional compressor it means the compressor is not running. Hope this helps.


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## scarybill (Oct 7, 2012)

bfjou812 said:


> What type of compressor is this, and what are you trying to accomplish with it? If that is known you might be able to get better answers. The reduction of pressure should reduce the time run under load, if it is a conventional compressor it means the compressor is not running. Hope this helps.


With that kind of output and power I would guess it is a screw compressor. Most times a screw does not have a "storage tank", it has a buffer and runs continuous.

Just my guess.


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## bfjou812 (Aug 15, 2008)

You're right about a screw compressor not having a storage tank most of the time,but in my 20 + years as a maintenance mechanic they feed into some type of storage tank. Even with that kind of CFM I would find it difficult to provide operating or shop air to a facility. My question was relating to the use of a VFD,Variable Frequency Drive, that has me baffled. That type of set up is not usually a "home" set up rather an industrial one. Which if that is the case some of the conventional answers are not practical.


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## scarybill (Oct 7, 2012)

Your right about the VFD. Im thinking hes running 480/3phase, not a home set-up. With most of the compressors at work we don't have much of a tank. I think the answers he might be looking for would come from other than here.


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## bfjou812 (Aug 15, 2008)

And with that said , was my original point.


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## bemegopi (Mar 19, 2014)

*compr details*

I have using 604 cfm screw type compressor

VFD high speed 2700 rpm
low speed 1200 rpm
2nd low speed 600 rpm

motor 90 kw

my question is,

i have using near 90 nos pneumatic double acting cylinder for various purpose. how to analyse this 604 cfm is enough or not? theoritically?


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## bfjou812 (Aug 15, 2008)

It seems that you would be fine according to your calculations you did in this thread
http://www.hauntforum.com/showthread.php?t=38898


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## Hippofeet (Nov 26, 2012)

Well, now I am just curious as to what the heck is going on here. I am sure it is mind-blowingly mundane, but still.

I hate compressor math. What you did in your other post is the way I do it, and I get the same numbers as you. Does that make us right? >.> Maybe, lol.

I imagine our recent posts on compressor math showed up in a search, and lured you here. So, do tell. Since this is clearly an industrial scenario (I have more experience with airveyance than cylinders, in an industrial setting) what is this theoretical double acting cylinder going to do? If you just want to have the compressor running less, an accessory tank will extend the time BETWEEN compression but will take longer to compress, and may not gain you anything. 

Can't you do some Millwright (i.e. mathematically challenged) testing? Mock up a rig to push up an equivalent weight with the cylinder you want to use, and see how far you can lower the required pressure and still do it? The math will get you right in the ballpark. Or does your work want it built right now, working right now, and working perfectly forever after? lol, it's like that sometimes.


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## bemegopi (Mar 19, 2014)

thank you hippofeet...


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## bemegopi (Mar 19, 2014)

how to convert SCFM to CFM?

i saw some methods but i cant understand.
what is the main difference between SCFM to CFM
my over all cylinder SCFM = 13, how to convert it to CFM ?


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## Hippofeet (Nov 26, 2012)

But you didn't answer any of my questions...

SCFM is STANDARD cubic feet per minute. So it is a corrected flow rate. 

The standard for Europe (according to Wiki) would be 1 bar, at 0 degrees C. So a European compressor or cylinder would say SCFM because it is giving it's flow rate at those conditions.

However, standards vary. Doesn't look very useful to me. I would be more concerned with the ACFM, actual cubic feet per minute, measured at the compressor, and then at the point of actuation. But, that would need to be measured.

Don't bother converting SCFM to CFM, waste of time, as the chances that you are running under the standard conditions as far as pressure, temperature, and humidity, are pretty slim.

Regards,

Hippo


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## bemegopi (Mar 19, 2014)

*Dear Hippo*

I have not a knowledge about pneumatics. i am Very new to this field. Some questions only i understood.

My compressor size is 604 CFM

And my 65 cylinder SCFM = 56 SCFM

I need to compare 604 CFM = 56 SCFM , so only i need that details. if my concept is wrong. can you tell a details about that?


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## bfjou812 (Aug 15, 2008)

Here is a link to convert SCFM to ACFM. Hope this helps

http://www.pdblowers.com/t6-scfm-standard-cfm-vs-acfm-actual-cfm.php

There are many other calculators,I just did a search for "converting SCFM to CFM".


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## bemegopi (Mar 19, 2014)

*thank you bfjou812*



bfjou812 said:


> Here is a link to convert SCFM to ACFM. Hope this helps
> 
> http://www.pdblowers.com/t6-scfm-standard-cfm-vs-acfm-actual-cfm.php
> 
> There are many other calculators,I just did a search for "converting SCFM to CFM".


its very useful...


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