CO2-spikes in instrument air system

[Ebbot]

Hi all,

I have a problem with CO2-spikes in an instrument air system. The spikes occurs when the air dryer unit (dessicant) switches tower. The air is also used as breathing air, and the CO2 is monitored. The analyser (ir-type) is located upstream of the dryer.

Any clues?

Thanks!

 

[rneill]

Not sure about the CO2 problem but I would question the acceptability of an instrument air supply system to meet Breathing Air Quality requirements. Many jurisdictions have extremely stringent standards and requirements for equipment used to supply breathing air, and quality standards on the breathing air itself, that I wouldn't have though a normal instrument air system would be able to meet.

 

[unclesyd]

I have to overwhelmly approve the post by rneill and add the famous words expressed when we installed a new plant instrument air system and someone said now we want have install a breathing air system, "NOT NO, BUT HELL NO" from the mouth if the plant engineer.

Now to your CO2 question:

Do you find any Co in the instrument air?

How is the instrument air generated?

Is there a carbon filter in line?

How are the dryers regenerated?

Remember that Atmospheric air has a little CO2, too much for some, that could be adsorbed and release during the change over.

 

[BigInch]

Is your air inlet being affected by proximity and drafts from a compressor or other nearby engine exhaust?

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch

http://virtualpipeline.spaces.live.com/

 

[Ebbot]

We think that CO2 is adsorbed in the regenerated dryer and releases during the change over. What can we do to avoid this?

The dryer is an old BURNETT & LEWIS, heat regenerated, with Activated alumina and Mobil Sorbead Grade R.

 

[BigInch]

Capture the CO2 at the air intake with a molecular sieve, or bubble through a caustic solution?

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch

http://virtualpipeline.spaces.live.com/