10 replies to this topic

[J_Leo]

Hello,

 

 

On one project, free draining is shown from the Package toward the Wet Air Receiver on P&ID, which mean the Air Compressor Skid has to be elevated

 

On second project, there is a high point shown on the piping between skid and receiver. Free draining is shown from high point toward the compressor package.

 

On the third one, “no pocket” is shown and there is a lowest point air trap between the compressor package and wet air receiver.

 

To me, the third one makes more sense. Is it normal for the air compressor skid to be elevated a couple of meters above grade?

 

Please see the attached simple sketch

 

Thank you,

Leo

 

 

 

Attached Files

•  sketch.pdf   434.62KB   27 downloads

Edited by J_Leo, 13 November 2015 - 11:31 AM.

[Art Montemayor]

Leo:

 

Why do you repeat your query title?  It is so much simpler to explain and communicate in an international engineering manner - like a detailed sketch or drawing.  You can make your sketch in a convenient Excel spreadsheet and submit it for answers or comments to your query.

 

It is very hard to follow a verbal description involving process equipment.  Drawings and sketches are the best and most efficient way to communicate.

[J_Leo]

Art,

 

Thank you for the valid suggestions. I have removed the repeat of the title and added a simple sketch I made.

 

Regards,

Leo

[Art Montemayor]

J_Leo:

 

See the attached Excel workbook for my comments and recommendation.

I'm assuming you have an oil-flooded screw air compressor.

 

 Condensate Removal - Air Compressor Aftercooler.xlsx   93.45KB   29 downloads

[breizh]

http://www.ecompress...tercoolers.aspx

 

J_leo,

 

You may find additional info using the link above

Good luck.

Breizh

[J_Leo]

Art,

 

Thank you very much for your sketch and explanation. The only problem is that the air compression package has the aftercooler and water separator included inside. I wish I had made it clear. So my question is about the piping between the package and the wet air vessel.

 

From the website Breizh provided, I found the system piping for Condensate Control.

http://www.ecompress...ng-systems.aspx

 

Here is what it says

"Make sure that the piping following the aftercooler slopes downward into the bottom connection of the air receiver. This helps with the condensate drainage, as well as if the water-cooled aftercooler develops a water leak internally. It would drain toward the receiver and not the compressor."

 

This statement is consistent with the first draining layout in my original post. 

 

Based on the statement above, I would think the Air Compressor Package is elevated. However, looking at the drawing titled "Compressed Air System Piping" on the same webpage, it looks like the package is not elevated. I found the same by checking some other Compressed Air System images on the internet. 

 

So I am confused.

 

Regards,

Leo

[Bobby Strain]

Just no pockets. This means you can have the piping installed to drain either or both directions.

 

Bobby

[manojkaila]

Dear J_Leo

 

As per my understanding if there is no vertical loop in compressor discharge line up to inter cooler. Then slop must be towards inter cooler/ separator because this the flow of air & along with this any moisture particle will be carried away. Same time moisture will condense in after cooler.

 

Regards, 

[J_Leo]

Just no pockets. This means you can have the piping installed to drain either or both directions.

Bobby

Thank you, Bobby.
So you agree with the third layout in my original post.

Edited by J_Leo, 15 November 2015 - 12:18 PM.

[Art Montemayor]

J_Leo:

 

You're confused because you have not shown any aftercooler in your sketches.  I don't think you interpreted Bobby's comment correctly.  You simply cannot have any condensate in a hot compressor discharge until it enters the after(or inter-)cooler.  It is in the coolers that the water condensate forms due to temperature and pressure.  Therefore, the issue of separating the water condensate from the air lies in the cooler and after the cooler.

 

Since you haven't shown were the cooler is located (and how), you have not shown any details of importance.  Until you do, we can't visualize what your problem is.  As I stated: words are not sufficient nor accurate in describing an engineering application.  A detailed drawing does that.

[J_Leo]

Art,

 

Thank you for your comments. The projects I looked at were all in FEED phase, therefore no details are available at this stage. Depending on the selection of the vendor, the layout of the system inside the package could be very different.

 

The air compressor aimed at is oil free screw type. The compressed air serves as plant air and instrument air (after drying). The packages includes intercooler and after-cooler. The water separators are most probably integrated into the skid as well. The wet air vessel in my sketch serves as a knock out drum in case any water is carried over.

 

Here is the link to the brochure of a vendor

http://www.atlascopc...795-1691251.pdf

 

For now, for condensate control outside of the package, I think it should be ok as long as there are no pockets along the pass and adequate drip legs are provided at low points, as I described in case 3 in my original post.

 

If I have a chance to work on this unit for an EPC job in the future, I would have a better picture by talking to compressor package vendor directly.

 

Regards,

Leo