Jump to content

Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Vertical Tank Selection

New Blog Entry

Low Flow in Pipes- posted in Ankur's blog


Cooling Water Return Side Vacuuming Issue

coolers sea cooling water cooler return vacuum

1 reply to this topic
Share this topic:
| More

#1 rak_iam


    Brand New Member

  • Members
  • 2 posts

Posted 27 March 2018 - 01:31 AM

Hello there,


We have one debutanizer overhead cooler with sea water as cooling media on tube side. Supply & return headers are on ground level with supply pressure of 25 psig and return header is kept open to sea out side of refinery. Cooler is at elevated level of 5 mtrs above ground. Both supply and return piping are of 6 inch each. Supply and return headers are of 30 inch and 24 inch resp.


It is observe that vacuum being produced on return line of cooler at 7 inHg. When throttling the return valve to 80%, then only the positive pressure (1 psig) seen on gauge. We are facing low HT efficiency of cooler.


Is the vacuum creation because of cooler at above ground? or due to pressure loss on tube side? 28 psi loss on tube side can be expected?


Any thoughts and remedy?


Thanks in Advance.

#2 Pilesar


    Gold Member

  • Members
  • 545 posts

Posted 27 March 2018 - 09:03 AM

The vacuum results from the gravity flow. Throttling the return line is the solution to keep the pipe full of liquid. See "Designing Piping for Gravity Flow" by P.D. Hills for a good explanation. The article is available on the internet. Search this forum for several past discussions about gravity flow (if you can get the search function to work... it causes me troubles often.)  Art Montemayor converted the Hills article into spreadsheet format which is available somewhere from this site.

Similar Topics