Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Centrifugal Gas Compressor Evaporative Cooling Injection Rate

Centrifugal Gas Compressor Evaporative Cooling Injection Rate

Centrifugal Gas Compressor Evaporative Cooling Injection Rate

I have a four stage centrifugal process gas compressor that has a wash liquid and a water injection used for anti-fouling and evaporative cooling of the process gas, respectively. I'm looking for guidance on how to best determine the maximum amount of water injection (for cooling purposes) that each stage can withstand without detrimental effects to the compressor (wash liquid injection rate will stay constant). I understand that the rule of thumb for wash liquid injection is no more than 3% of the mass flow rate, but does this the same for the cooling water injection? Is the 3% rule of thumb for total liquid injection (wash liquid plus water injection) or just wash liquid injection?

Any guidance that anyone may be able to give on this subject would be greatly appreciated.


RE: Centrifugal Gas Compressor Evaporative Cooling Injection Rate

The amount of water injection for cooling purpose depends on several parameters - procedure include:

- The heat capacity of the gas at constant pressure Cp
- The Mol. weight of the gas
- The total flow of the gas
- The pressure at the stage before injection
- The injection temperature of the cooling water
- The amount of water already contained in the gas
- The Delta T that is needed to be achieved at inlet of the stage from cooling

For instance suppose this is to avoid polymerization; you know that without cooling water the compression stage will produce a certain increase of temperature;
You also know the minimum temperature required at the outlet of the stage to avoid polymerization e.g 85 deg C -> your target temperature).

So basically you have to calculate what would be the inlet temperature (with water injection effect) that will lead to stay within 85 degC at outlet and you do this by adapting the amount of relative humidity required (can be by trial and error). Once you know the relative humidity you can estimate the water injection flow.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close