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

Oil/water mixture

Oil/water mixture

Oil/water mixture

Hello all,

I am trying to calculate the inside heat transfer coefficient for a 4 in diameter pipe transporting an crude oil/water mixture.
The crude oil is API 20° and two mixtures are to be analyzed, one for a 50% water cut and the other for a 70% water cut.
I don't know how to determine the viscosity and thermal properties of the mixture.

Please help. Thanks!

RE: Oil/water mixture

In the real world, you may find that transient inventory in the HX is sometimes mostly oil and sometimes mostly water, so calculating the inside htc based on 100% oil would be conservative.

Beware of the properties of this oil at the lowest film temp the calcs predict - viscosity may be high and also check if wax could precipitate out, forming an insulating layer on the tube id.

RE: Oil/water mixture


Do you think it would be conservative to calculate the inside htc based on 100% oil?
I read in some places that the viscosity of the oil/water mixture has a greater value than that of its separate components. Have you heard about this?

Thanks for your response.

RE: Oil/water mixture

I don't think you have the necessary info based on the above.

"mixture" is very vague - Is this a homogenous emulsion? separate? stratified? slug like? Is it fully formed before going into the pipe or mixed in the pipe.

Oil / water mixes are quite complex and very specific to the oil concerned. Above some percentages it all separates in some oils.

Flow rate / velocity becomes important. Is this truly a single phase liquid or have you got gas breakout from the crude?

What temperature is it running at?

Why is this important? a 4" pipe is small - without good insulation it will rapidly get to ambient conditions.

Without physical testing of samples you're just guessing IMHO

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Oil/water mixture

Yes, I've read about this too, but I must confess that I had chosen to ignore this information when I had to do design work many years ago similar to what you are working on now.

For press drop through the tube bank, the all water case may be controlling, unless you have high oil viscosity.

As Little Inch cautions, also check for gas break out in this mix if this is a crude heating application.

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