×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Introducing liquid propane in ethane vapor environment

Introducing liquid propane in ethane vapor environment

Introducing liquid propane in ethane vapor environment

(OP)
Hello,
If at the ambient temperature I pressurized a drum with 6 bar vapor ethane then I introduced a liquid propane to the drum, what will happen? will it prevent the propane from flashing (to avoid reaching CET) or will it flash faster with ethane in the system?

THANX.

RE: Introducing liquid propane in ethane vapor environment

It will depend on the temperature. If you intend to store propane without allowing it to flash then you need to set the pressure taking into account the temperature of liquid propane.

RE: Introducing liquid propane in ethane vapor environment

(OP)
Thanx all for replaying, the ambient temperature is approximately 23 degree centigrade; And I am intending of storing the liquid propane and vaporize it gradually but I don't want to reach the CET by introducing liquid propane to a none propane environment.

RE: Introducing liquid propane in ethane vapor environment

CET?

When I eyeballed the propane vapor pressure curve, it looked like "ambient" had to be 9 C to not flash propane at 6 barg.

Good luck,
Latexman

Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers

RE: Introducing liquid propane in ethane vapor environment

Tariqi
I have no idea what CET means! A small amount of propane will flash till the pressure in your vessel reaches the saturation pressure of propane at 23 deg C, then no more flashing occurs.

RE: Introducing liquid propane in ethane vapor environment

CET = Critical Exposure Temperature (?) to me, but in the context of this thread it might mean something different.

RE: Introducing liquid propane in ethane vapor environment

(OP)
CET means (critical exposure temperature) where the drum will fail at this temperature, in my case it is carbon steel so its CET is -29.

RE: Introducing liquid propane in ethane vapor environment

CET sounds like Critical Evaporative Temperature

RE: Introducing liquid propane in ethane vapor environment

In this context I believe cloa's definition.

RE: Introducing liquid propane in ethane vapor environment

If you want the exact solution you may have to fire up that ol' PVT software pacakge - but you may also just assume that the partial pressure of the propane is equal the the vapour pressure at the given temperatures. If thats higher than 6 barg then the propane will "flash" - if theres enough propane (compared to your total volume= then you may ultimately reach the P_vap of propane. You may also be able to find a table of k values for propaane/ethane that will make it possible to calculate the final pressure (given that you know the volume, anount of propane and ethane.

Best regards, Morten

RE: Introducing liquid propane in ethane vapor environment

hey Tariqi,

The rule is to pressure up with vapor of the same composition for VLE reasons. I think ethane is possibly not much better than N2. You are going to get flashing and potentially < -29C until you get some propane vapor. How cold initially only depends on the efficiency of vapor diffusion away from the point of vaporization.

Concentrate on the point of addition. A small flow controlled at the propane source, good ambient heat input, a stainless section of pipe (or SS braided hose), and watch for ice. Cold (ice) shows the point of vaporization.

Best wishes,
sshep

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!


Resources