×
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

Flammability

Flammability

Flammability

(OP)
Hello all,

Can somebody help me with the origin of this formular

UFLp=UFL+20.6(logP + 1)

Also, is it applicable to all paraffinic hydrocarbon or natural gas only

RE: Flammability

fikayo2004
The formula you cite probably derives from work published by the Bureau of Mines (Bulletin 627) which included empirical results for Natural Gas.
Two formulae are given
L (vo%) = 4.9 - 0.71 logP (atm)
U (vol%) = 14.1 + 20.4 logP (atm)
(The work reports a standard error of 0.53% for L and 1.51% for U.
Note that these were test results so the formulae represent "best fit" trend.  Other hydrocarbons will have different trends because the instability of the molecule is connected with its total energy content including heat of formation and temperature (enthalpy).
The results are reported at 28 degC.  Limits get wider as pressure and/or temperature increase.
The original work dates back to 1949 and was connected with natural gas explosions in Coal Mines.

Hope that helps you
David

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