Thomson Joule calculation
Thomson Joule calculation
(OP)
I am trying to calculate the temperature drop through a back pressure regulator I intend on using. The inlet to the valve is 332 K, and 3548.7 kPa. The media is air. the outlet of the valve will be 963.2 kPa, and I am looking for the temperature. I understand this is a Thomson-joule calculation, but I have not been able to find good data on this. Can anyone help?





RE: Thomson Joule calculation
RE: Thomson Joule calculation
RE: Thomson Joule calculation
Thanks.
RE: Thomson Joule calculation
http://www.nist.gov/data/nist23.htm
This is just an isenthalpic expansion from one pressure to another (ie: enthalpy is constant). But without a database of enthalpy or at least the Joule Thompson coefficient, I don't know how you'd do this.
If you do much thermodynamic work, you should consider purchasing the database from NIST.
RE: Thomson Joule calculation
I think Perry's Chemical Engineering Handbook has tabulated thermophysical properties for compressed air. Assuming you have an isenthalpic expansion to the lower pressure you'd be able to find the air's temperature at this pressure with the same enthalpy.
RE: Thomson Joule calculation
I think you would find it most useful to read this article on the Joule-Thomson effect:
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The reponse you got from 25362 is correct in that Perry's Handbook has relevant data, but the above article will help you understand how and why the Joule-Thomson effect works.
Milton Beychok
(Visit me at www.air-dispersion.com)
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