Throttling Process

ahmad.hasan · May 5, 2006

dear all

What is the throttling Process?
what is Joule homson Effect?

FredGarvin · May 5, 2006

Google is your friend.

http://en.wikipedia.org/wiki/Joule-Thomson_effect
http://www.answers.com/topic/joule-thomson-effect
http://www.chm.wright.edu/grossie/chm457/3_2_06.pdf [Broken]
http://www.madsci.org/posts/archives/apr99/924233920.Eg.r.html
http://www.mmr.com/jt.htm

Cyrus · May 5, 2006

A throttling process is a process that is isenthalpic. Thus, [tex] h_1 = h_2 [/tex]. This means that the following is also true, [tex] u_1 + P_1 v_1 = u_2 + P_2 v_2 [/tex]. So if you drop pressure in a throttling value, you increase the internal energy, and vise versa.

The Joule -thomson- effect deals with the fact that as you expand a gas it looses temperature. Note that for hydrogen; however, it gains temperaturee as it expands. This makes hyrdogen particularly dagnerous.

ahmad.hasan · May 7, 2006

Pressure drops in CNG kit Pressure regulator from 300 bar to 4 bar in 1st chamber due to expansion is it throttling process? temperature also drops in it.

Cyrus · May 7, 2006

Yes, that is exactly what it is.

Edit: wait, what do you mean by expansion? Is it going through a nozzle?

ahmad.hasan · May 8, 2006

no it is going throug valve (sloninoid valve) from storage cylinder through high pressure pipe into solinoid valve and then in the 1st stage chamber of pressure regulator.

Cyrus · May 8, 2006

Yes, it is a throttling valve.

ahmad.hasan · May 8, 2006

what is the value of joule-thomson coefficient for methane