Thermal Conductivity of gas mixture

[ercegs]

Hi, can someone direct me to a book, or website, whcih can show me how to calculate thermal conductivity and dynamic viscosity of mixture of gases?

My mixture consists of: Hydrogen, Nitrogen, Carbon monoxyde, Carbon Dyoxide, Methane and water vapor...

I need formula to calculate thermal conductivity, and viscosity..

Thank you for help in advance.

 

[speco]

Ercegs,

There are procedures in the TEMA (Tubular Exchanger Manufacturers Association) book for calculating the properties of mixed gases. However, you need the individual properties to do it.

Regards,

speco

 

[iainuts]

You can get properties for the individual fluids here:

http://webbook.nist.gov/chemistry/fluid/

But I'd recommend paying the $200 or $300 for the REFPROP database instead. It'll pay for itself very quickly if you do much thermo work.

http://www.nist.gov/srd/nist23.htm

 

[prex]

I suggest Perry-Chilton 'Chemical Engineers' Handbook', if you can have access to it: it has a long chapter entirely devoted to chemical and physical properties and to the prediction and correlation of physical properties.
In short, if you don't need a detailed discussion and references, this is what they suggest for gas mixtures at low pressures.
-thermal conductivity k=[Σ]y[sub]i[/sub]k[sub]i[/sub](M[sub]i[/sub])[sup]1/3[/sup]/[Σ]y[sub]i[/sub](M[sub]i[/sub])[sup]1/3[/sup]
-viscosity [μ]=[Σ]y[sub]i[/sub][μ][sub]i[/sub](M[sub]i[/sub])[sup]1/2[/sup]/[Σ]y[sub]i[/sub](M[sub]i[/sub])[sup]1/2[/sup]
where y is the mole fraction and M the molecular weight.

prex

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[ercegs]

Speco,

thank you very much...And can you tell me, for water vapor, I need cp, thermal conductivity etc...On the net, I have only found values for 1 bar, and I have 21 bar at 210deg celsius?

Is it possible to find somewhere these values, or these values are available only for 1 bar?

 

[25362]

Pay a visit to the site suggested by iainuts. You"ll find that water at 210[sup]o[/sup]C and 21 bar is a liquid.

 

[ercegs]

Yes, I saw that..but, someone is trying to convince me that Cp for water vapor at 210deg and 21 bar is 1.97kj/kgK (and that is the value for 210deg and 1 bar)...So I just wanted to see if I'm right

 

[786392]

Cp for water vapor is;I understand is at contant pressure.Thus Cp must vary with changed pressure conditions.
The Change of phase case involves absorbtion of(Latent)heat when boiling starts around atmospheric pressure.
Hope this is helping

Best Regards
Qalander(Chem)

 

[25362]

At 21 bar and 215[sup]o[/sup]C, the vapor Cp = 3.23 kJ/(kg.K), from the NIST table.