[nertil1]

Can anyone tell me where I can find the heat capacity (cp) of saltwater? I can't find in any of my engineering books or on the internet, I've looked everywhere I can think of. Any help is appreciated.

thanks
nertil

[ARGOS++]

Dear Nertil1;

I found some values in an older “LANDOLT & BÖRNSTEIN” different Concentrations.

Maybe you take a look there, otherwise I can scan it.

Good Luck!
                   ARGOS⁺⁺

[nertil1]

Can you please scan it if you don't mind?

[ARGOS++]

Dear Nertil1;

For sure! - The “LANDOLT & BÖRNSTEIN”

Hints:
-   You have to read it like a “Logarithmic Table”! – That means
     that the “0.” Is standing at begin of the column.
-   Spec. Wärme      =   specific Heat Capacity in kcal kg^-1 °K^-1
-   Beobachter         =  Observer (= original Reference)
-   proc.                 =   Percent (= %).
-   bis                    =   till   (for its duplication also the ‘”’ is used).
-   Temperatur             is given in Grad Celsius.

Example:  NaCl + 10 H₂O (= 24.5 proc) by 18°C  =   0.791
(I think for other values as the table you can interpolate with Excel.)

I hope it may be of help to you.

Good Luck!
                   ARGOS⁺⁺

[nertil1]

what does it mean by percent?
My feed stream coming in is 25 C, at 3.5wt% NaCl

[ARGOS++]

Dear Nertil1;

It seems you forgot my Hints/Legend.

I will try to translate the Example to English:

NaCl + 10 H2O (= 24.5 %wt/wt) by 18°C  =   0.791  kcal kg^-1 °K^-1

The table shows also that there is very nearly no other temperature influence as the volume change. If you like you can compensate it with tables you know.

In the Attachment I did a little work and only a “Linear Interpolation”, which seems to be a very good approximation in the first part of the graph, and that’s the region of your interest.

So your calculation should end:
    Cp_3.5% = Cp_1.6% - ΔCp_n /Δ%_n * (3.5% - 1.6%)   kcal kg^-1 °K^-1

    with:  ΔCp_n as the absolute ΔCp to the next neighbour.
what ends in:
    Cp_3.5% = 0.97800 - 0.03307 / 3.3 * (3.5 – 1.6) = 0.95896  * 4.184 kJoule/kCalorie     

=  4.012  kJoule kg^-1 °K^-1

Please check my calculation!

Could this be what you want, and clear as much as possible?

Good Luck!
                   ARGOS⁺⁺                   

[nertil1]

thanks a lot