Fouling resistance factor in sludge application 1

[youngengineerpl]

Hello all.

I am currently working on tube-tube heat exchanger for waste water treatment plant for which purpuse is to heat up the sludge.
Project covers 3 different cases that vary in sludge precentage solution (5/10/15%).

As it is my first encounter with such an application (sludge as an working agent) I am having some difficulties with establishing the fouling factor.
Therefore, I would like to ask if there are any guidelines how to find/calculate an accurate value? Any charts/tables?

What I got as designing input is just some thermal-related properties of sludge (thermal capacity, conductivity, viscosity etc.) but there is no additional info what the sludge comes from. Is there even a possible to asses the fouling factor having so limited data?

I would appreciate any feedback!

Best regards.

Przem.

 

[EdStainless]

With those levels of solids you will need high velocities to prevent settling.
Traditional fouling factors are for thin layers of scale, slime, or silt that are stuck to the surface impending heat transfer.
The effect of settling of bulk solids is an order of magnitude worse, but not permanent since it often can be washed out.
There is a lot of literature out there on slurry handling.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[MJCronin]

Post in "Heat Transfer & Thermodynamics" forum for better answers ....

MJCronin
Sr. Process Engineer