Fouling resistance factor in sludge application

[youngengineerpl]

I've initially posted it in "Boilers and Pressure Vessels..." but acting upon advices I am posting in here as well.

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.

 

[Christine74]

I think you have a big problem here if the appropriate fouling factor hasn't been determined based on previous operating history. TEMA does not list any recommended fouling factors for sludge, and most of their recommended fouling factors were established in the 1940s. It is unlikely that you will find any published data on suggested fouling factors for wastewater sludge.

The fouling factor you end up selecting for the sludge side of the exchanger will likely be the largest contributor to the calculated heat transfer coefficient, so the required overall size of the exchanger will be largely determined based on that fouling factor alone.

TEMA uses 0.003 hr-ft2-F/BTU for what I would guess might be a similarly fouling service (Bottoms Slurry Oil), but absent other data that could be way off.


-Christine

 

[pierreick]

Hi,
To me you should consider spiral heat exchanger for this type of application ( easy to clean) .
Shell and tube HX is not an option .
My 2 cents
Pierre

 

[pierreick]

Hi ,
A description of spiral heat exchanger .
Pierre