Plate heat exchanger - fouling coefficient 1

[plumberet]

For a plate heat exchanger, can I use C in the equation below to monitor the fouling ?

Q = C*A*LMDT

Or is there another way of calculating the fouling coeff for a plate exchanger ?

Thanks.

 

[chief]

Why not monitor the outlet temperature of your cooling medium, which in comparison to the inlet temperatures of both the coolant and the process liquid will give you an indication of fouling.

Offshore Engineering&Design

 

[plumberet]

Chief,

Thanks. Thought of doing what you have suggested. But the flows ( process and coolant ) need not be constant. So an increase in process flow will result in a higher exit temp which suggests an increase in fouling. Same problem if the coolant is at a higher temp.

One way out is to monitor the fouling coefficient which takes the variable variations into consideration. Just my view. I may be way off here.

Thanks.

 

[pmover]

Short answer - no. While you may note the changes, bear in mind that the C in your equation is dependent upon fluid properties and flow rates.

get the design criteria (including the fouling factor) for the exchanger and the exchanger process operating conditions.

the correct formula is Q=U A LMTD, where the fouling factor is included in the U coefficient. you will need to then write the equation for U of the exchanger (for current operation conditions and is dependent upon flow rates, fluid viscosity, P, T, etc.) and then determine the fouling factor.

short of doing this yourself, perhaps you can obtain the exchanger operating conditions and forward to exchange mfg and have them determine the fouling factor.

Good Luck!
-pmover

 

[chief]

I would suggest you record the flows and temperatures at varying plant conditions and construct a graph. This may give you a good visual aid to anticipate fouling.

Offshore Engineering&Design