Caloric Factor (Kc) and Fouling Factor

Have you tried D. Kerns "Process Heat Transfer"?

Iam calculating this based on D. Kern "Process Heat Transfer" only. The problem Iam facing is while calulating Kc. The hot side temperature difference is 16 deg F and API is 45. For this condition Iam not able to locate Kc value using graph.

What is the composition of the vacuum distillate?. May be is a multicomponent stream. First of all it is necessary to make a material and heat balance because at the top of the distillation column vapor is in equilibrium.I believe that the distillate is flowing in shell side of the heat exchanger and in the tubes side is going the cold crude as to recover the heat to be heated before being fed to the distillation column. It is a good economic process choice. I dont know if the distillate is partially or totally condensed. Kern gives the heat tarnsfer coefficient for condensing in shell side. after that you should follow the method to calculate the hi coefficient in tubes. And then the total heat transfer coefficient Uc ( clean). In tables values of Rd ( fouling factor) are given for the service. eventually calculate the Ud ( dirty) as to predict the operation time of the partially or totally condenser before to be cleaned.

I greatly recommend to design the heat exchanger with a tube side velocity of at least 3 ft/sec as to have a good heat transfer coefficient and avoid fouling.

Armando Hernandez

Senior process Engineer.

Yes vacuum distillate is a multicomponent stream. It is flowing in shell side and crude in tube side. Iam calculating the fouling factor of the existing heat exchanger and facing the problem which i've described above. It will be greatful if you could help me out.

I am going to send you some information about thess systems. I am so interested about to solve your problem.

I appreciate your response. Thank you in advance.