3 replies to this topic

[David Sugiman]

I'm currently working on a project to install a fixed bed reactor.
Referring to Perry Chemical Engineering Handbook seventh edition page 6-38 (equation 6-166 and 6-167) as well as using Kozeny-Carman Equation, I tried to approximate pressure drop across fixed bed.

The stream coming in to the reactor is a gas stream, with temperature about 300 deg.C and pressure about 6 barg. Based on Perry Handbook's equation and Kozeny-Carman Equation, predicted pressure drop is 10 times lower than actual pressure drop ( we have other fixed bed reactor that I can collect actual pressure drop reading).

My question is that is there better pressure drop model for fixed bed pressure drop approximation? Thank you.
I do notice that Perry Handbook stated that its equation is only valid for single incompressible fluid through an incompressible bed of granular solids, but I didn't manage to find other equation other than this.

[Andree]

Ergun equation - the reason of your deviation can be that Carman-Kozeny equation is for different flow regime (however, I do not know what it is in your case).

[Andree]

Or eventually Burke-Plummer equation (for turbulent flow only)

[David Sugiman]

Thank you very much for your information.

I have tried using Ergun equation and pressure drop approximation is very close to actual value.