Question

If we have very small dp/di<0.01, then we may use .............

• A. Ergun Equation
• B. Kozeny Carman Equation
• C. Sieder Tate Equation
• D. Arrhenius Equation

Hint:

Use Kozeny-Carman when the flow is highly laminar and dp/di is very small (less than 0.01).

Answer 1

The Correct Option is B

When the pressure drop per unit length ($\frac{dp}{di}$) is very small (i.e.,<0.01), the flow through a packed bed is considered to be in the creeping or laminar region. Under this condition, the Kozeny-Carman equation becomes applicable.
The Kozeny-Carman equation provides a relation for pressure drop in laminar flow conditions through porous media and is a simplified form of the Ergun equation, valid at very low Reynolds numbers (Re<1).
This equation assumes:
- Laminar flow
- Homogeneous bed structure
- Negligible inertial forces (hence very low dp/di)
Other options like the Ergun equation are more general and used for a wider range of Reynolds numbers, while Sieder-Tate is for heat transfer and Arrhenius is for reaction kinetics.