4 replies to this topic

[Alawi]

Hello every one,

Please help with reliable set of equations used to calculate the pressure drop across a catalyst bed. highly appreciated if any free simple software is available.

Kind reagrds

[Padmakar Katre]

Dear,

I hope the reactor which you have mentioned here is a fixed bed reactor and, if so, you can calculate the pressure drop by using <b>Ergun Equation</b><u></u>.

Pressure drop is calculated in terms of (ΔP/L), the pressure drop per unit length of packing.

[loganirado]

Hello

Yeah, try using the Ergun equation for modeling the pressure drop through the reactor.
It looks like the following:

dP/dW=[-(150(1-Φ)^2)/Φ^3 (μ*u)/〖d_p〗^2 -(〖1,75(1-Φ) ρ〗_gas u^2)/(d_p Φ^3 )](1-Φ) A_c ρ_cat

where,
u = the spacial velocity of the gas,
rho = the gas density
fi = the bed's void factor
Ac = the reactor's section area

[Bharat Abhyankar]

Using Ergun equation to predict pressure drop in fixed bed reactor requires data from catalyst vendor which can be proprietary or unavailable.
In such cases developing a simple Mathematical Model based on Ergun Equation can really help:

From operating plant actual ∆P in reactor for various flow rates can be recorded and plotted in as shown in attachment. This type of data can be represented as:

∆P
---- = [ A*(V)] + [B *(V2)]
L
Where A, B = Constants derived from graph.

This should solve the problem!

Attached Files

•  Delta P in Fixed Beds.jpg   24.39KB   79 downloads