1. The problem statement, all variables and given/known data Estimate the pressure drop in a tower packed with porous support. This tower is an integral part of a water oxygenation system and will need to operate over extended periods without cleaning. From the following data estimate the pressure drop you expect to see on start-up Diamter = 1.5m Height = 3m Support size = 0.004m 2. Relevant equations Δp = (uμh)/β u is liquid velocity μ is liquid viscosity (I.e. water) β is bead permitivitty (I.e the support) 3. The attempt at a solution I have had no problem calculating β and got 4.9 x 10^-9m Where I get stuck is finding 'u' for these problems I usually use the formula u = Q/A Volumetric flow rate over cross sectional area - however in this instance there is no information about the volumetric flow rate Should I assume a volumetric flow rate? Or is there a way to calculate it from the above information? (sometimes they give something away in the wording such as 'start up' - not sure what I should take from that) Are there any other equations I can use? This is a 15 mark question so I'm assuming there's a bit of calculation that needs to go into it.