The SO2 converter is packed with Vanadium pentoxide catalyst particles of density 2500 kg/mup to a height of 1 m in a vessel of cross-sectional area 0.04 m2. The mass of catalyst in the bed is 59 kg and the surface-volume mean diameter of the catalyst particles is 1 mm. A fluid of density 800 kg/m and viscosity 0.002 Pas flows upwards through the bed. Calculate (i) the volume fraction occupied by voids (ii) the pressure drop across the bed when the volume flow rate of the fluid is 0.72 m/h (iii) the pressure drop across the bed when it becomes fluidized. [10]