A gas absorption tower of diameter 2m contains ceramic Raschig rings randomly packed to a height of 5m. Air containing a small proportion of sulphur dioxide passes upwards through the absorption tower at a flow rate of 6m3/s. The viscosity and density of the gas may be taken as 1.80105 Pas and 1.2kg/m3 respectively. Details of the packing are given below: Ceramic Raschig rings Surface area per unit volume of packed bed, SB=190m2/m3. Voidage of randomly packed bed =0.71 [Ans.: 0.00916m ]