A packed tower is to be designed to absorb SO2 from air by scrubbing the gas with water. The entering gas contains 8% SO2 by volume and the leaving gas is to contain 0.5% SO2 by volume. The entering water is SO2 free. The water flow is twice the minimum required. The airflow rate on SO2 free basis is 1200 kg/h. The temperature is 30C and pressure is 1 atm. Equilibrium relationship is y* = 21.8 x, where x and y are mole fractions. Find NTU, HTU. It is planned to use1.5 inch Raschig rings/ 1.5 inch Berl saddles for this purpose. Estimate the height and diameter of tower if it operates at 60% of flooding velocity