EXAMPLE $5\mathrm{.}2$ A gas mixture containing $10\%$ SO$2$ and $90\%$ inerts at $1$ atm total pressure and $30\backslash$deg C is to be scrubbed with water to remove $97\%$ of SO$2.$ The inerts have essentially the properties of air. The feed gas rate is $1500$ kg$/$h and the water rate is $37,525$ kg$/$h at the tower bottom. Estimate in each case the diameter of a packed tower for this service if either $1(1)/(2)$ inch Raschig ring or $50$ mm plastic Pall ring is used as the packing. Calculate the pressure drop across the tower for the second case and the blower horsepower required if the packed height is $5$ m$.$ The liquid properties are like those of water. Both gas and liquid flow rates are the maximum at the bottom and design calculations may be based on these values. The flow rates at the top can be easily$$calculated