Calculate the pressure drop to be maintained across an isothermal packed bed of length $30m$ for maintaining a rate of flow of $50$ tonnes of air per square metre per day making use of the following data:

Viscosity $of$ air $=4{10}^{-5}kg{m}^{-1}{s}^{-1}$

Diameter $of$ particles $=5{10}^{-2}m$

Void fraction $=0\mathrm{.}35$

Temperature $of$ the bed $=300C$

Density $of$ air $at300C,=0\mathrm{.}635kg{m}^{-3}$

Exit pressure $=1$atm

Shape factor $=1$