answer b & c only

1. Air is flowing through a packed bed containing a mixture of particles in the following percentages, sizes and shape factors: 20%, 15 mm, shape factor 0.86 35%, 18 mm, shape factor 0.57 15%, 25 mm, shape factor 0.76 30%, 10 mm, shape factor 0.92 . The particles have a constant density of 1350 kg/m. The bulk density of the overall packed bed is 900 kg/m'. The bed has a diameter of 0.6 m and a height of 2.5 m. a. Calculate the mean hydraulic radius (TH) of the particle mixture for the air flow. b. The air enters the bed at 25 C and 202.65 kPa abs at the rate of 0.4 kys. The average molecular weight of air is 28.97. Air viscosity at the flow conditions is 1.845 X 10Pa.s. Calculate the pressure drop of the air in the packed bed. (Hint: First, guess the outlet pressure, P2 of the air flow. If your guess is far away from the resulted AP, repeat your calculations up to 2 trials only.) Now, the packed bed containing the mixture of these particles is fluidized using the airflow at 25 C and 202.65 kPa abs. The void fraction at the minimum fluidizing conditions is 0.5. If the height of the fluidized bed is 3.6 m, has the bed expanded? Explain your answer briefly