3500 kg of solid particles with the density of 2600 kg/m3 and the average diameter of 300 m has been placed inside a cylindrical vessel with the diameter of 0.8 m. Liquid with the density of 900 kg/m3 and viscosity of 0.002 Pa.s is passing upwards through the bed with a superficial velocity of 0.01 m/s and is fluidising the bed. The drag coefficient of particles is 0.1.

(a) Calculate the bed pressure drop at incipient fluidisation.

(b) Calculate the fluidised bed height.