The glass tube (100mm ID) fluidised bed pilot plant uses water as the fluid and pyrex glass beads (3.45 mm diameter, density 2.5 kg/l) as the particles. The pumped fluid can be re-circulated at a range of flowrates. What is the behaviour of a liquid fluidised bed by determining (a) the relationship between velocities of fluidisation and sedimentation (b) the relationship between pressure drop and liquid velocity (c) the relationship between voidage and fluidisation velocity and (d) the Reynolds number at minimum fluidisation?