Psychrometry and Grain Drying

In fluidized bed drying of agricultural grains, minimum fluidization velocity $v_{mf}$ is reached when:

Options:

• (A) Upward aerodynamic drag force of the fluidizing air balances the buoyant gravitational weight of the grain bed
• (B) All grain grains fly out of the exhaust stack
• (C) Grain temperature reaches $100^\circ\text{C}$
• (D) Pressure drop drops to zero