1. Plan definition

Although the transition from the bubbling regime to the transported bed regime depends essentially on the fluidization velocity (figure 1 ), this transition is only gradual. In practice, there is no precise fluidization velocity (such as the terminal velocity of free particle fall) at which the regime changes abruptly. As the fluidization speed increases, the size and number of bubbles gradually increase, and the suspension becomes increasingly agitated. At relatively high velocities (before U _t is reached), bubble shape becomes irregular and the system is in an intermediate regime known as turbulent fluidization.