Application of Fuzzy Control to Fluidized Bed

Fuzzy algorithms were applied to the fluidized bed control system which regulated the bed mode to be maintained in a bubbling condition under the alteration of particle properties and/or the deviation of bed hold-up. Variance of the pressure drop fluctuations through the bed was adopted successfully so as to identify the fluidizing mode and its intensity. Four controllers were compared experimentally employing the reasonings deduced from the combinations of four control rules and three membership functions, which were designed in consideration of the fluidization characteristics studied preliminarily. The rule, whose variable of the premise was the deviation of superficial gas velocity, controlled the system satisfactorily both in the transient state and steady state, compared to the rule with the variable of the deviation of pressure fluctuations variance for the change of setpoint fluidizing intensity. For the increment of the bed hold-up, the system was also controlled smoothly by the algorithm with the variables of the deviation of pressure fluctuations and the deviation of superficial gas velocity.