Patent ID: 8200367

Claim:
In a bulk material handling system having a material feeder, a material container configured to discharge material to the material feeder and a vibrator configured to vibrate the material container, a method for maintaining consistent flow comprising: a. periodically calculating a process variable associated with a material flow characteristic of the feeder during operation of the feeder, the process variable being an average feed factor calculated by the equation: FF avg = ∑ n = 1 N ⁢ MF % ⁢ ⁢ MS N wherein FF avg is the average feed factor, MF is the mass flow rate through the feeder and % MS is a ratio of a current motor speed of the feeder to a maximum motor speed of the feeder and N is a predetermined number of time intervals; b. determining a process variable slope during a selected time interval, the process variable slope defined as a rate of change in the process variable; c. determining a difference between the process variable slope and a threshold value; and d. adjusting the operation of the vibrator based on the value of the difference determined in step c.