Abstract: A gate-type feeder control system has level and weight sensors for monitoring the output of the system to a conveyor or other receiver, an electronic control circuit responsive to the sensors, and a hydraulic actuator circuit including a plurality of valves to provide the desired output of a feeder gate. In the electronic circuit, a master set point signal is entered and compared with the output signal from the sensors. The output flow to the receiver of the system is continuously adjusted by a deviation controller to reduce the deviation in these two signals. Erratic changes in system output are avoided by a deadband circuit introduced into the electronic circuitry to buffer excessive oscillation, overresponse and even instability caused by transient size change and lumping associated with bulk materials. The electronic circuit also includes an averaging module to average the level/weight of the material being discharged to obviate responding to peak levels.

Abstract: A load out chute system for controlling and directing the flow of relatively large quantities of bulk material, such as coal, is disclosed. The chute system includes an upper chute and a sliding gate valve positioned above the upper chute. A pair of hydraulic cylinders move the valve plates of the upper gate valve into partially overlapping relation for effective sealing of the flowpath. A lower chute pivots from a horizontal stored position to a position wherein the upper and lower flow paths align for discharging material. The lower chute includes a triangular skirt pivotally secured to an overhead structure and includes an arcuate bottom plate enabling the lower chute to cover the upper chute discharge opening when the lower chute is pivoted up. A corresponding curved retainer plate is operative to cover the lower chute inlet opening.