Linear pinch valve

Abstract

Abstract A system for providing proportional and continuous control of the level of a product within a bin includes a sensor which provides an output signal which is proportionally related to the actual level of the product within the bin, an analog controller which compares that output signal with a reference to derive therefrom an error signal, and further including means responsive to the error signal for providing a control signal which incorporates the work function associated with the bin, an actuator control circuit, an actuator, and a flow rate regulating device. The actuator control circuit responds to the control signal to appropriately modify the setting of the actuator and thus vary the flow rate established through the flow rate regulating device in a manner which returns the bin level to a desired value represented by the reference in the analog controller. The sensor may comprise a metallic rod and provide its output signal by determining the complex impedance existing between the rod and the bin wall, wherein the rod is partially immersed in the product. The flow rate regulating device may control the flow rate of discharge either into or from the bin. One such device comprises a linear pinch valve useful in regulating the flow rate of discharge from the bin which includes a conical transfer section and a three-point pinching mechanism. A general description of the analog controller and its relation to the bin''s work function is given. Finally, a circuit for providing appropriate signals when the bin level reaches maximum or minimum values is disclosed.

Inventors

• 👤 Fritz K Preikschat

Bibliographic Details