Bin gate for providing variable output flow rates

An assembly for controlling delivery of granular or powdered material from a bin opening, comprising:

• a single movable gate for selectively closing the bin opening or providing a selected flow rate of material through the bin opening when the movable gate is open, wherein the movable gate has a notch formed in one edge to form a low flow aperture in the movable gate that provides a low flow rate of material when the movable gate is positioned such that only the low flow aperture is exposed to the bin opening;
• a controller for controlling operation of the movable gate to adjust a gravity flow rate of material from the bin opening;
• and a two-stage flow enhancer, with a first stage comprising paddles positioned on a rotor in the bin opening to impel material in the direction of the low flow aperture and a second stage comprising paddles positioned on the rotor to break up material bridging above the low flow aperture and to impel material to exit through the low flow aperture, the rotor comprising a shaft that also supports the movable gate for arcuate motion and positioning under control of the controller to select the low flow aperture and other open or closed gate positions.

A method for controlling gravity flow delivery of granular or powdered material from a bin opening, comprising the steps of:

• providing at the bin opening a single movable bin gate with a low flow aperture;
• selectively positioning the bin gate using a single actuator to expose only the low flow aperture to the bin opening for material flow or to expose substantially all of the bin opening for material flow;
• and operating a flow enhancer, a first stage of the flow enhancer comprising paddles positioned on a rotating shaft that extends across the bin opening such that the paddles are angled to impel material toward a second stage, and the second stage of the flow enhancer comprising paddles positioned on the rotating shaft to break up material bridging above the low flow aperture and angled to impel material in a gravity flow direction to exit the low flow aperture.