Roller Gates with Infinite Variable Positioners (IVPs) Handling Corn

Published: November 22, 2017

Configuration of three silos feeding into one screw conveyor.

Client: Corn handling facility – USA

Size: 10 in | 255 mm

Quantity: 3 Vortex ® Roller Gates™


Each gate is equipped with…

Application: Discharge corn from three silos above into one screw conveyor. Provide a solution that allows total volumetric flow control, for precise batching
in an outdoor application.

IVP controllers, installed at a central location near the gates.


For this application, the customer specified IVPs to allow material flow control capabilities on both the opening and closing strokes. IVPs are highly accurate; when automated, the blade actuation increments will be within accuracies of +/- 4% of the total stroke. When operated manually using an IVP controller, the blade actuation increments will be within accuracies of +/- 2% of the total stroke. Because this facility uses all three IVPs in the same stage of production, all three IVP controllers are mounted in a central location near the gates, for operator convenience.

Because dry corn kernels are easily damaged when handled, each gate is equipped with a Special Service Inlet. Acting much like a funnel, a Special Service Inlet directs material flow toward the center of the gate and creates a dead pocket around the edges of the blade. This prevents materials from
packing and damaging against the blade seals, which keeps the seals free of
materials to avoid actuation and sealing issues.

Vortex Roller Gate with an electric actuator (yellow).

Electric actuators were specified for this application instead of pneumatic air cylinders. Electric actuators allow continued operations in harsh outdoor climates, whereas with pneumatic air cylinders, if climate becomes severe, moisture may freeze in plant air lines, causing actuation failure.

Each electric actuator is assisted by a potentiometer. The purpose of a potentiometer is to provide continuous variable position feedback along the full stroke of an electric actuator.

The Vortex Roller Gate is often recommended for use in outdoor applications because it utilizes PET blade seals. Unlike standard Nylon seals, PET seals do not swell when subjected to moisture, which could otherwise cause blade actuation issues.

To view the functionality of the Special Service Inlet, Vortex flow control
assemblies, and other features of the Vortex Roller Gate, please watch the animation.

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