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Venturi Emptying – A unique solution that makes emptying convenient

Thursday, January 4, 2018

Everyone's familiar with the method of filling color dosing systems using a Venturi loader, which is based on air pressure principles and is common to most dosing systems. But have you heard of Venturi emptying? We at LIAD have developed a unique venturi emptying mechanism for our ColorSave 1000 dosing unit models.

Of course, in order to change colors in a dosing unit it must first be emptied and then refilled with a different color. Emptying is usually carried out manually, most often through an emptying hatch in the base of the feeder, and emptying some feeders requires the removal of the entire feeder from the throat it's attached to.

The throat of the machine, which is the entry point of the raw material, is an area that is not readily accessible, especially in mid-sized to large injection molding machines and most extruders. The operator has to climb up the machine and sometimes it takes acrobatic skills to reach it. As far as safety goes, this is a dangerous operation as the operator could slip or bang himself. If we add to that the necessity of taking along a container to gather the colorant remaining in the feeder, we can conclude that it's a difficult and inconvenient procedure.

Emptying without climbing up

Our innovative development is a Venturi emptying mechanism located at the base of the feeder, where the emptying hatch usually is. Similarly to the Venturi filling mechanism, the Venturi emptying mechanism works by means of an air pressure principle, drawing out the colorant without the need for the operator to have physical access to the feeder. When the operator wishes to empty the colorant from the feeder, he does so through the machine's touch screen, which is accessibly located, and the feeder empties automatically.

Venturi emptying device

The emptying mechanism includes a piston that opens during emptying, and on the same time the air pressure draw out the colorant. In addition, when the Venturi emptying mechanism is activated the feeder's screw turns backwards in order to release grains of colorant from the screw area, improving the cleaning process. Furthermore, it's possible to add an air nozzle connected to the throat, opposite the feeder, which releases a jet of air directed towards the feeder's screw for even more efficient cleaning.

The container into which the residual colorant is emptied is located below, near the operator, so the change of color is carried out at the operator's level.

In the past year dozens of Venturi emptying mechanisms were purchased and the customers' reactions have been quite enthusiastic.