Combining the dirty tank, filter and clean tank in one assembly, the Eriez Hydroflow Star Filter uses vacuum elements to filter machine coolant in two stages. In the first stage, heavy solids quickly settle to the bottom of the tank and are removed by a drag conveyor. In the second stage, the filter element connects to the suction side of the pump and draws the fluid through, trapping solids on the surface.
According to the company, vacuum element filtration offers significant advantages over technologies such as drum and pressure filters. The angle of each filter panel provides a vertical drop for the dislodged, vacuum-compressed filter cake. Each element is interchangeable and can be removed for inspection and re-installed into the seal without concern for misalignment or proper sealing.
The element’s star shape and the filter panel’s compact, rectangular shape are designed to maintain structural integrity after removal from the filter. With the end caps removed, both sides of the filter panels can be easily cleaned, unlike with the circular construction used in drum filters.
Additional features include a slurry distribution ring for accurate introduction of cellulose pre-coat and a positive seal that eliminates solids bypass. An incorporated clean fluid “backflow” eliminates the need for large volumes of air (used in pressure filters) or scraper blades (used in drum filters), which can force solids through and into the clean stream and lodge dirt into the screen, reducing the open area for filtration. The system also is fully automatic, eliminating the need for complex hydraulic or air closure systems to seal pressure filters.