Beyond blade curvature, impellers differ in construction. A closed impeller has a backplate and a shroud enclosing the blades, giving high efficiency and pressure for clean air. An open or semi-open impeller leaves the blades exposed, which sacrifices some efficiency but tolerates dust and is easier to clean — useful in conveying and dust-laden duties. Blade width and count further tune the balance between flow and pressure.
Choosing the right impeller is about matching it to the gas and the duty point, not just buying the biggest. We build closed impellers for efficient ventilation and milling air, more rugged designs for forging and conveying, and reverse-engineer replacement impellers for any brand — all dynamically balanced to G6.3 before they ship.