High Viscosity Blades
High Viscosity Blades, supplied through Blade Depot®, a division of Norstone, Inc., are close clearance mixing blades built for high viscosity and laminar flow conditions. The blade shape follows the interior wall of the mixing vessel, with a diameter close to the container diameter itself. This close clearance geometry produces continuous wall contact, which supports heat transfer at the vessel wall and prevents stagnant product buildup on interior surfaces. Anchor impellers use a single curved arm, while gate impellers add horizontal or diagonal cross bars for additional shear at low Reynolds numbers. Both configurations mount to a stainless steel shaft and operate at low to moderate speeds, distinguishing them from the higher speed designs of Turbine Blades and Propeller Blades.
Characteristics
High Viscosity Blades are defined by the following properties:
- Close clearance geometry. The blade diameter is sized close to the container diameter, producing continuous contact along the vessel wall rather than the open clearance used by Turbine Blades or Propeller Blades.
- Low speed operation. High Viscosity Blades operate at low to moderate rotational speeds, suited to laminar flow rather than the turbulent flow generated by High Shear Impellers.
- High viscosity fit. The design is built for high viscosity, viscous, non-Newtonian products where laminar flow dominates the mixing regime.
- Two configuration options. Anchor impellers use a single curved arm, while gate impellers add cross bars for additional shear at low Reynolds numbers, distinguishing the two styles within this product line.
- Stainless steel construction. Both configurations mount to a stainless steel shaft, with coatings available for abrasion resistant or corrosion resistant applications.
Because High Viscosity Blades are generally selected for wall contact and low shear mixing rather than dispersion, they should be compared against High Vane Impellers or Turbine Blades where higher shear or lower viscosity is the process requirement.
When High Viscosity Blades Are Typically Selected
High Viscosity Blades are generally chosen for blending and heat transfer in vessels holding high viscosity or viscous formulations, and for processes where wall scraping and consistent stirring prevent product buildup. Compared to High Vane Impellers or Turbine Blades, which generate higher shear at lower viscosity, High Viscosity Blades are selected when gentle, low shear mixing and continuous wall contact are the process priority. Between the two configurations, a gate impeller is selected over an anchor impeller when the process requires additional shear from the cross bars, while an anchor impeller is selected when a simpler, single-arm design meets the wall contact requirement.
Applications
High Viscosity Blades support high viscosity mixing applications across the following use cases:
- Blending and heat transfer in vessels holding high viscosity or viscous formulations
- Chemicals, cosmetics, and other process systems where wall scraping and consistent stirring prevent product buildup
- Applications requiring gentle, low shear mixing rather than the high shear stirring produced by turbines
- Processes in taller or larger vessels where a gate impeller's added cross bars improve mixing uniformity
Related Products
High Viscosity Blades are one of seven product lines under Blade Depot®. For higher shear or lower viscosity applications, see High Vane Impellers or Turbine Blades. For high shear dispersion, see Polyblade®.