The outer diameter of the helical stirrer is equal to the pitch, and it is specifically used for stirring high viscosity liquids (200-500 Pa · S) and quasi plastic fluids. It is usually operated in laminar flow.
The blades of the ribbon mixer are ribbon shaped, with two to three ribbons installed on the screw in the middle of the mixer. The pitch determines the outer diameter of the ribbon.
Spiral belt agitators are typically operated in laminar flow and are suitable for mixing high viscosity liquids and quasi plastic fluids.