Paddle agitators consist of two flat paddle-shaped impeller blades extending to reach the tank walls. They are used if no extensive axial and radial flow is required. These impellers can produce a laminar low shear flow and are used for low viscosity liquid mixing, crystallization, dissolution, and heat transfer. They are typically operated at low speeds and predominantly give a tangential flow pattern. Secondary blades can be installed on the paddle blades to enhance the mixing of more viscous materials.
The impeller blades are inclined from the plane of rotation to create an axial flow pattern. This variation of paddle agitator is typically used for homogenizing suspensions.