Liquid agitation equipment typically comprises of a stationary vessel and a rotating mixing element, termed as the agitator, along with the agitator drive system. A vertical cylindrical vessel with a liquid height which is equal to the tank diameter is commonly used. The length to the diameter ratios can be changed depending on the plant layout. The top of the vessel can be provided with flat covers or dished ends depending on the operating parameters of the vessel. The vessel can have tank bottoms which are flat, dished or conical. The choice of the dished heads depends upon the operating pressure of the vessel and the process parameters.

A propeller is a high-speed axial flow impeller which is typically used for low viscosity liquids.

Pitched blade turbines are the most commonly used axial flow impellers. A pitched blade turbine consists of a hub on which four or six blades are mounted at an angle with respect to the horizontal

Hydrofoil impellers are commonly referred to as high efficiency impellers since they are designed to maximize fluid flow and minimize shear rate, and therefore these impellers are popular in a majority of mixer installations.

The Rushton turbine is a disk type (six blade turbine) radial flow impeller. The sweep diameter of the disk ranges from 66 to 75 percent of the vessel diameter.

Star shaped impeller having tapered blades provides intermediate shear levels. This type of impeller is used in polymerization reactor.

The impeller blades are mounted directly on the hub of paddle agitators. The paddles are normally operated at low speeds.

For fibrous material, back swept paddle impellers are effective. Compared with the flat blades, these have lower starting torques.

Anchor mixers are commonly used for mixing of viscous liquids with a viscosity range between 5000 and 50,000 cps.

Helical ribbons operate over a wide band of viscosities, ranging from low viscosity liquid to highly viscous materials upto 4,000,000 centipoise.

The saw tooth type impeller consists of a flat disk having saw tooth like edges on the external periphery.