agitatedtank

An agitatedtank, in industrial contexts often referred to as a stirred-tank reactor, is a vessel in which its contents are kept in motion by mechanical agitation. The primary purpose of agitation is to achieve a uniform composition, temperature, and in many cases mass and heat transfer with the surroundings or with added reactants.

Typical agitated tanks are jacketed or equipped with internal coils to control temperature, and feature an impeller driven by a motor. Baffles around the inner wall reduce vortexing and improve mixing. The choice of impeller (for example, Rushton turbine, pitched blade, or hydrofoil) depends on liquid viscosity, gas handling, and the desired flow regime. For gas-liquid processes, spargers or diffusers may introduce gas into the liquid.

Operating parameters include agitation speed, which determines Reynolds number and mixing intensity, as well as mixing time, temperature, and, when relevant, oxygen transfer rate and pH. Scale-up from lab to plant size requires maintaining similar mixing and mass transfer characteristics, often using power per volume criteria and computational or empirical models. Agitation can cause shear that harms sensitive materials or cell cultures, and foaming can present operational challenges.

Applications: agitated tanks are used across chemical production, pharmaceuticals, food and beverage processing, and wastewater treatment. They are common in fermentation as bioreactors and in polymerization or crystallization processes. The term is sometimes used interchangeably with stirred-tank reactor (STR) or agitated reactor, though specific configurations may vary.

In practice, design and operation emphasize safety, efficiency, and maintenance. Materials, seals, and cleaning procedures are chosen to suit the chemical environment and regulatory requirements.