Flow types

In stirring technology, there are generally two types of flow that are decisive for the stirring process and must be taken into account accordingly: laminar and turbulent.

What is laminar flow and what is turbulent flow?

In laminar flows, the medium flows in layers that do not mix into each other. The layers glide past each other. This is particularly the case at low flow velocities. Examples of laminar flows are the flow of blood in the human body or the flow of groundwater.

If the flow velocity is increased, irregular turbulence occurs in all three dimensions. The layered structure dissolves. The exchange of particles becomes increasingly chaotic and intensifies as the speed increases. This effect is often supported by installations in the agitator tank, so-called baffles. Examples of a turbulent flow are the poured milk in coffee or eddies and whirls in a river.

Laminar or turbulent stirring?

From the previous explanations, it can be deduced that the mixing or heat distribution within a mix takes place faster and more effectively with turbulent flows than with laminar flows. This is therefore always an option if the mix reacts insensitively to the flow and any shear forces. In contrast, laminar flow has a gentler effect on the mix. Sensitive substances should therefore be stirred laminar.