Ventilation agitation is the introduction of air or other inert gas (such as nitrogen) at the bottom of the reactor. Due to the lighter density, the gas forms bubbles moving up and agitating the liquid. The gas enters the tank through the distributor. The distributor is usually an annular pipe filled with small holes to evenly distribute the gas to the bottom of the reactor. The advantages of aeration and agitation are low energy consumption and soft mixing. It is suitable for occasions with gas phase participation and gentle agitation. The disadvantage is that the stirring force is small, and it is not suitable for the reaction with large viscosity and solid participation. Ventilation agitation was later developed into an airlift reactor.
Cyclic outside mixing
The external tank type agitation is to take the liquid in the tank from the bottom and then pump it back to the top of the reactor to form a mixture. The utility model has the advantages that the stirring has no dead angle and the energy consumption is small and is suitable for a liquid or a reaction involving a small number of solids. The disadvantage is that the stirring strength is low, and it is not suitable for the reaction with a large viscosity or a large amount of solid participation.