Boiler flow mixer

A vessel flow mixer is a continuously operated mixing vessel. Thanks to its special flow and agitator geometry, it produces an almost ideally mixed state. A homogeneous product is present in the mixing chamber at all times during the mixing process.

The identical components are continuously fed into the mixing vessel in the correct mass ratio. The product is fed in from above. At the same time, homogenised product is discharged at the bottom of the vessel via an adjustable discharge fitting. A high fill level in the vessel ensures that the mixing chamber is always completely filled and remains well mixed.

This mixing principle differs from that of a pipe mixer with plug flow. There, the principle of "first in - first out" applies and the residence time distribution is narrow. In the vessel flow mixer, on the other hand, the residence time distribution is wide. A product particle can remain in the vessel for a long time or be discharged quickly. This leads to macroscopically ideal mixing. This is not linked to the inlet and outlet flows.

The assumption of "ideal mixing" means that the composition of the mix in the boiler is identical to the discharge flow at all times. Newly introduced material flows only minimally disturb this state, as they are immediately surrounded and mixed by the total volume.

This modelling corresponds to the concept of the "Continuous Stirred Tank Reactor (CSTR)" in reaction technology. It is mathematically well described and allows flow and mixing processes to be scientifically modelled. Applications of this model to powders and bulk solids are common, especially in apparatus with intensive mixing tools.