ystral Whitepaper Innovation statt Tradition

4 “Stirring” or “Agitation” is of cruci- al importance in many areas of the process industry. Stirring is a neces- sity to mix different components with each other, or to prevent disintegrati- on, sedimentation or flotation of reci- pe components, in short, to achieve homogeneity and prevent separation. Agitation is also necessary to heat and cool the contents of the vessel and to equalize the temperature. Mel- ting, gassing, crystallizing, precipi- tating, and – up to a certain level - even dispersing and emulsifying, are also tasks for an agitator. For all the- se basic tasks, special emphasis is al- ways on homogeneous mixing of the vessel content. In the majority of cases, agitators are used for homogeneous mixing – the differences between traditi- onal agitators and innovative mi- xing technologies are significant here. There are also agitators that are to hinder homogeneous mixing in a tar- geted way. This is necessary for reac- tion columns in which an ingredient is added at the very top or a gas at the very bottom, which is then slow- ly distributed through the vessel, le- vel by level, with as long a residence time as possible in each individual lay- er. For this purpose, disc agitators or dissolver discs are used, which pro- duce a consistently tangential rather than axial flow. There are even agita- tors for segregation, degassing and phase separation. However, in the majority of cases, agitators are used for homogeneous mixing – and for this, the differences between traditional agitators used in various areas of the industry and innovative mixing technologies are immense. With state-of-the-art jet- streammixers, the process time com- pared to traditional agitators can be drastically reduced. Halving of the batch time with a more effective mixer alone Tab. 1 shows an example for a process sequence with the individual steps Mixing instead of stirring Traditional technologies in process engineering such as agitators and high speed dissolvers are not well suited as tools for homogeneous mixing, the differen- ces in effectiveness compared to innovative mixing technologies are significant. By using technologies from ystral, process times can be cut by up to 90% depending on the application. Fig. 1: Innovative mixing technologies enable enormous efficiency gains, for example in the production of paints and varnishes. Image: Wellnhofer Designs - stock.adobe.com Innovation beats Tradition – Mixing instead of stirring CONVENTIONAL AGITATOR | PROCESS TIME (MIN.) 20 10 30 10 20 20 40  10 20 45 45 45 45 Tab. 1: Process steps and times when using a conventional agitator. The total batch time is 360minutes, the effective stirring time is 250minutes (areas marked orange). Filling water Dosing components | Stirring Dissolving under Stirring Acid addition | Stirring Stirring until homogenous | pH adjustment Addition PAS under stirring Stirring until agglomerate free & fully hydrolyzed Caustic addition | Neutrali- zation under stirring Dosing active ingredients | Dosing color under stirring Stirring until homogenous Lab test Final Lab test | Release Viscosity & pH adjustment | Stirring