Geometry of Static Mixers

Static mixing devices usually consist of a combination of identical elements, stacked in series with each element turned ninety degrees relative to the next element. The first static mixer, the Multiflux mixer, was described by Sluijters [243]. This mixer developed at AKZO Corporation of the Netherlands splits the flow in rectangular converging and diverging channels see Fig. 7.136. 

Each element of the Multiflux mixer has two channels, as shown in Fig. 7.136. The channels start with a rectangular cross-section and then taper to a square cross-section in the middle of the element. From the square cross-section the channel 

The ISG mixer has four circular channels In each element, with material from the outside being led to the Inside and vice versa see Fig. 7.138. The flow through this mixer is not very streamlined and the individual channels are quite small, making this mixer unattractive for high-viscosity or thermally sensitive materials. 

The SMV mixer developed by the Swiss company Sulzer is made up of stacked corrugated plates with adjacent plates having opposite orientation. The length of one element is about one diameter usually several elements are placed in series with one element turned 90° relative to the element next to it. Because of the splitting and reorientation within one element, the mixing action is quite efficient. The mixer geometry and mixing action is shown in Fig. 7.139. This mixer is primarily used for low-viscosity fluids. 

The SMX mixer is manufactured and sold by Sulzer under license from Bayer. In fact, this mixer used to be called the BMK mixer, which stands for Bayer Kontinuier-lich Mischer (German for Bayer Continuous Mixer). It consists of crossed bars forming an approximately 45° angle with the axis of the pipe see Fig. 7.140. 

---