Dispersive mixer designs

Figure 12.23 Various distributive and dispersive mixer designs. (From Fig. 2 of Ref. [46]).

It is seldom possible to specify an initial mixer design requirement for an absolute bubble size prediction, particularly if coalescence and dispersion are involved. However, if data are available on the actual system, then many of these correlations could be used to predict relative changes in drop size conditions with changes in fluid properties or impeller variables. 

Control of Precipitate Formation. The problem with the character of the precipitated HML proved to be easily resolved with the particular lignin under study. When the addition of the glacial acetic acid was carried out at temperatures only as high as 50 °C, the reaction product was granular and did not retain large quantities of water in a semisolid mass. However, this condition required a redispersion of the solid after the oxalic acid catalyst had been added. This could be accomplished with mixers designed to homogenize and disperse materials in liquids. 

Several basic designs of the internal batch-type mixers are available. The most popular are the laboratory mixers manufactured by, e.g., Brabender or Haake, and their homologues on the larger scale manufactured by, e.g., Banbury or Moriyama dispersion mixers. 

---