Oslo crystallizer

OSHA TLV toxicity standard, for organotin compounds, 24 831 Oslo crystalizer, 8 139 OSME method, 11 520-521 Osmitrol, 5 169... 

OSLO crystallizers because MSMPR crystallizers operate with much higher slurry densities and lower levels of supersaturation. Forced circulation and DTB crystallizers are examples of MSMPR crystallizers. An OSLO crystallizer operating at high slurry densities with the slurry circulated to the vaporizer will perform like an MSMPR crystallizer. 

The reactants can be mixed in the circulation piping of a forced-circulation-type crystallizer, or Oslo crystallizer (Figure... 

FIGURE 64.9 A fluidized-bed (FB) crystallizer (an Oslo crystallizer ). (Reprinted from Mersmann, A., Ed., Crystallization Technology Handbook, Marcel Dekker, New York, 1995. With permission.)... 

Forced-circulation crystallizer with controlled solution supersaturation and controlled crystal bed (Oslo crystallizer)... 

Figure 11.2 Types of crystallizers (a) FC crystallizer, (b) DTB crystallizer, and (c) Oslo crystallizer.

Whereas the FC-type crystallizer is designed to safely avoid spontaneous nucleation only, additional measures and tools are integrated in the larger DTB and Oslo crystallizers to make their retention time longer leading to coarser crystals. 

One disadvantage of fines removal is the associated deterioration in the uniformity (cf Figures 11.22-11.23) of crystal size distribution (see Section 11.2.5). For this reason, DTB and Oslo crystallizers (synonyms for fluidized bed crystallizers) very often incorporate elutriation legs, with which the product can be classified while being removed. For this there are special construction designs available with which incrustation fragments can also be captured separately, which as a result carmot enter the product path (Figure 11.9). 

Whereas the fines dissolving is a strong tool to correct the effects of secondary nucleation, attrition, and breakage toward larger particle diameters, it also has one negative effect on the steady-state operation of the DTB and Oslo crystallizers most of the time it is too strong. Unfortunately, its intensity is difficult to control. 

The best-known representative of the group of fluidized bed crystallizers is the Oslo crystallizer [7]. Today, there are two known versions (Figure 11.16). The original design was developed in the 1920s by a Arm called Krystal A/S in Oslo, which explains the name. This design is susceptible to malfunctions in the case of products that tend to produce incrustations, as falling crusts can block the annular gap at the entrance to the fluidized bed. In the case of the crystallization of sodium chloride. 

The only exception to this is the Oslo crystallizer, which due to the system properties can also be operated at higher suspension densities. It is not unusual for the mass balances, however, to show suspension densities that are below the limit of 15% by mass. This can be easily remedied by the installation of a dear liquor outlet (Figure 11.25). The suspension in the crystallizer is concentrated as a result. Figure 11.26 shows the opposite measure, which is necessary when the suspension density is too high. In this case, the suspension is diluted by returning mother liquor (centrifuged filtrate). 

The feed point of the concentrated brine is the receiver tank B (Figure 16.19). The only crystallizer fed from here is the Oslo crystallizer. While the concentrated brine in this receiver is still undersaturated, the Oslo crystallizer can be fed with crystal-free solution all the time - the absolute precondition for the granular production in the Oslo-type crystallizer. 

The Messo Oslo-type crystallizer reached runtimes of around 3 weeks between washouts without any disturbance from scaling. This was a breakthrough in the Oslo crystallizer history for salt crystallization and the approved consequence of the inversion of the internal recirculation. The process required about 11 t/h of heating steam and evaporated 34 t of water per houn... 

---