Falling film crystallizer

Eig. 4. Falling-film crystallizer, semibatch. Tube length is 12.2 m tube diameter is 7.6 cm. 

Falling-film crystallization utilizes progressive freezing principles to purify melts and solutions. The technique established to practice the process is inherently cyclic. Figure 20-15 depicts the basic working concept. First a crystalline layer is formed by subcooling a liquid film on a vertical surface inside a tube. This coating is then... 

Commercial Equipment and Applications The falling-film crystallization process was invented by the MWB company in Switzerland. The process is now marketed by Sulzer Chemtech. Products successfully processed in the falling-film crystallizer are listed on Table 20-9. The falling-film crystallization process is available from the Chemtech Div. of Sulzer Canada Inc., 60 Worcester Rd., Rexdale, Ontario N9W 5X2 Canada. 

Sulzer A family of processes for separating or purifying organic chemicals by melt-crystallization without using solvents. Two systems are in use static crystallization and falling-film crystallization. The latter is proprietary to Sulzer Chemtec, Switzerland. 

Figure 7.10 Two Sulzer falling film crystallizers with 1000 tubes each and a 12m tube height under construction. (Courtesy of Sulzer Brothers, Inc.)...

Falling film crystallization, in which the liquid is circulated as a falling film over the crystal layer growing on the cooled wall. 

Falling film crystallization was developed by Sulzer Chemtech. Figure 2.3.5-7 shows a schematic of the process, which is characterized by three operating phases ... 

Figure 17.3 Flow diagram of a falling film crystallizer (Sulzer MWB process), (reproduced with permission from Sulzer Chemtech Ltd).

The purification procedures used for PMAA and PAA depend on the stereoregular forms [543]. With conventional polymers a variety of solvent/nonsolvent precipitation systems have been used for example, methanol/diethyl ether, water/hydrochloric acid, water/ butanone, ethanol/diethyl ether. Alternatively, the polymer is isolated by exhaustive dialysis, by freeze-drying [544] and by falling film crystallization [545]. 

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