Total Desalination of Brackish Water

Studies on three real brackish waters of different sources indicated that for the RO stage the optimum pressure will be between 40 and 50 bar. If modules of the spiral wound type are employed, for example ROGA 4160 HR, the Reynolds number, Re = h- ialva, at the inlet should be about 80. Although the 

The second stage of the hybrid-process is essentially a crystallization capable of crystallizing all solids dissolved in the feed resp. the brine of the RO stage. Parts of these substances tend to heavy scaling and, therefore, the choice of the crystallization equipment is limited. A proven solution is, of course, the agitated thin film evaporator. However, this type of equipment must lead to high specific treatment costs for two reasons  

Low treatment costs for the brine can only be expected if the heat transfer surfaces can be designed as tube bundles and if energy saving concepts like MSF, ME or VC can be applied. 

Promising crystallization processes like the seeding process and a modified MSF process, employing an inexpensive oil as heat carrier, are discussed in Reference 22. 

ATF Agitated Thin Film Evaporator VTE Vertical Tube Evaporator MSF Multi Stage Flash 

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Figure 6.27 Total desalination of brackish water by a combination of RO and crystallization.

Rautenbach, R. and Henne, K.-H., "Total Desalination of Brackish Water,"... 

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