CRYSTALLIZERS

Crystallizers are normally used to separate out crystalline salts such as Sodium chloride, Sodium sulphate, Ammonium sulphate etc.

There are two types of crystallizers that Pleiad designs – Evaporation-based and Cooling-based. In an evaporation-based crystallizer the liquid is concentrated by heating it to a level where it forms a super saturated solution. This solution is then let into a settler tank (Pre-thickener vessel) which is specially designed, and the residence time controlled, such that the salt progressively settles at the bottom and the solvent with dissolved salt stays at the top. This liquid is then passed through centrifugation where the salt is completely separated from the liquid.

Cooling Crystallization is the most energy efficient choice, when the solubility of the solute increases significantly with temperature. In a cooling-based crystallizer the liquid that is let into the settler tank (Pre-thickener vessel) is cooled down where the salt (such as sodium sulphate having very low solubility at low temperature) undergoes controlled nucleation. Thus, the salt settles at the bottom and the solvent with dissolved salt remains at the top of the tank. The liquid is then passed through centrifugation where the salt is completely separated from the liquid.

This process is very useful for plants where the salt output is in extremely large quantities, and especially for salt purification, which can be reused in the process or could be distributed in the market for other better purposes.

ADVANTAGE PLEIAD CYRSTALLIZERS

• Effective suspended solids management to bridge gap between pump & centrifuge
• Efficient settling tank (Pre-thickener vessel) design and residence time management to ensure optimal purity & separation
• Proper terminal velocities and settling calculations to ensure maximum separation
• Appropriate Centrate & Overflow (Mother Liquor) recycle and bleeding

APPLICATIONS:

1. Tannery    
2. Textile   
3. Speciality Chemicals   
4. Agro chemicals   
5. Pigments