Crystallizers and their various types

Crystallizers and their various types Crystallizer is nothing but a machine that works on the solid-liquid separation technique of forming solid crystals from a liquid solution, with the help of these crystallizers we convert waste water into solid crystals and clean water. Basically, a crystallizer eliminates various liquid wastes to create zero liquid discharge also known as ZLD.

This whole process of crystallization is divided into two parts which is primary nucleation and secondary nucleation. The first part also known as primary nucleation involves the growth of new crystals and the later part also known as secondary nucleation perpetuates growth and it is the main stage that causes mass production of crystals.

Crystallizers cooling This type of crystallizer works on crystallizers cooling method for converting liquid into crystals.

Crystallizers Cooling are mainly divided into two types:  

Vacuum Cooling Crystallizer Surface Cooling Crystallizer

Application This crystallizer is used for separation of Na₂SO₄, KCl, MgSO₄, Dextrose Monohydrate and Honey.

Crystallizers Evaporative

This type of crystallizer works on crystallizer evaporative process for converting liquid into crystals.

Crystallizers Evaporative are mainly divided into three Types: Type

Particle size Produced

Forced Circulation Crystallizer

0.2 – 0.8 mm

Draft Tube Baffle (DTB) Crystallizer

0.8 – 2.5 mm

OSLO Type Crystallizer

1.5 – 5.0 mm

Applications: Nacl, NH₄Cl, (NH₄)SO₄, Sucrose Waste water plants for chemicals / Pharmaceuticals Crystallizers Oslo Oslo type crystallizer is also called classified-suspension crystallizer. It is one of the oldest designs developed for the production of large, coarse crystals.

The basic design criteria are twofold:  

It provide help in DE supersaturation of the mother liquor by contact with the largest crystals present in the crystallization chamber It also help in keeping most of the crystals in suspension without contact by a stirring device, thus enabling the production of large crystals of narrow size distribution

Typical products are:     

(NH4)2 SO4 Na2SO4 AgNO3 hydrated mono sodium glutamate mono ammonium phosphate (MAP)

Crystallizers vacuum There are two types of vacuum crystallizers that can be used to crystallize the solution they are continuous and batch crystallizer. They uses condenser with a booster for maintaining a vacuum inside the crystallizer body. This vacuum support to generate a supersaturated solution when very low operating temperatures are required.

Typical products are: 

(NH4)2 SO4