Evaporation and Crystallization Plant

Product Description

Evaporation and Crystallization Plant
In the field of mass crystallization from solutions , we are expertise. We design and manufacture all basic types of crystallizers for the crystallization from solutions, such as the forced circulation (FC) evaporation crystallizer , the turbulence (DTB)  evaporation crystallizer, and the fluidized bed (OSLO)  evaporation crystallizer.

We are in a unique position to address the special needs of clients, depending on the required product crystal quality and size. In addition to the center piece of a crystallization system, the crystallizer, we offers clients the supply of optimized peripheral equipment, such as the preconcentration ( multiple effects, TVR, MVR) .

Type of Crystallizer:

1. Forced Circulation (FC) Crystallizer
The forced circulation (FC) crystallizer is the most common type of crystallizer in the industry. The average FC crystallizer evaporates solvent , thus increasing the supersaturation in the process liquor, and causing crystallization to occur. Most conventional FC units operate under vacuum, or a slight super atmospheric pressure. The FC consists of four basic components: the crystallizer vessel, which provides most of the volume dictated by the residence time requirements, the circulating pump, which provides the mixing energy, the heat exchanger, which supplies ernergy to the crystallizer ( in a typical evaporative crystallization operation), and the vacuum equipment, which handles the vapours generated in the crystallizer.

Slurry from the crystallizer vessel is circulated, in plug flow fashion, through the heat exchanger, and returned to the crystallizer vessel again, where its supersaturation is relieved by deposition of material on the crystals present in the slurry. The supersaturation is controlled so as to avoid spontaneous nucleation by sufficient circulation capacity. The evaporated solvent is conducted to the vacuum system, where it is condensed and removed.

The FC crystallizer is used for general, simple crystallization operations, where large crystal size is not a requirement. The FC design aim to protect the crystal size from reduction from the crystallizer environment, but has no features to aggressively increase the crystal size.
 

 

2. Turbulence (DTB) Crystallizer
The turbulence with draft tube and baffle (DTB) crystallizer is the typical modern type of crystallizer in the industry. This crystallizer has been named so because it provides for two discharge streams, one of slurry that contains the product crystals, and another, that is mother liquor (saturated solvent ) with a small amount of fines. The configuration of the crystallizer is such that it promotes crystal growth, and can generate crystals of a larger, average size than could be achieved in an FC. Most conventional turbulence crystallizers operate under vacuum, or at silght super atmospheric pressure.

The turbulence (DTB) crystallizer has been studied widely in crystallization theory, and can be modelled with accuracy. Its distinct zones of growth and clarified mother liquor make it possible to define in terms of kinetic parameters, and thus growth and nucleation rates can be determined. These features make the turbulence crystallizer very suitable to mathematical description, and thus subject to good operating control.

 

3. OSLO Crystallizer
OSLO crystallizer was invented by F. Jeremiassen, Oslo, Norway, in 1924, and it took the name of the city in which the design originated. It is also refered to as "fluid-bed-", and "Krystal-" type.

 

The primary advantage o f the OSLO crystallizer until today is the ability to grow crystals in the fluidize bed, which is not subject to mechenical circulation methods. As crystal in an OSLO unit will grow unhindered, to the size that its residence time in the fluid bed will allow. The result is that an OSLO crystallizer will grow the largest crystals. The slurry is removed from the crystallizer's fluidized bed and sent to typical centrifugation section. Clear liquor may also be purged from the crystallizer's clarification zone, if necessary.

Energy Efficiency of Evaporation Crystallization Plants:
The energy consumption of the system can be tailored to meet the customer's individual requirements by intelligent thermal configurations of the evaporation crystallization plant.

There are three basic possibilities to save energy:
Multiple-effect evaporation crystallization
TVR (Thermal vapour recompression) evaporation crystallization
MVR (Mechanical vapour recompression) evaporation crystallization

Application of one of these techniques will considerably decrease the energy consumption. Often it is feasible to combine two of these possibilites to minimise capital and operating costs. In highly sophisticated evaporation crystallization plants all three techniques may be applied.

Fields of application:
Sodium chloride , Ammonium nitrate, Ammonium sulphate, Sodium sulphate , citric acid , Threonine, Tryptophan, Sodium gluconate , Waste water with salt, Sea water desalinization ect.