Freeze crystallization of sodium chloride

• Evaporation rate: 7.5 T/H
• Crystallizer: OSLO continuous freezing crystallizer
• Material: Sodium chloride
• Main material: TA2

The OSLO continuous freezing crystallizer and the batch crystallizer have significant differences in operation mode, efficiency, product characteristics, etc. The specific comparison is as follows:

1.Operating method 

Oslo Continuous Freezing Crystallizer 

Continuous operation: The raw materials are continuously fed in, while the crystalline products and mother liquor are continuously discharged, achieving stable production. By automatically adjusting parameters such as temperature, concentration, and flow rate, stable crystallization conditions are maintained. 

Intermittent crystallizer 

Batch operation, single-time feeding, one-time discharge after crystallization, requires repeated start-stop. Each batch can adjust parameters (such as cooling rate, stirring intensity), suitable for small-scale or multi-variety production. 

2. Crystal formation efficiency and energy consumption 

Oslo Continuous Crystallizer 

High efficiency, continuous heat and mass transfer, large output per unit time, relatively low energy consumption. Strong stability, more uniform crystal particle size distribution. 
Intermittent crystallizer 

The efficiency is relatively low. Each batch requires re-heating and re-cooling, and the energy consumption is high. The particle size control is limited: crystal growth is affected by batch condition fluctuations, and uneven particle size is prone to occur. 

3. Product Characteristics 

OSLO crystallizer 

Crystal quality is stable: Continuous classification ensures that large crystals are preferentially retained, while smaller crystals are returned to the growth zone. The purity is high, and the mother liquor is continuously separated, reducing the presence of impurities. 

Intermittent crystallizer 

Batch-to-batch variations and parameter fluctuations may result in inconsistent crystal morphology and purity. 

4. Equipment Structure and Cost 

Oslo Continuous Crystallizer 

The structure is complex, requiring a hierarchical design, a circulating pump, and a precise control system. The initial investment and maintenance requirements are high. Regular cleaning of deposits is necessary. It is suitable for long-term operation. 

Intermittent crystallizer 

The structure is simple, with a single-tank design, low cost, easy cleaning and process switching. However, the labor cost is high and frequent operations (such as feeding and discharging) are required. 

5. Application Scenarios 

The OSLO continuous crystallizer is used for large-scale production (such as urea, citric acid, and salt purification). It is suitable for fields with strict requirements on crystal size and purity (such as electronic-grade chemicals). 

The intermittent crystallizer is used for small-batch production of high-value-added products (such as raw materials for drugs, special dyes).