Freeze-crystallization equipment

Working Principle 

Freeze crystallization equipment lowers the temperature of the solution, bringing it to a supersaturated state, thereby promoting solute crystallization. Its core principles include:

1. Cooling Surface Maintenance: Through a dynamic scraping mechanism, such as a scraper crystallizer, the crystal layer deposited on the inner wall of the crystallizer is continuously removed, avoiding the heat transfer efficiency reduction caused by scaling in traditional equipment.

2. Crystallization Control: As the material forms a supersaturated solution on the surface of the cooling jacket, the scraper removes the crystal layer while simultaneously promoting the separation of crystals from the mother liquor, achieving precise particle size control.

3. Low-Temperature Adaptability: Suitable for heat-sensitive substances or materials prone to freezing (such as sodium sulfate), preventing material decomposition through low-temperature operation from 0℃ to 30℃.

Equipment Types

1. Scraper Crystallizer: Through a dynamic scraper system and enhanced heat transfer design, the heat transfer coefficient is increased to 23 times that of traditional equipment, suitable for a variety of materials.

2. Vacuum Crystallizer: Low operating temperature (e.g., 15℃), high cooling power (e.g., 300kW), typically made of corrosion-resistant alloys.

3. Plate Heat Exchanger: In the freeze crystallization system, a plate heat exchanger is used, achieving a heat transfer coefficient of up to 3500 W/(m²·K), suitable for rapid heat exchange.

Equipment Features

1. Energy Saving and Rapid Operation: Through optimized refrigeration technology and a heat pump system, energy consumption is significantly reduced.

2. High Degree of Automation: Equipped with a PLC or DCS control system, achieving fully automatic operation and reducing manual intervention.

3. Strong Corrosion Resistance: Utilizing corrosion-resistant materials such as stainless steel and titanium, extending equipment lifespan.

4. High Crystallization Quality: Through precise control of the crystallization process, producing crystals with uniform particle size and high purity.

Application Scenarios

1. High-Salinity Wastewater Treatment: Such as treating high-salinity wastewater containing sodium chloride and sodium sulfate, achieving salt recovery and water resource reuse through freeze crystallization technology.

2. Chemical Product Production: Used for producing high-purity sodium sulfate, sodium chloride, and other chemical products.

3. Pharmaceutical Industry: Suitable for crystallizing temperature-sensitive drug components, protecting heat-sensitive components.

4. Environmental Protection: Used in zero-emission projects to treat and recover valuable components from wastewater.

Selection Recommendations: When selecting cryo-crystallization equipment, factors such as production scale, material characteristics, energy consumption requirements, and investment budget should be considered comprehensively. For example, for medium to large-scale projects, Qingdao Kangjinghui's equipment offers high cost-effectiveness and is suitable for scenarios with a processing capacity of ≥20 tons/day; for scenarios with high requirements for crystallization particle size control, Hebei Zhuopu's equipment offers flexible material selection and is suitable for sodium sulfate production.