Working Principle and Process Flow
The sodium sulfate double-effect evaporator operates in a two-stage evaporation process, starting with the pre-treatment of the sodium sulfate-containing solution to remove solid impurities and suspended particles. The solution is then passed through the first-effect evaporator, where it is heated with live steam to begin the evaporation process. The secondary steam produced in the first-effect evaporator is recycled and used as the heat source for the second-effect evaporator, continuing the concentration process.
Once the solution reaches the desired concentration, it enters a crystallizer, where sodium sulfate precipitates by controlling the temperature and pressure. The crystallized sodium sulfate is then separated via centrifugal forces, resulting in dry sodium sulfate crystals ready for use or sale.Key Features and Technical Parameters
Processing Capacity: Capable of handling up to 5 tons per hour (T/H) of sodium sulfate solution, depending on system design.
Evaporation Temperature: Single-effect evaporation typically operates at 80-90°C, while the second effect operates at a slightly lower temperature.
Vacuum Degree: Typically maintained between 0.02 and 0.06 MPa to ensure effective evaporation.
Crystallization Purity: The crystallized sodium sulfate can achieve a purity of over 97.5%, making it suitable for industrial applications like glass manufacturing.
Advantages of Sodium Sulfate Double-Effect Evaporators
Energy Efficiency: The double-effect system significantly reduces energy consumption by recycling the secondary steam produced during the first effect.
Rapid Processing: High processing capacity ensures fast treatment of high-concentration sodium sulfate solutions, making it ideal for large-scale operations.
Stable Operation: Designed for stable, continuous operation with simple maintenance requirements.
Resource Recovery: Enhances the recovery of sodium sulfate, reducing waste and supporting sustainable industrial practices.
Industrial Applications and Case Studies
Sodium sulfate double-effect evaporators are widely used in industries that produce or treat sodium sulfate, such as glass manufacturing and chemical processing. One notable case involved using a double-effect evaporator to treat wastewater containing sodium sulfate. The resulting sodium sulfate met industrial purity standards and was reused or sold, showcasing the system's ability to recover valuable resources from wastewater.
Material Selection and Durability
When choosing materials for the evaporator, factors such as corrosion resistance, temperature, and concentration levels must be considered. For sodium sulfate solutions, materials such as 316L stainless steel and duplex stainless steel (2205) are commonly used due to their resistance to corrosion in harsh chemical environments.
Conclusion
Sodium sulfate double-effect evaporators offer a rapid, energy-efficient solution for sodium sulfate crystallization and recovery. They are widely used in both sodium sulfate production and wastewater treatment, providing substantial cost savings while contributing to environmental sustainability by reducing waste and enhancing resource recovery. With their energy-saving advantages, stable performance, and rapid processing capabilities, these systems are an essential tool for industries seeking efficient and eco-friendly solutions.
