Sodium chloride evaporation crystallization equipment

Working Principle 

Sodium chloride evaporation crystallization equipment primarily utilizes the principle of evaporation. It heats a sodium chloride-containing solution, causing the water to evaporate and thus crystallizing out sodium chloride. The equipment has an internal heating system that precisely controls the heating temperature and time to ensure sufficient evaporation of water in the solution while preventing excessive decomposition or burning of the sodium chloride. In addition, the equipment is equipped with a rapid condensation system to recover the heat energy generated during evaporation, reducing energy consumption and improving economic efficiency.

Equipment Types

• Multi-Effect Evaporation Crystallizer: This type uses multiple evaporators connected in series, utilizing the secondary steam from the previous effect as the heat source for the next effect, improving energy efficiency. A common type is the triple-effect evaporation crystallizer, which uses a multi-stage evaporation and crystallization process to gradually crystallize out sodium chloride from wastewater through continuous concentration.

• MVR Evaporation Crystallizer: This type utilizes mechanical vapor recompression technology to compress the secondary steam generated during evaporation, increasing its temperature and pressure, and then using it as a heat source, resulting in significant energy savings.

• Forced circulation evaporation crystallization equipment: Suitable for treating high-concentration sodium chloride wastewater. It improves evaporation efficiency by 30%-50% through a forced circulation pump, while reducing energy consumption by 40%-60%.

Process Flow: 

• Taking a triple-effect evaporator crystallizer as an example, the process flow includes:

• Co-current: The solution and steam flow in the same direction. The feed liquid is pumped into the first effect and automatically flows to the next effect based on the pressure difference between effects. The finished liquid is pumped out from the last effect.

• Counter-current: The feed liquid is pumped from the last effect to the previous effects sequentially. The finished liquid is discharged from the first effect, and the feed liquid flows in the opposite direction to the steam.

• Mixed-flow: A combination of co-current and counter-current processes, combining the advantages of both while avoiding their disadvantages. However, it is complex to operate and requires a high degree of automation.

• Parallel-flow: Each effect produces finished liquid, and crystals precipitate in each effect. Crystals can be separated in a timely manner. This is generally used for the evaporation of saturated solutions.

Equipment Features:

• Fast and Energy-Saving: The application of multi-effect evaporation and MVR technology significantly improves energy utilization efficiency and reduces energy consumption.

• High degree of automation: Equipped with a PLC or DCS control system, achieving fully automated operation, reducing manual intervention, and improving production efficiency.

• Strong corrosion resistance: Utilizing corrosion-resistant materials such as titanium and Hastelloy, extending equipment lifespan.

• High resource recovery rate: Sodium chloride crystal recovery rate ≥95%, purity ≥98%, achieving resource utilization.

Application scenarios: Sodium chloride evaporation crystallization equipment is widely used in chemical, pharmaceutical, and environmental protection industries, primarily for treating wastewater containing sodium chloride, achieving sodium chloride recovery and water resource reuse. For example, in high-salinity wastewater treatment, evaporation crystallization technology separates sodium chloride from the wastewater, reducing salinity and meeting environmental discharge standards.