MVR Evaporation Concentration System

Working Principle

1. Pretreatment Stage: Before entering the evaporator, the waste liquid usually needs to undergo pretreatment to remove large particulate impurities, adjust the pH value, or add additives to improve evaporation efficiency and crystal quality.

2. Evaporation and Concentration Process:

• Heating and Evaporation: The pretreated waste liquid is sent to the heating chamber of the evaporator. In the evaporator, the waste liquid is heated through heating tubes to generate secondary steam.

• Steam Compression: The secondary steam is introduced into the steam compressor. The compressor increases the pressure and temperature of the secondary steam through mechanical compression, increasing its thermal energy.

• Recycling: The compressed high-temperature, high-pressure steam is reintroduced into the heating chamber of the evaporator as a heat source to heat the waste liquid. This process realizes the latent heat recovery of the secondary steam, reducing the demand for external fresh steam.

3. Vapor-Liquid Separation and Crystallization:

• Vapor-Liquid Separation: In the evaporator, the heated waste liquid continues to evaporate, and the generated secondary steam is separated from the concentrate. The separated secondary steam enters the compressor for recompression, while the concentrate flows into the crystallization chamber.

• Crystallization: The concentrate is further concentrated in the crystallization chamber to form crystals.

4. Condensation and Resource Recovery: 

• Secondary steam is condensed and reused in the alkali treatment unit, reducing pure water consumption and achieving water conservation and emission reduction.

• Energy Saving Effect: Rapid Energy Saving: Compared to traditional multi-effect evaporators, MVR evaporators can save 30%-80% of energy; evaporating 1 ton of water requires only 1555 kWh of electricity.

• Environmental Protection and Emission Reduction: The MVR system does not generate new pollutants and can recover useful substances from wastewater, achieving resource reuse.

Equipment Structure: 

The MVR evaporation and concentration equipment mainly consists of the following components:

1. Evaporator: The main equipment, including a heater and a separator. Common evaporator types include falling film evaporators and forced circulation evaporators.

2. Compressor System: The core equipment, responsible for compressing the secondary steam to increase its temperature and pressure. Commonly used compressors include centrifugal and Roots compressors.

3. Preheater: Utilizes waste heat from condensate to preheat the raw material liquid, reducing energy consumption.

4. Vacuum System: Maintains the vacuum level of the entire system, extracting some non-condensable gases and gases introduced by the solution to achieve a stable evaporation state.

5. Control System: Enables automatic control of the entire system, including monitoring and adjusting parameters such as temperature, pressure, and flow rate. Modern control systems typically use PLC or DCS for management.

Application Scenarios: 

• MVR evaporation and concentration systems are widely used in the following fields:

• Chemical Industry: Used in the production of chemical raw materials such as sodium sulfate, sodium persulfate, and sodium chlorite; fragrance purification; industrial process water treatment; seawater desalination; and the concentration and crystallization of organic additives.

• Pharmaceutical Industry: Used for the concentration, purification, and crystallization of pharmaceuticals to ensure high purity and stability.

• Food Industry: Used for fruit juice concentration, milk concentration, and syrup concentration.

• Environmental Protection: Used in wastewater treatment and waste liquid concentration projects to achieve resource recycling and compliant wastewater discharge.

MVR evaporation and concentration systems are widely used in industrial production due to their advantages such as rapid energy saving, environmental protection and emission reduction, and ease of operation. They are especially suitable for occasions with high requirements for energy saving and environmental protection.