Multi-effect forced circulation evaporation

Working Principle The multi-effect forced circulation evaporator combines multi-effect evaporation and forced circulation technologies. By operating multiple evaporators in series, it utilizes the secondary steam generated in the previous effect as the heat source for the next effect, achieving a rapid and energy-efficient evaporation process. The specific working principle is as follows:

1. Material Flow and Heating: The raw material liquid is preheated by the preheater and then enters the first-effect evaporator. The forced circulation pump draws the material from the bottom of the evaporator and sends it to the heating chamber (shell or plate heat exchanger), where it is heated to boiling using live steam.

2. Multi-effect Evaporation Process: The secondary steam generated in the first effect enters the second effect as a heat source, the secondary steam generated in the second effect enters the third effect, and so on. The operating temperature and pressure of each effect decrease progressively, creating a progressive temperature difference.

3. Reuse of Secondary Steam: The secondary steam generated in the last effect enters the condenser and condenses into water. Some non-condensable gases are discharged by a vacuum pump to maintain the system's negative pressure. The condensate can be recycled for preheating raw materials or other uses, reducing energy consumption.

4. The function of forced circulation: High-speed circulation (2-3 m/s) flushes the heating tube walls, preventing scaling or crystallization of materials. This is especially suitable for high-viscosity, easily crystallizing solutions, enhancing the heat transfer coefficient and improving evaporation efficiency.

Structural Features: 

The multi-effect forced circulation evaporator consists of the following main components:

1. Evaporators for each effect: Includes heating and separation chambers, used for heating materials and separating vapor and liquid.

2. Condenser: Used to condense the secondary steam generated in the last effect and recover condensate.

3. Circulation pump: Provides forced circulation power for the material, ensuring high-speed flow within the heating tubes.

4. Inter-effect pump: Used to transport materials from one effect to the next.

5. Vacuum and drainage system: Maintains negative pressure in the system, discharging non-condensable gases and condensate.

6. Operating platform, electrical instrument control cabinet, valves, and piping: Used for equipment operation, control, and connection.

Advantages: 

The multi-effect forced circulation evaporator adopts multi-effect series and forced circulation technology, combining the significant advantages of rapid energy saving and stable operation. It significantly reduces energy consumption by reusing secondary steam; the forced circulation system effectively prevents scaling and clogging, improving heat transfer efficiency, and is suitable for the concentration of high-viscosity, easily crystallizing materials. The equipment has a compact structure, a high degree of automation, and excellent long-term economic performance, making it an ideal choice for evaporation processes in the chemical, pharmaceutical, and food industries.

Application Scenarios: 

Multi-effect forced circulation evaporators are widely used in the following fields:

1. Chemical Industry: For the concentration of salts such as ammonium sulfate and sodium chloride.

2. Food Industry: For the concentration of fruit juices, milk, etc.

3. Pharmaceutical Industry: For the concentration of antibiotics, plant extracts, etc.

4. Environmental Protection: For the zero-discharge treatment of high-salinity wastewater.