The working process of a falling film evaporator is a complex process involving multiple steps, with the main purpose of removing solvents from the solution through evaporation, thereby increasing the concentration of the solution. The following is a typical working process of a falling film evaporator, organized based on publicly available information:

      1. Preparation

      1. Testing material concentration: Before driving, it is necessary to first test the concentration of the material to be concentrated to ensure that it meets the evaporation requirements.

      2. Check the system status: Check the gas supply pressure and whether the condensate drain valve is open to drain the condensate in the system. At the same time, check whether the sealing of detachable connections (such as flanges, bolts, and joints) is intact, as well as the correct position of each valve switch.

      3. Check the cooling water of the equipment: Ensure that the cooling water supply to the mechanical seals of each effect material pump is normal to avoid equipment overheating and damage.

      2、 Driving process

      1. Open the valve and pump:

        Open the discharge valve and sequentially turn on the feed pump, circulation pump (if the system requires circulation operation), and discharge pump (if continuous production is used). Note that these pumps usually require a certain level of liquid before they can be turned on to avoid dry running damage.

        At the same time, open the reflux valve to establish circulation within the system, and close the discharge valve to avoid premature outflow of materials.

      2. Start the vacuum pump:

        When there is material flowing out of the reflux valve, start the vacuum pump to reduce the pressure inside the system and promote the evaporation process. First, close all exhaust valves, then start the vacuum pump until the desired vacuum level is reached.

      3. Introduce steam:

        When the system reaches a certain degree of vacuum, open the steam shut-off valve and introduce steam into the evaporator shell side. Steam heats the materials inside the system, causing them to start evaporating.

        As the evaporation process progresses, the temperature inside the separator gradually increases. When the separator temperature reaches the preset value (such as 60 degrees), start the steam compressor and gradually increase the compressor frequency according to the system pressure and current situation to maintain stable operation of the system.

      4. Adjust the feeding and discharging:

        During the evaporation process, it is necessary to adjust the feed and discharge rates in a timely manner according to the liquid level and evaporation rate in the system. For intermittent production, after the feeding is completed, the feeding valve and feeding pump are closed to achieve reflux evaporation until the material in the system reaches the target before discharging. For continuous production, the material balance and evaporation stability in the system are maintained by adjusting the opening of the feed control valve and the discharge control valve.

      3、 Parking and Cleaning

      1. Parking sequence:

        Close the steam valve and vacuum pump, stop heating and vacuuming operations.

        Cycle the material before concentration in the system for a period of time (such as about ten minutes) to replace the concentrated material.

        Stop the operation of the feed pump, circulation pump, and discharge pump in sequence.

        Stop the cooling water supply to each circulating pump.

      2. Cleaning equipment:

        Regularly clean the equipment to prevent scaling and contamination. When cleaning, appropriate cleaning agents (such as 2% NaOH solution) can be used to clean according to normal driving procedures, and the cleaning time is generally 3-4 hours. The length of the car washing cycle should be determined based on the viscosity of the material and the usage of the equipment.

      4、 Notes

      Throughout the entire workflow, it is necessary to regularly check whether the liquid level in each separator is too high to prevent material leakage.

      Regularly check whether the cooling water of each circulating pump is sufficient to avoid mechanical seal damage.

      Regularly check material concentration and steam pressure to ensure stable system operation.

      Avoid positive pressure in the system during the evaporation process to prevent safety accidents.

      The detailed execution of the above workflow and strict adherence to precautions can ensure the stable and efficient operation of the falling film evaporator and extend the service life of the equipment.