Sodium sulfate evaporation mvr forced circulation heat exchanger is seriously blocked
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Sodium sulfate MVR is very easy to block in the tube. It cannot be dissolved by rinsing with water, so it can only be blocked in the tube!
Choose a heat exchanger that is not wall-mounted and has a self-cleaning structure.
Sodium sulfate is relatively easy to make. Generally speaking, there will be no pipe blockage. Maybe the manufacturer's design is unreasonable, or your own parameter control is unreasonable.
The structure may be unreasonably designed. If the material boils and evaporates in the tube, the tube will dry out. Once the material is saturated with salt, it is very easy for salt to form on the tube wall. Another reason is that the material is impure and has many impurities. Sodium sulfate is a powdery crystal. Many impurities can easily cause salt to form on the tube wall, thus blocking the tube. If not cleaned in time, the tube will be blocked.
Our impurity content is not high, COD is about 300, and the strong circulating current rises quickly.
As the concentration increases, sodium sulfate crystals precipitate, and the specific gravity of the material increases. If the power of the strong circulation pump motor is small, the pump current will increase, and the motor will burn out in severe cases. Unfortunately, I encountered this once. Later, I added a frequency converter to control the speed. This has the disadvantage of limiting the flow rate. If the flow rate is small, there is also the risk of salt formation on the pipe wall.
Since ancient times, there are no MVRs that can evaporate without clogging the pipes. They can only be washed regularly, and they cannot be washed after a long time. In our environmental protection equipment department, those MVRs have cleaning systems. I heard that they are cleaned once a week when they are stopped.
Specially designed for high COD and high salt concentrates, it is not recommended to use mother liquor as it is easy to scale and reduce evaporation efficiency. New process, new technology. The mother liquor at the back end of the three-effect evaporator can be evaporated directly by the dryer, drying the liquid into a solid in one step.