What are the requirements for the quality of water entering an MVR evaporator?
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I would like to ask fellow sea enthusiasts: what are the requirements for the quality of water entering an MVR evaporator, and in what situations is it not suitable for use? Thank you!
Based on what I’ve observed, here are my thoughts: 1. If viscous substances appear during the concentration process, they can cause blockages in tubes such as those used for falling film or forced convection, or they can prevent proper flow and result in poor heat exchange; therefore, processes where viscous substances are likely to form may not be suitable. 2. Water with a tendency to form scale may also not be suitable. 3. If there are complex salts in the solution, separate crystallization is generally required; otherwise, salt deposition on the walls of the crystallizer and other areas is likely to occur. 4. Solutions with large fluctuations in properties are not very suitable. Since I’m not an expert in MVR, what I say may not be correct. Most use methods that may not be applicable.
MVRs have the same water quality requirements as multi-effect evaporators; what was mentioned above are basically common issues with evaporators. As for point 4, MVRs actually have an advantage, as they are easier to adjust compared to multi-effect evaporators, whose adjustment is quite complicated
A temperature rise of around 25 degrees at the inlet and outlet of the steam compressor means that the increase in the boiling point for the evaporation, concentration, or crystallization of the material should not exceed 15 degrees； Theoretically, any level of temperature rise can be achieved through multi-stage compression, but power consumption will also increase; it is necessary to compare this with the actual operating costs of multi-effect or distillation towers. Secondly, it should be as close as possible to the requirements for multi-effect materials, such as COD, viscosity, etc