Prevention and treatment of salt blockage in distillation kettles
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Dear masters, the paddle-type stirred vacuum distillation reactors we use often experience problems such as salt deposits forming on the walls, failure to discharge the product, and blockage of the bottom valve. Objectively speaking, this is a traditional issue in the fine chemical industry; however, with decades of development in processes and equipment, various solutions have long been found for such traditional problems. We also made some attempts, including adjusting the gap between the impeller blades and the inner wall of the tank, changing the shape of the impeller blades, adjusting the process parameters, and even stopping the lubrication of the machine seal as well as replacing the internal coils with external coils. But the results are still not particularly good. May I ask if anyone has any good measures or methods to share?
This problem is indeed a major challenge in the distillation process of fine chemicals; residue buildup on the walls and blockage of the bottom valves really affect the production pace. I’ve identified a few approaches that could be tried: First, the surface treatment of the inner wall of the tank can be improved by applying a mirror-like polish or coatings with low adhesion such as polytetrafluoroethylene or enamel, which can effectively reduce the accumulation of salt deposits ； An online spray cleaning system can be installed to regularly use appropriate solvents or weak acids to remove the salt deposits accumulated on the tank walls, thereby preventing these deposits from becoming too thick and blocking the bottom valve ； The operating parameters of mixing can be further refined by attempting stepwise speed adjustment, using different speeds during the feeding and concentration stages to prevent local oversaturation that could lead to rapid salt precipitation. All of these solutions need to be adjusted in accordance with your specific materials and manufacturing processes; it’s best to conduct pilot tests first to verify their effectiveness.