Analysis of scaling phenomenon in coking residual ammonia distillation tower

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As environmental protection policies have become increasingly strict in recent years. The requirements for the treatment of remaining ammonia are also increasing. However, in the past two years, many coking companies have discovered that ammonia evaporation towers that used to operate very stably have experienced problems such as reduced processing capacity, poor indicators, and increased maintenance frequency. The main reason for this problem is: The quality of the water entering the ammonia evaporation system has changed. In order to meet environmental protection requirements, water from many other sections has also been collected into the ammonia evaporation section for unified treatment. The remaining ammonia water itself has a lot of impurities. Coupled with this external water, during the distillation process after entering the ammonia evaporation tower, a large amount of sludge scaling is generated in an alkaline environment, which adheres to the inner wall of the tower, tray mass transfer parts, liquid receiving system and other parts, affecting the liquid phase channel and reducing the mass transfer efficiency. As a result, the above problems occurred. To solve this problem, I think we should start from the following aspects:: 1. Strengthen the oil removal work before remaining ammonia enters the tower. This can be achieved by adding oil removal devices, increasing the replacement of oil removal parts, flushing frequency, and using new and efficient oil removal equipment. 2. Optimize the structure of the ammonia evaporation tower body and tower internals to better adapt to normal operation under high-scale conditions. 3. Control the amount of alkali added and adjust the pH value in the tower (this must be combined with the water inlet requirements of the subsequent biochemical part).