The ammonia nitrogen level in the water purified by acidic vapor stripping is above the standard
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In the single-tower pressurized side-stream extraction process, the ammonia nitrogen level at the bottom of the purification water tower is around 100; after cooling, this value rises to around 200. Since there are no leaks in the heat exchanger, what could be the cause?
Have you learned about the alkali injection process in sewage stripping units? This is certainly not a panacea, but it is one of the methods.
Common reasons for unqualified purified water: 1. Excessive feed load, too high concentration of raw materials, or presence of other components in the raw materials； 2. Inadequate operational adjustments, such as insufficient steam supply, excessive or insufficient extraction from side streams, and an inappropriate temperature distribution within the tower system ； 3. Tray detachment ； 4. Internal leakage in the heat exchanger ； 5. Analytical testing deviations.
At the bottom of the tower and after passing through the heat exchanger, the ammonia nitrogen levels are around 100, while the sulfide levels are around 80. After cooling via air cooling and water cooling, the ammonia nitrogen level rises to around 200, while the sulfide level remains unchanged. Are there any other reasons for leaks in the exhaust heat exchanger?
What is the optimal level of ammonia nitrogen?
Yes, if all other parameters (such as sulfides) are within the acceptable range and only the ammonia nitrogen level is too high, adding alkali is a good solution.
1. The ammonia content in the feed is too high, making it impossible to separate it. 2. The temperature at the bottom of the tower is too low, so ammonia does not vaporize and rise upward. 3. The amount of material taken out via the side stream is insufficient, resulting in a high ammonia concentration in the separated liquid. 4. It might be possible to add alkali to see if that helps.
The alkali slag injection continues, and scaling is quite severe at the bottom of the tower as well as in various heat exchangers. It’s certain that the ammonia nitrogen level in the effluent is high, but it shouldn’t increase after passing through the air-cooled and water-cooled units – what could be the reason?