Abnormalities in control process parameters of the ammonia vaporization tower and reboiler
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The specific phenomena are as follows: 1. During the operation of the ammonia evaporation tower reboiler, the temperatures at the bottom and top of the tower do not meet the design requirements (actual temperatures: 78°C/94°C), and parameters such as ammonia and ammonia nitrogen volatilized from the wastewater remain above the specified limits for an extended period； 2. In order to ensure that parameters such as ammonia and ammonia nitrogen in the wastewater are within acceptable levels, and to bring the temperatures at the bottom and top of the ammonia evaporation tower to the design values, some steam is directed directly into the tower. As a result, the temperatures at the top and bottom of the tower rise to (93°C/104°C), and the pressures at these locations fluctuate significantly, making stable operation impossible. Frequent \"water spraying\" occurs at the top of the tower, and the ammonia gas does not meet the conditions necessary to proceed to the next processing stage (ammonia decomposition) ； 3. The temperature of the upper middle part of the reboiler (outer wall) was measured to be around 140°C using a thermometer; the temperature in the lower part was 40°C, while the temperature in the middle part was 80°C℃ ； The temperature of the pipe leading from the top of the reboiler to the ammonia vaporization tower (outer wall) is approximately 93℃ ； The reboiler is not functioning optimally ；
Try raising the tower liquid level a bit.
What is the tower pressure? Are the fluctuations severe?
The pressure at the bottom of the tower is around 25 Kpa, while the pressure at the top is around 10 Kpa. Currently, the temperature cannot be increased using indirect ammonia vaporization; when direct steam is used for ammonia vaporization, the pressure at the top exceeds 10 Kpa, prompting water to be injected for venting from the top of the tower. It is suspected that the reboiler is blocked；
Does the reboiler have a steam trap? Is the drain valve operating properly?
The water supply to the reboiler is normal; it seems that the heat source at the top of the reboiler isn’t being delivered there, so I suspect there is a blockage at the top of the reboiler
The temperature at the lower part of the reboiler is low; first, check the problems in the condensate pipeline, as a blockage is likely the cause
Confirm that the steam condensate flow is unobstructed; there are no indirect heating devices in the middle and lower parts of the reboiler, while heating devices are present in the middle and upper parts.
If the reboiler is blocked, there should be no heat exchange; with a functioning trap, the steam consumption won’t be high. You can use the steam consumption as a clue to diagnose the issue.
That’s right; very little steam is used. Upon disassembly, it was found that the internal tube bundles were severely clogged and difficult to clean, so we plan to have a professional team handle it. Thank you for your advice, friend.
Confirm that the steam condensate flow is unobstructed; there are no indirect heating devices in the middle and lower parts of the reboiler, while heating devices are present in the middle and upper parts.