Judgment of leakage of two-inlet and two-outlet packing in ammonia synthesis tower and leakage of thermal exchange packing
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The synthesis system has been a little abnormal recently. It is suspected that the two inlets and two outlets of the synthesis tower or the hot exchange packing are leaking. However, the system only has a sampling point for the second outlet, and there are no sampling points for the hot and cold air inlet and outlet of the heat exchange. Dear friends, please analyze what are the similarities and differences in the impact of these two packing leaks on the system. Can you determine where the leak occurs without a sampling point? This post was last posted by * Edited by aoye613 on 2009-3-7 18:11 ]
The same thing between the two is that the net ammonia value of the system is reduced, but the difference is that the net ammonia value of the synthesis tower is different. the difference: The leakage can be determined based on the temperature rise of the bed of the synthesis tower. If the net ammonia value of the system is 12, the net temperature rise of the synthesis tower is approximately 12 * 14.5~15.0, it means heat exchange leakage, otherwise it is a synthesis tower.
Can we still collect sample gas from the vent valve behind the tower and the water cooler vent valve for ammonia content comparison? If we do not do ammonia content analysis, the problem can be clearly seen from the temperature. If the packing between the second inlet and the second outlet leaks, it means that part of the second inlet (higher pressure) gas does not enter the synthesis tower and directly comes out of the second outlet pipeline. In this way, the temperature of the second outlet will drop, because the temperature of the second inlet gas is much lower than that of the second outlet gas. Similarly, if the cold and heat exchanger leaks, the water cooling temperature will drop.
1. There should be a pressure gauge or differential pressure gauge on site, and you can also take samples. Is the ammonia content at the second outlet sampling point significantly reduced? If so, it indicates that the synthesis tower may be leaking. ； If it doesn't or even rises, the heat exchanger may be leaking. 2. As mentioned above, judge from the temperature. It is necessary to compare the previous production conditions and valve adjustment conditions. 3. Judge based on the situation when the load changes. Under low load and stable conditions, if the circulation volume is suddenly increased, the leakage will increase due to the increase in pressure difference. Judging based on the temperature changes mentioned above, if the water cooling inlet temperature does not rise or fall, it means that the heat exchanger may leak, otherwise it may be a leak in the synthesis tower.
The method proposed by everyone is very effective. Two days ago, we stopped the car and inspected the synthetic heat exchanger. We found that all the fillers in the upper part of the heat exchanger had been taken away by the air flow, and a large number of two-phase gases were short-circuited. Although the synthesis temperature was still normal, the circulation volume increased significantly compared with before, and the pressure also increased to a certain extent. Thanks again! !