The heat exchanger is damaged; how should the conversion temperature be controlled?
Thread Content
We use a 3+1 process; the heat exchanger tubes through which the sulfur dioxide drawn in passes have failed, resulting in very little flue gas reaching section four of the converter. The heat exchange efficiency is very poor, and the chimney emits a lot of smoke. At the same time, the conversion temperature was also abnormal: the inlet temperature in Stage 1 was very low, requiring the use of an electric furnace to maintain it, while the catalyst temperature was more than 20 degrees higher than normal. The inlet temperature in Stage 2 was about 10 degrees lower than before. The outlet temperature is too high. The inlet temperature at stage 3 is about 40 degrees higher than the normal value, while the inlet temperature at stage 4 is about 5 degrees higher than normal. Since the heat exchanger cannot be replaced immediately. To prevent the catalyst from being damaged, we currently use an electric furnace to maintain a certain temperature. If the temperature at the outlet of stage 2 is too high, or if the temperatures at the inlet and outlet of stage 3 are too high, we inform the purification team to open the air supply vents appropriately, so that the acid concentration remains under control. The chimney is still emitting a lot of smoke. How should such a situation be handled? How to control it can reduce the amount of smoke coming from the chimney.
Based on what you’ve described, the damage to the tubes of the heat exchanger is likely due to the presence of condensed acid (or acid foam) in the flue gas coming from inlet 1. Our factory has encountered this issue before; after installing new heat exchangers, we added an acid (foam) collector ahead of the heat exchanger inlet, and the result was excellent – no problems have arisen in 8 years. Sections 3 and 2 have higher temperatures than Section 1. Generally speaking, it might be due to a shift in temperature, but given the situation you described, since temperature control requires coordination with processes such as purification, it is likely not a case of a temperature shift. It is very possible that the catalyst in Section 1 is damaged, and it would be best to replace it. These are my personal opinions; please feel free to correct me.
It would be best to mention the temperature conditions in each section, the inlet and outlet pressures in each section, as well as the gas concentration, so that everyone can conduct a more reliable analysis. Based on the current situation, a shift in temperature does occur, but the cause remains unknown. Also, what is the current opening degree of each valve?
Replace the heat exchanger: simply remove the tubes from the old one, repair them, and install new ones.
When a heat exchanger is damaged, there is usually a spare one available; if temperature control becomes impossible, the equipment has to be replaced
It shouldn’t be just a problem with leaks in the heat exchanger; such leaks generally have little impact on temperature parameters. Unless the heat exchanger needs to be discarded, taking the opportunity to shut down the system and plug the leaks will resolve the issue. This post was last edited by zx9527007 on 2009-3-28 19:02.]
Is it during the two-way exchange that the SO3 produced at the second stage exchanges heat with the SO2 absorbed in the first stage? Please introduce the heat exchange process: