Is exhaust smoke related to the fiber demister?
Thread Content
A few days ago, there were intermittent episodes of smoking from the exhaust gases generated in our plant’s sulfur-based acid production process; each episode lasted about 5 to 6 minutes, and it didn’t happen very often, only occasionally. When smoking occurred, it resembled smoke rings (according to some people), and the smoke was quite dense. Could this be related to the fiber demisters at the outlets of the first and second absorption towers? What could be the cause?
There are many reasons for smoking. Based on the situation described by the poster, I personally think: 1. Continuously sample and analyze moisture and acid mist levels； 2. Check and observe whether there are any issues with the acid absorption pump, as well as the condition of the acid distributor (flanges, amount of acid applied, etc.) ； 3. Check the liquid seal, the mist eliminator itself, flanges, etc., depending on the situation, to determine whether there are any conditions that could cause gas short circuits ； 4. Determine the indicators for one rotation and one absorption rate ； These are my personal opinions; I hope those with more expertise can point out any mistakes.
It is likely that the sulfur dioxide concentration in your exhaust gases is unstable and fluctuates greatly. These changes in concentration affect the conversion efficiency of the converter, which in turn leads to a decrease in the absorption rate. As a result, the levels of sulfur trioxide in the exhaust gases exceed the allowed limits, causing the exhaust to emit smoke. You can measure the sulfur dioxide concentration in the flue gas and adjust it accordingly. The above are purely personal opinions, for the original poster’s reference.
The acid pump and acid distribution device should be checked.
Fiber mist eliminators can remove acid mist particles of 5um or less, which means they can significantly reduce acid mist. However, the particle size of acid mist is very small, so it is impossible to rely on it to ensure no smoke is produced. We also need to look for problems in your production control metrics and equipment.
The last edit to this post was made by shen*rong2006 on 2009-9-3 at 07:54. In my opinion, it’s likely just a control issue; there would be no intermittent smoking if there was a problem with the equipment. Could it be a problem with the control of acid concentration? Perhaps uneven water addition to the circulation tank is causing uneven acid concentration? Personal opinion
It is possible to check for any issues with the acid absorption pump and whether the acid separation process is functioning properly. Additionally, excessive levels of sulfur trioxide in the exhaust gases can also cause the exhaust to emit smoke.
Thank you all for your valuable insights. As for the more common reasons for such issues, they can certainly be ruled out. Some managers suggested that it might be due to the degasser; I would like to ask if this is indeed a possible cause?
If it’s a problem with the demister, then there won’t be intermittent white smoke. Are there any significant fluctuations in the flue gas temperature entering the tower, the acid temperature entering the tower, and the acid flow rate?
The main thing to analyze is what is being emitted – acid mist, sulfur dioxide, sulfur trioxide, or something else. If smoking occurs intermittently, I think it’s due to system fluctuations; the possibility of a malfunction in the demister is low.
The connection to the demister is likely minimal; it could be due to uneven acid distribution within the tower or unstable flow rate of the circulation pump.