Converter Three stages No conversion
Thread Content
Production of acid from 100,000 tons of pyrite, with two rotations and two absorptions, a 3+2 converter, and temperature recovery through three stages without conversion. I hope members will engage in active discussions. Thank you!
1. First, check what the overall conversion rate is. The temperature differences among the three stages are not significant originally. If the overall conversion rate is fine, it’s best to verify the temperature display readings; if there is a large difference between them, check whether this is caused by an error at the inlet of stage 1 (an abnormally high inlet temperature for stage 1). 2. Second, take another look at the gas concentration to see if it is caused by an excessively low level of gas concentration. 3. It would be best to provide the temperature and pressure at each stage, so that everyone can use this information to answer.
The overall conversion rate is approximately 98.5%, with a gas concentration of about 8.5%. Section Import Temperature °C Export Temperature Import Pressure Kpa Export Pressure 1 420 586 16.3 15.5 2 468 503 14.5 14.1 3 448 442 12.9 11.6 4 421 436 5.7 5.5 5 417 419 5.3 4.6
Judging from the temperature rises in the other sections, the conversion rate at the outlet of section 2 will not exceed 90%; therefore, section 3 must have a certain conversion rate, otherwise the overall conversion rate will not reach 98.5%. Check the thermocouples and insulation.
I suggest you measure the gas concentration again to confirm whether it is indeed 8.5%. If so, it may be necessary to check the vanadium content in the catalyst during a major overhaul.
I think we should check the temperature measurement again, as all the other sections are normal.
The inlet temperature at the second layer is high; how many temperature points are there on the same level of the bed?
The temperature was also lowered to two degrees before, but it didn’t work. Design four, two for entry and two for exit.
It’s similar to my situation: there is basically inversion in the three stages, and absorption is required in those three stages. The concentration of sulfur trioxide is high, so it’s necessary to control its decomposition into sulfur dioxide; therefore, temperature control needs to be taken into consideration. The specific reason is still under consideration; it might be a problem with the double-track design. Your binary value is a bit high; based on the maximum temperature difference method, your conversion rate should be less than 98.5%
If nothing else works, increase the inlet temperature by 200°C and heat it for 4 hours (under high heat), then gradually reduce it back to the original value and give it a try.
After checking your temperature, I think your three-stage catalyst has not reached its ignition temperature; if that’s the case, check the bypass valve