Please, guys, help solve this problem

The absorption rate is only 98.5% – what kind of absorption process is this?

If the sulfur spray gun is clogged, consider two possible causes: 1. Insufficient insulation, which needs to be improved. 2. If there are mechanical impurities in the liquid sulfur or if the pipes are not clean, it is advisable to install a filter before the sulfur injection nozzle; the pore size of the filter screen should be at least smaller than that of the nozzle, and proper insulation for the filter must also be ensured.

Reply to 1# kzh0056: In terms of absorption efficiency, it is necessary to check the selected acid separator and mist eliminator; if these devices are not properly configured, acid mist will be carried along in the SO2 gas exiting the tower.

First of all, thank you to all the brothers above for their answers! 1. It seems that installing a filter before the sulfur gun won’t work; the outlet of the gun has a diameter of 3 mm, but the sulfur enters through three inclined openings (these openings are likely also 3 mm in diameter but are angled). The sulfur exits through one opening only. Adding a filter to the pipeline would create too much resistance. Our sulfur pump already operates at a high current level, which causes it to trip frequently; adding more resistance would likely lead to even more frequent tripping. For reference, our sulfur pump has a flow rate of 1.5 m3/h and a head of 80 m. The sulfur combustion furnace and the sulfur purification tank are roughly at the same level. Is there something wrong with the selection of this sulfur pump for my application? Why does it keep tripping? 2. The concentration of the concentrated sulfuric acid we use for absorbing sulfur trioxide is 93–96%. The temperature of the gas entering the tower is 26 degrees Celsius, while the temperature of the gas exiting the tower is 45 degrees Celsius. The temperature of the gas entering the tower is 165 degrees Celsius, and that of the gas exiting the tower is 55 degrees Celsius. The demister is made of glass fiber; it used to get clogged all the time, and we have already replaced it 3–4 times. This one is new. We produce sulfur dioxide by burning pure oxygen with sulfur, and then convert it into sodium bisulfite. The problem lies with the removal of sulfur trioxide, and it’s really annoying. I would appreciate it if you could give me some more advice. My QQ number is 57033248, and my email address is kzh_0056@163.com

Reply to 5# kzh0056 regarding the shutdown of the sulfur pump: Check the insulation vapor pressure of the pump; either too low or too high is not ideal. A value around 140 degrees should suffice. If it exceeds 159 degrees, the viscosity of liquid sulfur increases significantly, and the load on the pump also rises greatly； Furthermore, it may not be good if the gap between the impeller inside the pump casing and the casing itself is too small. I have seen cases where it was easy to turn the shaft by hand, but the pump would stop operating after just a few minutes of operation; yet it was still easy to turn the shaft by hand after it stopped, which is strange. Therefore, I believe this is due to an overly small gap, causing the liquid sulfur in that gap to heat up due to friction, which in turn increases its viscosity. For liquid sulfur filters, it is actually possible to use a tubular filter with a larger filtering area; the increase in resistance is minimal. What’s necessary is to design it as a jacketed type to ensure insulation. We didn’t have such filters before, and the rust and other impurities resulting from the corrosion of the liquid sulfur tanks would be drawn in by the liquid sulfur pump. The pump could not operate for long before its load had to be reduced. Later, we manufactured our own tubular filters, and since then the system hardly ever stops operating or has its load reduced due to clogs in the filters. It’s sufficient to clean the debris from the filters whenever there’s an opportunity to shut down the system.

Reply to 6# zpqing: Thank you for your reply. We plan to install a mesh cage made of 6mm stainless steel, with a length of 400mm, and cover it with a layer of 40-mesh filter screen at the inlet of the sulfur pump. The most critical issue at present is that we use 99.8% pure oxygen to burn sulfur; as a result, a large amount of sulfur trioxide is generated, estimated to be around 4-5%. Even after absorption using concentrated sulfuric acid (in a tubular acid separator), 1.5% of sulfur trioxide remains. What should we do? How can this problem be solved? I hope someone can add me on QQ at 57033248 so we can discuss this together. Thank you

In the blink of an eye! Hello! Could you add me on QQ at 57033248? There are some issues with the process in our company where sulfur is burned to produce sulfur dioxide. I’d like to discuss this with you; please add me on QQ and we can talk tonight, okay? Thank you in advance! ! !

The acid concentration used for absorption should be kept between 98.3% and 98.5%, which will allow for the effective absorption of sulfur trioxide, with an absorption rate of 99.95%.

Reply to 7# kzh0056: I’m not sure what your SO2 concentration is? If you control the burning temperature at a higher level, for example at 1100–1200°C at the outlet of the sulfur incineration furnace, then the concentration of SO3 will drop to around 0.5%–1%. This is a solution that kills three birds with one stone: the load on absorption is very low, and the production of SO2 is minimized. If we find another way to increase the absorption rate, the problem will be solved.