Seeking help regarding the flame out issue in the acidic gas combustion furnace
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Guys, we have an H2S acidic gas wet-process acid production furnace that, when operating solely on acidic gas, both flame detectors light up for only a short while before going out completely； When natural gas and sour gas are burned simultaneously, both flame detectors are functioning properly. For flame detection, we are using the Durag D-LX101 model. Do those of you with field experience know what’s going on here? This problem has been bothering me for a long time, and we spent a lot of time trying to figure it out on site. Due to this issue, we suspected that the location of the burner’s flame detection device was incorrect; later, we changed the location of this device from the side to the front panel, but it still didn’t work. I’m seeking help!
To be honest, I’m not sure either, because we followed the same approach; we thought that if the position was incorrect, it might not be possible to detect anything, and also that the voltage used for monitoring wasn’t stable
It seems that infrared measurement is being used these days; indeed, it’s not very stable. For the two furnaces here, all four measurement points show half working and half not working (intermittently).
What type of flame detector are you using? Has the problem been resolved now?
What model is your flame detector? Generally, they are infrared, right?
Infrared detection – well, it was also verified many times at the beginning
Generally, both gas and oil combustion emit ultraviolet light, while coal combustion emits infrared light. I’m a bit surprised that an infrared flame detector can still detect it. However, this time, during our second round of rectification, we passed the inspection using ultraviolet and infrared dual-band flame detection; let’s take a look at the specifics of the rectification work
1. Check the flame, the alignment of the flame detector, the detection channel, and the lens； 2. Check/set the sensitivity, and adjust the detection lower limit of the flame detector ； According to the description, there is a signal at first and then it cuts off automatically; it seems that the threshold for the flame signal is set too high. Let’s see if there’s a way to adjust it.
What was the specific reason found?
It burns gas, so it’s relatively clean; both the channels and lenses are clean. The only thing that’s not certain is whether the flame detector can be aligned with the flame； The sensitivity of the flame detector has been set to its lowest value
The last edit to this post was made by fpiliuwei on 2020-5-14 at 15:02. Another possibility is that the detection principle of the Durag D-LX101 flame detector you are using involves detecting only the ultraviolet light generated by flame combustion; there isn’t enough ultraviolet light produced by the combustion of acidic gases, so the flame detector cannot detect it. In sulfur recovery burners, ultraviolet flame detectors are unable to detect effectively the flame generated by the combustion of acidic gases; the combustion of such gases does not produce enough ultraviolet light, and the limited amount of ultraviolet light available to the detector results in poor or absent flame detection signals ； Additional explanation regarding the shortcomings of infrared flame detectors: While flame detectors that detect infrared radiation can provide reliable flame detection signals for sulfur recovery burners, the refractory lining at high temperatures also emits infrared light, which can be detected by these infrared flame detectors. This affects the accurate detection of the flame, resulting in the appearance of a \"false flame.\" In cases where the flame has actually gone out, a flame detection signal may still be generated. The flame detector available on the market that can address all the above issues at the same time is the Duiker DFD2 flame detector. You can look for the relevant information on your own. I hope the above information is useful to you.