High-temperature thermocouple comes back to life
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The high-temperature thermocouple in our vaporizer got damaged after being in use for some time; the DCS indicated a broken connection. However, it started to show readings again during the middle shift yesterday. The data displayed isn’t entirely accurate, but it still has some value as a reference. I wonder why this kind of phenomenon occurs; I hope experts can help solve it
It’s likely that the burned-out thermocouple wires have stuck together, forming another thermocouple；
I wonder if you have gone to the site to check the condition of the thermocouples? If it has been checked and indeed is broken, then it’s just as the person on the first floor said!!
1. It was never actually disconnected; the disconnection alarm was triggered for other reasons. 2. It was due to high temperatures, which caused the original wires to fuse together again (the temperature must have exceeded a certain limit at some point)
Due to the high furnace temperature, it is not possible to perform disassembly and inspection online, and therefore it is also impossible to check whether the high-temperature thermocouple is damaged online. Are there any other reasons?
Resurrection from death is superstition; thermocouples can’t do that either. I suspect that after some time the curve will drop sharply or show fluctuations
It’s possible that somewhere there’s a loose connection
By measuring the resistance value of the thermocouple, it is possible to determine whether the thermocouple wires have melted together after breaking; in such a case, the contact resistance will definitely be higher than that resulting from welding
A loose connection is the most likely cause; it’s possible that the terminals are not in good contact in certain areas, and then things improve again due to high temperatures or vibrations.