Flame detectors issues

[jeem]

We have been facing issues with the flame detectors not detecting the flame and that's happening multiple times with our ethylene furnace. What could best be done to avoid such issues as it is repetitive?

[ivani1]

Are there any preliminary findings?

[jeem]

It was identified in all these time that there was presence of dust against which cleaning was required to be performed.
Now this issue, I am not sure how this could be preventively managed to avoid detection issues again.