There is a wall-opposed flame monitor detecting coal, oil and gas combustion in the burners, attached to the furnace walls in a coal-fired power plant.
I'm looking for suggestions to clear the dust or particulates from the lens, as it is affecting the signal and leads to tripping.
Right now, it is cleaned by supplying purged air from the core air fan. However, this has been found to not be effective as the contaminants still exist.
What would be the cause of such an ineffective system? Could the purge air system be improved by using higher pressure air from other components?