US Patent 7777977 Flame scanner collimator body

A flame scanner collimator, which monitors flames produced by a fossil fuel fired combustion chamber, includes: a substantially cylindrical collimator body defining a hollow portion; a first chamber connected to a second chamber, the first and second chambers defining the hollow portion, the second chamber having a larger diameter than the first chamber; and a plurality of slots each extending in substantially a same direction as a longitudinal axis defining the body. Each slot extends through the body to the first and second chambers to allow cooling/purge air flow therethrough.