Using sound to measure furnace gas temps 1

[athomas236]

I was reading the other day that the time taken for sound to cross a furnace can be used be used to calculate the velocity of sound in the flue gas which can in turn be used to calculate the mean temperature across the "line of sight".

Does anyone have any experience with this method of temperature. If you have I would be please to hear about it about it compared with optical or radiation pyrometers.

athomas236

 

[davefitz]

These are called acoustic pyrometers, and were marketed about 10-15 yrs ago by Diamond Power. There are several EPRI papers that describe their use in automatically scheduling the use of furnace wallblowers or sootblowers. Also, see the Proceedings of the American Power conference circa 1990-1995.

Some poeple wanted to use them in lieu of furnace outlet thermoprobes.

They need to be calibrated to the actual gas molecular weight, which varies during startup vs full load ( or vs excess air ).