Temperature fluctuations on catalytic wires

The phenomenon of localized temperature fluctuations on catalytic platinum wires, known in industry as "flickering" has been studied using a high resolution infra-red detector. Temperature fluctuations with peak-to-peak amplitudes as high as 300-50 0[degrees]C were observed for the butane oxidation reaction using this technique. It is shown that such fluctuations can have a definite influence on the rate of platinum loss during reaction. The effects of major variables such as time, mass velocity, reactant concentration, and wire diameter on the amplitude of the fluctuations were explored. Wire diameter was found to have the strongest influence. On the basis of the measured frequency spectra of the fluctuations, it was concluded that the effect of turbulence on the rates of heat and mass transfer is the most probable cause of the observed oscillations in temperature.