Experimental assessment of thermal radiation behavior emitted by solid porous material

Abstract

Porous media burners have been the focus of many studies due to the advantage in different applications in industry, which exhibit a directional emission of thermal radiation and low emission of pollutants. Indeed, these characteristics yields benefits regarding productivity by an environment friendly process. Thus, this work analyzes the behavior of radiation heat flux emitted by materials of different linear densities and porosities, varying the rate of air/fuel mixture and the flame power. In this way, was constructed an experimental setup that consists in a supply system of air/fuel, data acquisition, burner support for the radiation sensor, and the radiometer. This structure enables the displacement from 0°C to 90°C allowing the analysis of radiation in the area of a semisphere. The results shown that the silicon carbide has higher radiation efficiency than zirconia, due the higher thermal conductivity and emissivity. However, the silicon carbide degraded in one of the measurements. The ZrO2 media has proved challenging to stabilize for equivalence ratios below 0.6. Regarding the porosity, it is concluded that the higher the porosity, the greater the radiation efficiency, the expected result because there is a larger contact area for the reaction to occur within the pores.