There has been an increased interest in high temperature air combustion provided by the current regenerative burners for many industrial processes. Initially, the interest was focused on processes in the steel industry; however, because of the high efficiency, low emissions and even heat distribution, this technology is envisioned for other industrial applications as well. To this end, a detailed characterization of the regenerative burner flame is required to understand the combustion performance and to develop the models used to simulate different industrial furnaces. The measurements discussed in this paper come from an ongoing project to compare conventional and regenerative burner flames and their application to different industrial processes. This paper describes the in-situ temperature, composition and radiative flux measurements taken in these flames.
The flames studied here are produced by a conventional low NOx burner with and without pre-heat and a self regenerative burner. The burners were operated at 200 kW with an excess oxygen of between 4 and 5%. The flame temperatures were measured with the laser-based CARS technique and suction pyrometer. The radiant flux at the wall was measured with a 2 pi and a narrow angle radiometer. A thermal load was applied to the combustion products with the intent of simulating an industrial process. The temperature measurements show that the regenerative flame has a lower mean temperature and an even distribution throughout the furnace. The fluctuating component of temperature is shown to be significantly smaller for the regenerative flame as compared to the conventional flames. The radiant properties of the flames are different as well. The regenerative flame is shown to have a slightly higher emissivity than does the conventional flame. The incident radiant flux from the regenerative flame is much higher than that of the conventional flame (with and without preheat).