EFFECT OF BURNER ANGLE AND EXCESS AIR RATIO ON DIRECT FLAME IMPINGEMENT HEATING

摘要

Direct Flame Impingement (DFI) is a form of rapid heating that could be applied extensively in the metal heating industry to significantly reduce heating times over conventional methods of heating. DFI involves firing an open flame directly onto a work-piece, and heating a specified location rather than heating an entire enclosure. The potential benefits of this method of heating include: 1. High thermal efficiency, as energy is only being added where it is needed. 2. High heating rates, resulting in fast part processing, i.e. high productivity. 3. Improved part quality due to less surface oxidation. However, some of the potential drawbacks to this technology include: 1. Increased grain growth due to high temperature exposure. 2. Temperature non-uniformity throughout the portion of the piece being heated. 3. Distortion due to high temperatures. The goal of this study was to investigate the effect of burner angle and excess air ratio on heating time and temperature uniformity of the portion of the part being heated.