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The Effect of a Flame Holder Shape Modification Toward the Diffusion Flame Stability Zone Shift

The flame stability limit, which was involving the critical flow condition, lift off and blow out, could be affected by the burner geometry in the combustion system installation. Consequently a flame holder should be put in, to hold the flame as big as possible on a stable condition. The flame holder itself, is a device to hold the flame, whereas the flame holder could disturb the air and fuel flow. The fluid flow will be disturbed if the forces work on the fluid flow will be interrupting their stability. The fluid flow blockage by the flame holder will generate vortex and this vortex will end up with a turbulence condition. This turbulence condition will shift the critical stability limit and will produce a perfect combustion. In this research a concentric jet flow burner was implemented and the fluid flow speed and air speed was variated. To achive a perfect result, it is necessary to visualize the flow pattern using a schlieren photograph system. A thermocouple was introduce to measure the flame temperature and to know the temperature distribution. It is recocnized that a flame holder could be able to increase the flame stability zone. The hollow shaft flame holder was the one who could increase the stability zone significantly, because this kind of flame holder could hold the flame excellently and no lift off take place. The flame temperature distribution increase. The temperature increase has the smallest range compare with the combustion using the other kind of flame holders.