Abstract
The phenomenon of flame merging is observed when two burners on which diffusion microflames are established approach parallel to each other. On this phenomenon, the way to predict the distance between burner axes that makes the flame-tops merged at various burner diameters and flowrates are discussed. It is found that the maximum distance that makes the flame-tops merged agrees with the flame width (maximum horizontal diameter of flame) before interaction. In other words, the flame-tops are found to be merged when the distance between burner axes is less or equal to the flame width.