Abstract: A process and apparatus for the combustion of liquid fuel provides an extremely intense blue/violet flame having a temperature in excess of 3000.degree. F. with combustion under near perfect stoichiometric conditions without the formation of soot. The liquid fuel is atomized and mixed with air within a nozzle and enters a flame tube surrounding the nozzle as a conical stream where it is further atomized by jets of air directed to converge on the stream and mixed with secondary combustion air to obtain the desired combustion mixture. Yet further atomization of the liquid fuel-air mixtures within the flame tube can be obtained as a consequence of at least partial vaporization of the liquid fuel therein through the heat of the flame tube. An advantageous relationship exists between the size, angle and point of convergence of the air jets with the atomized conical stream, the flame tube diameter and length and the location of the nozzle therein and the fuel feed.