An atomizing nozzle particularly suited for your use in compact combustion chambers. Successful combustion of liquid fuels having generally high viscosity and widely varying properties such as distillation temperatures, distillation rates and impurities, including "heavy" and waste oil. Improved combustion is accomplished through the use of viscosity control and improved fuel atomization. Use of a nozzle utilizing "shearing" of the fuel by an atomizing fluid stream which intersects the fuel at approximately right angles. Recombination of liquid fuel particles is prevented by the use of a controlled "exit orifice" in the burner nozzle. The nozzle also features continuous circulation of the fuel in the nozzle body which establishes orientation of impurities contained in the fuel relative to the exit orifice so that they are expelled through the orifice. Combustion of conventional distillate fuel oil such as API No. 1 and 2 is also provided.