The smokeless liquid two-phase burner system of the present invention relates to a method and apparatus for burning a wide variety of flammable liquids using an integrated burner system. The system has both a primary injection path and an alternate injection path for the fuel to be burned, as well as a main air pump or blower. The present invention also provides a method and apparatus for selectably injecting a secondary stream of a gas or vapor or volatile liquid into a flare system for the purpose of enhancing combustion. The apparatus is self-contained and self erecting on a transportable trailer.