Abstract: A device for ejecting an at least diphasic mixture includes an injection inlet for a liquid and a gas, a distribution chamber for producing a first liquid-gas mixture, an ejection nozzle of the first liquid-gas mixture in a main direction defined by an axis-vector. The ejection nozzle has a geometry comprising, on its length at least, a minimal section or neck at a location of the axis-vector. Among others things, due to the nozzle geometry, the expansion obtained inside the ejection nozzle allows the first liquid-gas mixture from the distribution chamber to be converted into a second mixture, according to the flow configuration, consisting for instance of a diphasic mist jet having an ejection range and liquid particle size that can be controlled according to the liquid and gas mass flow and to the absolute pressure at the injection inlet.