Nozzle including a venturi tube creating external cavitation collapse for atomization

A nozzle for atomizing a liquid received from a supply means in non-atomized form under pressure with a gas dissolved therein, said nozzle comprising means for forming a Venturi tube with a converging entrance cone for receiving the liquid from the supply means, a throat of a substantially constant transverse dimension "d.sub.n " that defines an included angle in the throat of substantially 0.degree. and that increases the velocity and reduces the static pressure of the liquid, and an exit cone for conveying liquid from said throat to an exit port, said exit cone being characterized by an included angle of divergence that, over at least a portion of the distance from said throat, increases from the included angle of said throat to a maximum angle as a function of the distance from the throat and, at any given position displaced from said throat, is greater than or equal to an included angle at any position intermediate said throat and the given position and by a length "1" of at least about d.sub.n wherein the supply means delivers the liquid to said throat under conditions that enable the formation of gas cavities in the liquid, wherein said exit cone maintains the static pressure of the liquid at a level that enables the gas cavities to expand in said exit cone, and wherein said throat and exit cone convey the liquid in a substantially disturbance-free flow whereby the liquid static pressure increases to a level that initiates gas cavity collapse only after the gas cavities leave said nozzle, the gas cavity collapse producing forces that atomize the liquid.