ENERGY EFFECTS IN BUBBLE NUCLEATION

The size and number of bubbles produced by the desorption of supersatu rated gases from water are shown to be a primary function of the energ y available for bubble formation in a flowing system; this energy is t hat not dissipated in turbulence and friction. The number of nucleatio n sites is greatly increased when certain impurities are present, part icularly surface-active agents. Low saturation pressures can produce v ery large numbers of very small bubbles when added energy is provided for discharge. High gas concentrations produce excess large bubbles wh ich pass up rapidly through the much slower rising bubble mass. A comb ination of low saturation pressure followed by higher pressure for flo w, such as by liquid pumping, results in bubble characteristics which can be controlled for applications.