Experimental Investigation of Bubble Formation from a Nozzle and an Orifice. 1st report. Frequency of Bubble Formation for Upward Gas Injection.

Gas was injected into a bath vertically upward through a nozzle, an orifice, or a lance nozzle. The frequency of bubble formation at the exit of these injection devices was determined by counting the number of bubbles per second from visual images recorded using a high-speed video camera. The measurements were carried out under the condition that the effect of the gas chamber volume on the bubble formation was negligible. An empirical correlation of the bubble frequency was proposed as a function of gas flow rate, inner diameter of the nozzles and orifices, and the physical properties of gas and liquid. This correlation could estimate measured values of the frequency of bubble formation even for a high gas flow rate within a scatter of ±30% regardless of the injection devices.