In many gas-liquid processes

the initial bubble size is determined by a series of operation parameters along with the sparger design and gas-liquid flow pattern. Bubble formation models for variant gas-liquid flow patterns have been developed based on force balance. The effects of the orientation of gas-liquid flow

gas velocity

liquid velocity and orifice diameter on the initial bubble size have been clarified. In ambient air-water system

the suitable gas-liquid flow pattern is important to obtain smaller bubbles under the low velocity liquid cross-flow conditions with stainless steel spargers. Among the four types of gas-liquid flow patterns discussed

the horizontal orifice in a vertically upward liquid flow produces the smallest initial bubbles. However the orientation effects of gas and liquid flow are found to be insignificant when liquid velocity is higher than 3.2 m·s

-1

or the orifice diameter is small enough.