Bubble formation by water release in nozzle---II. Influence of various parameters on bubble size

摘要: Abstract Our aim was to study the parameters influencing size of bubbles formed by release water under pressure through a nozzle in dissolved air flotation process. The nozzles were simulated glass tubes with constriction (Reynolds tubes). A micro-cinematographic technique used visualize formed. We particularly interested influence physical parameter (the tube geometry) and some physical-chemical (connected surface energy composition water). Tube geometry plays key role: greater conical divergence angle, degree turbulence smaller obtained. On other hand, coalescence on walls hydrophobic leads formation macrobubbles. Surfactants ethanol encourage largest break up into microbubbles. Electrolytes, reducing electrostatic repulsion, favour bubble coalescence.