Abstract
Bubble formation phenomena in a two-phase gas/liquid system occur in many industries that involve boiling; such as desalination stations, nuclear reactors, chemical plants, and fluid piping transportation and processes. Bubble formation phenomena cause problems, such as a decrease in equipment efficiency, vibration, noise, and solid surface erosion. Applications of the acoustic emission (AE) technique for monitoring bubble formation and burst stages in boiling processes are marginal in terms of extension in comparison to other applications of the AE technique. The use of the AE technique in this experimental investigation covers the frequency range between 100 and 1000 kHz, showing that the AE sensor can detect acoustic emissions from an occurrence of bubble formation. Statistically, it was found that the best AE parameter indicator for bubble formation was AE-RMS (root mean square).
Highlights
Bubble formation and cavitation are common phenomena in many industrial processes that include gas–liquid systems or just liquid flow, such as manufacturing processes, which use gas or water jets that are blown into a liquid to provide energising processes, and in gas–liquid flows that commonly occur in chemical processing plants
This paper focuses on monitoring and diagnosis of bubble occurrence in boiling processes using acoustic emission (AE) technology and depends on previous analysis and its investigation
It was observed that AE parameters, such as AE-RMS and threshold levels, are sensitive, robust and reliable in the monitoring and detection of bubble activity and the movement towards the surface of the water
Summary
Bubble formation and cavitation are common phenomena in many industrial processes that include gas–liquid systems or just liquid flow, such as manufacturing processes, which use gas or water jets that are blown into a liquid to provide energising processes, and in gas–liquid flows that commonly occur in chemical processing plants. This paper starts with the definition of cavitation, which is followed by a general presentation of bubble occurrence phenomena, and of the acoustic techniques that are suitable for monitoring and detection of bubble formation at the early stages of the boiling processes. The AE technique has been used to diagnose the bubble formation process and monitor bubble departure from the heating surface of the boiler to the surface of the liquid container during pool boiling [13]. In another investigation, centring on twophase flows, Addali [14] found that the gas void fraction (GVF) can be determined by measurement of the acoustic emission. A thermocouple was fixed inside the pool boiling vessel 3 mm above the surface of the boiler heater
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
