Ultrasonic Principle of Operation
A piezoelectric transducer emersed in the water bed, converts a high frequency, electronic signal into a high frequency mechanical oscillation. As the oscillation speed is increased to a level where the water particles can no longer follow the oscillating surface, a momentary vacuum and strong compression occur, leading to the explosive formation of air bubbles (cavitation). At cavitation, broken capillary waves are generated and minute droplets break the surface tension of the water and are quickly dissipated into the air, taking vapor (1 micron diameter) form and absorbed into the airstream.
The operating principle of ultrasonic humidification
The principle of ultrasonic humidification is based on the superimposition of two effects:
1. Cavitation bubble implosion
The change in amplitude of the oscillator gives rise to powerful water hammers that release tiny cavitation bubbles. The implosion of the bubbles on the surface emits tiny water aerosols into the ambient air.
2. Capillary wave theory
The ultrasonic oscillators generate regularly formed Rayleigh surface waves in the water tank. Minute water aerosols are also emitted into the ambient air on the crests of these waves.
By superimposing these two effects, the use of ultrasonic humidifiers enables a homogeneous aerosol mist to be produced with minimal energy consumption!
