Ultrasonic humidifiers are designed to meet requirement of pure humidity at low temperature for various industrial application cutting compressor cost to reduce air temperature.
A piezoelectric transducer immersed in a water bed, converts a high frequency, electronic signal into a high frequency mechanical oscillation. The water tries to follow the high frequency oscillation but cannot because of its comparative weight and mass inertia. 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 tiny (1-micron diameter) droplets break the surface tension of the water and are quickly dissipated into the air, taking vapor form and absorbed into the air stream.