Ultrasonic atomization standing wave

The experimental system for measuring the sonoluminescence spectrum of alkali-metal atom emission from an aqueous solution is similar to that for measuring the MBSL spectrum from water. Degassing the solution is an important procedure because the presence of dissolved air affects the emission intensity. In an air-saturated solution, no observation of alkali-metal atom emission has been reported, whereas continuum emission can be observed. A typical experimental apparatus using ultrasonic standing waves is shown in Fig. 13.3 [8]. The cylindrical sample container is made of stainless steel, and its size is 46 mm in diameter and 150 mm in... 

Ultrasonic atomization is sometimes also termed capillary-wave atomization. In its most common form, 142 a thin film of a molten metal is atomized by the vibrations of the surface on which it flows. Standing waves are induced in the thin film by an oscillator that vibrates vertically to the film surface at ultrasonic frequencies. The liquid metal film is broken up at the antinodes along the surface into fine droplets once the amplitude of the capillary wave exceeds a certain value. The most-frequent diameter of the droplets generated is approximately one fourth of the wavelength of the capillary wave,1 421 and thus decreases with increasing frequency. 

Figure 2.24. Ultrasonic standing wave atomization of melt. Top schematic. Bottom photograph. (Courtesy of Prof. Dr-Ing. Klaus Bauckhage at University of Bremen, Germany.)...

In ultrasonic standing wave atomization, increasing the amplitude of the sonotrodes and/or the gas pressure reduces the mass median diameter of the droplets generated.[143]... 

Ultrasonic nozzles are designed to specifically operate from a vibration energy source. In ultrasonic atomization, a liquid is subjected to a sufficiently high intensity of ultrasonic field that splits it into droplets, which are then ejected from the liquid-ultrasonic source interface into the surrounding air as a fine spray (Rajan and Pandit 2001). A number of basic ultrasonic atomizer types, like capillary wave, standing wave, bending wave, fountain, vibrating orifice, and whistle, etc., exist. 

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