Excitation of a progressive wave in a lossy ultrasonic transmission line and an application to a powder-feeding device

This paper describes several excitation methods of a progressive wave in an ultrasonic lossy transmission line and its application to powder-feeding devices. The use of a lossy transmission line causes the reflected wave to reduce in magnitude. Therefore, the wave, transmitted from the driving source, becomes dominant in the line. That is, the progressive wave is generated, without attention to acoustical matching in the received end. A symmetric mode, an asymmetric mode and a rotating asymmetric mode were used for the progressive wave and an acrylic pipe was appropriated for the ultrasonic lossy line. Construction and characteristics of a trial device are shown. It was found that the device is useful for feeding and supplying a small amount of powder.