A Study of Ultrasonic Radiation Dissipation in Powder Processing System.

A model of ultrasonic radiation damping was proposed to describe the dissipation of ultrasonic vibration energy in solid processing system on basis of vibration damping theory. Four kinds of polyethylene particles with a diameter from 0.15mm to 0.85mm and bulk densities from 499.6 kg·m-3 to 252.5 kg·m-3 accordingly, were used as powder material and filled in a plexiglas storage bin. Ultrasonic energies absorbed by these kinds of particles were detected by the receiver at different levels. The results showed that the longer distance between receiver and source of ultrasonic vibration and higher bulk density of powder material would lead to higher energy absorption. It was also found that the dissipation of ultrasonic vibration energy along a bar of object as the internals was much higher than that along the wall of storage bin because of more radiation area from the object. The experimental result can be predicted by the radiation damping model proposed in fairly good accuracy. Furthermore a method of level gauging could be developed to meet the requirement of many applications, for instance, an online measurement of particle material and replace other level gauging methods such as γ-ray. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]