Abstract:
It is difficult to directly measure the viscosity of molten materials, such as glass, as it is being processed. Several ultrasonic techniques are being developed that will, hopefully, allow this measurement to be made in situ, or at least in-line. In the first technique, ultrasonic shear waves are generated at one end of a buffer rod with conventional piezoelectric transducers. The other end of the buffer rod is in contact with the molten liquid. The reflection coefficient of these shear waves is a function of the viscosity of the molten liquid. In the other technique, ultrasonic waves are generated directly in the molten liquid with a pulsed laser. They are detected with a laser interferometer after they travel some distance over the surface of the liquid. Since the attenuation of these waves is also a function of viscosity, this is also a valid technique for measuring viscosity. This technique has the added advantage of being totally noncontact. However, optical access is required and it is only applicable in those situations in which the surface of the glass is exposed, i.e., no cold cap. Experimental results will be presented and discussed as well as the application of these techniques to the vitrification of hazardous wastes.
(Ref. SXVIII-019-97)
Source: NDE of Ceramics '97 May 4-7, Symposium on Nondestructive Evaluation of Ceramics
at the American Ceramic Society 99th Annual Meeting, Cincinnati, Ohio.
Buying the Symposium Proceedings from the American Ceramic Society.
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