Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2018-2019).

In the pyrometallurgical industry, smelting vessels are subjected to extreme heat stress, as well as chemical andx000D
abrasive reactions. The lining of the vessels suffer from severe degradation over time. Early detection ofx000D
degradation in the refractory lining is essential to avoid sudden vessel failures and to prevent unscheduledx000D
shutdowns. The acoustic ultrasonic-echo (AU-E) technique is widely used to detect the refractory degradationx000D
and remaining thickness of smelting vessels. This technique uses a piezoelectric transducer (PZT) for manualx000D
impact detection of the signal reflected from the shell of the vessels, in order to determine the remainingx000D
thickness of the refractory lining. These reflections are caused by local changes of material properties such asx000D
voids or interfaces between different materials. The reflected waves are analyzed in both the time andx000D
frequency domains to determine the condition of the vessels. However, the PZT detection system has lowx000D
sensitivity with single frequency ability, thus requiring manual impact with multiple PZTs to cover variousx000D
frequency ranges. This represents the company-specific problem.x000D
The primary objective of this project is to design broadband acoustic sensors with a flat response over a broadx000D
frequency range, that operate at temperatures >300°C. Following the successful design of the flat-responsex000D
broadband acoustic sensor, we will explore the option of high-temperature fiber coating for high acousticx000D
response. In collaboration with Hatch Ltd., we will then develop a transmitter and receiver for ultrasonicx000D
signals, capable of generating and receiving a frequency sweep pulse (chirp) in the 1 kHz - 250 kHz range (ax000D
standard non-destructive testing (NDT) acoustic generator). The joint transmitter and receiver unit will detectx000D
the weak receiver signal at minimal loss. This innovative research will lead to promising applications inx000D
acoustic sensing instrumentation and NDT detection.