Assessment of Eccentricity for Multiple Nonmetallic Pipes Using Microwave Sensing

Double pipes are employed in various industrial sectors, such as oil and gas, mining, and fluid transfer. Normally, the pipes are assumed to be concentric, however, environmental factors may cause misalignment of their axes and cause the so-called eccentricity. This may affect other important parameters, such as flow rate, and burst pressure. Yet, there are limited studies on techniques for detecting and estimating the eccentricity. In this article, for the first time, we propose techniques to detect and estimate eccentricity in double nonmetallic pipes using microwave sensing. For this purpose, we employ an array of antennas scanning the pipes along the azimuthal direction. Receiver antennas with similar angular separations with respect to a transmitter antenna and on the opposite sides of that are assumed to have similar responses when the transmitter is on the eccentricity axis. Using such receiver responses, we demonstrate the possibility to detecting the axis eccentricity as well as estimating the eccentricity value by constructing an inversion curve
a priori
. The proposed method is validated through simulation and experimental results.