Leak Detection for Cooling Water tubes of Steam Condenser

概要

論文の詳細を見る
A small experimental apparatus with three 2.5 cm ψ(inner diameter 2.0 cm) tubes was a model of steam condenser. A tube led atmospheric pressure had a 1.0 mm ψ tiny hole and inside of the shell was kept lower than atmospheric pressure. Air was sucked into the shell through a tiny hole generating aerodynamic turbulence and friction with a broad spectrum of sound which associated strong ultrasonic components. Noise spectra obtained from this experiment were significant enough to see the difference between a tube with a hole and a tube with no holes. A bimorph type transducer of 40KH ultrasonic probe was also very effective to detect ultrasonic noise from a hole. A bimorph type transducer, a little smaller diameter than a tube's, was inserted to the other end of tube in advance to avoid picking sounds from its back. When the probe was slowly pulled out and it came upon a hole, it scanned 40KH of ultrasonic noise. The probe was blank to other frequencies except 40KH and a sudden build-up of 40KH ultrasonic signal on oscilloscope indicated the existence of the hole. These methods of leak detection for tubes will be very effective and available in ships and other industrial fields.
鳥羽商船高等専門学校の論文