METHOD AND SYSTEM FOR TORSIONAL WAVE INSPECTION OF HEAT EXCHANGER TUBES

摘要

The invention provides an improved method and device for inspecting heat
exchanger tubes (410) from within the tube inside diameter that overcomes the
shortcomings of the prior art. It adapts a guided-wave probe approach that
makes use of a torsional wave mode instead of a longitudinal wave node
disclosed in the prior art. The torsional wave mode (T) has many advantages
over the longitudinal wave mode (L) for detecting defects. When energized by
suitable instrumentation, the probe (400) is caused to generate a torsional
mode signal that is transmitted to the heat exchanger tube (410) from the
waveguide tube (460). When reflected signals from defects in the heat
exchanger tube (410) walls are returned to the inspection opening end of the
heat exchanger tube (410), the reflected defect signals are transmitted to the
probe waveguide tube (460) for amplification, detection and characterization
of the reflected signal.