Automated ultrasonic examination system for heat transfer tubes in a

Abstract

An automated ultrasonic examination system for heat transfer tubes in a boiler makes it possible to perform ultrsonic examination from inside of the heat transfer tubes without necessitating the removal of scale from the outer surfaces of the boiler tubes by polishing and without necessitating access to places where manual measurements are difficult or impossible to make. The system includes an insert tube adapted to be inserted into a cylindrical header to which one of the heat transfer tubes are connected, an insert tube moving device for moving the insert tube in the axial direction of the header and revolving it about its own axis, an ejection nozzle provided on the insert tube, a water pump for feeding pressurized water to the ejection nozzle, a cable adapted to be inserted from the ejection nozzle into the heat transfer tube as passed through the insert tube by the pressurized water fed from the water pump, a cable accommodation tank for accommodating the cable, a revolving submerged ultrasonic probe mounted at the tip end of the cable, and an ultrasonic examination unit for processing signals sent from the probe and displaying the results of examination. Preferably, a device for detecting a length of the cable inserted into the heat transfer tube is provided in the automated ultrasonic examination system.