Method for delivering a tool to the interior of a heat exchange tube

摘要

A delivery system for remotely driving an eddy current probe through the tubing of a heat exchanger. The system uses a flexible shaft and air pressure to move an inspection probe through the heat exchanger tubes. The flexible shaft initially drives the probe through a sealed conduit to deliver the probe to the tube end at which point a seal on the shaft near the probe head contacts the tube inner surface allowing a buildup of air pressure behind the seal, thus driving the probe through the tube.

主权项

1. A method of delivering a tool through a channel head plenum and into a heat transfer tube of a heat exchanger comprising the steps of:
inserting a delivery conduit into the channel head plenum of the heat exchanger, with one end of the delivery conduit in fluid communication with one end of the heat transfer tube and a second end of the delivery conduit outside of the channel head plenum; inserting the tool into the second end of the delivery conduit; inserting a flexible shaft into the second end of the delivery conduit in back of the tool so that the tool is between the flexible shaft and the heat transfer tube; pushing the flexible shaft and the tool through the delivery conduit and into the heat transfer tube; slidably sealing the flexible shaft around an inner circumference of an inner wall of the heat transfer tube with a first seal to form a substantially fluid tight seal while enabling the flexible shaft to move within the heat transfer tube; slidably sealing the flexible shaft to an interior wall of the delivery conduit with a second stationary seal so that an interior of the delivery conduit and the interior of the heat transfer tube between the first seal and the second seal becomes a substantially fluid tight chamber; and forcing a fluid into the one end of the heat transfer tube to move the tool through a portion of the interior of the heat transfer tube.