Method and apparatus for treating interior cylindrical surfaces and ablating surface material thereon

Abstract

A method and system for treating internal surface material overlying the interior of a tubular a substrate, and more particularly, to a system for ablating contaminates and other unwanted material from an internal surface using a pulsed laser beam ( ). The system includes three main sub-systems: a back end ( ), a work head ( ), and an umbilical tube ( ) to protect conduits communicating between the back end ( ) and the work head ( ). The back end ( ) includes heavy and bulky equipment such as a laser ( ), chiller ( ), pressurized air source ( ), suction system ( ), waste containment system ( ), and electric power source ( ). A conveyance such as a trailer ( ) may enclose the back end ( ) to make it transportable. The work head ( ) includes a propeller driven rotating mirror assembly ( ), and a lens assembly ( ). During operation, the work head ( ) is inserted in the tube or pipe and the laser ( ) activated. An air flow ( ) in the tube drives the propeller ( ) to rotate the mirror ( ). The mirror assembly ( ) in the work head ( ) distributes pulses from the laser beam in a circle ( ) described about the axis ( ) of the work head ( ) and directs them to the interior surface material. Ablated detritus is swept away and suctioned through a conduit attached to the tube behind the work head ( ) and thence to the waste containment system ( ) in the back end ( ). Electric power, laser energy, control and monitor signals, air, and suction are transported between the back end ( ) and the work head ( ) through the conduits encased within the umbilical tube ( ). The umbilical tube ( ) may be used to draw the work head ( ) out of the tube to clean the entire interior surface ( ).