Thermal processing of closed shape workpieces
Systems and methods for heat treating closed shape workpieces are provided. In one example implementation, a method can include imparting relative motion of the closed shape workpiece such that the perimeter surface of the closed shape workpiece is moved relative to the lamp heat source from a first position where a first portion of the closed shape workpiece is presented to the lamp heat source to a second position where a second portion of the closed shape workpiece is presented to the lamp heat source. The method can include emitting lamp heat onto the perimeter surface of the closed shape workpiece from the lamp heat source during imparting of relative motion of the closed shape workpiece. The method can include implementing a flux control procedure during emitting of lamp heat onto the perimeter surface of the closed shape workpiece.
1 . A system for thermally treating a cylindrical workpiece, the system comprising:
a vessel configured to impart rotational motion for the cylindrical workpiece;
a lamp heat source operable to focus lamp heat onto a portion of a perimeter surface of the cylindrical workpiece;
a control system operable to:
control the vessel to initiate and ramp up the rotational motion of the cylindrical workpiece to a desired rotational speed;
ignite the lamp heat source after the desired rotational speed is achieved; and
control the vessel to move the perimeter surface of the cylindrical workpiece relative to the lamp heat source from a first position where a first portion of a perimeter surface of a the closed shape cylindrical workpiece is presented to the lamp heat source to a second position where a second portion of the perimeter surface of the closed shape cylindrical workpiece is presented to the lamp heat source, the second portion being located proximate to the first portion, at least 90 % of the perimeter surface of the closed shape cylindrical workpiece being located between the first portion and the second portion,
wherein the control system comprises a temperature sensor configured to measure a temperature of the perimeter surface of the cylindrical workpiece, the temperature sensor comprises a thermal radiometer positioned such that a field of view associated with the temperature sensor is directed to a portion of the cylindrical workpiece after it has rotated through light from the lamp heat source and such that the field of view does not include light from the lamp heat source.
2 . The system of claim 1 , wherein the control system is operable to implement a flux control procedure during emission of lamp heat onto the perimeter surface of the cylindrical workpiece to reduce overheating of the first portion of the cylindrical workpiece.
3 . The system of claim 1 , wherein the control system is configured to implement a flux control procedure based at least in part on data indicative of the temperature of the cylindrical workpiece.
4 . The system of claim 1 , wherein the system comprises one or more gas dispensers configured to provide a cooling gas to an outer surface of the cylindrical workpiece or one or more gas dispensers configured to provide a cooling gas to an inner surface of the cylindrical workpiece.
5 . The system of claim 1 , wherein the lamp heat source comprises:
an arc lamp; and
an elliptical reflector operable to focus light emitted from the arc lamp onto the perimeter surface of the closed shape cylindrical workpiece.
6 . The system of claim 1 , wherein the cylindrical workpiece is a metal pipe.
7 . The system of claim 1 , wherein a solid rod of thermally conductive material is located in the cylindrical workpiece.
8 . The system of claim 1 , wherein a fluid cooled pipe is located in the cylindrical workpiece.