Claims
- 1. Apparatus for accurately determining position with respect to the vertical tubes of a nuclear steam generator wherein the tubes are disposed in an array of parallel rows and parallel columns, with the tubes in each column having their axes aligned in a common column plane and with a predetermined spacing between the tubes of adjacent columns, said apparatus comprising: a fluid lance nozzle having a fluid outlet orifice, transport means for moving said nozzle past the columns of tubes closely adjcent thereto in directions perpendicular to the column planes thereof, said orifice being disposed for discharging a stream of fluid parallel to the column planes, and eddy-current sensing means carried by said nozzle and having a sensing axis disposed parallel to the column planes, said sensing means being responsive to disposition of said sensing axis in a lancing position coplanar with one of the column planes for generating a predetermined output signal level, said orifice being disposed so that the fluid stream therefrom will pass between adjacent columns when said sensing axis is disposed in the lancing position thereof.
- 2. The apparatus of claim 1, wherein said sensing means is circularly cylindrical in shape with said sensing axis being the axis of the cylinder.
- 3. The apparatus of claim 1, and further including mounting means fixedly mounting said sensing means on the workpiece.
- 4. The apparatus of claim 1, wherein said sensing means is mounted on top of the workpiece.
- 5. The apparatus of claim 1, and further including control means coupled to said sensing means for providing operating power thereto and for receiving and displaying output signals therefrom.
- 6. The apparatus of claim 1, wherein said transport means moves said sensing means in a path alongside and parallel to the closest row of tubes, said output signal varying between a maximum amplitude when said sensing axis is coplanar with the column plane of one of the tubes in said closest row of tubes and a minimum amplitude when said sensing axis is midway between the column planes of two adjacent tubes in said closest row of tubes.
- 7. The apparatus of claim 6, wherein said output signal resulting from continuous movement of said sensing means along said path is a substantially sinusoidal signal.
- 8. The apparatus of claim 1, wherein said nozzle includes plural outlet orifices.
- 9. The apparatus of claim 8, wherein at least two of said orifices are respectively disposed on opposite sides of said sensing axis and discharge streams of fluid parallel to said axis and in the same direction.
- 10. The apparatus of claim 9, wherein said sensing axis lies in a sensing plane parallel to said column planes, one of said two nozzles being spaced from said sensing plane one-half the distance between the column planes of adjacent tubes in the closest row of tubes and the other of said two nozzles being spaced from said sensing plane a distance equal to an integral number of times the distance between the column planes of adjacent tubes in the closest row of tubes.
- 11. A fluid lance nozzle adapted to be moved among and accurately positioned with respect to the vertical tubes of a nuclear steam generator wherein the tubes are disposed in an array of parallel rows and parallel columns, with the tubes in each column having their axes aligned in a common column plane and with a predetermined spacing between the tubes of adjacent columns, said nozzle comprising: a tubular body having a fluid outlet orifice disposed for discharging a stream of fluid parallel to the column planes, a mounting plate carried by said body, a support bracket mounted on said mounting plate, an eddy-current sensor having a sensing axis, said sensor being supported by said support bracket in a mounted position with said sensing axis disposed parallel to the column planes, said sensor being responsive to disposition of said sensing axis in a lancing position coplanar with one of the column planes for generating a predetermined output signal level, said orifice being disposed so that the fluid stream therefrom will pass between adjacent columns when said sensing axis is disposed in the lancing position thereof.
- 12. The nozzle of claim 11, wherein said tubular body has a flattened portion thereon to which said mounting plate is attached.
- 13. The nozzle of claim 11, wherein said sensor is mounted on top of said tubular body.
- 14. The nozzle of claim 11, and further including spacer means of a non-magnetic electrically insulating material disposed between said sensor and said support bracket.
- 15. The nozzle of claim 11, wherein said support bracket comprises a generally cup-shaped member with a circularly cylindrical side wall having the axis thereof disposed at said sensing axis, said sensor being circularly cylindrical in shape and receivable in said support bracket coaxially therewith.
- 16. The nozzle of claim 15, and further including a generally cup-shaped spacer with a circularly cylindrical side wall disposed between said sensor and said support bracket in nested relationship therewith.
- 17. The nozzle of claim 16, wherein said sensor is fixedly secured to said spacer and said spacer is fixedly secured to said support bracket.
- 18. The nozzle of claim 11, wherein said tubular body has two fluid outlet orifices respectively disposed on opposite sides of said sensing axis and respectively discharging streams of fluid parallel to said sensing axis and in the same direction.
BACKGROUND OF THE INVENTION
This application is a continuation of application Ser. No. 06/576,678, filed Feb. 3, 1984 now abandoned.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
576678 |
Feb 1984 |
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