Minature sludge lance apparatus
View Patent ↗A miniature sludge lance for a steam generator in a pressurized water nuclear reactor is provided. The sludge lance is structured to enter the steam generator via an inspection opening and has a body sufficiently thin to fit between adjacent tubes. The sludge lance rail has at least two types of nozzle assemblies that may be attached thereto. One nozzle assembly rotates and another nozzle assembly translates in a vertical direction. A drive assembly, a mounting assembly, an oscillation assembly, and flow straighteners are also provided.
1. An oscillator assembly for a for a sludge lance that is used in a steam generator, said steam generator having a shell defining an enclosed space, at least one primary fluid inlet port, at least one primary fluid outlet port, at least one secondary fluid inlet port, at least one secondary fluid outlet port, a plurality of substantially unifornily sized tubes extending between, and in fluid communication with, said at least one primary fluid inlet port and at least one primary fluid outlet port, said tubes disposed in a substantially regular pattern having substantially uniform, narrow gaps between at least some of adjacent tubes, said shell having at least one inspection opening disposed adjacent to said plurality of tubes, wherein said tubes in said plurality of tubes are arranged in rows and have a centerline and said tube centerlines in a given row are substantially uniformly spaced having a substantially uniform tube centerline distance between adjacent tubes, said sludge lance including a mounting assembly, a rail, a drive assembly and a nozzle assembly, said mounting assembly structured to support said drive assembly and said rail, said rail having an elongated body and a drive shaft, said rail body having a first end and a second end, said rail body sized to pass between adjacent tubes, said rail body defining a water passage and a drive shaft passage, said drive shaft rotatably disposed in said drive shaft passage, said rail body structured to be movably coupled to said drive assembly, said rail body having lateral sides, at least one rail body lateral side having a plurality of sprocket holes, said rail water passage structured to be coupled to, and in fluid communication with, a water supply, said drive assembly structured to move the rail through said inspection opening, said drive assembly coupled to said mounting assembly, said nozzle assembly having a body assembly, said nozzle assembly body assembly sized to pass between adjacent tubes, said nozzle assembly body assembly defining a water passage, said nozzle assembly body assembly structured to be coupled to the rail body with said nozzle assembly body assembly water passage being in fluid communication with said rail body water passage, said oscillator assembly comprising:
a housing assembly, a motor having an elongated output shaft and a gear assembly;
said oscillator assembly motor coupled to said oscillator assembly housing assembly;
said oscillator assembly gear assembly having a first gear and a second gear, said first and second gears being operatively coupled;
said first gear fixed to said oscillator assembly motor output shaft;
said second gear having a central opening;
said drive shaft having a second end extending from said rail;
said drive shaft second end disposed within and through said second gear central opening;
whereby said drive shaft moves axially through said second gear central opening;
said oscillator assembly motor structured to produce a cyclic motion; and
said oscillator assembly operatively coupled to said drive shaft whereby said drive shaft moves cyclically.
2. The oscillator assembly of claim 1 wherein said oscillator assembly gear assembly is a miter gear assembly.
3. The oscillator assembly of claim 1 wherein:
said nozzle assembly body is elongated and includes at least two lateral nozzles, said nozzles being in fluid communication with said nozzle body water passage; and
said at least two lateral nozzles are structured to move relative to said rail.
4. The oscillator assembly of claim 3 wherein:
said nozzle assembly body is coupled to said drive shaft; and
whereby movement of said drive shaft causes said nozzle body to move relative to said rail.
5. The oscillator assembly of claim 1 wherein the second end of said drive shaft is biased to move linearly, in one axial direction towards said rail body.
6. The oscillator assembly of claim 5 wherein the drive shaft moves axially, slidably through said second gear,
7. he oscillator assembly of claim 5 wherein said drive shaft second end is keyed.
8. The oscillator assembly of claim 1 wherein rotation of said second gear imparts linear motion to said drive shaft.