Sludge lance for cleaning a steam generator

Abstract

A sludge lance system for cleaning a tube bundle of a steam generator is disclosed. The sludge lance system comprises a mount, an index drive, and a sludge lance comprising a longitudinal rail, a manifold, an oscillator assembly, and a distal head. The oscillator assembly comprises a rotary output shaft. The distal head comprises a body portion, a first nozzle body on a first side of the distal head, and a second nozzle body on a second side of the distal head opposite the first side. The first nozzle body is rotatable relative to the body portion about a first longitudinal axis in a first direction in response to a rotation of the rotary output shaft. The second nozzle body is rotatable relative to the body portion about a second longitudinal axis in a second direction opposite the first direction in response to the rotation of the rotary output shaft.

What is claimed is: 
     
         1 . A sludge lance system for cleaning a tube bundle of a steam generator, wherein the steam generator comprises at least one hand hole opening which provides access to an elongate central tube lane within the tube bundle, wherein the elongate central tube lane defines a longitudinal axis, wherein said sludge lance system comprises:
 a mount positioned outside the steam generator;   an index drive supported by the mount; and   a sludge lance movable along the longitudinal axis of the elongate central tube lane by the index drive, wherein the sludge lance comprises:
 a proximal end; 
 a distal end; 
 a longitudinal rail; 
 a manifold extending proximally from the longitudinal rail; 
 an oscillator assembly extending from the manifold, wherein the oscillator assembly comprises a rotary output shaft; and 
 a distal head extending distally from the longitudinal rail, wherein the distal head comprises:
 a body portion; 
 a first nozzle body positioned on a first lateral side of the body portion, wherein the first nozzle body comprises a first plurality of nozzles, and wherein the first nozzle body is rotatable relative to the body portion about a first longitudinal axis in a first direction in response to a rotation of the rotary output shaft of the oscillator assembly; and 
 a second nozzle body positioned on a second lateral side of the body portion opposite the first lateral side, wherein the second nozzle body comprise a second plurality of nozzles, wherein the second nozzle body is rotatable relative to the body portion about a second longitudinal axis in a second direction in response to the rotation of the rotary output shaft of the oscillator assembly, and wherein the second direction is opposite the first direction. 
 
   
     
     
         2 . The sludge lance system of  claim 1 , wherein each of the plurality of first nozzles are to emit fluid along a first flow path, wherein each of the plurality of second nozzles are to emit fluid along a second flow path, and wherein the first flow paths and the second flow paths are mirrored about a central vertical plane of the distal head. 
     
     
         3 . The sludge lance system of  claim 2 , wherein rotation of the first nozzle body and the second nozzle body is synchronized to maintain the first flow paths and the second flow paths mirrored about the central vertical plane. 
     
     
         4 . The sludge lance system of  claim 1 , wherein the sludge lance is solely supported by the mount and the index drive. 
     
     
         5 . The sludge lance system of  claim 1 , wherein the sludge lance is a cantilever sludge lance supported by the mount and the index drive. 
     
     
         6 . The sludge lance system of  claim 1 , wherein the sludge lance is unsupported at the distal end. 
     
     
         7 . The sludge lance system of  claim 1 , wherein the index drive is operably engaged with the rail and prevents horizontal and vertical movement of the rail, and wherein the index drive is to advance the distal head along the elongate central tube lane by advancing the rail along the longitudinal axis. 
     
     
         8 . The sludge lance system of  claim 1 , wherein the index drive comprises a plurality of first rollers engaged with a top face of the rail and a plurality of second rollers engaged with a bottom face of the rail, and wherein the plurality of first rollers and the plurality of second rollers are to advance the distal head along the elongate central tube lane by advancing the rail along the longitudinal axis. 
     
     
         9 . The sludge lance system of  claim 1 , wherein the rail comprises a first drive shaft operably engaged with the first nozzle body and a second drive shaft operably engaged with the second nozzle body, and wherein the first drive shaft and the second drive shaft are operably engaged with the rotary output shaft of the oscillator assembly. 
     
     
         10 . The sludge lance system of  claim 9 , wherein the manifold comprises a transmission to convert the rotation of the rotary output shaft of the oscillator assembly to rotation of the first drive shaft and the second drive shaft in opposite directions. 
     
     
         11 . The sludge lance system of  claim 9 , wherein the first drive shaft and the second drive shaft of the rail are rotationally lockable relative to the rail prior to attaching the rail to the manifold during assembly of the sludge lance. 
     
     
         12 . The sludge lance system of  claim 11 , wherein the first drive shaft and the second drive shaft are rotationally unlocked upon attachment to the manifold during assembly of the sludge lance. 
     
     
         13 . A sludge lance system for cleaning a tube bundle of a steam generator, wherein the steam generator comprises at least one hand hole opening which provides access to an elongate central tube lane within the tube bundle, wherein the elongate central tube lane defines a longitudinal axis, wherein said sludge lance system comprises:
 a mount positioned outside the steam generator;   an index drive supported by the mount; and   a sludge lance movable along the longitudinal axis of the elongate central tube lane by the index drive, wherein the sludge lance comprises:
 a proximal end; 
 a distal end; 
 a longitudinal rail; and 
 a distal head extending distally from the longitudinal rail, wherein the distal head comprises:
 a body portion defining a central vertical plane; 
 a first nozzle body positioned on a first lateral side of the central vertical plane, wherein the first nozzle body comprises a first plurality of nozzles, and wherein the first nozzle body is rotatable relative to the body portion about a first longitudinal axis; and 
 a second nozzle body positioned on a second lateral side of the central vertical plane opposite the first lateral side, wherein the second nozzle body comprise a second plurality of nozzles, wherein the second nozzle body is rotatable relative to the body portion about a second longitudinal axis, wherein each of the plurality of first nozzles are to emit fluid along a first flow path, wherein each of the plurality of second nozzles are to emit fluid along a second flow path, and wherein the first flow paths and the second flow paths are mirrored about the central vertical plane. 
 
   
     
     
         14 . The sludge lance system of  claim 13 , wherein rotation of the first nozzle body and the second nozzle body is synchronized to maintain the first flow paths and the second flow paths mirrored about the central vertical plane. 
     
     
         15 . The sludge lance system of  claim 13 , wherein the sludge lance is solely supported by the mount and the index drive. 
     
     
         16 . The sludge lance system of  claim 13 , wherein the sludge lance is unsupported at the distal end. 
     
     
         17 . The sludge lance system of  claim 13 , wherein the index drive is operably engaged with the rail and prevents horizontal and vertical movement of the rail, and wherein the index drive is to advance the distal head along the elongate central tube lane by advancing the rail along the longitudinal axis. 
     
     
         18 . The sludge lance system of  claim 13 , wherein the sludge lance further comprises an oscillator assembly, wherein the rail comprises a first drive shaft operably engaged with the first nozzle body and a second drive shaft operably engaged with the second nozzle body, and wherein the first drive shaft and the second drive shaft are operably engaged with a rotary output shaft of the oscillator assembly. 
     
     
         19 . The sludge lance system of  claim 18 , wherein the first nozzle body and the second nozzle body are rotatable in opposite directions about their longitudinal axes in response to a rotation of the rotary output shaft of the oscillator assembly. 
     
     
         20 . The sludge lance system of  claim 18 , wherein at least one of the first drive shaft and the second drive shaft is rotationally lockable relative to the rail.