KR100323126B1 - Automated Sludge Lance - Google Patents

Abstract

Automated sludge lances and methods are described for depositing sludge from a tube in a steam generator. The lance guide and water lance move in the steam generator and are directed to the fluid between the tubes, effectively cleaning the sludge from the tubes. The remote control system is installed outside the steam generator for easy access. Automated sludge lances and methods can be used where there are no tube lanes, annular chambers, or combinations thereof.

Description

Automated sludge lance

FIELD OF THE INVENTION The present invention relates to apparatus for cleaning steam generators, and more particularly, to automated sludge lances and methods for cleaning sludge from steam generator tubes of steam generators.

In nuclear power plants, steam generators such as recirculating steam generators and one-time steam generators are used for heat exchange when generating steam to drive turbines. The first fluid heated in the core of the reactor passes through a bundle of tubes in the steam generator. The second fluid, usually water, supplied to the space around the tube receives heat from the tube and is converted to steam to drive the turbine. The second fluid is directed back to the space around the tube after cooling and condensation, providing a continuous steam generation cycle. Due to the constant high temperature and stringent operating conditions, sludge builds up in the lower part of the tube and in the tube sheet supporting the tube. Such sludge is mainly composed of iron oxide such as magnetite, thereby reducing the heat transfer efficiency of the tube and promoting corrosion. Therefore, the tube must be cleaned regularly to remove the sludge. Various devices and methods may be used to accomplish this task.

US Pat. No. 4,566,406, "Sludge Removal Apparatus for Steam Generators," describes the firm attachment of a manifold to a tube sheet to hold it in place on the top surface of the tube sheet during normal steam operation. Openings are provided on the wall of the steam generator for removal.

The “Steam Generator Sludge Removal System” of US Pat. No. 4,079,701 describes the placement of a header at an elevation of sludge to be removed from around the tube in order to allow a circumferential fluid stream to be set at the elevation of the sludge. A fluid lance moving along the line between the headers will emit a fluid jet perpendicular to the moving line of the fluid lance. The lance can also be rotated by removing sludge.

“Sludge Lance Wand” in US Pat. No. 4,700,662 describes a lance for cleaning a one-time steam generator. Since the lance has a curved portion with a fixed radius of rotation, it is necessary to manually operate the lance to insert the lance between the tubes in the tube bundle of the steam generator.

“Trailer Sludge Lance” in US Pat. No. 4,980,120, assigned to the assignee of the present invention, describes a trailer lance for cleaning sludge located between steam generator tubes. In operation, the lance is inserted through the hand hole into the passageway or space between the tubes of the tube bundle.

In addition, US Pat. No. 5,194,217, "Trailer Sludge Lance with Mobile Expansion Nozzle," assigned to the assignee of the present invention, describes a trailer type sludge lance with a mobile expansion nozzle made of stretchable material.

In addition, the background technology description of US Patent No. 4,980, 120 introduces various technologies such as US Patent Nos. 4,556,406, 4,079,701, and 4,700,662.

In addition to the above technique, U. S. Patent No. 4,407, 236 to Schukei et al describes the introduction of thin strip steel springs into a tube lane for a sludge lance cleaning a reactor steam generator. And, the tube front end of the capillary tube is directed downward for the fluid to eject under high pressure.

Lee US Pat. No. 4,827,953 relates to an automated, flexible lance for secondary side sludge removal of a steam generator. This patent describes a flexible lance which has a plurality of flexible hollow tubes extending longitudinally along the flexible member and which is remotely controlled in the steam generator. The flexible member is configured to be difficult to access the coupling structure of the steam generator while there are a plurality of nozzles at one tip.

Lee, US Pat. No. 5,065,703, describes an improved automated flexible lance for the aforementioned steam generator.

US patent application Ser. No. 08 / 126,453, filed September 24, 1993, describes a trailer annular sludge lance.

However, there is still a need for a remotely controlled automated sludge lancing method and apparatus that will place and adjust the sludge lance in a steam generator in place, and drive assemblies are installed outside the steam generator for easy access. This gives the drive assembly a practical convenience, and eliminates the concerns of harsh environments and space limitations. In addition, there is no damage to the steam generator due to loose parts remaining inside. However, it is desirable to have an apparatus and method that can work in an annular chamber and / or in the absence of a tube lane of a steam generator so that a wider sweep area is possible.

The present invention is to solve the above problems of the prior art, to provide an automated sludge lance and method for cleaning the steam generator.

The method according to the invention allows the lance guide and the water lance to be positioned external to the steam generator and to remotely position the lance guide and the water lance at a predetermined position with a drive assembly attached to a fixed flange of the steam generator. This removes the sludge located between the plurality of tubes in the steam generator. The lance guide is located at a preselected location within the steam generator and the water lance held therein is oriented between the tubes for cleaning. .

The lance of the present invention uses a lance guide steered outside the steam generator by a drive assembly to remove sludge located between the tubes of the tube bundles in the steam generator. The lance guide holds a water lance that moves in concert with and separately from the lance guide to clean the tube.

It is therefore an object of the present invention to provide an automated sludge lance for cleaning a tube in a steam generator.

Another object of the present invention is to provide an automated method for cleaning the steam generator.

Another method of the present invention is to provide a remote control system for a sludge lance.

It is a further object of the present invention to provide an automated sludge lance that is simple in design, robust in structure and economical to manufacture.

Various new forms that characterize the invention are particularly pointed out in the appended claims, which form part of this disclosure. Operational advantages for the understanding of the present invention are achieved by its use, reference is made to the accompanying drawings and the technical details will be illustrated as preferred embodiments of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In the accompanying drawings, the same reference numerals will be used for the same parts. First, reference numeral 10 in FIG. 1 is an automated sludge lance according to the present invention. In this embodiment the automated sludge lance 10 is attached to the fixing bracket 8 via a hand or inspection hole 6 in the absence of a tube lane 4 of the steam generator 2. The automated sludge lance 10 adjusts the lance guide 12, the water lance 14 movably located in the lance guide 12, and both the lance guide 12 and the water lance 14. The drive assembly part 22 is included. The lance guide 12 and the water lance 14 are moved to a selected position between the tubes 3 in the absence of a tube lane 4 of the steam generator 2. The proximity sensor 35 attached to the lance guide header 34 first identifies the positions of the tubes and determines the lanes between the tubes in between. At that point the water lance 14 advances into the lanes between the tubes between the tubes 3 to remove sludge by injecting a fluid, such as water, under high pressure between the tubes 3. Similar ways of removing sludge are described in US Pat. Nos. 4,980,120 and 5,194,127. As used herein, the term "water lance" means that some fluid is discharged from the lance 14 under high pressure.

The lance guide 12 is basically a channel having a structure that can accommodate the water lance 14 in a somewhat U-shape, and may be made of metal such as aluminum or plastic such as polypropylene. The water lance 14 preferably comprises a cast polymer reinforced with a single piece of fiber, such as a stainless steel front and rear manifold, a pressure tube wrapped with at least one preferably multiple fibers, a polyurethane matrix body. The water lance 14 may be constructed similarly to the fluid dispensing member described in US Pat. Nos. 4,980,120 and 5,194,127.

The rows of holes 16 are preferably located below the centerline of the lance guide 12 and the water lance 14 for press fit with the remotely controlled tractor-driven assembly 22. In a preferred embodiment, tractor-type drive assembly 22 includes a belt 18 secured by pins driven by pulley 20. The pinned belt 18 is preferably a flexible metal belt, and the pulley 20 is preferably a grooveless stainless steel wheel.

In this arrangement, high traction is achieved by engaging several holes 16 at a time, and the flow path in the water lance 14 is not affected even when the pressure tubes are joined to the maximum number in the design. The flow path of the water lance begins at the rear manifold 14b, where the water is filtered and distributed to each pressure tube. The pressure tubes transfer water through the water lance body to the front manifold 14a, where the water is remixed in a single reservoir to direct it to the water spray nozzles. U.S. Patent Nos. 4,980,120 and 5,194,127 describe, by reference, a fluid dispensing member suitable as a water lance in the present invention. The nozzles may be arranged at the front end of the water lance in a variety of ways, but it is desirable to set two nozzles on opposite sides symmetrically with each other at a 90 degree angle to the water lance so that one point is directly above and the other point is directly below. desirable. The remote control drive assembly 22 is installed in the monitoring hole 6 and drives the lance guide 12 and the water lance 14 along the region where there is no tube lane of the steam generator. The manipulator or lance guide assembly 22 is connected to the servo motors 24 and 26 via a tractor drive system that is correctly fastened. Lane-to-lane and positioning measurements between the tubes (3) are performed using computer software using encoder position feedback and proximity probes (35, 37) located at the tip of lance guide (12) and lance guide head (34). Controlled by

The movement of the water lance 14 is driven by the servo motor 26 via a tractor drive that is precisely connected to the fastening hole 16 in the water lance body. The servo controller motors 24, 26 allow the water lance 14 to spray water as it is inserted as well as contracted between the tube lanes. In addition, the driving force is adjusted to read the obstacles in the tube lane and prevent excessive stress of the water lance.

Next, in FIG. 2, the rotatable drive assembly 28 having a position feedback for completely rotating the tube sheet to the first support plate range or between the support plates is provided with a lance guide 12 and a water lance ( 14 is connected to the lance guide drive assembly 22 where there is no tube lane to drive 14. In addition, cutting water lances and sludge height measurement tools can also be rotated at heights above the sludge deposits. The rotary drive assembly 28 provides full rotation to remove sludge from both the bisected steam generators. It is also possible to provide the movement at a predetermined angle. The rotation drive assembly 28 as shown in detail in FIG. 5 includes a rotation drive motor 30. The rotary bearing assembly 32 facilitates movement by the rotary drive assembly 28.

The servo controller motors 24, 26, 30 consist of digital drive control hardware and amplifiers necessary to adjust the lance guide 12 and water lance 14 positions. The controller may choose to exceed the requirements of the control system so that other options may be added in the future. Instructions from a computer system (not shown in the figures) are directed by the servo controller motor and are based on encoder data translated into control signals in the mechanical system. Instructions to the servo controller are preferably made by an 80486 microcomputer station located outside of the containment and are continuously operated during the lancing operation. Microcomputers preferably use user-friendly software based menus that can allow relatively easy single action commands or complex multi-command sequences. The operator specifies the range or lane to be lanced, the number of passages via the keyboard or mouse, and the control system alerts when the operator experiences problems such as lane failure, high water levels, indexing problems or pump problems. To automate the entire lancing process. The system can also report daily progress and the graphical output, such as software, is flexible enough to accumulate various access points, steam generator tube patterns, lancing methods and report options.

The lance guide is a device equipped with a motor that is advanced through the hand hole of the steam generator and is accessed along the absence of a tube lane in the center of the steam generator and is filed on September 24, 1993. The trailer annular sludge lance described in 126,453 is approached along the annulus around the tube bundle of the steam generator. Various monitoring mechanisms may be employed outside the guide header 34 through the body of the lance guide for insertion between the tubes in the steam generator tube bundle. When only binding and limiting the bars within the bundle, the sludge lancing mechanism within the bundle can penetrate through the entire tube bundle, which typically includes a region of sludge pile depth.

Of the lancing mechanisms used, cutting lancing is most commonly used. Two high pressure jet nozzles are combined to cut the sludge and tube sheet and to clean broach holes high in the support plate. The water lance in front of it holds the water jet nozzles placed in front of the lance and is used to strip off the tube and remove softer sludge so that the cutting lance can be inserted unrestricted. Two other tools, optical monitoring strips and sludge height measuring tools, combine fiber and other specifics to monitor conditions in the steam generator before and after lancing. Water and the sludge contained therein are removed via other hand holes by a well-known high-volume suction system.

Like the lances described in US Pat. Nos. 4,980,120 and 5,194,217, the sludge lances of the present invention are made of high impact strength plastics such as polycarbonate or acetal and / or metals such as aluminum, stainless steel, brass or combinations thereof. Can be.

Some steam generators have a membrane or inner shell that covers the tube bundle except about 8 inches from the tube sheet. As shown in FIG. 1, one enters from the hand hole 6, which has a diameter of about 2.5 inches, to the area 4 without the tube lane. In some steam generators, the other hand hole has a diameter of about 3.5 inches. The annular chamber 5 is about 3.5 to 4 inches wide. Of course, other steam generators will have different dimensions depending on their specifications. CANDU steam generators are geometrically limited. That is, the size of the water lance is limited to about 0.100, 0.115 or about 0.125 in thickness, 1.25 or 1.5 inches in width, and 8 to 10 feet in length. Due to space limitations, the sludge lance 10 must have the ability to fit in tight places. 3 shows a trailer annular sludge lance remotely controlled by a sludge lance drive assembly 22. The guide rail 41 is provided with an axis that moves at an angle of 0 to 90 degrees such that the track member 40 advances to and around the annular chamber or annulus 5 of the steam generator 2. Another embodiment includes the use of a single flexible track to receive the water lance 14 or the use of the manipulator head 42 as the track itself to direct the water lance 14 between the tubes. The track is located inside the annular chamber 5 of the steam generator 2. Insertion and deflation of the water lance 14 and the lance guide is a metal pinned to the drilled hole 16 of the water lance and the lance guide for precise positioning as described above for the absence of a tube lane. It is preferable to do it through the drive belt 18. As already mentioned, the water lance 14 and the lance guide 12 drive motors 24, 26 are installed in the drive assembly 22, which drive gears as shown in FIG. 5. It is connected with the drive assembly part 28 which rotates through the assembly part 29. As shown in FIG.

In manufacturing steam generators, tie rods are used to support the support plates. Usually, the binding rod is a 3/4 inch steel member which may prevent the lance from cleaning between the tubes after the steam generator is built. Due to the large number of binding rods in the steam generator, a large area of the steam generator remains uncleaned in the prior art. The method and sludge lance of the present invention can clean up the sludge more effectively between the tubes of the steam generator 2.

4 shows a flexible water lance 14 in a partially retracted state. This flexible water lance 14 is bent in a round rim so as not to obstruct. In this embodiment, any guide channel 44 further supports the lance guide 12 and the water lance 14. The lance guide head 34 points the water lance 14 between the tubes of the steam generator at any selected location. The flexible water lance 14 forms a rounded rim at one end when partially contracted.

As shown in FIG. 5, the lance guide and the water lance drive assembly 22 preferably comprise two servo motors 24, 26 mounted perpendicular to the bracket 46. Pulley 20 is fitted in bracket 46 along a metal belt 18 secured with a pin. Each servo motor has its own bracket located on each side of the lance guide 12 and water lance 14, as shown in the various figures. All brackets are hingedly connected. This allows the opposite tip to open up like a bracket therein to facilitate the provision of the lance guide 12 and the water lance 14 there. Guide roller assembly 48 helps to maintain proper orientation. The belt 18 is fastened to one side of the lance guide 12, and the other belt 18 is clamped so that the bracket 46 can be clamped to seal where the water lance 14 is fastened. ) Can be adjusted by hand. Similar fasteners 50 couple the drive component 22 to the drive installation component 52. Optionally the guide support bracket 54 stabilizes the entire assembly in the steam generator.

Although specific embodiments of the present invention have been described in detail to illustrate the application and principles of the present invention, modifications and improvements may be made by those skilled in the art based on the above description. All such modifications and improvements are excluded herein for the purpose of brevity and readability, but all fall within the scope of the following claims.

1 is a perspective view of the present invention illustrating a water lance in place in a steam generator except a portion of the steam generator.

2 is a perspective view similar to FIG. 1 as another embodiment of the present invention.

3 is a perspective view similar to FIGS. 1 and 2 showing the remote control system of the present invention for automatically manipulating an annular trailer type sludge lance.

4 is a perspective view similar to the above figure, showing a state in which the water lance is partially contracted without a steam generator.

5 is a partial front view of an automated sludge lance in accordance with the present invention.

2 ---- steam generator 3 ---- tube

4 ---- without tube lane 5 ---- annular chamber

6 ---- hand hole or inspection hole 8 ---- fixing bracket

10 ---- Automated Sludge Lance 12 ---- Lance Guide

14 ---- Water Lance 14a ---- Rear Manifold

14b ---- front manifold 16 ---- hole

18 ---- pinned belt 20 ---- pulley

22 ---- driven assembly parts

24, 26, 30 ---- servo motor

28 ---- rotary drive assembly

29 ---- gear belt assembly parts 32 ---- rotary bearing

34 ---- Lance Guide Head

35, 37 ---- Proximity sensor

40 ---- track member 41 ---- India rail

46 ---- bracket

48 ---- guide roller assembly parts 50 ---- fasteners

52 ---- Drive fixed assembly

54 ---- Guide Support Bracket

Claims (19)

Placing a lance guide in a predetermined position in the hand hole of the steam generator, the water lance being movably received; Remotely advancing the lance guide and the water lance to a selected position within the steam generator with first driving means; Remotely inserting the water lance between the tubes of the steam generator by a second driving means; And Directing fluid between the tubes to remove the sludge from the tubes, wherein the sludge is disposed between the plurality of tubes in the steam generator. The method of claim 1 wherein the step of advancing includes advancing the lance guide simultaneously with the water lance. 3. The method of claim 2, wherein said water lance is located between a plurality of tubes in a steam generator that are first returned to a predetermined position within said lance guide before advancing. 2. The method of claim 1, wherein placing in the predetermined position comprises installing first and second drive means in the steam generator to advance the lance guide and the water lance and inserting the water lance between the tubes. A method of removing sludge located between a plurality of tubes in a steam generator comprising the step. The sludge of claim 1 further comprising the step of removing sludge between the tubes with the lance guide and the water lance located in the absence of the tube lane of the steam generator. Method of removal. A lance guide configured to move remotely within the steam generator; It is housed movably in the lance guide and is configured to move remotely with the lance guide and extends from the lance guide by a predetermined angle and a predetermined length between the tubes of the steam generator, the fluid being A water lance configured to receive fluid and configured to direct fluid to the steam generator to remove sludge from the steam generator; First means for moving said lance guide with said water lance in said steam generator; And An automated sludge lance for removing sludge located between the tubes in the steam generator, the second means for moving the water lance out of the lance guide between the tubes of the steam generator. 7. The automated sludge lance of claim 6 wherein said first and second means of movement are for removing sludge located between tubes in a steam generator configured to be installed on a flange outside said steam generator. 8. The apparatus of claim 7, wherein the first and second moving means comprise two servo motors that are remotely controlled, each of the servo motors having a pulley for driving the belt, the lance guide and the water lance, respectively. Is an automated sludge lance for removing sludge located between tubes in a steam generator that is to be driven separately by the servo motor. 9. The automated sludge lance of claim 8 wherein said water lance and said lance guide comprise sludge positioned between tubes in a steam generator comprising a plurality of fastening holes extending longitudinally. 10. The automated sludge lance of claim 9, wherein each belt includes pins for fastening the fastening holes of the water lance and the lance guide. 9. A tube in a steam generator as set forth in claim 8, wherein said first and second moving means further comprise a bracket for each servo motor which is hingedly attached to one end and clamped at both ends. Automated sludge lance to remove sludge located between them. 8. The automated sludge of claim 7 wherein said first and second means of transport remove sludge located between tubes in a steam generator installed on a flange for access to the absence of a tube lane of said steam generator. Lance. 8. The automated sludge lance of claim 7 wherein said first and second means of movement remove sludge located between tubes in a steam generator installed on a flange to access an annular chamber of said steam generator. The method of claim 1, further comprising: means for providing rotational motion about the lance guide and the water lance to remove the sludge at various angles. Automation for removing sludge located between the tubes in the steam generator. Sludge lance. Installation means for securing the remote control system to a flange on an outer wall of the steam generator; Fastening means for manipulating the sludge lance inside the steam generator; First drive means configured to receive the lance guide for manipulating the lance guide to a predetermined position; The water lance being movably positioned to steer the water lance to a predetermined first position and at least a predetermined second position with the lance guide at a selected angle for insertion and contraction between the tubes of the steam generator. Second drive means configured to receive a lance guide; And A remote control system for a sludge lance consisting of electronic means for adjusting the first and second drive means. 16. The remote control system according to claim 15, further comprising means for rotating the lance guide and the water lance in the steam generator. 16. The remote control system of claim 15, wherein each drive means consists of a servo motor attached to a bracket, the servo motor having a pulley for driving a second pulley with a belt. 18. The remote control system of claim 17 wherein the belt includes a pin configured to engage the plurality of holes in the water lance and the lance guide. 19. The remote control system of claim 18, wherein the bracket is hingedly attached to one end near the steam generator and configured to be sealed at the other end.