EP1124093B1 - Flexible lance for working on or inspecting a tube plate of a steam generator - Google Patents

Abstract

A flexible lance (1) for processing or inspecting a tube plate (161) of a steam generator (163) has a flexible metallic first strip and a supply line carried lengthwise on it, for a processing- or inspection-head (171) arranged at the free end of the first strip. A first link arranged lengthwise on the first strip has a higher bending/flexural strength than the first strip, the first link specifically not serving for the supplying of, or the control/drive of, the processing- or inspection head (171), the supply line being a hose, a capillary, an electrical line or an optical glass-fibre.

Description

The invention relates to a flexible lance for processing or inspecting a tube plate of a steam generator, having a flexible metallic first band and a longitudinally guided supply line for a processing or inspection head arranged at the free end of the first band.

Such a flexible lance is eg in EP-A-0501648 disclosed.

In the tubesheets of steam generators, in particular of nuclear steam generators remain after a certain period of time stuck impurities. These impurities can in some places have a height of a few centimeters. Since the impurities are very hard, there is a risk of damaging the closely spaced steam generator pipes (denting).

For tube sheets of steam generators, it is therefore necessary to regularly check on the secondary side whether and to what extent deposits have formed between the heating tubes. If necessary, these deposits must be removed to prevent damage to the heating pipes.

This happens for the adherent deposits primarily by spraying. For example, from the European patent specification EP 0 084 867 a spraying method is known in which a high-pressure water jet is injected from a spray head located in the pipe outlet in the spaces between the heating tubes.

However, it has been shown that firmly adhering deposits in the interior of the tube bundle can not be completely removed. To ensure efficient cleaning of the tubesheet, it is therefore necessary to To direct the spray head directly into the spaces between the heating tubes and direct a high-pressure liquid jet directly to the deposits inside the heating tube bundle.

To guide a supply line for an inspection head and / or to guide a liquid supply line for said spraying is off EP 0 815 388 B1 a flexible lance known. This has a flexible metallic band, which has in its longitudinal direction successively arranged recesses through which a flexible supply line is threaded for a arranged at the free end of the tape processing or inspection head. This tape has the disadvantage that it can buckle laterally, especially at a high feed force. This is of particular importance if the supply line or one of the supply lines is a capillary or an optical fiber. Such glass fibers are used to illuminate the spot to be cleaned and / or to observe. Capillaries and glass fibers have the property of breaking below a certain minimum radius of curvature.

The invention is therefore an object of the invention to provide a flexible lance that is easy to manufacture and in which the supply line is still protected from damage by bending the lance.

This object is achieved in relation to the above-mentioned flexible lance according to the invention by a longitudinally arranged on the first band first chord, which has a higher bending stiffness than the band and wherein the first band is integrally formed.

In this context, a tendon means any, in particular reversible or elastic, flexible stiffening element extended along the longitudinal direction. With the string, the band is easily stiffened, without that the size of the lance would increase as a result. The chord, whose diameter preferably does not exceed that of the supply line, namely can be guided laterally next to the supply line.

Due to the increased bending stiffness of the tendon kinking of the band is certainly avoided. A lateral buckling of the band could also cause it to get permanent deformation. This danger is also prevented by the tendon.

By choosing the type of chord, a balance can be made between flexibility and the required stiffness of the flexible lance, largely independent of the thickness of the band. An increase in the strip thickness would namely at the same time increase the entire width of the flexible lance, which would adversely affect their usability in the pipe interspaces.

According to a preferred embodiment, the first tendon does not serve the supply or control of the processing or inspection head. The tendon in this case is therefore available only for stiffening the metallic band.

The supply line is preferably a hose, a capillary, an electrical line or an optical glass fiber. In such supply lines, the stiffening of the band is particularly advantageous because these supply lines are particularly sensitive to kinking and can be easily damaged.

According to another preferred embodiment, the band in the longitudinal direction of successively arranged openings through which the first tendon is threaded. In this way, the tendon production technology is particularly easy fastened to the belt.

It is particularly advantageous if the band has between its openings perpendicular to the longitudinal direction shaped portions which extend alternately on one and the other side of the band. In this way, a largely rectilinear channel can be formed, into which the tendon can easily be inserted by threading through the openings.

According to another preferred embodiment, the flexible lance has a second chord which has a higher bending stiffness or bending strength than the band and which is spaced from and in the same way as the first chord.

The two tendons are preferably arranged symmetrically on both sides of the supply line. With two tendons, the band is particularly safe and reliable against kinking and also protected against twisting or twisting.

For example, the first chord or one of the chords is designed as a wire, in particular as a spring steel wire, as a rope, in particular as a steel cable, and / or as a fiberglass element. As a chord, a Bowden cable can be used, which can be used in the interior guided tension and pressure cable to drive an optional on processing or inspection head recovery or gripping pliers.

According to a preferred development, the flexible lance has an integral flexible metallic second band, which is arranged in the longitudinal direction and connected to the first band. The second band further reduces the risk of kinking of the flexible lance.

According to a preferred embodiment, the first band and the second band are connected to each other by the first chord and optionally by the second chord. The tendon is used in this case not only to increase the rigidity, but also as a connecting element of the two bands.

Preferably, the open side of a first formation on the first band for receiving the supply line from the second band forming a guide channel is covered.

By the first shaping on the one hand and the second band on the other hand, a largely closed guide channel can be formed, in which one or more supply lines can be securely guided against damage along the flexible lance.

Preferably, the first band and the second band alternately abut the first string for connecting the two bands. The first tendon is threaded through the first band and / or the second band. The same applies to the optional second tendon.

For this purpose, the first band preferably has a first row of openings arranged one behind the other in the longitudinal direction, and the second band has a second row of openings arranged longitudinally one behind the other. To connect the bands, the first tendon is then preferably guided through the openings of the two bands. The same applies to the optional second tendon.

According to a particularly preferred embodiment, the first band is formed between its openings perpendicular to the longitudinal direction, and the second band is formed between its openings in the opposite direction. This makes it possible to guide the first chord for connecting the two bands in manufacturing technology particularly simple manner through the openings.

In a particularly simple manner, this is possible if at least one of the bands protrudes with its shaped areas in the openings of the other band. The two bands are thus inserted in this case in the lateral direction.

According to a very particularly preferred embodiment, the second band of the flexible lance in the region of the guide channel is formed. In other words, the second band is formed on the other side like the first band to form the guide channel with a longitudinally extending second configuration. As a result, a particularly spacious guide channel is formed.

Preferably, the second formation is disposed over the open side of the first formation such that the formed guide channel extends, viewed in a cross-sectional plane through the bands, substantially symmetrically on both sides of the bands.

Thereby, it is advantageously possible to guide the supply line in the flexible lance so that it comes to rest, preferably in the middle, on a line on which the flexible lance has or would have a neutral fiber. This ensures that the supply line is particularly little stressed in a lateral bending of the flexible lance.

Preferably, the first molding and optionally the second molding in the longitudinal direction of successively arranged recesses, in particular slots on. This ensures that the first band or optionally the second band would not be impermissibly stiff for some applications due to its particular shape or shape. By choosing slot width and slot spacing, a minimum radius of curvature can be set. At the minimum radius of curvature, in which the frontal edges or surfaces of the slot openings come into contact with each other, a further deflection of the flexible lance is much more difficult, ie largely prevented lateral kinking. This enhances the effect already achieved by the tendon or the tendons.

In another development, the first tendon or at least one of the tendons has a higher bending stiffness than both ligaments together.

FIG 1

ein erstes Ausführungsbeispiel einer flexiblen Lanze nach der Erfindung in einer Querschnittsdar- stellung,

FIG 2

zwei Bänder der flexiblen Lanze der Figur 1 vor ih- rem Verbinden in einer Längsansicht,

FIG 3

eine Querschnittsdarstellung des ersten Bands der flexiblen Lanze der Figur 1,

FIG 4

eine Querschnittsdarstellung des zweiten Bands der flexiblen Lanze der Figur 1,

FIG 5

ein zweites Ausführungsbeispiel der flexiblen Lanze nach der Erfindung in einer Querschnittsdarstel- lung,

FIG 6

die flexible Lanze der Figur 3 in einer Längsan- sicht und

FIG 7

eine schematische Darstellung des Einsatzes der flexiblen Lanze beim Bearbeiten oder Inspizieren eines Rohrbodens eines Dampferzeugers.

Two embodiments of a flexible lance according to the invention are described below with reference to the FIGS. 1 to 6 explained in more detail. Show it:

FIG. 1

A first embodiment of a flexible lance according to the invention in a cross-sectional view,

FIG. 2

two bands of flexible lance the FIG. 1 before joining in a longitudinal view,

FIG. 3

a cross-sectional view of the first band of the flexible lance of FIG. 1 .

FIG. 4

a cross-sectional view of the second band of the flexible lance of FIG. 1 .

FIG. 5

A second embodiment of the flexible lance according to the invention in a cross-sectional representation,

FIG. 6

the flexible lance of the FIG. 3 in a longitudinal view and

FIG. 7

a schematic representation of the use of the flexible lance when working or inspecting a tube plate of a steam generator.

In FIG. 1 a flexible lance 1 is shown, which is composed of a one-piece flexible metallic first band 3 and a one-piece flexible metallic second band 5. The two bands 3, 5 are made of stainless steel with a wall thickness between about 0.1 and 0.2 mm. The width b of the bands is about 30 mm. In its center, the first band 3 has a first form or formation 13. Opposite, the second band 5 has a second formation 15 in the opposite direction. The two bands 3, 5 are flush with their flat sides along their longitudinal direction connected to each other. In this case, a guide channel 16 is formed by the two formations 13, 15, in the supply lines 17, 19, for example, an optical glass fiber, a capillary or a hose or an electric cable, are guided. The guide channel 16 is closed on both sides by one of the bands 3, 5, so that the supply lines 17, 19 are protected against mechanical damage.

The two supply lines 17, 19 are arranged symmetrically on both sides of a central axis 21.

The two bands 3, 5 are connected by two tendons 27, 29 with each other. The two tendons 27, 29 are symmetrically mounted on both sides of the central axis 21. Their mutual distance a is about 15 mm.

The two bands 3, 5 each alternately wrap around each of the two tendons 27, 29, so that the first band 3 and the second band 5 alternate alternately on each of the two tendons 27, 29. As a result, the two bands 3, 5 are connected to each other in a much easier and more flexible manner.

In FIG. 2 the two bands 3, 5 are shown in a longitudinal view, in a state prior to assembly to the flexible lance first

Out FIG. 2 it can be seen that the formations 13 (see also FIG. 3 ) or 15 (see also FIG. 4 ) are extended in a longitudinal direction 31 of the flexible lance 1. Each of the formations 13, 15 is of slot-like recesses 33rd or 35 interrupted, by which it is avoided that the flexible lance 1 is excessively stiff due to the existing formations 13, 15.

The distance d of the - in the longitudinal direction - only a few tenths of a millimeter wide and laser-cut slot-like recesses 33, 35 is about 5 mm, the slot width about 7 mm. This results in a minimum radius of curvature of about 40 mm.

In FIG. 2 It can also be seen how the bands 3, 5 are connected to each other by means of the tendons 27, 29 not shown in this figure. For this purpose, the first band 3 has a first row 43 in the longitudinal direction equidistant rectangular openings 44 arranged one behind the other. In an analogous manner, the second band 5 has a second row 45 in the longitudinal direction 31 equidistant rectangular openings 46 arranged one behind the other. The areas 48 (see also FIG. 3 ) or 49 (see also FIG. 4 ) between the openings 44 and 46 of the first band 3 and the second band 5 are formed in the opposite direction. The cross section of the rectangular openings 44, 46 is about 3.5 x 4.5 mm.

The two bands 3, 5 are in the region of their central formations 13 and 15 and with respect to their rows 43 and 45 successively arranged openings 44 and 46 substantially identical. To form the flexible lance 1, the bands 3, 5 are laid out in a quasi 180 ° phase-shifted manner one above the other. This is indicated by means of the auxiliary line 30. When assembled to the flexible lance 1, the formed regions 48 come to lie between the openings 44 of the first band 3 in the openings 46 of the second band 5 and protrude into these openings 46. Likewise, the formed portions 49 project in opposite directions into the openings 44 of the first band 3. In this state, a rectilinear channel for receiving the first chord 27 is formed by the formed portions 48 and 49. By insertion the first tendon 27 in this channel, the two bands 3, 5 are interconnected, as shown in FIG. 1 is shown.

Further rows of equidistant openings with shaped areas 50 of the band 3 (see also FIG FIG. 3 ) or formed regions 51 of the second band 5 (see also FIG FIG. 4 ) serve in an analogous way the recording of the second tendon 29 (see FIG. 1 ).

The two tendons 27, 29 are designed as mehrfaseriges steel rope, which is stiffer than the bands 3, 5.

On the outside, the first band 3 has rows 52, 53 of further openings which serve to engage a feed device which is not explicitly shown. Likewise, the second band 5 has outboard rows 54, 55 of apertures having a greater extent as compared to the apertures of the rows 52, 53 of the first band 3 in the longitudinal direction 31. This ensures that, for example, a toothed wheel of said feed device comes into contact only at the openings of the rows 52, 53 of the first band 3, which is important if, especially with a small radius of curvature, the two bands 3, 5 in the longitudinal direction 31 slightly relative to each other. Jamming the lance 1 on the gear is thus excluded.

A second embodiment of a flexible lance 1 according to the invention is shown in FIG FIG. 5 shown. In this embodiment, only a single band 60 is present. As in the associated longitudinal view of FIG. 6 As can be seen, the band 60 has a first row 62 of apertures 64 through which a first chord 27 is threaded. On the opposite side, the band 60 has a second row 66 of openings 68 through which a second chord 29 is threaded in the same way as the first chord 27. The rows 62, 66 extend in the longitudinal direction 31. Between the Openings 64 and 68, respectively, have bands 60, 70, 71 and 72, 73 respectively, which extend alternately on one and the other side of band 60 (see FIG FIG. 5 ). In this way, the two tendons 27, 29 are largely straight in a simple manner in the band 60 can be inserted and connected to this. In the middle between the two tendons 27, 29 located in the strip plane, the strip 60 has a third row 78 with openings 80, through which a supply line 70, in the example shown a capillary, is guided. Also in the region of the third row 78, the band 60 is alternately shaped or bent out in different directions as in the rows 62, 66, so that the supply line 70 is likewise largely linearly insertable into the band 60 and comes to lie in the band plane. The supply line 17 terminates at the free end of the belt 60 in a spray nozzle 82 having a processing or inspection head 171 (see also Figs FIG. 7 ).

In FIG. 7 the use of the flexible lance 1 for processing or inspecting a tube plate 161 of a steam generator 163 is shown. The steam generator 163 is shown only partially with tubes shown in cross-section 165. The tubes 165 are arranged in bundles on both sides of a pipe lane 164, which is accessible from outside through a hand hole 166 in a wall 167 of the steam generator 163. For manipulation or inspection, a manipulator 169, which is indicated only schematically, is introduced into the tube lane 164 and is movable back and forth in the direction 168. Via a drive roller 170 of the manipulator 169, the flexible lance 1 is inserted into the spaces between the tubes 165. In this way, a processing or inspection head 171 attached to the end of the flexible lance can be brought close to the points to be cleaned or inspected between the tubes 165. The lance 1 moves in the direction 172 and is unwound from an external drum, not shown.

Further details of the manipulator 169 and details of the intended use are in columns 4 to 7 of EP 0 815 388 B1 described.

Claims (12)

1. Flexible lance (1) for working on or inspecting a tube plate (161) of a steam generator (163), having an integral, flexible metallic first strip (3; 60) and a supply line (17, 19), which is guided on the said first strip in the longitudinal direction (31), for a working or inspection head (171) which is arranged at the free end of the first strip (3; 60),
   with a first tendon (27) which is arranged on the first strip (3; 60) in the longitudinal direction (31) having a higher flexural stiffness than the strip (3; 60).
2. Flexible lance (1) according to Claim 1, characterized in that the first tendon (27) does not serve to supply or actuate the working or inspection head (171).
3. Flexible lance (1) according to Claim 1 or 2, characterized in that the supply line (17, 19) is a hose, a capillary, an electrical line or an optical glass fibre.
4. Flexible lance (1) according to one of Claims 1 to 3,
   characterized in that the strip (3, 5; 60) has openings (44, 46; 64) which are arranged successively in the longitudinal direction (31) and through which the first tendon (27) is threaded.
5. Flexible lance (1) according to Claim 4,
   characterized in that the strip (60) between its openings (64) has regions (70, 71) which are formed perpendicular with respect to the longitudinal direction (31) and extend on one side and on the other side of the strip (60) in an alternating fashion.
6. Flexible lance (1) according to one of Claims 1 to 5,
   characterized by a second tendon (29) which has a higher flexural stiffness than the strip (3, 5; 60) and is attached in the same manner as the first tendon (27) and at a distance therefrom.
7. Flexible lance (1) according to Claim 6,
   characterized in that the two tendons (27, 29) are arranged symmetrically in relation to the supply line (17, 19).
8. Flexible lance (1) according to one of Claims 1 to 7,
   characterized in that the first tendon (27) or one of the tendons (27, 29) is in the form of a wire, in particular in the form of a spring steel wire, in the form of a cable, in particular in the form of a steel cable, and/or in the form of a fibreglass element.
9. Flexible lance (1) according to one of Claims 1 to 8,
   characterized by an integral flexible metallic second strip (5) which is arranged in the longitudinal direction (31) and is connected to the first strip (3).
10. Flexible lance (1) according to Claim 9,
    characterized in that the first strip (3) and the second strip (5) are connected to one another by the first tendon (27).
11. Flexible lance (1) according to Claim 9 or 10,
    characterized in that the open side of a first formation (13) on the first strip (3) for holding the supply line (17, 19) is covered by the second strip (5) so as to form a guiding passage (16).
12. Flexible lance (1) according to one of Claims 9 to 11,
    characterized in that the second strip (5) is formed with a second formation (15), which extends in the longitudinal direction (31), on the other side to the first strip (3) in order to form the guiding passage (16).

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