EP0045454B1 - Manipulator for the positioning of a tubular sonde - Google Patents

Description

The invention is in the field of remotely controllable devices for inspection and / or repair of tube heat exchangers and is to be used in the structural design of a manipulator which is fixed to the tube mouths of the heat exchanger tubes which are contained in a tube plate.

A known manipulator of this type consists of a rigid support body, a support which can be moved along the support body, a boom mounted on the support wing and a mouthpiece arranged at the free end of the boom for introducing the tube probe into the respective heat exchanger tube. As far as possible, the manipulator should be able to access all of the pipe orifices which are contained in an approximately semicircular pipe field in the pipe plate. For this purpose, the support body is provided with a linear guideway and can be fixed in parallel to the tube plate by means of pin-like clamping devices. The support is also positioned parallel to the pipe plate and on the supporting body. Finally, the boom can be moved linearly on the support surface facing the tube plate and can be pivoted parallel to the tube plate. Due to the linear movements of the support and the boom as well as the pivoting movement of the boom, the mouthpiece can be aligned and fitted onto a pipe mouth (DE-OS 2263143). This known manipulator is not accessible to pipe orifices that are located above the supporting body. This is especially the case with high-performance heat exchangers in which the tube field is only a short distance from the partition of the heat exchanger.

In another known manipulator, this sits on a carriage that can be moved on a rail. The rail protrudes from the outside through the manhole in the floor space of the heat exchanger and is anchored to the flange of the manhole. The rail also has a rectilinear part which runs parallel to the tube plate of the heat exchanger and on which the manipulator can be fixed with the aid of one or two centering mandrels which can be inserted into the tube mouths. The manipulator itself consists of a housing, a support body for an attached swivel drive and a boom attached to the swivel drive, which carries the mouthpiece at its free end for guiding a tube probe. The housing can be moved on the slide in the longitudinal direction of the rail, the supporting body can also be moved linearly in the longitudinal direction of the rail in a guide frame of the housing and the boom can perform a pivoting movement. The two linear movements and the swiveling movement make it possible to move the boom mouthpiece towards the individual pipe mouths. However, such pipe openings, into which the centering mandrels of the manipulator engage, cannot be accessed without changing the position of the manipulator on the rail. The boom is limited by the centering mandrels in its range of motion, so that a certain part of the pipe mouths is accessible only by moving and re-centering the manipulator (DE-OS 28 30 306).

Another known manipulator works according to the so-called finger walker principle. In such a manipulator, the support body consists of two arms arranged at right angles to one another, which are displaceable relative to one another. Each arm is provided at both ends with expandable and retractable expanding mandrels with which the respective arm can be fixed in the pipe mouth of the pipe plate. The two expanding mandrels of one arm must be sufficient to hold the manipulator as a whole when the other arm moves. Such a manipulator is a relatively complicated structure, which must not only have the location control for the boom carrying the mouthpiece, but also the locomotion control for the walking mechanism (DE-OS 2552341).

Starting from a manipulator with the features of the preamble of claim (DE-PS 22 63 143), the invention has for its object to design the support body, support and boom so that all pipe mouths of the tube plate are accessible even with large capacity heat exchangers without moving the manipulator are.

To solve this problem it is provided according to the invention that the support body is provided with at least three mutually independently lockable in pipe mouths of the tube plate, distributed over the length of the support body in the form of extendable and retractable expanding mandrels that the boom with its joint head on the Axis of rotation of a rotary drive is attached, which is flanged to the support plate facing the support plate at its free end, and that the distance between the mouthpiece and the axis of rotation is greater than the vertical distance of the axis of rotation from the tendon delimiting the approximately semicircular tube field.

In a manipulator designed in this way, the arm is arranged above the supporting body between the support and the tube plate and can therefore cover an angular range greater than 180 °. In addition, due to the dimensioning provided, the boom can therefore also reach positions with its mouthpiece that are above the supporting body or even on the other side of the support. If the boom reaches one of the at least three expanding mandrels, it can be retracted; the manipulator will nevertheless held by the other expanding mandrels as a whole. This means that the assembly and centering of the manipulator, once carried out, is retained regardless of which pipe mouth is controlled in each case. Another advantage is that only two drives are required to position the mouthpiece, since the swivel drive of the boom is arranged stationary on the support.

• Figur 1 in einem Längsschnitt eines Dampferzeugers die Seitenansicht des in der einen Primärkammerhälfte am Rohrboden befestigten und zentrierten Manipulators;
• Figur 2 die Draufsicht auf den Manipulator nach Fig. 1 mit Blickrichtung von unten, wobei vier Ausleger- und zwei Support-Positionen dargestellt sind;
• Figur 3 die Ansicht in Blickrichtung A auf den Manipulator nach Fig. und
• Figur 4 im Ausschnitt eine Variante für den Ausleger des Manipulators mit Teleskopverstellung.

The invention is explained in more detail below with reference to the drawing which shows several exemplary embodiments. In a simplified representation, the parts that are not necessary for understanding the invention are shown:

• 1 shows in a longitudinal section of a steam generator the side view of the manipulator fastened and centered on the tube sheet in one primary chamber half;
• Figure 2 is a plan view of the manipulator of Figure 1 looking from below, showing four boom and two support positions.
• 3 shows the view in viewing direction A of the manipulator according to FIGS
• Figure 4 in a detail a variant for the boom of the manipulator with telescopic adjustment.

The steam generator DE shown in FIG. 1 for pressurized water nuclear reactors has a boiler wall 1 with a welded-in tube sheet 2 and a dome wall part 1a for the two primary chamber halves 1 a, 1 b. The heat exchanger tubes 3 are welded into the tube sheet, of which only three are more clearly drawn out and the others are only indicated by dashed lines, with tube openings 3a pointing into the primary chamber 1a, 1b. The primary medium, treated normal water, which is heated in the core of the reactor pressure vessel, not shown, passes through a primary circuit pipeline, also not shown, via an invisible inlet connection, for. B. in the primary chamber half 1a, which is separated from the primary chamber half 1b by an arched partition 4. It enters the tube bundle 3.1 via the mouths 3a, gives its heat to that in the. Secondary chamber II contained, to be evaporated secondary medium and flows via the U-tube bends into the second tube bundle 3.2, which it leaves via the tube orifices 3a and thus fed back into the primary chamber half Ib and its outlet pipe (not shown) into the primary circuit for the purpose of reheating in the reactor core can be. The heat-exchanging pipes 3 of the steam generator DE must be subjected to a periodic check for cracks. This is done with a tube probe RS of an eddy current measuring device which can be moved into the tubes 3 and which is shown in FIG. 1 in a retracted position in the area of the tube mouth. In addition to the eddy current measuring probe RS mentioned, this can also be cleaning tools for cleaning pipes from the inside or repair tools, by means of which detonators can also be inserted to seal cracks.

The manipulator M is used to manipulate all of these probes, which consequently serves for remote-controlled positioning of the tube probes RS, which are used for inspection and, if necessary, repair, at the tube mouths 3a of the tubes 3 of steam generators DE for the nuclear reactors contained in the tube plate 2. Instead of steam generators, it could also generally be a heat exchanger with a corresponding tube plate 2. The probe RS is connected to a flexible supply hose 5.1, which at the same time serves as a push hose for the pipe probe RS at its end and which is mounted so that it can move back and forth within a flexible guide hose 5.2. Supply and guide hose 5.1, 5.2 are drawn out enlarged for a section in FIG. 1 and designated 5 as a whole. The guide hose 5.2 ends in a mouthpiece 6, which is supported by the free end of a boom 7 pivotably mounted in a tube-transverse plane.

As shown in FIG. 1 in connection with FIGS. 2 and 3, the manipulator M has a supporting body 9 with a guideway 10 in the form of a spindle, which can be fastened to the pipe orifices 3a by means of spaced-apart expanding mandrels 8, a bearing mounted on the supporting body 9 and on its guideway 10 rectilinear in the direction of x rectilinearly movable support 11 as well as the already mentioned arm 7 pivotably supported on the support 11 in a tube-transverse plane. The supporting body 9 consists of an elongated frame construction with end plates 9.1, which with the pivot bearings for the two ends of the one having an external thread Spindle 10 are provided. A drive motor 12 for the spindle 10 is also flanged to one of the circuit boards 9.1. The support 11 is a rigid cantilever beam, which is mounted with its traveling nut body 11.1 on the spindle 10 so that when the spindle 10 is rotated the support can be moved back and forth in the x direction depending on the direction of rotation, but cannot rotate with it. For this purpose, the support 11 grips with a U-shaped holding part 11.2, indicated schematically in FIG. 1, with upper and lower holding spaces 11.21, 11.22, corresponding upper and lower guideways 9.2 of the support body 9. Through the angled end 11.23 of the upper guiding arm 11.21, which is not a engages shown guide bar of the support body 9, it is ensured that the support 11 can not fold down. All the guide surfaces on the support 11 and their counter surfaces on the support body 9 for moving the support in the x direction can be provided with roller bodies (not shown in more detail) in order to achieve a rolling instead of a sliding friction.

At the free end of the support 11 on an upper wing 9.3 of the same with in work po sition of the manipulator M vertical axis of rotation 13 flanged the housing of a swivel drive 14, which is a continuously adjustable rotary motor, with the axis of rotation 13 of which serves as a joint head bearing body 7.1 of the boom 7 is connected. The length of the support body 9, the support 11 and the boom 7 is now each dimensioned such that by moving the support 11 in the x direction and by pivoting the boom 7 by the angle ϕ in an angular range of at least 360 ° -2a , as explained in detail later, with the mouthpiece 6 of the boom 7 any pipe mouth 3a of the pipe field 30 can be reached (FIG. 2). The tubular field 30 is indicated in FIG. 2 in sections by a grid of lines crossing at right angles and by the dash-dotted outline of a circular section.

The expansion mandrels 8 are extended and retracted (see in particular FIG. 1) by means of expanding mandrel drives consisting of a push rod 8.2 having the expanding mandrel 8 at its free end and a drive housing 8.3 for the push rod 8.2, which acts as a pneumatic cylinder for the corresponding (not shown) ) Push rods 8.2 having pneumatic pistons can be designed. The expansion mandrels 8 are extended and retracted in the shown working position of the manipulator in the z direction, see arrow. Structure and function of such expanding mandrels are known per se and z. B. in DE-OS 25 52 341 described in more detail so that a detailed explanation can be omitted here.

2 and 3 show that at least three, in the present case there are four expandable mandrels 8 that can be extended and retracted and distributed over the length of the supporting body 9. Fig. 2 further clarifies on the basis of the boom positions 7, 7 ', 7 "and 7"' that the boom 7 can be pivoted in an angular range of 360 ° -2a, and can be pivoted continuously, so that the mouthpiece 6 is aligned with any pipe mouth 3a and so the tube probe RS can be easily retracted. The tube probe RS is also expediently tapered at its entry end in order to facilitate the insertion in the event of slight lateral deviations. The angle a is defined by the relationship cos a = m: n, where n is the length of the boom 7 and m is the perpendicular from the boom pivot point 13 to the pipe field limiting chord 301. This becomes clearer when looking at Fig. 2 and the boom positions 7, 7 ", 7" 'and 7'. From position 7 of the boom shown with solid lines, it can be moved by swiveling clockwise gu into position 7 ". It thus reaches the pipe field limiting chord 301 and the pipe orifices lying on this chord. Now the support 11 is moved in the direction x1 , so all pipe orifices lying in this direction can be reached from the mouthpiece 6 to the outermost position 7 ″, with the exception of the pipe orifices occupied by the expanding mandrels 8c and 8d. Therefore, when the boom with its mouthpiece 6 is just in front of the pipe mouth covered by the expanding mandrel 8c or 8d, the expanding mandrels are briefly retracted or retracted in the direction z1 (FIG. 1), but the remaining expanding mandrels 8a, 8b and 8d (in the case of the lifted expanding mandrel 8c) remain in engagement. The fastening and centering position of the manipulator M or of the support body 9 is thus retained. The same applies when moving to the pipe mouth covered by the expanding mandrel 8d; this expanding mandrel 8d is disengaged to test the corresponding heat exchanger tube, while the remaining 8a, 8b and 8c remain engaged. If the remaining pipe orifices lying on the limiting chord 301 are to be approached, the boom 7 must be pivoted into the position 7 ', for which purpose it is necessary to bring it into a central position, i. H. to move the support 11 so that the pivot point 13 lies on the axis of symmetry y. Then it is possible to pivot the boom 7 in the counter-pointer direction ϕ □ into the position 7 '. When the pipe orifices then move away from the limiting chord 301, the expanding mandrel 8a is pulled in briefly, as has already been explained in principle, so that 1. the boom can continue to be moved and 2. also a test of the pipe blocked by the expanding mandrel. As can be seen, the mouthpiece 6 of the boom 7 reaches all pipe orifices 3a of the pipe field 30 by appropriate adjustment operations, regardless of whether the pipe field is based on a Cartesian or a polar coordinate system. To report the respective position of the boom 7, its rotary motor 14 is assigned an angle encoder, and the support 11 can e.g. B. with the pinion of a length encoder with a rack parallel to the spindle 10 attached to the support body 9, so that from the corresponding pulses of the length and angle encoder via a computer on a control panel, the exact tube position in Cartesian coordinates, which the Mouthpiece 6 occupies straight, can be calculated. As can be seen, the manipulator M is positioned symmetrically to the axis of symmetry y and the length of the arm 7 is also matched to this position. The electrical supply lines for the adjusting motors 12 and 14 as well as the length and angle encoders, and also the pneumatic supply lines for the expanding mandrel cylinders 8.3 are omitted for the sake of simplicity.

3, an expanding mandrel 8 'is indicated by dashed lines, which could be used in a second embodiment instead of the two expanding mandrels 8c and 8b, so that the manipulator M would be equipped with the expanding mandrels 8a, 8' and 8d. Three expanding mandrels represent the minimum per manipulator, since two of them are in The test position of the manipulator M must always be engaged. The first version with four expanding mandrels, however, provides increased clamping security, since if one of the at least three expanding mandrels that fail to engage at the same time fails, two are still engaged. It is also possible to provide more than four expanding mandrels.

Fig. 4 shows in detail a boom 70, which is adjustable in length, due to a telescopic linkage with cylinder part 71 and piston part 72. Such a boom can be shortened in length by almost half, which z. B. has the advantage that - see Fig. 2 - for pivoting the boom from position 7 to position 7 'it does not need to be moved into the central position. In addition, the advantage can be achieved that no such precise adjustment of the boom length and the dimensions of the support 11 and the support body 9 need be made to the inner contours of the steam generator chamber; such a manipulator would be more universal, i. H. Can be used for different steam generator sizes with different primary chamber dimensions.

In addition to the expanding mandrels, an even better, vibration-proof support of the manipulator M within the primary chamber half 1b can be achieved in that the support body 9 has a support device 15 with at least one support foot 15.1 which can be braced laterally against the partition 4. This is advantageously a pneumatic piston-cylinder arrangement. The support foot 15.1 is z. B. articulated with a ball joint to the piston rod 15.2 to adapt to the curvature of the partition 4.

The dash-dotted partial representation of the manipulator M in the left part of FIG. 1 within the primary chamber half 1a shows that it is possible to move the mouthpiece 6 into acute-angled niches 16, which are caused by the convex curvature of the partition 4, but with the flexibility of guide and supply hose 5.2, 5.1 special requirements are made.

In the case of a straight tube steam generator, the primary chamber of the steam generator is not divided by a partition 4; in this case it would be advantageous to use a manipulator M by doubling. d. H. Reflection on its expanding mandrel connection axis is to be thought and thus has a support 11 with a bracket 7 on each side of the longitudinal axis of a support body 9 doubled in this way. In this case, both swivel arms could even work at the same time, which would make it possible to achieve around half the test time compared to a manipulator with only one arm.

The manipulator M is inserted through the manhole ML (the cover, not shown, of which is removed for this purpose) when the steam generator primary chamber is drained, and is brought into the test position that can best be seen in FIG. 2. All that is required is a short stay of operating personnel in protective suits in the primary chamber. After the test has been carried out, the manipulator M is correspondingly disassembled and removed. It is also fundamentally possible, in order to prevent operators from entering the steam generator primary chamber, by attaching a rail system protruding from the outside through the socket to the primary chamber on the manhole spigot ML1, on which the manipulator M is mounted on the outside and then operated remotely in his test position can be moved, as already explained in DE-OS 28 30 306.

Claims (5)

1. A manipulator for positioning a tube probe at the openings of heat exchanger tubes by remote control of the tube probe which is connected to supply hoses and which serves for the inspection and/or repair of the heat exchanger tubes, the tube openings being contained in a tube plate over an approximately semi-circular tube area, consisting of

a) a rigid carrier body which is provided with a linear guide track and which can be fixed in the tube plate parallel thereto by means of pin- shaped clamping devices,

b) a support mounted on the carrier body parallel to the tube plate and so as to face away from the latter, and which can be moved along the carrier body,

c) an arm which is pivotably-mounted parallel to the tube plate on the carrier surface of the support which faces towards the tube plate, and

d) a mouthpiece which, for introduction of the tube probe into a respective heat exchanger tube, is arranged at the free end of the arm and can be aligned with and placed over a tube opening, characterised in that

e) the carrier body (9) is provided with at least three clamping devices in the form of extendable and retractable expanding plugs which can be locked independently of one another in tube openings (3a) in the tube plate (2) and which are distributed over the length of the carrier body ;

f) the arm (7) is fixed with its swivel head (7.1) on the axis of rotation (13) of a swivel drive (14) which is flangedly secured at its free end to the carrier surface of the support (11) which faces towards the tube plate, and

g) the distance (n) between the mouthpiece (6) and the axis of rotation (13) is greater than the vertical distance (m) from the axis of rotation (13) to the chord (301) which bounds the approximately semicircular tube area.

2. A manipulator according to Claim 1, characterised in that the arm (7) is adjustable as regards its length.

3. A manipulator according to Claim 2, characterised in that the arm is a telescopic arm (70) having telescopic rods (71, 72).

4. A manipulator according to one of Claims 1 to 3, characterised in that the carrier body (9) has four expanding plugs (8a-8d) which are evenly distributed over its length.

5. A manipulator according to one of Claims 1 to 4, wherein the steam generator to be inspected is a U-tube steam generator having a primary chamber which is divided into two primary chamber halves by a curved partition, characterised in that the carrier body (9) has a support arrangement (15) comprising at least one support foot (15.1) which can be laterally braced against the partition (4).

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