WO2023194617A1 - Automated device for measuring tubular pipe thickness using ultrasound - Google Patents

Abstract

The invention relates to an automated device (1) for measuring the thickness of tubular pipes (2) using ultrasound, comprising: - a frame (100) comprising support elements (120, 130) capable of supporting a pipe (2); - a measurement head (200) mounted to slide in a motorised manner relative to said frame along the tubular wall and comprising an annular body (210) capable of surrounding this wall, the measurement head further including at least one measuring apparatus mounted to slide on said annular body, each apparatus comprising an ultrasonic probe capable of measuring the thickness of said tubular wall in a measurement area in contact therewith, and an injector fitted with a nozzle capable of ejecting a coupling fluid onto said tubular wall in each measurement area before each measurement area is brought into contact with the probe.

Description

Automated device for measuring the thickness of tubular pipes using ultrasound

The present invention generally relates to the problem of measuring the thickness of tubular pipes intended for the transport of fluids.

The tubular metal pipes constituting the pipelines of certain industrial installations tend to corrode and/or erode at their internal surface due to the continuous circulation of liquids or gases inside them for long periods of time.

This loss of material due to corrosion and/or erosion leads to a reduction in the thickness of the tubular wall of these pipes which can ultimately generate occasional fluid leaks and/or their deterioration.

In order to guarantee the integrity of these pipes, regulations require regular inspections during which their thickness must be measured at numerous control points.

These regular measurements, which make it possible in particular to precisely determine their thinning and estimate their remaining lifespan, must be carried out using non-destructive methods so as not to damage the pipes.

We generally use ultrasound probes operated manually by one or more operators.

Ultrasounds are mechanical waves that propagate in elastic media. When these waves encounter an interface between two environments of different natures, there is reflection of all or part of the incident wave.

Such an ultrasonic probe comprises an ultrasonic transmitter coupled to an ultrasonic receiver. The transmitter emits an ultrasonic wave from the accessible external face of the tubular wall of the pipe which is partially reflected on its internal face so as to return to impact the receiver.

The thickness of the tubular wall can then be determined by multiplying the known propagation speed of the ultrasonic wave in the material (this being for example of the order of 5920 m/s in steel) by the delay separating the emission of this wave from the reception of its reflected echo.

Unfortunately, the ultrasonic waves emitted to carry out these thickness measurements are very sensitive to the presence of air spaces interposed between the probe and the external face of the pipe wall.

In addition to the attenuation effects, the air has an acoustic impedance very different from that of the probe wear plate and the constituent material of the pipe being inspected, so the presence of even a very A thin air gap between the probe and the external face of the wall of the pipe can prevent the effective transmission of the sound energy of the wave emitted in the wall of this pipe.

This is why it is essential to apply a coupling fluid to the measurement zone, prior to positioning the probe, to avoid the presence of such interspersed air blades, so as to optimize the transmission of the sound energy of the ultrasonic wave between the probe and the tubular wall of the pipe.

These coupling fluids generally come in the form of non-toxic, moderately viscous liquids, gels, or pastes.

This multiplicity of manual operations to be repeated by the operator for each thickness measurement to be carried out on a pipe makes these control phases particularly time-consuming and therefore costly.

The present invention therefore aims to improve the situation.

For this purpose, it offers an automated device for measuring the thickness of tubular pipes using ultrasound, characterized in that it comprises:
- a frame comprising support elements capable of supporting said pipe;
- a measuring head mounted movable to slide in a motorized manner with respect to said frame along the tubular wall of said pipe and comprising an annular body capable of surrounding said tubular wall, this measuring head further comprising at least a measuring device mounted movable to slide on said annular body,
each said measuring device comprising an ultrasonic probe capable of measuring the thickness of said tubular wall at the level of a measuring zone located in contact with it, as well as an injector equipped with a nozzle capable of ejecting a coupling fluid on said tubular wall at each said measuring zone before it comes into contact with said probe.

The device according to the invention thus makes it possible to measure in an automated manner and with great reliability the thickness of the tubular wall of a pipe in numerous zones distributed over the length of this wall.

According to preferred characteristics of said automated thickness measuring device according to the invention:
- said measuring head comprises several said measuring devices arranged on said annular body being distributed angularly in a regular manner around the axis of this body;
- said measuring head comprises two first said measuring devices aligned along a first sliding axis;
- said two first measuring devices are arranged so that their probes are aligned along a first vertical axis crossing the axis of said annular body, and so that their injectors are also aligned along a second vertical axis offset by a predetermined spacing screw -vis this first vertical axis;
- said measuring head comprises two second so-called measuring devices aligned along a second sliding axis;
- said two second measuring devices are arranged so that their probes are aligned along a first horizontal axis crossing the axis of said annular body, and so that their injectors are also aligned along a second horizontal axis offset by a predetermined screw spacing - opposite this first horizontal axis;
- said measuring head is also mounted to slide in a motorized manner in transverse and vertical directions;
- said device comprises distance sensors each capable of measuring the distance separating it from said tubular wall of the pipe so as to enable the centering of this tubular wall on the axis of said annular body;
- said distance sensors are arranged on said annular body being distributed angularly in a regular manner around the axis of this body; and or
- said device comprises means for measuring the length of said tubular wall of the pipe.

The presentation of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration but not limitation, with reference to the appended drawings, in which:

represents a three-quarter perspective view of an automated device according to the invention for measuring the thickness of tubular pipes by ultrasound;

is an enlargement from another angle of part of the device of the ;

represents a perspective view of the measuring head of the device of the ;

is a perspective view of one of the measuring devices included in the measuring head of the ; And

represents a perspective view from another angle of the measuring device of the .

There represents an automated device according to the invention 1 for measuring the thickness of tubular pipes by ultrasound.

As shown on this , the measuring device 1 consists of a frame 100 intended to accommodate a tubular pipe 2 to be inspected and on which a measuring head 200 is movably mounted.

We define in relation to this measuring device 1 an orthogonal reference frame XYZ comprising three perpendicular axes in pairs, namely:
- an X axis, defining a longitudinal, horizontal direction,
- a Y axis, defining a transverse, horizontal direction, which with the X axis defines a horizontal XY plane, and
- a Z axis, defining a vertical direction, perpendicular to the horizontal XY plane.

In the remainder of the description and with reference to the reference defined above, the terms "longitudinal" or "longitudinally" will refer to a direction parallel to the axis direction parallel to the Y axis, and the terms "vertical" or "vertically" will refer to a direction parallel to the Z axis.

The support frame 100 comprises a metal frame 110 made by mechanical welding and equipped with four feet 111 through which it rests on the ground.

This support frame 100 also comprises two support elements 120, 130 arranged opposite each other and intended to support the two ends of the tubular wall 3 of a pipe 2 extending longitudinally between two connectors 4, here of the union type of hammer.

Each support element 120, 130 comprises a rectangular plate 121, 131 extending along a vertical transverse plane and provided in its upper part with a semicircular receiving notch 122, 132 whose diameter is advantageously chosen to allow the reception of a wide range of pipes having tubular walls of different diameters.

The first support element 120 is fixedly mounted on the chassis 110, while the second support element 130 is mounted movably with longitudinal sliding on this same chassis, so as to allow their longitudinal spacing to be adjusted to the length of the tubular wall 3 of conduct 2.

The support frame 100 further comprises means 140 for measuring the length of this tubular wall 3, these means consisting in this case of a laser-type distance sensor installed on the plate 121 of the first fixed support element 120.

The distance sensor 140 is able to send a laser beam oriented longitudinally towards the plate 131 of the second mobile support element 130 which will reflect part of it towards this sensor.

Measuring the delay separating the emission of the ray from the reception of its reflected part makes it possible to determine the distance between the sensor 120 and this plate 122, and thereby the length of the tubular wall 3 of the pipe 2.

Alternatively, the distance sensor used may be of a different type, for example ultrasonic.

The measuring head 200 is mounted to slide in a motorized manner with respect to the support frame 100 along the longitudinal axis movable to slide in a motorized manner with respect to this support frame 100 along the transverse Y and vertical Z axes.

To do this, this measuring head 200 is fixed on a lifting plate 150 (visible on the ) movable vertically in a motorized manner with respect to a housing 160 mounted sliding in a motorized manner on a transverse rail 170, the two ends of which are mounted sliding on two longitudinal rails 180.

The measuring head 200 comprises an annular metal body 210 extending along a vertical and planned transverse mean plane, as illustrated in Figures 1 and 2, to surround the tubular wall 3 of the pipe 2.

The annular body 210 consists of a main C-shaped part 211 fixedly mounted on the lifting plate 150, and a curved closing branch 212 mounted pivotally articulated along a longitudinal axis by its upper end on the end upper part of the main part 211, between a raised position not shown in which this branch 212 extends above the main part 211 so as to allow the latter to envelop the tubular wall 3 of the pipe 2 via a transverse movement of the measuring head 200, and a lowered position illustrated by Figures 1 to 3 and where this branch 212 closes at least partially this annular body 210.

An electric cylinder 213 connecting the top of the main part 211 and the curved closing branch 212 also ensures the retention of this branch 212 in the raised position against the force of gravity.

The measuring head 200 also includes four identical upper 230, lower 231, and side 232, 233 measuring devices, arranged on the annular body 210 being distributed angularly in a regular manner (at 90° from each other) around the axis of this body 210.

Aligned along the same vertical axis, the upper 230 and lower 231 measuring devices are mounted movable to slide along this vertical axis via respective linear actuators 240, 241 secured to the main part 211 of the annular body 210, between a retracted position illustrated on Figures 2 and 3, and a maximum advanced position not shown in which they project inside this annular body 210.

Aligned along the same horizontal axis, the lateral measuring devices 232 and 233 are mounted movable to slide along this horizontal axis via respective linear actuators 242, 243 secured respectively to the main part 211 and the branch 212 of the annular body 210, between a rearward position illustrated in Figures 2 and 3, and a maximum advanced position not shown in which they project inside this annular body 210.

With reference to Figures 4 and 5, each measuring device 230, 231, 232, 233 comprises a hollow housing 234 housing an ultrasonic probe 235 capable of measuring the thickness of the tubular wall 3 of the pipe 2 at the level of the zone contact with said probe.

Powered by an electrical cable not shown which connects to the two connectors 235A, 235B, the probe 235 comprises a pellet 235C projecting out of the housing 234 and is designed to come into contact with the tubular wall 3 of the pipe 2.

As illustrated by transparency on the and in order to optimize the contact of this pellet 235C with this tubular wall 3 of the pipe 2, the probe 235 is advantageously mounted movable to slide with respect to the housing 234 along an axis parallel to the sliding axis of this last, between a retracted position and a protruding position, being urged towards its protruding position by a compression spring 236.

Furthermore and in order to avoid the presence of air blades between the pellet 235C of probe 235 and the external face of the wall 3 of the pipe 2 which would disrupt the proper propagation of the ultrasonic waves through this wall 3, each device measurement 230, 231, 232, 233 comprises an injector 237 also housed in the housing 234 and being equipped with a nozzle 237A capable of ejecting a coupling fluid on this external face of the wall 3 at the level of the measurement zone of the corresponding probe 235 before coming into contact with this wall 3.

Conventionally presented in the form of a liquid, a gel or a non-toxic paste, the coupling fluid is sucked up by a pump connected by a pipe not shown connecting to the orifice 238 to a reservoir also not shown. The injector 237 is thus capable of ejecting under pressure a determined quantity of this fluid via the nozzle 237A and thanks to a valve 237B electrically controlled by a cable 239.

As illustrated by Figures 3 and 4, the upper 230 and lower 231 measuring devices are arranged so that their ultrasonic probes 235 are aligned along a first vertical axis V ₁ crossing the axis A of the annular body 210, and so that their injectors 237 are also aligned along a second vertical axis V ₂ offset transversely by a predetermined spacing e with respect to this first vertical axis V ₁ .

In the same way, the lateral measuring devices 232 and 233 are arranged so that their ultrasonic probes 235 are aligned along a first horizontal axis H ₁ crossing the axis A of the annular body 210, and so that their injectors 237 are also aligned along a second horizontal axis H ₂ offset vertically by this same predetermined spacing e with respect to this first horizontal axis H ₁ .

The measuring head 200 finally comprises three distance sensors 250, 251, 252 arranged on the annular body 210 being advantageously distributed angularly in a regular manner (at 120° from each other) around the axis of this body 210 and capable each to measure the distance separating it from the tubular wall 3 of the pipe 2, so as to enable the centering of this tubular wall 3 on the axis of the annular body 210.

We will now describe in detail the operation of the measuring device 1 according to the invention.

In its rest configuration, the measuring head is arranged at a first end of the transverse rail 170 and occupies its most rearward longitudinal position located just in front of the fixed support element 120.

The opening of the main C-shaped part 211 of its annular body 210 is turned towards the second end of this transverse rail 170, with the closing branch 212 which occupies its raised position.

Firstly, the movable support element 130 is moved so that its longitudinal spacing from the fixed support element 120 corresponds to the length of the tubular wall 3 of the pipe 2.

We then position the pipe 2 on the support frame 100 so that the two ends of its tubular wall 3 come to rest on the support elements 120 and 130.

The distance sensor 140 can therefore measure the length of this tubular wall 3 and determine from this length the longitudinal movement step of the head 200 which will be applied between two thickness measurement operations carried out on pipe 2.

The measuring head 200 is then moved transversely towards the pipe 2 so as to surround its tubular wall 3.

The branch 212 can then be lowered so as to at least partially close the annular body 210.

From the distance measurements to the tubular wall 3 of the pipe 2 carried out by the distance sensors 250, 251, 252, the measuring head 200 is moved vertically into a centering position in which the respective axes of the annular body 210 and of the tubular wall 3 are combined so that all of the probes 235 extend along radial axes to that of this tubular wall 3.

The measuring head 200 is then moved vertically by the value of the predetermined spacing e so that the injectors 237 of the lateral measuring devices 232, 233 are aligned along the horizontal diametric axis of this tubular wall 3 of the pipe 2.

These lateral measuring devices 232, 233 then slide transversely until the nozzles 237A of their injectors 237 are positioned near this tubular wall 3, then coupling fluid is ejected from these nozzles 237A on the external face of the wall tubular 3.

These two lateral measuring devices 232, 233 then return to their original position and then the measuring head 200 returns to its centering position.

This measuring head 200 is then moved transversely by the value of the predetermined spacing e so that the injectors 237 of the upper 230 and lower 231 measuring devices are aligned along the vertical diametric axis of this tubular wall 3 of the pipe 2 .

These upper 230 and lower 231 measuring devices then slide vertically until the nozzles 237A of their injectors 237 are positioned near this tubular wall 3, then coupling fluid is ejected from these nozzles 237 on the wall 3.

These two upper 230 and lower 231 measuring devices then return to their original position and then the measuring head 200 returns to its centering position.

The upper 230, lower 231 and lateral 232, 233 measuring devices then slide simultaneously respectively vertically and horizontally until the pellets 235C of their respective probes 235 come to rest, under elastic stress of the springs 236, against the tubular wall 3 at the level of the four measuring zones previously covered with coupling fluid.

The four probes 232 then simultaneously measure the thickness of the tubular wall 3 at these four measuring zones, then the four measuring devices 230, 240, 250, 260 return to their original position.

The measuring head 200 then advances longitudinally at the previously defined step.

The steps described in paragraphs [62] to [69] are then reproduced so as to obtain four new thickness measurements of the tubular wall 3 of the pipe 2 at the level of a second longitudinal zone of this wall 3, then the measuring head 200 advances again longitudinally at the previously defined pitch to a third longitudinal zone of the wall 3 and so on to the second end of the latter.

According to alternative embodiments not shown of the device according to the invention, the measuring head can also be mounted movable to rotate in a motorized manner on itself so as to allow it to follow the profile of the curved tubular wall of a pipe to inspect.

According to other embodiment variants not shown, the number and arrangement of the measuring devices and/or distance sensors arranged on the annular body of the measuring head may also differ.

The ultrasonic probe and the injector of each measuring device can, for example, be spaced apart longitudinally rather than transversely or vertically. Such a design has the advantage of limiting the movements of the measuring head to eject the coupling fluid on the four measuring zones. The head is then simply moved longitudinally by the value of this spacing, all of the measuring devices then slide simultaneously so that the injector nozzles are positioned close to the tubular wall of the pipe, and the four injectors simultaneously eject coupling fluid on the four measuring zones.

However, this design has the disadvantage of causing the pellets of the ultrasonic probes to come into contact with areas of the tubular wall devoid of coupling fluid when positioning the nozzles of the injectors close to the tubular wall of the pipe, which has tends to lead to premature wear of the probes.

According to yet other embodiment variants not shown:
- the measuring device according to the invention can also comprise an electronic label reader capable of reading information mentioned on a label affixed to the pipe and making it possible, for example, to detect the reference and/or certain parameters of the pipe (length, diameter, profile, etc.) in order to adapt the measurement strategy accordingly;
- the pipe support elements are adjustable in height while the measuring head is fixed vertically; and or
- the distance sensors making it possible to center the tubular wall of the pipe on the axis of the annular body of the measuring head are arranged on the support frame and not on the measuring head.

In general, it is recalled that the present invention is not limited to the embodiments described and represented, but that it encompasses any variant of execution within the reach of those skilled in the art.

Claims (10)

1. Automated device for measuring the thickness (1) of tubular pipes (2) by ultrasound, characterized in that it comprises:
   - a frame (100) comprising support elements (120, 130) capable of supporting said pipe (2);
   - a measuring head (200) mounted movable to slide in a motorized manner vis-à-vis said frame (100) along the tubular wall (3) of said pipe (2) and comprising an annular body (210) capable of come to surround said tubular wall (3), this measuring head (200) further comprising at least one measuring device (230, 231, 232, 233) mounted movable to slide on said annular body (210),
   each said measuring device (230, 231, 232, 233) comprising an ultrasonic probe (235) capable of measuring the thickness of said tubular wall (3) at the level of a measuring zone located in contact with it, as well that an injector (237) equipped with a nozzle (237A) capable of ejecting a coupling fluid on said tubular wall (3) at each said measuring zone before it comes into contact with said probe (235).
2. Automated thickness measuring device (1) according to claim 1, characterized in that said measuring head (200) comprises several said measuring devices (230, 231, 232, 233) arranged on said annular body (210) in being distributed angularly in a regular manner around the axis of this body (210).
3. Automated thickness measuring device (1) according to claim 2, characterized in that said measuring head (200) comprises two first said measuring devices (230, 231) aligned along a first sliding axis.
4. Automated thickness measuring device (1) according to claim 3, characterized in that said two first measuring devices (230, 231) are arranged so that their probes (235) are aligned along a first vertical axis (V ₁ ) crossing the axis (A) of said annular body (210), and so that their injectors (237) are also aligned along a second vertical axis (V ₂ ) offset by a predetermined spacing (e) opposite of this first vertical axis (V ₁ ).
5. Automated thickness measuring device (1) according to one of claims 3 or 4, characterized in that said measuring head (200) comprises two second said measuring devices (232, 233) aligned along a second sliding axis .
6. Automated thickness measuring device (1) according to claim 5, characterized in that said two second measuring devices (232, 233) are arranged so that their probes (235) are aligned along a first horizontal axis (H ₁ ) crossing the axis (A) of said annular body (210), and so that their injectors (237) are also aligned along a second horizontal axis (H ₂ ) offset by a predetermined spacing (e) opposite of this first horizontal axis (H ₁ ).
7. Automated thickness measuring device (1) according to one of claims 1 to 6, characterized in that said measuring head (200) is also mounted to slide in a motorized manner in transverse and vertical directions.
8. Automated thickness measuring device (1) according to one of claims 1 to 7, characterized in that it comprises distance sensors (250, 251, 252) each capable of measuring the distance separating it from said tubular wall (3) of the pipe (2) so as to enable the centering of this tubular wall (3) on the axis of said annular body (210).
9. Automated thickness measuring device (1) according to claim 8, characterized in that said distance sensors (250, 251, 252) are arranged on said annular body (210) being distributed angularly in a regular manner around the axis of this body.
10. Automated thickness measuring device (1) according to one of claims 1 to 9, characterized in that it comprises means (140) for measuring the length of said tubular wall (3) of the pipe (2) .