KR20160110652A - Test apparatus for detecting defect of pipe using reomte field eddy current - Google Patents

Abstract

The present invention relates to a test device to detect a defect of a pipe by using a remote field eddy current. According to the present invention, the test device to detect a defect of a pipe by using a remote field eddy current includes: an exciter part stored in a pipe, and forming a magnetic field by receiving a current; a receiver part separated from the exciter part in a longitudinal direction of the pipe, and detecting the magnetic field; a shaft equipped with the exciter part and the receiver part; and a support part installed on the shaft, and attached to the inner wall of the pipe. Therefore, the present invention is capable of having the excellent reliability of measurement by preventing the eccentricity of the exciter part and attaching the receiver part to the pipe.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a piping defect inspection apparatus using a long-field eddy current,

The present invention relates to a piping defect inspection apparatus using a long-field eddy current, and more particularly, to a piping defect inspection apparatus using a far-field eddy current which is excellent in measurement reliability and capable of conducting a test of piping defects under various conditions .

When a low frequency alternating current is applied to a metal pipe, a magnetic field is formed even in a far field region at a certain distance from the coil. In this area, it is possible to non-destructively evaluate the internal and external defects and the thickness variation of the conductive pipe by inserting the probe coil inside the pipe. This is called the Remote Field Eddy Current (RFEC) technology. The far-field eddy current technology was used to evaluate the external corrosion of the fluid tube, and recently it has been applied in various fields such as heat exchanger customs pipe, oil pipeline, and nuclear power plant.

Conventionally, a connecting rod is installed between an exciter and a receiver, and then a connecting rod is pushed through a separate rod or the like in the pipe to detect a defect in the pipe. In this case, it is not easy to adjust the distance between the exciter and the receiver, eccentricity of the exciter may occur, the receiver may not know whether it is in contact with the inner wall of the pipe, and the moving distance of the exciter and receiver may not be known. There is a problem.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a piping defect inspection apparatus using a far-field eddy current excellent in measurement reliability by preventing the eccentricity of the exciter base and making the receiver unit adhere to the pipeline .

In addition, it is possible to provide a piping defect inspection apparatus using a far-field eddy current capable of replacing a configuration affecting a magnetic field and adjusting a gap between the receiver unit and the excitation base, .

According to the present invention, there is provided an apparatus for inspecting piping defects using a long-field eddy current, the apparatus comprising: an exciter base accommodated in the pipeline and forming a magnetic field by applying an electric current; A receiver unit that is spaced apart from the exciter base along the longitudinal direction of the pipe in the pipe and detects the magnetic field; A shaft on which the exciter base and the receiver are mounted; And a supporter mounted on the shaft and closely contacting the inner wall of the pipe. The apparatus for inspecting piping defects using a long-field eddy current is provided.

Preferably, the exciter base includes a coil body on which the coil is wound, and a flange that is replaceably installed at both ends of the coil body.

Here, the receiver unit may include: a receiver base surrounding the shaft; a receiver for detecting a magnetic field; And a receiver support mounted on the receiver base and supporting the receiver in a radial direction of the pipe.

Preferably, the receiver base is movable along the outer surface of the shaft.

The receiver support includes a first link linked with the receiver base, a second link linked with the first link and the receiver, respectively; And an elastic part linked to the receiver base and elastically supporting the first link.

The apparatus may further include a driving unit mounted on the shaft for moving the shaft.

Here, the driving unit may include an odometer.

The driving unit may include a body mounted on the shaft, and a main wheel mounted on the body and moving along the inner wall of the pipe upon receiving external power.

The driving unit may further include an auxiliary wheel mounted on the body.

Here, the support part includes a support base mounted on the shaft, a support wheel part hinged to the support base, And an elastic support portion for elastically supporting the support wheel portion in the radial direction of the pipe.

The support base includes a protrusion protruding outward from an outer circumferential surface of the support base. The support wheel includes a wheel shaft hinged to the protrusion, and a support wheel coupled to the wheel shaft, A spring support portion provided parallel to the longitudinal direction of the pipe and coupled to the projection portion; an elastic transmission portion movably provided on the spring support portion and engaged with the wheel shaft; And a spring mounted on the spring support portion and elastically supporting the elastic transmission portion in a direction in which the wheel is in close contact with the inner wall of the pipe.

According to the present invention, there is provided an apparatus for testing piping defect defects using a long-field eddy current with excellent measurement reliability.

Further, according to the present invention, there is provided an apparatus for testing piping defect defects using a far-field eddy current capable of conducting a test of piping defects under various conditions.

Further, since the exciter base is not eccentric by the support portion, the measurement reliability is excellent.

Further, since the receiver portion is elastically supported in the pipe radial direction, the receiver portion is always in close contact with the inner wall of the pipe, and the measurement reliability is excellent.

In addition, it is possible to change the configuration affecting the magnetic field so that the experiment can be performed under various conditions.

Further, by making the interval between the receiver section and the excitation section adjustable, the experiment can be performed under various conditions.

In addition, by conducting experiments under various conditions, it is possible to calculate optimum conditions in the case of pipeline defect inspection using distant field eddy currents.

FIG. 1 is a perspective view of a piping defect inspection apparatus using a long-field eddy current according to an embodiment of the present invention,
FIG. 2 is a side view of an apparatus for testing piping defect defects using the long-field eddy current of FIG. 1,
FIG. 3 is an exploded perspective view of a piping defect inspection apparatus using the long-field eddy current of FIG. 1,
FIG. 4 is an exploded perspective view of an excitation base of a piping defect inspection experiment apparatus using the far-field eddy current of FIG. 1,
FIG. 5 is a perspective view of a receiver portion of a pipette defect testing apparatus using the far-field eddy current of FIG. 1,
FIG. 6 is a perspective view of a supporter portion of a piping defect inspection experiment apparatus using the long-field eddy current of FIG. 1,
FIG. 7 is a perspective view of a driving unit of a pipe defect inspection apparatus using the long-field eddy current of FIG. 1,
FIG. 8 is an experimental graph of a piping defect inspection apparatus using the far-field eddy current of FIG. 1; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a piping defect inspection apparatus using a long-field eddy current according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a piping defect inspection apparatus using a long-field eddy current according to an embodiment of the present invention, FIG. 2 is a side view of a piping defect inspection apparatus using a far-field eddy current of FIG. 1, Fig. 3 is an exploded perspective view of a piping defect inspection apparatus using a long-term eddy current of the pipe. 1 to 3, an apparatus 100 for testing a pipe defect using a long-field eddy current according to an embodiment of the present invention includes a shaft 110, an exciter base 120 mounted on the shaft 110, A receiver 130 mounted on the shaft 110, a supporter 140 mounted on the shaft 110, and a driving unit 150 mounted on the shaft 110.

The shaft 110 is disposed on the central axis of the pipe P as a structure in which the exciter base 120, the receiver 130, the support 140 and the drive 150 are installed. The arrangement of the shaft 110 is maintained by the support portion 140.

FIG. 4 is an exploded perspective view of an excitation base of a piping defect inspection experiment apparatus using the far-field eddy current of FIG. 1; FIG.

The excitation base 120 is configured to generate a magnetic field for measuring a defect of the pipe P by receiving a current from an external power source.

The remote field eddy current (RFEC) technique is a technique that, in a test object such as a pipe (P), electromagnetic energy generated by an exciter passes through a pipe wall, flows through a certain distance along the outer wall, A magnetic field is formed when a low-frequency alternating current is passed through the coil C of the excitation unit 120 as a kind of electromagnetic application non-destructive testing using through-wall transmission characteristics.

The excitation base 120 is accommodated in the pipe P and arranged so as to have the same axis as the pipe P. [ That is, the excitation base 120 is provided in a substantially cylindrical shape smaller than the diameter of the pipe P, and the center axis is disposed so as to be equal to the central axis of the pipe P. This arrangement in which the exciter base 120 is not eccentrically held is continuously maintained by the support unit 140, and thus the measurement reliability of the pipette defect testing apparatus 100 using the far-field eddy current is excellent (see FIG. 2 )

The magnetic field formed by passing an alternating current through the coil C flows in two ways along the axis of the pipe P. [ The first is the direct magnatic field generated by the exciter. The direct magnetic field is rapidly attenuated along the pipe axis due to the action of eddy currents generated in the wall of the pipe P while interacting with the pipe P near the excitation base 120. [ It is possible to overcome the skin effect of the wall of the pipe (P) near the excavator base (120) and to transmit the pipe (P) along the outside of the pipe (P) As shown in Fig. Since the magnetic field is larger than the rapidly attenuated direct magnetic field at a certain distance in the axial direction of the pipe (P), it penetrates into the pipe (P) again and enters the second magnetic field, indirect magnetic field. The region where the indirect magnetic field is formed is called the remote field.

The coil C is wound around the coil body 121 to receive an alternating current and flanges 122 are provided at both ends of the coil body 121 to prevent the coil C from coming off. Referring to FIG. 4, the flange 122 is detachably coupled to the coil body 121. By varying the configuration affecting the magnetic field during excitation of the excitation 120, the effect on the far field eddy current signal under various conditions can be assessed. That is, by experimentally replacing the flange 122 with the coil body 121 and replacing the flange 122 with aluminum, plastic, stainless steel, steel, or the like, It is possible to acquire the phase and amplitude data of the device and optimize the device configuration.

5 is a perspective view of a receiver portion of a piping defect inspection apparatus using the far-field eddy current of FIG. 1;

5, the receiver unit 130 measures a defect of the pipe P by detecting an indirect magnetic field generated by the exciter base unit 120. The receiver unit 130 includes a receiver base 131, A receiver 132, and a receiver support 133.

The receiver unit 130 is installed in a remote field area inside the pipe P and is provided such that the receiver 132 is brought into close contact with the inner wall of the pipe P so that the magnetic field generated by the skin effect And the defects of the pipe P are measured. The receiver 132 is provided with a detection coil and can detect a magnetic field and is supported in the radial direction of the pipe P by the receiver support portion 133 and brought into close contact with the inner wall of the pipe P. [

The receiver base 131 is configured to move the receiver 132 along the axial direction of the pipe P. [ The receiver base 131 is disposed to surround the shaft 110 and is movable along the outer surface of the shaft 110. The interval between the receiver 132 and the excitation unit 120 is adjusted in accordance with the movement of the receiver base 131 and the optimum distance range is measured through the change in transmission / reception interval between the exciter 120 and the receiver 132 And the effect on the far-field eddy current signal can be evaluated according to each interval.

The receiver support portion 133 is a structure for closely fitting the receiver 132 to the inner wall of the pipe P. [ The first link 133a is linked and rotatable on the receiver base 131 and the second link 133b is linked to the first link 133a and the receiver 132 to be rotatable. On the other hand, the first link 133a is elastically supported in the radial direction of the pipe P by the elastic portion 133c. Therefore, even when the pipe P is tested with a different pipe diameter, the receiver 132 is closely contacted to the inner wall of the pipe P by the elastic portion 133c, so that the pipe defect inspection device 100 using the far- Measurement reliability is excellent.

6 is a perspective view of a supporter portion of a piping defect inspection apparatus using the long-field eddy current of FIG. 1;

The support part 140 is arranged so that the shaft 110 and the excitation part 120 are not eccentric but have the same central axis as the central axis of the pipe P. [

The support base 141 includes a plurality of protrusions 141a formed with a hollow portion to which the shaft 110 is inserted and which protrudes outward from the outer circumferential surface. The support wheel 142 is rotatably coupled to the wheel shaft 142a by being hinged to the protruding portion 141a so that the support wheel 142a is brought into contact with the inner wall of the pipe P of the support wheel 142b by the rotation of the wheel shaft 142a Is determined.

The wheel shaft 142a is elastically supported by the elastic support portion 143 in such a direction that the support wheel 142b is in close contact with the inner wall of the pipe P. [ That is, the wheel shaft 142a is elastically supported in such a direction that the angle between the wheel shaft 142a and the hypothetical axis parallel to the longitudinal direction of the pipe P becomes large.

The spring support portion 143a is provided to be parallel to the longitudinal direction of the pipe and is mounted on the protrusion 141a. The elastic transmission portion 143e is movably provided on one end of the spring support portion 143a and the other end is connected to the wheel shaft 142a . A spring 143d is mounted on the spring support portion 143a to transmit an elastic force to the elastic transmission portion 143e so that the wheel shaft 142a is elastically deformed in a direction in which the support wheel 142b is in close contact with the inner wall of the pipe P. [ .

A plurality of protrusions 141a, a support wheel portion 142 and an elastic support portion 143 are provided so that the plurality of support wheels 142b are in close contact with the inner wall of the pipe P so that the shaft 110 and the exciter base 120 And has the same central axis as the central axis of the pipe P without being eccentric. Therefore, the measurement reliability of the pipe defect inspection apparatus 100 using the long-term eddy current is excellent.

FIG. 7 is a perspective view of a driving unit of a piping defect inspection apparatus using the long-field eddy current of FIG. 1;

The driving unit 150 moves the shaft 110 along the longitudinal direction of the pipe P so that the excitation part 120 and the receiver part 130 are moved to measure the defects in the respective areas of the pipe P .

The driving unit 150 includes a body 151 mounted on the shaft 110 and a main wheel 152 and an auxiliary wheel 153 mounted on the body 151.

The main wheel 152 is driven by an external power source and the body part 151 connected to the main wheel 152 is moved to move the shaft 110. The main wheel 152 is brought into close contact with the pipe P so that the body part 151 is prevented from sagging downward. On the other hand, an odometer (not shown) is installed in the driving unit 150, and the odometer is installed in the main wheel 152 in this embodiment. By providing the odometer on the main wheel 152, the moving distance of the exciter base unit 120 and the receiver unit 130 can be accurately known. The auxiliary wheel 153 assists the movement of the shaft 110 along the main wheel 152.

The driving unit 150 is provided to be replaceable. By varying the configuration affecting the magnetic field, such as the excitation 120, the effect on the far field eddy current signal under various conditions can be assessed. Accordingly, in the present invention, by experimenting with replacement of the body part 151 with aluminum, plastic, stainless steel, steel or the like, it is possible to calculate the influence on the magnetic field according to the change in the material of the body part 151, .

Hereinafter, the operation of one embodiment of the piping defect inspection experiment apparatus using the above described far-field eddy current will be described.

First, the spring 143d of the support part 140 is compressed, and the elastic part 133c of the receiver part 130 is compressed and inserted into the pipe P.

The spring 143d is restored to transmit the elastic force to the elastic transmission portion 143e and the wheel shaft 142a is elastically supported in the direction in which the support wheel 142b is in close contact with the inner wall of the pipe P, So that the support wheel 142b is brought into close contact with the inner wall of the pipe P. [ Eccentricity between the shaft 110 and the exciter base 120 is prevented by the plurality of support wheels 142b being in close contact with the inner wall of the pipe P. [ Further, the elastic portion 133c is restored and the first link 133a is elastically supported in the radial direction of the pipe P. The receiver 132 is brought into close contact with the inner wall of the pipe P.

A magnetic field is formed when an AC current is applied to the coil C while the exciter base 120 is not eccentric and the receiver 132 is in close contact with the inner wall of the pipe P. [ The direct magnetic field is rapidly attenuated along the pipe axis due to the action of the eddy current generated in the wall of the pipe P while interacting with the pipe P near the excitation base 120. The indirect magnetic field transmitted through the pipe P The receiver 132 detects it. Measure the defects of the pipe (P) from the detected indirect magnetic field. Since the exciter base 120 is not eccentric and the receiver 132 is in close contact with the inner wall of the pipe P, the measurement reliability of the pipe defect inspection apparatus 100 using the far field eddy current is excellent.

FIG. 8 is an experimental graph of a piping defect inspection apparatus using the far-field eddy current of FIG. 1; FIG.

The flange 122 of the excitation base 120 may be separated and replaced with aluminum, plastic, stainless steel or steel or the receiver base 131 may be moved so that the distance between the receiver 132 and the excitation base 120 is varied Or a factor affecting the magnetic field or an interval between the receiver 132 and the excitation unit 120 by experimenting with the drive unit 150 or the shaft 110 replaced with aluminum, plastic, stainless steel, (P) defect measurement test under various conditions can be facilitated. As shown in the graph of FIG. 8, an optimum device can be constructed by evaluating the influence on the far-field eddy current signal by measuring the magnitude of the magnetic field under various conditions.

Therefore, according to the present invention, there is provided a piping defect inspection experiment apparatus using a far-field eddy current excellent in measurement reliability by preventing the eccentricity of the excitation base and bringing the receiver into close contact with the piping.

In addition, it is possible to provide a piping defect inspection apparatus using a far-field eddy current capable of replacing a configuration affecting a magnetic field and adjusting a gap between the receiver unit and the excitation base, Is provided.

The scope of the present invention is not limited to the above-described embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

100: Experiment equipment for piping defects using long-term eddy current
110: shaft 120: female donation
130: Receiver part 140: Support part
150:

Claims (11)

An apparatus for inspecting piping defects using a long-term eddy current,
An excitation base accommodated in the pipe and receiving a current to form a magnetic field;
A receiver unit that is spaced apart from the exciter base along the longitudinal direction of the pipe in the pipe and detects the magnetic field;
A shaft on which the exciter base and the receiver are mounted; And
And a support part mounted on the shaft and closely attached to the inner wall of the pipe. The method according to claim 1,
Wherein the excitation base comprises:
A coil body wound around the coil body; and a flange installed at both ends of the coil body so as to be interchangeable. The method according to claim 1,
The receiver unit includes:
A receiver base surrounding the shaft; a receiver for detecting a magnetic field; And a receiver support mounted on the receiver base and supporting the receiver in a radial direction of the pipe. The method of claim 3,
Wherein the receiver base is provided to be movable along the outer surface of the shaft. The method of claim 3,
The receiver-
A first link linked to the receiver base; a second link linked to the first link and the receiver, respectively; And an elastic part that is linked to the receiver base and that elastically supports the first link. The method according to claim 1,
Further comprising a driving unit mounted on the shaft for moving the shaft, wherein the driving unit moves the shaft. The method according to claim 6,
Wherein the driving unit includes an odometer. ≪ RTI ID = 0.0 > 8. < / RTI > The method according to claim 6,
The driving unit includes:
And a main wheel installed on the body and moving along an inner wall of the pipe under an external power supply, the apparatus comprising: a body mounted on the shaft; . 9. The method of claim 8,
Wherein the driving unit further comprises an auxiliary wheel installed in the body part. ≪ RTI ID = 0.0 > 8. < / RTI > The method according to claim 1,
The support unit
A support base mounted on the shaft, a support wheel portion hinged to the support base, And an elastic support part for elastically supporting the support wheel part in the radial direction of the pipe. 11. The method of claim 10,
Wherein the support base includes a protrusion protruding outward from an outer peripheral surface,
Wherein the support wheel portion includes a wheel shaft hinged to the protruding portion, and a support wheel coupled to the wheel shaft,
The elastic support portion
A spring support portion provided parallel to the longitudinal direction of the pipe and coupled to the projection portion; an elastic transmission portion movably provided on the spring support portion and engaged with the wheel shaft; And a spring mounted on the spring support part and elastically supporting the elastic transmission part in a direction in which the wheel is in close contact with the inner wall of the pipe.

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