JP2881658B2 - Ultrasonic testing equipment for pipe structures - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an ultrasonic flaw detector for a pipe structure, and more particularly to a method for ultrasonically flaw detecting a welded portion of a furnace wall support bracket of a boiler furnace wall from inside the furnace. Ultrasonic testing apparatus suitable for

[Conventional technology]

The furnace wall of a boiler is generally constructed by welding a steel strip 2 to a furnace wall tube 1 as shown in FIG. On the outside of the furnace wall tube 1, a furnace wall support 3 required for supporting the furnace wall is welded to the furnace wall tube 1 and a welding portion 6.
The outside of the furnace is entirely covered with a heat insulating material 5, and the heat insulating material 5 is also protected by the outer wall 4.

If the boiler is used for a long time, a crack may be generated in the welded portion 6, and if the crack is generated, the continuous use of the boiler is hindered. Therefore, conventionally, the outer wall 4 and the heat insulator 5
, And after the scale of the welded portion 6 is removed, magnetic particle testing or penetration testing is performed.

Further, the inside of the furnace wall tube 1 is filled with water 10 for propagating ultrasonic waves, and ultrasonic waves are incident on the inside surface of the furnace wall tube 1 by the ultrasonic transmission / reception probe 9, and the ultrasonic waves are converted into the furnace. A method has also been proposed in which water is propagated through the inner wall of the furnace wall tube 1 through the water 10 inside the furnace wall tube 1 and further transmitted to the outer tube wall of the furnace wall tube 1 so that the welded portion 6 is subjected to ultrasonic flaw detection. No. 63-6459).

[Problems to be solved by the invention]

In general, the above-described flaw detection of the welded portion 6 of the furnace wall support fitting 3 by the magnetic particle flaw detection and the penetrant flaw detection is performed by using the outer wall 4 and the heat insulating material 5.
To remove after removing, and because the flaw detection range is vast,
The removal of the outer wall 4 and the heat insulating material 5 and the recovery after the flaw detection require a great deal of man-hours. In addition, the water 10 to be filled into the furnace wall tube by the conventional ultrasonic flaw detection method needs to be strictly controlled in water quality such as deoxidation treatment and chemical treatment so as not to corrode the inner surface of the furnace wall tube. These water quality controls are always necessary during the flaw detection, and furthermore, a large amount of water 10 is charged, requiring a large number of man-hours.

Further, flaw detection of the welded portion 6 of the furnace wall support fitting 3 is performed by using a periodic inspection period of the boiler equipment specified by law. In this case, during the periodical inspection period, a cutting operation of the furnace wall tube 1 and a cleaning operation of the inside of the furnace wall tube 1 are also performed for the purpose of investigating the aging state of the furnace wall tube 1. For this reason, the conventional ultrasonic flaw detection method that cannot be performed unless the inside of the furnace wall tube is filled with water 10 cannot be performed in parallel with these operations.
The inspection period of the boiler has to be extended for flaw detection of the welded portion 6, and a decrease in the operation rate of the equipment is a problem.

On the other hand, a case where the welded portion 6 of the furnace wall support 3 is inspected without leakage by the ultrasonic flaw detection method will be described with reference to FIGS. 19 and 20. In order to detect the entire weld width of the welded portion 6 without flaws, the ultrasonic transmission / reception probe 9 repeats several scans at a predetermined pitch in the circumferential direction of the furnace wall tube 1 even in consideration of the ultrasonic effective beam width. There must be. In addition, it is necessary to perform these flaw detections twice in the forward and reverse directions (flaw detection from the A side and flaw detection from the B side) twice along the tube axis direction to determine whether there is a crack. Further, since the furnace wall tube 1 is not smooth, the scanning of the ultrasonic transmission / reception probe 9 becomes unstable, and the pressing force against the furnace wall tube surface cannot be constant.

For this reason, there is a problem that the inspection efficiency is low and the inspection accuracy is poor, and further, since the flaw detection range is wide, the probe is worn out, and there is also a problem in terms of economy.

In addition, in order to inspect the welded portion 6 of the furnace wall support bracket 3 by the ultrasonic flaw detection method, as shown in FIG. 21, an operator enters the furnace and directly inspects and collects an inspection record. However, the inside of the furnace was sealed, filled with dust of fuel ash, and furthermore, there was a problem in terms of safety and hygiene because the part to be inspected was located at a high place. Further, since all of these inspections and inspection record collection are performed by workers, human errors are likely to occur, and it is difficult to maintain highly accurate inspections over a wide inspection range.

For this reason, development of a new ultrasonic flaw detector is demanded.

The present invention has been made in view of the above circumstances, and by detecting a welded portion of a furnace wall support bracket of a furnace wall tube from the inside of the furnace without filling the inside of the furnace wall tube with water,
It is an object of the present invention to provide an ultrasonic flaw detector capable of significantly reducing the number of steps and performing inspections without flaw detection with high efficiency and with high accuracy and economical efficiency.

It is still another object of the present invention to provide an ultrasonic inspection apparatus capable of performing an ultrasonic inspection with safety and hygiene even when the inspection target is located at a high place in a dust environment in a furnace.

[Means for solving the problem]

In order to achieve the above-described object, a flaw detection apparatus according to the present invention includes an ultrasonic transmission probe including a plurality of transducers that project ultrasonic waves to a subject, and an ultrasonic wave that propagates through the subject. And a pair of ultrasonic receiving probes composed of the same number of transducers as the ultrasonic transmitting probe are arranged, and a pair of probes are arranged to face each other in the scanning direction. Then, the plurality of ultrasonic transmission probes are respectively arranged so as to project ultrasonic waves to different predetermined portions of the subject, and the plurality of ultrasonic reception probes are respectively provided at different predetermined portions of the subject. The ultrasonic waves reflected and propagated are arranged at positions where they can be received.

Desirably, a probe switching device for switching between the ultrasonic transmission probe and the ultrasonic reception probe for oscillation and reception in accordance with the scanning direction is further provided, and the ultrasonic transmission probe and the ultrasonic transmission probe are further provided. It is provided with means for urging the sound wave receiving probes slidably with respect to the scanning plane.

Further, the ultrasonic flaw detector according to the present invention, in which flaw detection is performed on the back surface of the subject from the front surface through an ultrasonic beam, the probe for axial flaw detection and the probe for circumferential flaw detection are provided on the subject surface. On the other hand, a longitudinal axis moving mechanism that moves in the longitudinal direction,
A scanning device including a vertical axis moving mechanism for moving the front-rear axis moving mechanism in the vertical direction, and a horizontal axis moving mechanism for moving the vertical axis moving mechanism in the horizontal direction; , A driving device for moving the front-rear axis moving mechanism, the vertical axis moving mechanism, and the horizontal axis moving mechanism, the axial defect detecting probe and the circumferential defect detecting probe. An ultrasonic flaw detector that transmits and receives flaw detection signals to the child,
A display device for displaying the flaw detection result in an image, a recording device for recording the flaw detection result, and an optimum control value for the driving device, the ultrasonic flaw detection device, the display device, and the recording device according to the flaw detection conditions, An arithmetic processing unit that controls the function of each device;
It is characterized by having.

[Action]

In the ultrasonic flaw detector according to the present invention, ultrasonic waves having an angle (α, θ) with respect to the tube axis are incident from the inside of the furnace substantially opposite to the welded portion and the tube axis, so that the ultrasonic waves are generated on the furnace wall. It propagates through the pipe members and reaches the weld. If there is a crack in the welded portion, the ultrasonic wave is reflected at the cracked portion, and can be received at a target position with respect to the tube axis at the position where the ultrasonic wave enters through the member of the furnace wall tube. . Therefore, the outer wall,
There is no need for work such as removal of the heat insulating material and the like, and there is no need to fill the inside of the furnace wall tube with a medium (water) for transmitting ultrasonic waves.

Further, since the plurality of transducers constituting the ultrasonic transmission probe are arranged so as to project ultrasonic waves to different predetermined portions of the subject, the transducers at the inspected portion (welded portion) are arranged. The effective beam can be widely distributed. Ultrasonic waves projected from the vibrators arranged in this manner are incident from the furnace inner tube wall on the side opposite to the part to be inspected, and propagate through the member of the specimen, thereby covering a wide area of the part to be inspected. To reach. If cracks or welds are present in the part to be inspected, the ultrasonic waves are reflected by the part, and the reflected ultrasonic waves also pass through the member of the object to be inspected, and the wall surface of the furnace inner tube on the opposite side of the part to be inspected. It is transmitted to. An ultrasonic receiving probe composed of a plurality of transducers arranged so as to be able to receive ultrasonic waves reflected / propagated at different predetermined parts of the subject is arranged on the tube wall, so that the probe is wide. Even ultrasonic waves reflected and propagated in a part of the inspection range can be received by any one of the plurality of transducers.

Even when flaw detection is performed in a wide range of the inspected portion (welded portion) without leakage, it is not necessary to repeat probe scanning at a predetermined flaw detection pitch. Further, the ultrasonic transmission probe and the ultrasonic reception probe are supported so as to be pressed against the object surface with a constant force while being in contact with the object, so that the object surface is not smooth. In both cases, the scanning of the probe is not unstable, the pressing force of the probe is constant, and wear can be prevented.

In addition, in the straddling scanning flaw detection method, a pair of probes (ultrasonic transmitting probe and ultrasonic receiving probe), which are arranged to face each other in the scanning direction, are connected to the outward path by a probe switching device. Since the flaw detection is performed in the forward and reverse directions (flaw detection from the A side and flaw detection from the B side) in the return-to-return direction, it is not necessary to perform the flaw detection twice by changing the direction of the probe.

In addition, the automatic ultrasonic flaw detector for a wall according to the present invention uses a horizontal axis moving mechanism, a vertical axis moving mechanism, and a front-rear axis moving mechanism that constitute a scanning device to form a furnace wall tube through an ultrasonic beam. A probe for flaw detection in the axial direction and a probe for flaw detection in the circumferential direction, which detect flaws on the outside of the furnace from the inside of the furnace, are placed laterally to the furnace wall.
The scanning device is configured to move three-dimensionally in the longitudinal direction and the front-back direction.
It can be moved freely by a traveling mechanism equipped with an electric hoist, etc., so even if the furnace wall support bracket welded part located at a high place can be ultrasonically flawed from inside the furnace, there is no need to remove the heat insulating material or the outer wall .

In addition, a driving device for rotating the motors of the horizontal axis moving mechanism, the vertical axis moving mechanism, and the front-rearward axis moving mechanism that constitute the scanning device, an axial defect detection probe, and a circumferential defect detection probe. An ultrasonic flaw detector that sends and receives flaw detection signals to the tentacles, a display that displays the flaw detection results on an image, and a recorder that records flaw detection results are installed at remote locations, and these devices are optimally controlled according to flaw detection conditions. Since it is controlled by the arithmetic processing unit that calculates the value, it is not necessary for the operator to enter the furnace and perform the inspection and collect the inspection record.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 illustrate the principle of ultrasonic flaw detection according to the present invention. FIG. 1 is a partially cutaway perspective view showing an example of ultrasonic flaw detection, and FIG. 2 is a furnace inside of FIG. FIG. 3 is a side view of FIG. 2, and FIG. 4 is a view taken along the line AA 'of FIG.

When detecting a crack in the welded portion 6 to be inspected, the ultrasonic transmission probe 7 and the ultrasonic reception probe 8 are applied to the furnace inner surface of the furnace wall tube 1 so that the furnace is located outside the furnace from inside the furnace. A crack generated in a weld 6 between a furnace wall tube 1 and a furnace wall support 3 is detected.
In this case, the refraction angle (θ) of the ultrasonic wave transmitting probe 7 and the ultrasonic wave receiving probe 8 and the angle (α) formed with the tube axis are determined by the following equation (1) due to a geometric relationship.

Here, α: the angle between the ultrasonic probe and the furnace wall tube axis L: the distance from the furnace wall tube center line to the ultrasonic wave incident position D: the distance from the position where the ultrasonic probe is applied to the part to be inspected Dimension θ: refraction angle of ultrasonic probe FIGS. 5 and 6 (side views of FIG. 5) show, for example,
7 schematically shows a flaw detection state when flaw detection is performed on a furnace wall having an outer diameter of 25.4 mm and a wall thickness of 4.2 mm, and flaw detection waveforms at that time are shown in FIGS. 7 to 10. Flaw detection is performed from two directions, forward and reverse, along the tube axis direction.

Here, when flaw detection is performed on the welded portion 6, first, flaw detection is performed from the B side in FIGS. 5 and 6, and as shown in FIGS. 8 and 10, a large reflected wave from the surface of the welded portion 6 is obtained as shown in FIGS. B returns. This situation is the same regardless of the presence or absence of cracks.

On the other hand, when the welded part 6 is inspected from the side A in FIGS. 5 and 6, if there is no crack, no reflected wave is seen as shown in FIG. 7, but if there is a crack, FIG. A reflected wave F from the crack is returned as shown in FIG. Therefore, based on the above equation (1), α, θ, and the like of each probe can be selected, and the flaw detection at the welded portion 6 can be performed by observing the flaw detection waveform.

In addition, although the above-mentioned example demonstrated the flaw detection method of the boiler furnace wall structure which welded the strip to the pipe, if the present invention is a pipe structure, even if something like a strip is not welded to the pipe, However, an ultrasonic wave is incident from the outer surface of the tube, propagates the ultrasonic wave through the tube member to the portion to be inspected, and the reflected wave from the portion to be inspected also passes through the tube member, and the reflected wave from the tube opposite to the portion to be inspected is exposed. Since it can be received on the surface, it can be applied to flaw detection of such a structure.

11 to 14 show an embodiment of the ultrasonic flaw detector of the present invention, FIG. 11 is an overall configuration diagram of the apparatus, and FIG.
FIG. 13 is a front view of the inside of the furnace showing a flaw detection situation by the apparatus of FIG. 11, FIG. 13 is a view taken along the line BB ′ of FIG. 12, and FIG.
It is an arrow view.

FIG. 11 shows a state where a metal-welded portion (not shown) attached to the outside of the furnace of the furnace wall tube 1 is inspected from inside the furnace. Numerals 9a and 9b in the figure are probes for ultrasonic transmission composed of a plurality of transducers for projecting ultrasonic waves from the inside of the furnace to the furnace wall tube 1, and numerals 10a and 10b are parts to be inspected outside the furnace. Reflection
This is an ultrasonic receiving probe composed of a plurality of transducers for receiving propagating ultrasonic waves inside the furnace.

The ultrasonic transmission probe 9a and the ultrasonic reception probe 10b are arranged to face each other with respect to the scanning direction. Have.

Each probe is fixed to the probe support 11 by a pin 14 so that each probe is located in the valley between the furnace wall tube 1 and the furnace wall tube 1, and is fixed to one end of the probe support 11. The shaft thus provided is fitted into a hole provided in the gantry 12, a spring 16 is wound around the shaft, and a screw 15 is provided at an end of the shaft.

In addition, the ultrasonic transmission probes 9a and 9b and the ultrasonic reception probes 10a and 10b each have a roller 13 at a contact portion with the furnace wall tube 1 and perform scanning following the furnace wall tube 1. Uneven furnace wall tube 1
Even in this case, stable scanning can be performed, and the pressing force against the furnace wall tube 1 can be kept constant by the action of the spring 16 mounted on the probe support lot portion and the sliding portion of the pedestal hole.

During the flaw detection, the couplant supply passages (not shown) are provided inside the ultrasonic transmission probes 9a and 9b and the ultrasonic reception probes 10a and 10b so that the couplant can be automatically supplied by other means. ) Is provided.

Ultrasonic transmitting probe 9a, 9b and ultrasonic receiving probe 1
The vibrators constituting 0a and 10b are as shown in FIG. 12 to FIG. In this embodiment, a welded portion 6 of a furnace wall support fitting 3 attached to a furnace outside of a furnace wall constituted by a furnace wall tube 1 having an outer diameter of 25.4 mm and a wall thickness of 4.2 mm is used for flaw detection. Transducers 9a and 9b have flaw detectors 19a, 19b and 19c, respectively.
Is composed of three transducers 20 for coupling and a cup rig check, and the ultrasonic receiving probes 10a and 10b are respectively provided with three transducers 19a ', 19b' and 19c 'for flaw detection and a coupling rig with three couplings. It is constituted by one of the check transducers 20.

Next, the operation of the ultrasonic flaw detector configured as described above will be described.

Transducer 19a for flaw detection constituting probe 9a for ultrasonic transmission
Are set at an angle α ₁ with the axis and a refraction angle θ ₁ so that the ultrasonic waves to be projected reach the central region of the welded portion. Then, the refractive angle theta ₁ at the crack or weld the weld central region portion ultrasound reflected and propagates, the angle alpha ₁ of the axis and in order to receives ultrasonic waves reflected and Propagation in _parts' The ultrasonic wave is received by the flaw detecting transducer 19a 'constituting the installed ultrasonic receiving probe 10a, and ultrasonic flaw detection of the partial region is performed.

Further, the vibration for flaw detection constituting the ultrasonic transmission probe 9a set by the angle α ₂ and the refraction angle θ ₂ with the axis so that the effective beam projected from the vibrator 19a arrives. Child
Ultrasonic waves are projected by 19b. Then, the ultrasonic wave is reflected and propagated at the crack or the welded portion in the region, and the angle α ₂ ′ with the axis and the refraction angle θ ₃ are formed so as to receive the ultrasonic wave reflected and propagated in the region. The ultrasonic wave is received by the flaw detecting transducer 19b 'constituting the set ultrasonic receiving probe 10a, and the area is subjected to ultrasonic flaw detection.

Further, in an area deviating from the effective beam width projected from the vibrators 19a and 19b, an angle α ₃ with the axis and a refraction angle θ ₃ are set so that the effective beam reaches the area. Transducer 19 for flaw detection constituting probe 9a for ultrasonic transmission
Ultrasonic waves are projected by c. Then, the ultrasonic wave is reflected and propagated in the crack or the welded portion in the region, and the angle α ₃ ′ with the axis and the refraction angle θ ₂ are formed so as to receive the ultrasonic wave reflected and propagated in the region. The ultrasonic flaw detection is performed by the flaw detecting transducer 19c 'constituting the ultrasonic receiving probe 10a set in the above.

As described above, if a flaw is detected using a pair of three probes, the whole area of the weld can be detected by one scan. The ultrasonic transmission probes 9a and 9b, the ultrasonic reception probes 10a and 10b, and the acoustic coupling state between the furnace wall tube 1 and the furnace wall tube 1 at the time of flaw detection were checked for the coupling check provided on each probe. Vibrator
This is done by detecting the bottom echo of the strip projected from 20.

Further, the ultrasonic flaw detector for the straddle scanning method according to the present invention includes an ultrasonic transmission probe 9b having the same specifications as a pair of the ultrasonic transmission probe 9a and the ultrasonic reception probe 10a described above. And the ultrasonic receiving probe 10b are provided to face each other in the scanning direction.

Therefore, the flaw detection from the A side is performed using a pair of the ultrasonic transmission probe 9a and the ultrasonic reception probe 10a, and the flaw detection performed from the B side thereafter is shown in FIG. Using the probe switching device 17, a pair of switching flaw detection of the ultrasonic transmission probe 9b and the ultrasonic reception probe 10b is performed.

This flaw detection result can be confirmed by the ultrasonic flaw detector 18.
In this way, by using a pair of probes arranged opposite to each other in the scanning direction for the forward path and the return path, the flaw detection in the forward and reverse directions (flaw detection from the A side and flaw detection from the B side) can be performed in one round trip. I can do it.

In the above-described embodiment, a method has been described in which the contact between the probe and the subject is scanned by following the surface to be inspected via a plurality of rollers to stably scan the probe and prevent abrasion. A method in which a beard-shaped member having excellent wear properties is provided, and scanning is performed following the surface to be inspected to achieve stable scanning and wear resistance of the probe.

In addition, the number of transducers constituting the ultrasonic transmission probe and the ultrasonic reception probe has been described in the case of using three transducers each. However, the number of transducers depends on the size of the surface to be inspected and the effective beam width of the transducer. The number of transducers used can be increased or decreased.

Next, another embodiment of the ultrasonic flaw detector of the present invention is shown in FIGS.
This will be described with reference to FIG.

FIG. 15 is an overall configuration diagram of the automatic ultrasonic flaw detection system for a wall surface, and shows a state where a furnace wall support bracket welded portion 6 attached to the outside of the furnace wall tube 1 is inspected from a remote position. In the drawing, reference numeral 21 denotes a traveling device, which can be freely moved throughout the furnace by means of a traveling member 22 and an electric hoist 23 provided at the upper part of the furnace, and an arbitrary inspected portion of the furnace wall tube 1 (furnace wall support). Metal fittings are fixed inside the furnace with magnets 24a, 24b, 24c, 24d.

The configuration of the scanning device 21 will be described with reference to FIG. The axial flaw detection probe 25 is pressed against the inner surface of the furnace wall tube 1 by the front-rear axis movement mechanism 27a. Mechanism
27b presses against the furnace inner side surface of the furnace wall tube 1.

The front-rear axis moving mechanisms 27a and 27b are vertically moved by a dust-proof vertical axis moving mechanism 28 covered with a bellows 30. Further, the vertical axis moving mechanism 28
Is moved in the horizontal direction with high accuracy by the two-system horizontal axis moving mechanisms 29a and 29b covered with the bellows 31a and 31b and dustproofed. The operating principle of the front-rear axis moving mechanism units 27a and 27b is such that nuts (not shown) fitted to the screws 32a and 32b are moved by rotating the nuts by motors 35a and 35b.

Further, the vertical axis moving mechanism section 28 and the horizontal axis moving mechanism sections 29a, 29
The operating principle of b is that the screw 3 fitted to the nut (not shown)
The motors 3, 34a, 34b are moved by being rotated by motors 36, 37a, 37b. Meanwhile, the motor 35
a, 35b, 36, 37a, 37b are rotated by a driving device 39 disposed at a remote position as shown in FIG. 17, and this driving device 39 is optimally adapted to flaw detection conditions. It is controlled by an arithmetic processing unit 40 that calculates a control value.

Further, the arithmetic processing unit 40 includes an ultrasonic flaw detector 41 for transmitting / receiving a flaw detection signal to / from the axial flaw detection probe 25 and the circumferential flaw detection probe 26, and a display device 42 for displaying a flaw detection result as an image. For the recording device 43 for recording the flaw detection result, the optimal control value is calculated and controlled in accordance with the flaw detection conditions, and the axial defect flaw detection probe 25 and the circumferential flaw are also controlled. The medium supply device 44 that supplies a couplant to the flaw detection probe 26 is also controlled.

Next, using the thus configured system, the furnace wall support bracket welding portion 6 attached to the furnace outside of the furnace wall tube 1 is used.
Is described from the inside of the furnace.

First, the traveling member 22 installed in the upper part of the furnace and the electric hoist
23 is operated from a remote position to move the scanning device 21 to the inside of the furnace wall support bracket welded portion 6 inside the furnace. Then, magnets 24a, 24b, 24
A magnetic force is generated in c and 24d to fix the scanning device 21 to the furnace wall.

Next, when an appropriate flaw detection condition is input to the arithmetic processing device 40 installed at a remote position outside the furnace, the driving device 39, the medium supply device 44,
An optimum control value is calculated for the ultrasonic flaw detector 41, the display device 42, and the recording device 43, and the movement of each device is controlled. here,
The driving device 39 controls the motors 35a, 35 under the control of the arithmetic processing device 40.
By rotating b, the axial flaw detection probe 25 or the circumferential flaw probe 26 attached to the front-rear axis movement mechanism 27a, 27b
Is pressed against the surface of the furnace wall tube 1.

At this time, the medium supply device is controlled by the control of the arithmetic processing device 40.
44 is started and the couplant via the medium supply cable 46 is supplied to the above-mentioned probe 25 for axial flaw detection or the probe 26 for circumferential flaw detection, and the acoustic coupling with the furnace wall tube 1 is measured. The flaw detection signal from the ultrasonic flaw detector 41 controlled by the arithmetic processing unit 40 can be transmitted to the furnace wall tube 1.

In this state, the motor 36 automatically rotates and the vertical axis moving mechanism
The front / rear axis moving mechanism units 27a and 27b are moved by 28 to scan the axial defect detecting probe 25 and the circumferential defect detecting probe 26 in the vertical direction.

Next, the motors 37a and 37b start rotating and the horizontal axis moving mechanism 29a,
29b, the longitudinal axis moving mechanism section 28 and the longitudinal axis moving mechanism section 2
The probe 25 for axial flaw detection and the probe 26 for circumferential flaw detection are scanned in the lateral direction via 7a and 27b. in this way,
A flaw detection signal obtained by three-dimensionally scanning the probe 25 for flaw detection in the axial direction and the probe 26 for flaw detection in the circumferential direction in the front-rear direction, the vertical direction, and the horizontal direction is transmitted through the flaw detection cable 38 to Through the ultrasonic inspection device 41, the arithmetic processing device 40 performs arithmetic processing, the inspection result is displayed on the display device 42, and the recording is output by the recording device.

In the embodiment shown in FIGS. 15 to 17 described above, the case where the welded portion of the metal fittings on the outer side of the boiler furnace wall tube is subjected to ultrasonic inspection from the inside of the furnace has been described. Needless to say, the present invention can be applied to inspection of outer walls of ships and the like. Further, the size of the scanning device of the present invention is not particularly limited, and there is no problem even if this scanning device is disassembled / assembled or folded.

〔The invention's effect〕

According to the apparatus of the present invention, flaw detection of the welded portion of the furnace wall of the boiler and the furnace wall support metal, without removing the outer wall and the heat insulating material from the inside of the furnace,
In addition, ultrasonic flaw detection can be performed without filling the inside of the furnace wall tube with water, thereby removing the outer wall and heat insulating material, which previously required a lot of man-hours, and restoring them, and furthermore, inside the furnace wall tube. The quality control of the water to be filled into the container can be omitted. In addition, it is not necessary to extend the periodic inspection period specifically for flaw detection because flaw detection can be performed concurrently with the furnace wall tube cutting work and the furnace wall tube cleaning work that are performed during the periodic inspection period, and the boiler equipment operation The rate can be improved.

Further, according to the apparatus of the present invention, since the probe is composed of a plurality of transducers, the effective beam width on the surface to be inspected is widely distributed, and the probe is used even when performing inspection without flaw detection leakage. The scanning pitch may be coarse, and the probe may be moved in the scanning direction.
Since the probes are arranged facing each other, by selectively using these probes in accordance with the scanning direction, flaw detection from normal and reverse directions can be performed in one round trip. This has the effect of increasing inspection efficiency. In addition, since the probe is supported so as to be pressed against the surface to be inspected with a certain force in contact with the object, even when the surface of the object is not smooth, the scanning of the probe is stable, and The effect that the pressing force of the child is also constant is obtained.

Further, according to the ultrasonic flaw detector of the present invention, since the inspection and the recording of the record from the inside of the furnace can be performed by automatic control from a remote position, the inside of the furnace is in a dust environment and the inspected part is located at a high place. Even in this case, it is possible to maintain a safe and hygienic and highly accurate inspection.

[Brief description of the drawings]

FIG. 1 shows the principle of ultrasonic flaw detection according to the present invention, and is a partially cutaway perspective view showing an example of ultrasonic flaw detection, FIG. 2 is a front view of the inside of the furnace of FIG. 1, and FIG. Fig. 4 is a side view, Fig. 4 is a view taken along the line AA 'in Fig. 2, Figs. 5 and 6 are explanatory views showing the flaw detection state of the welded part, and Fig. 7 is Figs. 10 is a graph showing each of the flaw detection waveform examples, FIG. 11 is an overall configuration diagram showing one embodiment of the ultrasonic flaw detection apparatus of the present invention, FIG. 12 is a front view inside the furnace showing a flaw detection situation by the apparatus of FIG. , Thirteenth
FIG. 14 is a view taken along the line BB ′ in FIG. 12, and FIG.
FIG. 15 is an overall configuration diagram showing another embodiment of the ultrasonic flaw detector of the present invention, FIG. 16 is a configuration diagram of the traveling device in FIG. 15, and FIG. FIG. 18 is a block diagram showing the conventional flaw detection method, and FIG.
FIG. 19 and FIG. 20 are explanatory diagrams showing problems in the method of FIG. 18, and FIG. 21 is an explanatory diagram showing an operation example of the conventional ultrasonic inspection. 1 ... furnace wall tube, 2 ... steel strip, 3 ... furnace wall support bracket, 4 ...
... outer wall, 5 ... heat insulating material, 6 ... welded part, 7 ... probe for ultrasonic transmission, 8 ... probe for ultrasonic reception, 9a, 9b ... probe for ultrasonic transmission, 10 ... water, 10 a, 10 b ... ultrasonic receiving probe, 11 ... probe support, 12 ... stand, 13 ... roller, 14 ... pin, 15 ... screw, 16 ... Spring, 17
...... Probe switching device, 18 ... Ultrasonic flaw detector, 19a, 19a ',
19b, 19b ', 19c, 19c' ... vibrator, 20 ... coupling check vibrator, 21 ... scanning device, 22 ... traveling member,
23… Electric hoist, 24a, 24b, 24c, 24d… Magnet, 25…
... Axial flaw detection probe, 26 ... Circumferential flaw detection probe, 27a, 27b ... Front / back axis moving mechanism, 28 ... Vertical axis moving mechanism, 29a, 29b ... Horizontal axis Mechanism part, 30, 31a, 31b ……
Bellows, 38 ... flaw detection cable, 39 ... drive device, 40 ... arithmetic processing device, 41 ... ultrasonic flaw detection device, 42 ... display device,
43 ... Recording device, 44 ... Medium supply device, 45 ... Drive cable, 46 ... Medium cable.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Fuki Odawara 3-2-22-2 Wakaoji Temple, Amagasaki City, Hyogo Kansai Electric Power Co., Inc. (72) Inventor Yukio Nomazaki 6-9 Takaracho, Kure City, Hiroshima Prefecture No. Babcock Hitachi Ltd. Kure Factory (72) Inventor Masaharu Moronaga 6-9 Takaracho, Kure City, Hiroshima Prefecture Inside Babcock Hitachi Kure Factory (56) References JP-A-54-114697 (JP, A) JP-A-62-148853 (JP, A) JP-A-61-105460 (JP, A) JP-A-62-2152 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 29/00-29/28

Claims (4)

(57) [Claims] An ultrasonic transmission probe comprising a plurality of transducers for projecting ultrasonic waves to an object, an ultrasonic wave propagating through the object and receiving the ultrasonic waves. An ultrasonic receiving probe composed of the same number of transducers as the transducers is paired, and the pair of probes are arranged to face each other in a scanning direction, and the plurality of ultrasonic transmitting units are arranged. The credit probes are respectively arranged so as to project ultrasonic waves to different predetermined portions of the subject, and the plurality of ultrasonic receiving probes are respectively reflected and propagated at different predetermined portions of the subject. An ultrasonic flaw detector for a pipe structure, which is arranged at a position where it can receive ultrasonic waves. 2. A probe switching device for switching between the ultrasonic transmission probe and the ultrasonic reception probe for oscillation and reception in accordance with a scanning direction. Item (1): An ultrasonic flaw detector for a pipe structure. 3. The apparatus according to claim 1, further comprising means for slidably urging the ultrasonic transmission probe and the ultrasonic reception probe with respect to a scanning plane. An ultrasonic flaw detector for a pipe structure as described in the above. 4. An apparatus for detecting flaws on the back surface of an object from an upper surface through an ultrasonic beam, wherein a probe for flaw detection in an axial direction and a probe for flaw detection in a circumferential direction are arranged in front and rear directions with respect to the surface of the object. A scanning device comprising: a longitudinal axis moving mechanism for moving, a longitudinal axis moving mechanism for vertically moving the longitudinal axis moving mechanism, and a horizontal axis moving mechanism for moving the longitudinal axis moving mechanism in the horizontal direction. A traveling mechanism for moving the scanning device to the region to be inspected, the front-rear axis moving mechanism, the vertical axis moving mechanism,
A driving device for moving the horizontal axis moving mechanism, an ultrasonic flaw detection device for transmitting and receiving flaw detection signals to the axial flaw detection probe and the circumferential flaw detection probe, and a display device for displaying a flaw detection result on an image And a recording device for recording the flaw detection result, and a calculation for calculating the optimum control values for the driving device, the ultrasonic flaw detection device, the display device, and the recording device in accordance with the flaw detection conditions, and controlling the function of each device. An automatic ultrasonic flaw detector for a pipe structure, comprising: a processing device.