JPH0421817B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an ultrasonic measuring device, and more particularly, to an ultrasonic measuring device that can move inside a subject without requiring special power and can perform accurate measurements. During periodic inspections of boiler equipment, especially large boilers required for high-temperature, high-pressure power generation, the tubes of superheaters, reheaters, etc. have the above-mentioned high temperature and high pressure flowing inside them, and high-temperature gas flows on their outer surfaces, so these tubes are inspected. It is necessary to carefully inspect the body for any reduction in wall thickness or damage, and since the boiler operation will be stopped during the inspection, it is desirable that the inspection period be short. However, these superheater tubes are located in combustion gas passages at high places, and dust and clinker adhere to their outer surfaces, and detection accuracy is extremely low when inspecting from the outside of the tube unless these dust and clinker are removed. In reality, there is hardly any space for workers to remove dust, and there are a large number of pipes to be inspected. For this reason, it is not practical to inspect these tubes from the outside, and it is necessary to inspect them from inside the tube. FIG. 1 shows a conventional example of a device that performs inspection from inside a tube. Reference numeral 5 in the figure is a probe, and an insertion tube 4 is connected to the probe 5. 2 is a pressure receiver attached to the insertion tube 4, which is an ultrasonic wave transmission medium (usually water) that passes through the tube body 1, which is the object to be examined.
The resistance causes self and probe 55 to advance. The following problems have been pointed out in this type of device, and improvements are desired. (1) In order to move the probe forward, the pressure receiver 2 must produce a large pressure receiving effect, and for this reason, the pressure sensor must have a long flow in the axial direction. However, if the length of the pressure receiving element 2 is made too long, the device will not be able to move forward in the curved pipe section. (2) As the size of the pressure sensor increases, the weight of the pressure receiving section also increases, so a gas space 3 is formed within the pressure sensor 2 to reduce the specific gravity of the pressure sensor. necessarily make it difficult. (3) In addition, turbulent flow of the medium occurs on the downstream side of the pressure sensor, which tends to generate bubbles, and since there is no means for removing bubbles, there are also problems such as a decrease in flaw detection accuracy due to the bubbles. An object of the present invention is to provide an ultrasonic flaw detection device which can move freely inside a specimen and can greatly improve flaw detection accuracy by eliminating air bubbles and eliminating the above-mentioned problems. There is a particular thing. In short, the present invention provides an ultrasonic measuring device that is inserted into a pipe to detect the presence or absence of an abnormality in a pipe wall, in which a front alignment moving member and a rear alignment moving member are connected to each other via flexible connectors at the front and rear of the measuring device main body. A front conical guide is provided in front of the front alignment member, a rear conical guide is provided behind the rear alignment member, and the front and rear conical guides of the front conical guide are connected to the movable member. This is an ultrasonic measuring device characterized in that a bubble extinguishing guide is provided at the rear of each device. Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, an ultrasonic measuring device main body 40 that emits and receives ultrasonic waves 4 includes a probe 13 having an annular vibrator 14, and a reflecting surface that is located opposite to the probe 13 and has a substantially conical or substantially conical shape. It is composed of a total reflecting mirror 15 whose outer surface of a cone is a reflecting mirror with a curvature. A front alignment moving member 41a and a rear alignment moving member 41b are connected to the front and rear of the measuring device main body 40 by flexible connecting bodies. Various types of flexible connectors may be used, but in the case shown, the wire 16 is placed in the center and the coil spring 8 is placed around the periphery to provide a flexible connector. Next, the structure of the alignment moving member will be explained using the rear alignment moving member 41b as an example. 42
A base plate constitutes the main body of the alignment moving member, and arms 44 are each rotatably attached to this base plate via pins 43. 45 is a guide roller attached to each arm 44. Attached to each arm 44 is a pawl 18, each pawl 18 engaging two brackets 48 which are moved by a movement shaft 47.
These brackets 48 are pressed in the direction of movement of the apparatus by a spring 8 of a flexible connector located at the rear of the centering moving member. This pressing force is the claw 1
8 to the arm 44, and the arm 44 attempts to direct the guide roller attachment side end toward the outside of the tube body 5 with the pin 43 as the center, and the roller 45 is pressed against the inner surface of the tube body 5. As a result, the ultrasonic measuring device main body 40 is positioned on the center line of the tubular body 5 and aligned. Front alignment moving member 41a
It also has the same configuration as the rear centering moving member described above. Next, reference numerals 50a and 50b denote front guides formed in substantially conical shapes, which are attached to the front of the front centering moving member 41a via the same flexible connectors as described above. 51a and 51b are similarly configured rear guide elements, which are also connected to the rear part of the rear alignment moving member 41b via flexible connectors. Furthermore, reference numerals 52 and 53 connect the front conical guide 50b to the rear conical guide 51 through flexible connections.
This is a bubble extinguisher guide attached to the rear of a.
FIG. 3 shows details of the bubble extinguishing guides 52 and 53, which are formed into an umbrella shape as a whole by attaching a plurality of blades 55 radially to a central shaft 54. Next, the inventors conducted tests on the operating state of the device by changing the shape, material, size, etc. of the guide. As a result, guide elements 50a, 50b, 51
The maximum diameter D of a and 51b is the inner diameter of the tube pair 5 which is the object to be examined.
It was confirmed that it is preferable to set it to 70% or more. The apex angle θ of the guide is preferably about 15° to 60°. θ
If it is made too large, bubbles may be generated due to the turbulent flow of the medium 12. Figure 4 shows the maximum diameter of the guide.
The results of a comparison of the pumping force inside the tube in a state where the maximum diameter is 35 mm or 70% of the inner diameter of the subject are shown. Diagram A shows the pumping force of the conical guide, and diagram B shows the pumping force of the spindle-shaped guide shown in FIG. 1. As is clear from these diagrams,

[Table] Evaluations based on the shape of the guide can be summarized as follows. Note that if the blades 55 of the umbrella-shaped guide are made of a flexible material such as rubber, it is effective for removing air bubbles attached to the inner surface of the tube.

[Table] FIG. 6 shows another embodiment in which a conical guide 56 is attached to a connecting rope 57 with its axis eccentric. This member is formed separately from the above-mentioned flaw detection device, and the most advanced umbrella-shaped guide 5
It may be connected to the tip of 2. The guide mounted at an eccentric position causes the medium 12 flowing inside the tube to cause the tube body 5 to
Inside, in the radial direction of the tube (indicated by the arrow in the figure)
It vibrates to remove air bubbles attached to the inner surface of the tube.
However, in order to avoid the adverse effects of vibration of the guide, the umbrella-shaped guide 52 at the tip is replaced with the conical guide 5 at an eccentric position.
It is preferable that the connecting cable between the terminal and the terminal 6 is made longer. When the main body of the apparatus is moved by the flow of the ultrasonic transmission medium by implementing the present invention, the force exerted by the moving fluid on the front conical guide is greater than the force exerted by the rear conical guide. The former receives forward force from the fluid at the bottom of the cone, while the latter receives the force of the fluid from the top of the cone.As a result, the position between the two does not change much, making it easier to set the inspection position of the measuring device. It facilitates Furthermore, since a bubble extinguishing guide is provided, air bubbles in the fluid can be effectively removed, so that the accuracy of inspection can be improved.

[Brief explanation of drawings]

Figure 1 is a side view of a conventional ultrasonic measurement device, Figure 2
FIG. 3 is a perspective view of an umbrella-shaped guide; FIGS. 4 and 5 are diagrams showing the relationship between the medium flow rate and the pumping force of the guide;
FIG. 6 is a sectional view of a conical guide showing another embodiment. 5... Pipe body, 41a, 41b... Centering moving member, 50a, 50b, 51a, 51b... Conical guide, 52, 53... Guide for defoaming, 56
... Eccentric mounting guide, 57 ... Connecting cable.

Claims (1)

[Claims] 1. In an ultrasonic measuring device inserted into a pipe to detect the presence or absence of an abnormality in the pipe wall, the front alignment moving member and the rear part are connected via flexible connecting bodies at the front and rear of the main body of the measuring device. A front conical guide is provided in front of the front aligning member, a rear conical guide is provided behind the rear aligning member, and the front and rear conical guides are connected to the front conical guide. An ultrasonic measuring device characterized in that bubble-eliminating guides are provided at the rear of each guide. 2. The ultrasonic measuring device according to claim 1, wherein the apex angle of the front conical guide and the rear conical guide is between about 15° and about 60°.