JPH0731165B2 - Compressive strength measuring device for waste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is for the external treatment / disposal of a waste containing a radioactive waste generated in a nuclear power plant or the like in a container such as a drum can after being solidified with cement or the like. Regarding the compressive strength measuring device for waste, which estimates the compressive strength of the solidified body required for quality control when it is carried out to the site by calculating the ultrasonic wave propagation velocity in the solidified body, especially the solidification of the transmitter and receiver The present invention relates to an apparatus for measuring the compressive strength of a waste body by improving the adhesion to the body, the shape, the pressing method, the received wave detection method and the like so that accurate and rapid measurement can be performed.

[Prior Art] Conventionally, as an apparatus for estimating the compressive strength of a cement-solidified waste body from an ultrasonic wave propagation velocity, as disclosed in Japanese Patent Publication No. 60-37440, a drum can containing the cement-solidified body is disclosed. There is a device that calculates an ultrasonic wave propagation velocity in a solidified body by using a transmitter and a receiver provided at positions facing each other (that is, a waste body). In addition, as described in JP-B-63-48305, by pressing the surface of the container containing the solidified body with a shoe to bring the container into close contact with the solidified body, it is difficult for the surface wave to propagate and the oscillator Press the container wall with the tip of the receiver or the receiver to increase the adhesion between the transmitter and the receiver and the solidified body so that direct waves can easily pass through, and the ultrasonic wave is transmitted from the transmitter to face this. An apparatus is also known in which an ultrasonic wave is received by a receiver and the ultrasonic wave propagation velocity passing through the solidified body is calculated. Further, as disclosed in Japanese Patent Laid-Open No. 63-45556, the ultrasonic transmitter and the ultrasonic receiver are fixed to a rotating cylindrical container for a predetermined time, and the ultrasonic wave and the ultrasonic receiver are rotated together for a shorter time. There is also proposed a device for measuring ultrasonic waves.

[Problems to be Solved by the Invention] However, according to such a conventional technique, it is difficult to distinguish between a so-called surface wave propagating in the solidified body container and a transmitted wave propagating in the solidified body. There is a problem that erroneous measurement occurs. In the invention described in Japanese Examined Patent Publication No. 63-48305, the container is pressed from the outside in order to improve the measurement accuracy and the transmitter and the receiver are also pressed to improve the adhesion to the solidified body, but it is still satisfactory. No results have been obtained, and the measurement operation is complicated.

In view of the above problems of the conventional art, the object of the present invention is to measure the ultrasonic wave velocity and to calculate the compressive strength of the waste, so that a large area in the waste can be measured more accurately and quickly. To do so. In particular, the present invention aims at embodying a measure for preventing erroneous measurement due to the influence of so-called surface waves.

[Means for Solving the Problems] In order to achieve the above-mentioned object, according to the present invention, a transmitter for transmitting an ultrasonic wave and a receiver for receiving the ultrasonic wave, and a waste container in which the transmitter and the receiver are solidified is contained. Equipped with a transmitter / receiver pressing means for pressing against the surface of the waste stored in, the propagation time of the ultrasonic wave propagating between the transmitter and the receiver is measured, and the compressive strength of the waste is based on the measurement result. In the device for measuring the compressive strength of a waste body, the propagation time is measured by receiving by the receivers at a plurality of different positions with respect to the transmission by one transmitter, and the container is propagated through the container measured by each receiver. The propagation time due to the surface wave and the propagation time due to the direct wave traveling straight in the waste are distinguished by comparing with the ratio of the distances of the propagation paths of the surface wave or the direct wave to each receiver. During propagation It is characterized in that the compressive strength of the waste is obtained based on the interval.

Alternatively, a surrounding wave pressing means for pressing the surface of the waste body at substantially continuous lines or surfaces surrounding the transmitter and the receiver in the vicinity thereof is provided, and the surface wave propagating through the container and the waste received by the receiver. It is characterized in that the direct wave traveling straight in the object is distinguished by the difference in their amplitudes, the propagation time is measured based on the direct wave, and the compressive strength of the waste is obtained.

[Operation] In this configuration, when a plurality of different receivers perform transmission for one transmitter to measure the propagation time, the propagation time due to the surface wave and the propagation time due to the direct wave are measured by each receiver. To be done. The ratio of the propagation time of the surface wave measured by each receiver coincides with the ratio of the distances of the propagation paths of the surface waves to each receiver. Further, the ratio of the propagation time of the direct wave matches the ratio of the distances of the propagation paths of the direct wave to each receiver. Therefore, the measured propagation time by the surface wave and the propagation time by the direct wave are distinguished by comparing with the ratio of the distances of the propagation paths of the surface wave or the direct wave to each receiver. Therefore, the propagation time due to surface waves is eliminated and the compressive strength of the waste body is obtained based on the propagation time for direct waves. However, if there is no set of propagation time due to the direct wave having a ratio matching the distance ratio of the propagation path of the direct wave, it indicates that there is a problem inside the solidified waste material.

Further, when the surrounding pressing means is provided, since the surface wave is attenuated by the surrounding pressing means, between the surface wave and the direct wave,
A large difference occurs in the amplitude. Therefore, for example, by setting a gate voltage intermediate between the amplitude of the received surface wave and the amplitude of the direct wave to block the signal component of the surface wave, the surface wave and the direct wave can be easily distinguished.

When the container is made of steel or the like, the surface wave may be received before the direct wave, but according to the present invention,
As described above, since the surface wave and the direct wave are distinguished from each other, accurate compression strength based on the direct wave can be obtained.

The ultrasonic wave propagation velocity is obtained based on the time required for the receiver to receive the ultrasonic wave after the transmitter transmits the ultrasonic wave and the distance between the transmitting point and the receiving point. At that time, the ultrasonic wave transmitted by the transmitter propagates as a surface wave and a transmitted wave, but the surrounding pressing means attenuates this surface wave propagating on the container surface at the surrounding pressing portion near the transmitter and the receiver. . At the same time, the surrounding pressing means enhances the adhesion of the container portion around the transmitter and the receiver to the solidified body, and the transmitter / receiver pressing means presses the transmitter and the receiver against the waste material to transmit the transmitter. Also, the adhesion of the receiver to the solidified body is improved. Therefore, the surface wave is eliminated as much as possible, and only the transmitted wave that correctly reflects the compressive strength of the solidified body is satisfactorily transmitted to the solidified body and detected.

If the adapter structures at the tips of the transmitter and the receiver are thin, the close contact with the waste is further improved, and the transmitted wave is propagated efficiently. Further, the surface wave component is attenuated by mounting the neoprene rubber. This is because, assuming that the surface wave is a shear wave, its propagation velocity V _s is V _s = (G / ρ) ^1/2 , and therefore a medium with G≈0 or ρ≈∞ does not transmit the surface wave.

Further, three or more transmitters and receivers are simultaneously pressed on the circumference on the same horizontal plane to measure the ultrasonic wave propagation time at a plurality of positions simultaneously or sequentially, or the transmitters and receivers on other than the same horizontal plane are measured. Press the receiver at the same time,
By measuring between transmitting position and receiving position at different heights, ultrasonic wave propagation speeds in various directions and parts can be obtained in a short time without the need to rotate the waste and move the transmitter and receiver. . Furthermore, by sequentially switching the transmission and reception of the ultrasonic transducer that doubles as a transmitter and receiver,
A wider area is measured with a smaller number of ultrasonic transducers.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an apparatus according to an embodiment of the present invention.
As shown in the figure, this device includes a plurality of ultrasonic transducers 1 for transmitting or receiving ultrasonic waves, and transmitter / receiver pressing means 4 for pressing each ultrasonic transducer 1 against the surface of the waste body 3. Further, as partially shown in FIG. 2, a surrounding pressing member 5 is provided which presses the surface of the waste 3 at substantially continuous lines or surfaces surrounding the ultrasonic transducers 1 in the vicinity thereof. Further, the transmitter / receiver pressing means 4 has a piston / cylinder mechanism for pressing the ultrasonic vibrator 1 against the waste body 3, and is integrally fixed to the frame 8 together with the ultrasonic vibrator 1. There is. The frame 8 is attached to the frame 9 so as to be vertically movable.

Four ultrasonic transducers 1 are arranged at the same height at a 90 ° pitch, and two ultrasonic transducers 1 are provided at different heights. It should be noted that, for example, as shown in FIG.
You may make it possible to provide a group.

Further, as shown in FIG. 2, the tip of the ultrasonic transducer 1 is
The adapter structure 2 is provided, and the adapter structure has a thin tip and is fitted with neoprene rubber 6, for example, a diameter of 10 mm.
The waste 3 is contacted in terms of degree.

The waste body 3 is composed of a drum and a cement-solidified body of the waste housed therein, and is placed on the carriage 10 for measurement and then conveyed to the measurement position.

The transmitter / receiver pressing means 4 is configured to hold the ultrasonic vibrator 1 at its tip and press the ultrasonic vibrator 1 against the waste 3 with a uniform pressing force.

The surrounding pressing member 5 is made of a hard substance such as SUS, and a soft substance 7 such as neoprene rubber is attached to the tip thereof. Further, as shown in FIG. 2, it has a shape such that the waste body 1 is pressed by a square or circular contact portion around the ultrasonic transducer 1, and the transmitter / receiver pressing means 4 is provided.
It is supported and pressed by pressing means (not shown) different from. The surrounding pressing member 5 is pressed against the waste 3 at the same time as the ultrasonic vibrator 1 is pressed.

In this configuration, when measuring, the waste 3 is installed in the apparatus with the frame 8 being raised, and then the frame 8 is lowered and positioned with respect to the waste 3. Then, when the ultrasonic transducer 1 and the surrounding pressing member 5 are pressed against the waste 3 at the same time and with the same pressure, and ultrasonic waves are output from one ultrasonic transducer 1, the ultrasonic waves solidify in the waste 3. While passing through the body, a part of it travels through the container on the surface of the waste 3 and reaches another ultrasonic transducer 1 of the same set, and is detected by these. However, the surface wave component is attenuated by the surrounding pressing member 5 to which the soft substance 7 is attached, and further attenuated by the neoprene rubber 6, so that the detected surface wave component is a very small amount. On the other hand, the transmitted wave component is solidified with each ultrasonic transducer because each ultrasonic transducer is in contact with the waste 3 through the narrow contact portion area and the pressing force by the surrounding pressing member 5 is also applied. Since it has high adhesion to the body, it propagates between ultrasonic transducers very efficiently.

Here, as shown in FIG. 4, if the distance from the ultrasonic transducer 1a that emits ultrasonic waves to the ultrasonic transducer 1b that faces the ultrasonic transducer 1b and receives ultrasonic waves is l, other ultrasonic waves are generated. The distance to the ultrasonic transducer 1c to receive is the same height, because it is arranged at 90 ° pitch Therefore, the ratio of the time to travel between the ultrasonic transducers 1a and 1b and the time to travel between the ultrasonic transducers 1a and 1c is And 2: 1 for surface waves. Therefore, this determines whether the detection signal is a transmitted wave or a surface wave.

Fig. 5 shows the ultrasonic transducer 1b or
It is a graph which shows the detection signal which 1c outputs.

This detection signal includes a surface wave component S and a transmitted wave component P as shown in the figure, but the time t ₁ when the ultrasonic transducer 1a transmits ultrasonic waves and the ultrasonic transducer 1b or 1c is transmitted. Wave component P
At time t ₂ and when ultrasonic transducer 1a and ultrasonic transducer
The propagation velocity of the ultrasonic wave is obtained based on the distance from 1b or 1c.

Then, the transmission and reception of ultrasonic waves are sequentially performed by the ultrasonic vibrators 1 while all the ultrasonic vibrators are pressed against the waste body, and as shown in FIG. Path P _{1 above} or path P ₂ between different heights
The propagation velocity in each direction is calculated and used to estimate the compressive strength of the solidified body. According to this, as shown in FIG. 7 (a), the transmitter 11 and the receiver 12 have been clearly divided and arranged separately so that they are discarded in order to measure the areas A ₁ and A _2. While the rotation of the body 3 or the movement of the transmitter 11 and the receiver 12 was required, as shown in the figure (b), measurement of many areas with the same number of elements with the waste body etc. fixed. Can be done.

Although the surface wave component S and the transmitted wave component P are discriminated by utilizing the difference in the distance between the ultrasonic transducers in the above description, the surface wave component S and the transmitted wave component as shown in FIG. It is also possible to extract only the transmitted wave component P using a predetermined gate voltage value intermediate to the component P, and measure the propagation time based on this to calculate the propagation velocity.

As described above, according to the present invention, the direct wave and the surface wave or their propagation times can be distinguished from each other.
It is possible to obtain an accurate compressive strength due to the propagation time of the direct wave.

[Brief description of drawings]

1 is a perspective view of an apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged view of the vicinity of the transmitter / receiver of the apparatus of FIG. 1, and FIG. 3 is an arrangement of ultrasonic transducers. FIG. 4 is a schematic diagram showing a state, FIG. 4 is an explanatory view showing a method of discriminating a transmitted wave in the device of FIG. 1, FIG. 5 is a graph showing an output signal of an ultrasonic transducer of the device of FIG. 1, FIG. 6 is a schematic diagram showing a state in which the measurement region of the apparatus of FIG. 1 is viewed from the side, and FIGS. 7A and 7B are top views of the measurement region of the apparatus of FIG. It is a schematic diagram which shows a mode when it sees from compared with the past. 1: Ultrasonic transducer, 2: Adapter, 3: Waste, 4: Transmitter / receiver pressing means, 5: Envelope pressing member, 6: Neoprene rubber, 7:
Soft material, 8,9: frame.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuro Yagi 1-14-1 Minami-Differential Office, Yokohama City, Kanagawa Pref. JGC Co., Ltd. (72) Hiroshi Fujisawa 1-1-14-1 Minami-Differential Office, Yokohama City, Kanagawa Prefecture (72) Inventor Takuji Ujihara 3-28-17 Shinmachi, Setagaya-ku, Tokyo (72) Inventor Isao Oda 3276-2 Wakashiba-cho, Ryugasaki-shi, Ibaraki Prefecture (72) Inventor ▲ Sakaki ▼ Yokohama, Kanagawa Prefecture 2-6-4 Hashido, Seya-ku, Iwate Seiya Dormitory (56) References JP 59-651 (JP, A) JP 60-39557 (JP, A) JP 62-34360 (JP, U)

Claims (2)

[Claims] 1. A transmitter for transmitting ultrasonic waves and a receiver for receiving ultrasonic waves, and a transmitter / receiver for pressing the transmitter and receiver against the surface of a waste containing a solidified waste in a container. In the compressive strength measuring device for waste, which is provided with a slave pressing means, measures the propagation time of ultrasonic waves propagating between the transmitter and the receiver, and obtains the compressive strength of the waste based on the measurement result. The propagation time is measured by performing reception by receivers at a plurality of different positions with respect to the transmission by the child, and the propagation time by the surface wave propagating in the container measured by each receiver and traveling straight through the waste. Characterized by comparing the propagation time of the direct wave with the ratio of the distances of the propagation paths of the surface wave or the direct wave to each receiver, and obtaining the compressive strength of the waste based on the propagation time of the direct wave. Abolition Body of compressive strength measurement device. 2. A transmitter for receiving ultrasonic waves, a receiver for receiving ultrasonic waves, and a transmitter / receiver for pressing the transmitter and the receiver against the surface of the waste containing the solidified waste in a container. In a device for measuring the compressive strength of waste, which measures the propagation time of ultrasonic waves propagating between the transmitter and the receiver and obtains the compressive strength of the waste based on the measurement result, Receiving by the receiver, the surrounding child pressing means is provided to press the surface of the waste body at a substantially continuous line or surface surrounding the child in each vicinity.
The surface wave signal propagating through the container and the direct wave signal traveling straight through the waste are distinguished by their amplitude differences, and the propagation time is measured based on the direct wave signal to determine the compressive strength of the waste. An apparatus for measuring the compressive strength of waste, which is characterized in that