KR101043344B1 - Manufacturing Method for Clamp-on type Ultrasonic Transducer using a multi-path - Google Patents

Abstract

The present invention relates to a multi-line outer wall type ultrasonic transducer manufacturing method. The present invention includes a center transmitting transducer and a center receiving transducer for measuring the amount of fluid flowing in the circular pipe using ultrasonic waves passing through the center of the circular pipe; And an auxiliary transmitting transducer and an auxiliary receiving transducer for measuring an amount of fluid flowing in the circular pipe by using an ultrasonic wave having a path deviating from the center of the circular pipe. Producers provide a multi-line outer wall-mounted ultrasonic transducer, characterized in that each of which is provided with a plurality.

Therefore, according to the present invention, the amount of fluid flowing in the circular pipe can be accurately measured, and the installation of the transducer is easy.

Multi-line outer wall-mounted ultrasonic transducer, clamped, round pipe

Description

Manufacturing Method for Clamp-on type Ultrasonic Transducer using a multi-path

The present invention relates to a method for manufacturing a multi-line outer wall type ultrasonic transducer for measuring a flow rate in a pipe, and more particularly, a multi-line that can more accurately measure the amount of fluid flowing in a circular pipe. The present invention relates to an outer wall type ultrasonic transducer manufacturing method.

Ultrasonics is generally defined as 'sounds invisible to human beings' and has the property of propagating well in solids as well as gases and liquids. The first scientific study of ultrasound was at the end of World War I, when French physicist P. Lange-Binin attempted to use ultrasound to detect submarines.

Ultrasonic waves are essentially the same as sound waves in the audible range, but because of their high frequencies and short wavelengths, they generate quite strong vibrations, which are not seen in normal sound waves. Ultrasound is a short pulse whose path is directional, and bats can use ultrasound to identify objects that are thin at night. An ultrasonic flowmeter is used for measuring the flow rate using the characteristics of such ultrasonic waves.

There are many ways to measure flow in a pipeline, such as a water pipe. The axial vane method has been widely used because of its simple structure and low cost. Electromagnetic methods have been used where accuracy is required because of their excellent measurement accuracy. However, because the axial vane must be installed inside the pipeline and the electromagnetic flowmeter must be flanged in the form of a single pipe in the middle of the pipeline, there is a problem that the water must be cut off during installation, and the operation of the water pipe must be stopped to check or repair after installation. .

On the other hand, the flow meter using ultrasonic waves can be divided into two types: the invasive ultrasonic transducer shown in Fig. 1 (a) and the clamp-on type ultrasonic transducer shown in Fig. 2 (b).

Invasive ultrasonic transducers transmit or receive ultrasonic waves in direct contact with the fluid. Since there should be no pipe wall or other material between the transducer and the fluid, there is a difficulty in installing a hole in the pipe wall and there is a problem in that the flow rate of the corrosive fluid cannot be measured.

On the other hand, the external wall-mounted ultrasonic transducer has the advantage that it can be easily installed on the pipe wall to measure the flow rate. Errors may occur. Therefore, there is a problem that it is inadequate to use for accurate measurement to the extent that it is possible to determine whether or not leaks.

The present invention has been made to solve the above problems, an object of the present invention is to be able to accurately measure the flow rate, and to be easy to install, maintain and manage. It is also an object of the present invention to provide a multi-line external wall type ultrasonic transducer capable of measuring the flow rate of corrosive fluid, hot or cold fluid.

In order to achieve the above object, the present invention comprises a center transmitting transducer and a center receiving transducer for measuring the amount of fluid flowing in the circular pipe using ultrasonic waves passing through the center of the circular pipe; And an auxiliary transmitting transducer and an auxiliary receiving transducer for measuring an amount of fluid flowing in the circular pipe by using an ultrasonic wave having a path deviating from the center of the circular pipe. Producers provide a multi-line outer wall-mounted ultrasonic transducer, characterized in that each of which is provided with a plurality.

In addition, the ultrasonic waves generated by the auxiliary transmission transducer may move in parallel to the ultrasonic waves generated by the central transmission transducer.

The auxiliary transmitting transducer and the corresponding auxiliary receiving transducer may be mounted within a range of a semicircle based on the cross section of the circular pipe.

Furthermore, the plurality of auxiliary transmission transducers may be mounted to be symmetrical with respect to the center transmission transducer.

In particular, the flow rate is preferably measured using the jet path (Z-path) method.

On the other hand, the auxiliary transmitting transducer and the auxiliary receiving transducer, the contact surface which is in contact with the circular pipe is inclined with respect to the bottom surface; And a piezoelectric vibrator installed in the wedge.

)과 동일한 것이 가능하며, 상기 웨지 입사각은 상기 원형 파이프의 종류 및 상기 원형 파이프 내부를 흐르는 유체의 종류 중 적어도 어느 하나에 따라 달라질 수 있다.Of course, the inclination angle of the contact surface with respect to the bottom surface is a wedge incidence angle at which ultrasonic waves are incident from the wedge to the circular pipe (

The wedge incidence angle may vary depending on at least one of the type of the circular pipe and the type of fluid flowing inside the circular pipe.

)을 산출하는 단계; 스넬의 법칙을 이용해서 상기 원형 파이프의 안쪽 입사각(

) 및 상기 원형 파이프의 바깥쪽 굴절각(

)를 산출하는 단계; 스넬의 법칙을 이용해서 상기 원형 파이프의 바깥쪽 굴절각으로부터 웨지 입사각(

)를 산출하는 단계; 및 상기 웨지 입사각에 따라 웨지의 접촉면이 경사지도록 가공하는 단계;를 포함하는 다회선 외벽부착식 초음파 트랜스듀서 제조방법을 제공한다.The present invention is to select the direction of the ultrasonic wave passing through the inside of the circular pipe fluid side refracting angle (

Calculating c); Using Snell's law, the inner angle of incidence

) And the outward deflection angle of the circular pipe (

Calculating c); Using Snell's law, the wedge angle of incidence from the

Calculating c); And processing the inclined contact surface of the wedge according to the incidence angle of the wedge.

)과 동일한 것이 바람직하고, 상기 유체쪽 굴절각(

)은 30°이하인 것이 가능하다. In particular, the inclined inclination angle of the contact surface is a wedge incidence angle at which ultrasonic waves enter the circular pipe from the wedge (

It is preferable that the same as the

) Can be 30 ° or less.

Of course, the wedge incidence angle may vary depending on at least one of the type of the circular pipe and the type of the fluid flowing inside the circular pipe.

According to the present invention, it is possible to measure the amount of fluid in the pipe more accurately by using multiple lines, so that accurate measurement to the extent that it is possible to determine whether or not leaks can be determined. In particular, even when a flow disturbance such as vortex is formed in the flow in the pipe, the flow rate can be accurately measured.

In addition, since it does not need to be installed in a direct contact with the fluid, it is possible to measure the flow rate of the corrosive fluid, the hot or cold fluid, and the installation of the ultrasonic transducer is easy. That is, it may be temporarily attached to the wall of the pipe or may be permanently attached. Therefore, it is easy to inspect or repair during use.

According to the present invention, it is possible to detect the rational flow rate management and rapid leak area, to minimize the space constraints when installing, and can be easily installed in large diameter round pipe.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

2 is a conceptual diagram of an ultrasonic transducer according to the present invention. A description with reference to FIG. 2 is as follows.

The disconnection method of FIG. 2A is a method used in the prior art. However, in the present invention, in addition to the central transmission transducer and the center receiving transducer, the auxiliary transmission transducer and the auxiliary receiving transducer are provided separately, and the multi-line method of FIG. 2 (b) is used. That is, ultrasonic waves are transmitted and received in multiple lines rather than in single lines. This multi-line method can measure a variety of values for the fluid flowing in the pipe compared to the disconnection method can improve the accuracy of the flow measurement. For example, when using three lines as shown in FIG. 2 (b), more accurate flow rate is measured through various calculation processes such as averaging the flow rate estimate in the pipe calculated from the measured value on each line. can do. In this case, 'C' means the center of the circular pipe.

Unlike a single line, a multi-line may mean a plurality of lines, and in particular, may include a Top-Middle-Bottom 3 path (TMB 3 lines).

On the other hand, when using multiple lines, the profile of the fluid passing through the inside of the pipe can be measured more accurately. Since the fluid passing through the inside of the pipe changes in speed due to various factors such as resistance from the center of the pipe to the inner side, more information about the fluid can be obtained than in the case of the multi-line.

3 is a perspective view showing a state in which a multi-line outer wall type ultrasonic transducer according to the present invention is installed in a circular pipe. In FIG. 3, only the transmission transducer is illustrated for convenience of description, and the reception transducer corresponding thereto is not illustrated. However, the transmission transducer and the reception transducer have the same configuration, and the installation method is also the same. . In addition, in the present embodiment, only two auxiliary transducers are shown, but three or more may be installed to increase the accuracy of the flow measurement.

Furthermore, in the present invention, although it is expressed as a transmit transducer and a receive transducer, it is possible that the transmit transducer and the receive transducer are bidirectional transducers, each of which can transmit and receive functions. Even in this case, it is mounted and functions in the same manner as described in the present invention.

A description with reference to FIG. 3 is as follows.

The multi-line external wall type ultrasonic transducer according to the present invention includes a center transmission transducer 20 for measuring the amount of fluid flowing in the circular pipe 10 by using ultrasonic waves passing through the center of the circular pipe 10. And a center receive transducer 120.

In addition, the present invention is an auxiliary transmission transducer (30, 40) and the auxiliary receiving transformer for measuring the amount of fluid flowing in the circular pipe 10 by using an ultrasonic wave having a path deviating from the center of the circular pipe (10) The producers 130 and 140 are provided.

In particular, the auxiliary transmission transducers 30 and 40 include a first auxiliary transmission transducer 30 and a second auxiliary transmission transducer, and the auxiliary receiving transducers 130 and 140 include a first auxiliary receiving transducer 130. ) And a second auxiliary receiving transducer 140. However, the auxiliary receiving transducers 130 and 140 are shown in FIG. 5.

That is, according to the present invention, a plurality of auxiliary transmission transducers 30 and 40 and a plurality of auxiliary receiving transducers 130 and 140 are provided, respectively, and are different from the center transmitting transducer 20 and the center receiving transducer 120. Additional transducers with paths are provided.

4 is an exploded perspective view showing a center transmission transducer according to the present invention. On the other hand, since the center receiving transducer also has the same shape as the center transmitting transducer, detailed description thereof will be omitted. A description with reference to FIG. 4 is as follows.

In the center transmission transducer 20 according to the present invention, a piezoelectric vibrator 24 is installed on a base 22, and the piezoelectric vibrator 24 is equipped with a BNC connector connection part 26. In addition, the BNC connector connection portion 26 is formed of a structure in which the BNC connector 28 is mounted.

At this time, the base 22 is made of a wedge shape, it may be made of a plastic material. In particular, the base 22 may be made of Engineering Plastic PEEK-1000 (PolyEtherEeKetone). The base 22 has a flat bottom surface, and the flat bottom surface is in contact with the circular pipe 10.

On the other hand, the piezoelectric vibrator 24 includes a circular piezoelectric ceramic vibrator for generating longitudinal waves (thickness vibration), and may be 1 MHz in length and length.

FIG. 5 is a cross-sectional view of FIG. 3, in which a path through which ultrasonic waves pass is shown by a thick solid line. A description with reference to FIG. 5 is as follows.

When the ultrasonic transducer is installed in three lines on the outer wall of the tube, that is, when two auxiliary transmitting transducers are installed, ultrasonic waves are propagated as shown in FIG.

In the present invention, the ultrasonic waves generated by the auxiliary transmission transducers 30 and 40 move in parallel to the ultrasonic waves generated by the central transmission transducer 20. In other words, the path of the ultrasonic wave transmitted from the first auxiliary transmission transducer 30 and received by the first auxiliary receiving transducer 130, and transmitted from the center transmission transducer 20 to the center receiving transducer. The paths of the ultrasonic waves received at 120 are parallel to each other. This feature is the same in the second auxiliary transmission transducer 40.

In particular, the ultrasonic waves transmitted from the central transmission transducer 20 do not intersect the ultrasonic waves transmitted from the first auxiliary transmission transducer 30 and the ultrasonic waves transmitted from the second auxiliary transmission transducer 40.

In the present invention, the auxiliary transmission transducers 30 and 40 and the corresponding auxiliary receiving transducers 130 and 140 are mounted within a range of a semicircle based on the cross section of the circular pipe 10. In other words, the first auxiliary transmitting transducer 30 and the first auxiliary receiving transducer 130 are divided into semicircles divided by a line connecting the center transmitting transducer 20 and the center receiving transducer 120. Located in the phase. This feature is the same in the second auxiliary transmission transducer 40 and the second auxiliary receiving transducer 130.

In the present invention, the plurality of auxiliary transmission transducers 30 and 40 are mounted to be symmetrical with respect to the center transmission transducer 20, respectively. In other words, the first auxiliary transmission transducer 30 and the second auxiliary transmission transducer 40 may be mounted at positions symmetrical with respect to the center transmission transducer 20.

FIG. 6 is a conceptual diagram for describing a wedge incident angle in FIG. 5. Hereinafter, a method of calculating the wedge incidence angle around the position at which the first auxiliary transmission transducer is mounted will be described.

= 30°) 이내에서, 파동의 굴절 투과가 가능한 위치를 선정한다. 즉, 제1보조 송신트랜스듀서(30)가 장착될 위치를 선정한다.Let d be the outer diameter of the tube and t be the thickness of the tube. 1/2 distance of the radius from the center (

= 30 °), select the position where the wave can be transmitted through refraction. That is, the position where the first auxiliary transmission transducer 30 is mounted is selected.

)를 산출한다. 즉,

, (

: 유체에서 파동 전파속도,

: 관 벽에서 파동 전파 속도)를 이용한다.Then, using Snell's law, the incidence angle inside the tube wall

) Is calculated. In other words,

, (

= Wave propagation velocity in a fluid,

: Wave propagation velocity in the pipe wall.

)를 산출한다. 즉,

을 이용한다.Then, using the triangular sine formula, the angle of refraction outside the tube wall (

) Is calculated. In other words,

Use

)를 삼각함수 공식에 의해서 산출할 수 있다.

를 이용하면 상기 제1보조 송신트랜스듀서(30)와 상기 제1보조 수신트랜스듀서(130)를 견고하게 고정할 수 있다.At this time, the angle corresponding to the position of the transmission point outside the pipe wall (

) Can be calculated by the trigonometric formula.

By using the first auxiliary transmission transducer 30 and the first auxiliary receiving transducer 130 can be firmly fixed.

)로부터 웨지 입사각 (

)을 산출한다.

(

: 웨지에서 파동 전파속도)에 의해서 산출할 수 있다.Using Snell's law, the angle of refraction outside the tube wall

Wedge incidence angle from

) Is calculated.

(

It can be calculated from the wave propagation speed in the wedge).

)에 따라 웨지의 접촉면이 경사지도록 가공하는 것이 가능하다.The wedge incident angle thus calculated (

It is possible to process so that the contact surface of the wedge is inclined.

)은 상기 원형 파이프의 종류 및 상기 원형 파이프 내부를 흐르는 유체의 종류 중 적어도 어느 하나에 따라 달라지지는 것을 알 수 있다.As described above, the wedge incident angle (

) May vary depending on at least one of the type of the circular pipe and the type of fluid flowing in the circular pipe.

For example, let us say that the outer diameter of the tube described earlier is d = 114.3 mm and the thickness of the tube is t = 2.9 mm. When the fluid in the pipe is water, the pipe material is stainless steel (STS 304), and the transducer wedge material is plastic (PEEK 1000), it is calculated using the preceding equation.

= 27°이고,

= 1500 m/s,

=3281.3 m/s임을 알 수 있다. then,

= 27 °,

= 1500 m / s,

It can be seen that = 3281.3 m / s.

이고,

이다.

ego,

to be.

로 계산된다.Also,

.

로 계산된다. therefore,

.

)은 30°이하인 것이 바람직하다. 왜냐하면, 스넬의 법칙을 이용하여 웨지를 통하여 입사하는 각도를 계산하였을 때, 원형 파이프의 중심에서 이루는 각도가 30°를 넘어가게 되면 초음파가 관 벽에서 유체로 투과할 수 없기 때문이다. Meanwhile, the fluid side deflection angle (

) Is preferably 30 ° or less. This is because when the angle of incidence through the wedge is calculated using Snell's law, the ultrasonic wave cannot penetrate into the fluid in the tube wall if the angle formed at the center of the circular pipe exceeds 30 °.

7 is an exploded perspective view showing an auxiliary transmission transducer according to the present invention. In particular, FIG. 7 shows only the first auxiliary transmission transducer and has the same similar shape as the first auxiliary receiving transducer, the second auxiliary transmitting transducer and the second auxiliary receiving transducer. A description with reference to FIG. 7 is as follows.

In the first auxiliary transmission transducer 30 according to the present invention, a piezoelectric vibrator 34 is installed on the wedge 32, and the BNC connector connection 36 is mounted on the piezoelectric vibrator 34. In addition, the BNC connector connection part 36 has a structure in which the BNC connector 38 is mounted.

Since only the wedge 32 has a difference from the center transmission transducer 20, the first auxiliary transmission transducer 30 will be described based on the difference.

The wedge 32 is formed in a substantially wedge shape, and may be made of a plastic material. The wedge 22 may be made of Engineering Plastic PEEK-1000 (PolyEtherEeKetone).

In particular, the wedge 32 is processed such that the contact surface 32b in contact with the circular pipe 10 is inclined with respect to the bottom surface 32a. Unlike the base 22, the circular pipe 10 is fixed to the contact surface 32b instead of the bottom surface 32a. This is because the ultrasonic waves generated by the piezoelectric vibrator 34 are transmitted to the circular pipe 10 through the contact surface 32b rather than the bottom surface 32a.

)과 동일한 것이 바람직하다. 이에 대해서는 도 8을 참조해서 설명한다.At this time, the inclination angle of the contact surface 32b with respect to the bottom surface 32a is a wedge incident angle at which ultrasonic waves enter the circular pipe from the wedge (

It is preferable that the same as). This will be described with reference to FIG. 8.

On the other hand, it is also possible to firmly mount the auxiliary transducer to the circular pipe, and to form a fixing jig hole (not shown) on one side of the wedge 32 to allow the ultrasonic wave to enter the circular pipe at a predetermined angle.

FIG. 8 is a conceptual view illustrating the inclination angle of FIG. 7. A description with reference to FIG. 8 is as follows.

)에 맞닿아 있는 각은 90°-

가 됨을 알 수 있다. 웨지에서 발생하는 초음파의 경로와 평행한 선(②)을 보조선으로 생성하면, 초음파의 경로와 평행한 선(②)에 의해서 형성되는 각은 90°-

가 된다. 따라서, 웨지의 바닥면과 접촉 면은 서로 수직을 이루므로, 접촉면의 경사각은 웨지 입사각(

)과 동일함을 확인할 수 있다.Since the tangent line (①) from the center and the tangent of the circular pipe are vertical, the wedge incident angle (

Angle of contact is 90 °-

It can be seen that. If a line (②) parallel to the path of the ultrasonic wave generated in the wedge is generated as an auxiliary line, the angle formed by the line (②) parallel to the path of the ultrasonic wave is 90 °-

Becomes Therefore, since the bottom surface and the contact surface of the wedge are perpendicular to each other, the inclination angle of the contact surface is the wedge incident angle (

You can see the same as).

9 is a conceptual diagram illustrating a Z-path method. A description with reference to FIG. 9 is as follows.

In the multi-line external wall type ultrasonic transducer of the present invention, the flow rate is preferably measured by using a jet path method (Z-path).

In this case, the jet path method is a pair of the transmitting transducers 20, 30, 40 and the receiving transducers 120, 130, 140. In other words, the upstream (UP) and downstream (DN) transducers constitute one pair, and one is installed on the upstream (UP) side of the measuring pipe and the other is installed on the downstream (DN) side of the opposite pipe wall. Facing diagonally is the 1-Traveres (Z-method).

In the present invention, the transmission transducers 20, 30, 40 are attached to the outer wall of the circular pipe 10, an electrical signal is applied to the piezoelectric vibrator, and ultrasonic waves generated by the piezoelectric vibrator are propagated through the wedge or the base. Ultrasonic waves are transmitted through the piezoelectric vibrators of the receiving transducers 120, 130, and 140 through the walls of the circular pipe 10 and the fluid inside the pipes. At this time, physical deformation occurs according to various factors such as the flow of the fluid, and the deformation is an electrical signal. The flow rate can be measured by changing the measurement to.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

1 illustrates an ultrasonic transducer according to the prior art.

2 is a conceptual diagram of an ultrasonic transducer according to the present invention;

Figure 3 is a perspective view showing a state in which a multi-line external wall type ultrasonic transducer according to the present invention is installed in a circular pipe.

4 is an exploded perspective view showing a center transmission transducer according to the present invention.

5 is a cross-sectional view of FIG. 3.

6 is a conceptual diagram for explaining the wedge incident angle in FIG.

7 is an exploded perspective view showing an auxiliary transmission transducer according to the present invention.

8 is a conceptual view illustrating the inclination angle of FIG. 7.

9 is a conceptual diagram illustrating a Z-path method.

<Description of Signs for Main Parts of Drawings>

10: round pipe 20: center transmission transducer

30: first auxiliary transmission transducer 40: second auxiliary transmission transducer

120: center receiving transducer 130: first auxiliary receiving transducer

140: second auxiliary receiving transducer

Claims (12)

delete delete delete delete delete delete delete delete Select the direction of the ultrasonic wave passing through the inside of the circular pipe,

Calculating c); Using Snell's law, the inner angle of incidence

) And the outward deflection angle of the circular pipe (

Calculating c); Using Snell's law, the wedge angle of incidence from the

Calculating c); And And processing the inclined contact surface of the wedge according to the angle of incidence of the wedge. 10. The method of claim 9, The inclined inclination angle of the contact surface is a wedge incident angle at which ultrasonic waves enter the circular pipe from the wedge (

Method for manufacturing a multi-line outer wall type ultrasonic transducer characterized in that the same as 10. The method of claim 9, The fluid side deflection angle (

) Is a method for manufacturing a multi-line outer wall type ultrasonic transducer, characterized in that less than 30 °. 10. The method of claim 9, And the wedge incidence angle depends on at least one of the type of the circular pipe and the type of the fluid flowing in the circular pipe.

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