KR101146518B1 - A Clamp-on type Multipath Ultrasonic Flowsensor and Installation Method thereof - Google Patents

Abstract

The present invention relates to an external multi-line ultrasonic flow sensor.

The present invention includes a center transmission sensor and a center reception sensor for measuring the amount of fluid flowing in the circular pipe using ultrasonic waves passing through the center of the circular pipe; An auxiliary transmitting sensor and an auxiliary receiving sensor measuring an amount of fluid flowing in the circular pipe by using ultrasonic waves having a path deviating from the center of the circular pipe; And a fixing device having a jig and a strap detachably mounted to the pipe to attach the center and auxiliary transmitting sensors and the receiving sensors to the outer wall of the pipe.

According to the present invention, the amount of fluid flowing in the circular pipe can be more accurately measured using multiple lines, and can be firmly attached to the outer wall of the circular pipe.

Ultrasonic Flow Sensors, Clamp Type, Round Pipe, Straps

Description

A Clamp-on type Multipath Ultrasonic Flowsensor and Installation Method

The present invention relates to an external multi-line ultrasonic flow rate sensor, and more particularly, an external multi-line ultrasonic flow rate which can more accurately measure the amount of fluid flowing in a circular pipe using multiple lines and can be firmly attached to the outer wall of the circular pipe. It relates to a sensor and its installation 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.

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

Invasive ultrasonic flow sensor is in direct contact with the fluid to transmit or receive ultrasonic waves. 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 type ultrasonic flow sensor 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 inappropriate 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. In addition, an object of the present invention is to provide a multi-line outer wall type ultrasonic flow rate sensor that can measure the flow rate of corrosive fluid, high temperature or low temperature fluid.

In order to achieve the above object, the present invention comprises a center transmitting sensor and the center receiving sensor for measuring the amount of fluid flowing in the circular pipe using the ultrasonic wave passing through the center of the circular pipe; An auxiliary transmitting sensor and an auxiliary receiving sensor measuring an amount of fluid flowing in the circular pipe by using ultrasonic waves having a path deviating from the center of the circular pipe; And a fixing device having a jig and a strap detachably mounted to the pipe to attach the center and auxiliary transmitting sensors and the receiving sensors to the outer wall of the pipe.

The sensor may be provided in plurality, and the auxiliary transmission sensor and the auxiliary reception sensor corresponding thereto may be mounted within a range of a semicircle based on the cross section of the circular pipe.

The plurality of auxiliary transmission sensors may be mounted to be symmetrical with respect to the center transmission sensor.

The auxiliary transmitting sensor and the auxiliary receiving sensor are wedges in which the contact surface in contact with the circular pipe is inclined with respect to the bottom surface; And a piezoelectric vibrator installed in the wedge.

The jig of the fixing device may be provided with a receiving groove for receiving the sensor so that each sensor is detachably mounted, and a strap support groove for allowing the strap to be seated on the outer surface.

The strap may wrap around the outer circumferential surface of the pipe to urge a plurality of jigs attached to the pipe.

The fixing device may further include a strap fixing part for fixing the strap mounted on the pipe and the jig.

On the other hand, the present invention comprises a center transmitting sensor and the center receiving sensor for measuring the amount of fluid flowing in the circular pipe using the ultrasonic wave passing through the center of the circular pipe; An auxiliary transmitting sensor and an auxiliary receiving sensor measuring an amount of fluid flowing in the circular pipe by using ultrasonic waves having a path deviating from the center of the circular pipe; Straps surrounding the center and the auxiliary transmission sensor and the reception sensor; includes, the strap support groove is formed in the sensor to attach the center and the auxiliary transmission sensor and the reception sensor to the outer wall of the pipe It includes an external multi-line ultrasonic flow rate sensor, characterized in that.

On the other hand, the present invention uses a center transmitting sensor and a center receiving sensor for measuring the amount of fluid flowing in the circular pipe by using the ultrasonic wave passing through the center of the circular pipe, using an ultrasonic wave having a path deviating from the center of the circular pipe In the external multi-line ultrasonic flow rate sensor including an auxiliary transmitting sensor and an auxiliary receiving sensor for measuring the amount of fluid flowing in the circular pipe, the center and the auxiliary transmitting sensor and the receiving sensor is detachably mounted to the pipe It includes a method of installing an external multi-line ultrasonic flow rate sensor, characterized in that a plurality is attached to the outer wall of the pipe through a fixing device having a jig and a strap.

The jig accommodates the sensor so that each sensor is detachably mounted, and the strap may wrap around the outer circumferential surface of the pipe to press a plurality of jigs attached to the pipe.

According to the external multi-line ultrasonic flow sensor and the installation method of the present invention has the following effects.

First, it is possible to measure the amount of fluid in the pipe more accurately by using the multi-line, so that the accurate measurement that can determine whether or not leaks. 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.

Second, 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, high temperature or low temperature fluid, it is easy to install the ultrasonic flow sensor. 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.

Third, reasonable flow rate management and rapid leak area detection can be detected, space constraints can be minimized during installation, and large diameter round pipes can be easily installed.

Fourth, since the center and the auxiliary transmitting sensor and the receiving sensor can be detachably mounted on the pipe through the fixing device, the installation structure becomes simpler and it is possible to firmly fix several sensors at once.

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

The disconnection method of FIG. 2A is a method used in the prior art. However, in the present invention, in addition to the center transmission sensor and the center reception sensor, the auxiliary transmission sensor and the auxiliary reception sensor 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 sensor according to the present invention is installed in a circular pipe. In FIG. 3, only the transmitting sensor is illustrated for convenience of description, and the corresponding receiving sensor is not illustrated. However, the transmitting sensor and the receiving sensor are mostly the same in configuration, and the installation method is also the same, and thus the description thereof will be omitted. In addition, in the present embodiment, only two auxiliary sensors are shown, but three or more may be installed to increase the accuracy of the flow measurement.

In addition, although the present invention is expressed as a transmitting sensor and a receiving sensor, it is possible that each of the transmitting sensor and the receiving sensor can be a bidirectional sensor capable of both transmitting and receiving 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 flow rate sensor according to the present invention is a center transmission sensor 20 and a center for measuring the amount of fluid flowing in the circular pipe 10 using ultrasonic waves passing through the center of the circular pipe 10. It includes a receiving sensor 120.

In addition, the present invention, the auxiliary transmission sensor 30, 40 and the auxiliary receiving sensor 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 ( 130,140).

In particular, the auxiliary transmission sensors 30 and 40 include a first auxiliary transmission sensor 30 and a second auxiliary transmission sensor, and the auxiliary reception sensors 130 and 140 include a first auxiliary reception sensor 130 and a second beam. A jaw receiving sensor 140 is included. However, the auxiliary receiving sensor 130, 140 is shown in FIG.

That is, in the present invention, a plurality of auxiliary transmission sensors 30 and 40 and a plurality of auxiliary receiving sensors 130 and 140 are provided, respectively, using additional paths different from the center transmitting sensor 20 and the center receiving sensor 120. Flow sensor is provided.

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

In the center transmission sensor 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 flow rate sensor is installed in three lines on the outer wall of the pipe, that is, when two auxiliary transmitting sensors are installed, the ultrasonic wave is propagated as shown in FIG.

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

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

In the present invention, the auxiliary transmission sensor (30, 40) and the corresponding auxiliary receiving sensor (130, 140) is mounted in the range of a semi-circle based on the cross section of the circular pipe (10). In other words, the first auxiliary transmission sensor 30 and the first auxiliary reception sensor 130 are positioned on a semicircle divided by a line connecting the center transmission sensor 20 and the center reception sensor 120. . This feature is the same in the second auxiliary transmitter sensor 40 and the second auxiliary receiver sensor 130.

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

FIG. 6 is a conceptual diagram for describing a wedge incident angle in FIG. 5. Hereinafter, a method of calculating the wedge incident angle centering on the position where the first auxiliary transmission sensor is mounted will be described.

= 30°) 이내에서, 파동의 굴절 투과가 가능한 위치를 선정한다. 즉, 제1보조 송신센서(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 sensor 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,

.

)를 삼각함수 공식에 의해서 산출할 수 있다.

를 이용하면 상기 제1보조 송신센서(30)와 상기 제1보조 수신센서(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 sensor 30 and the first auxiliary receiving sensor 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 달라지는 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 material is stainless steel (STS 304), and the flow sensor wedge is plastic (PEEK 1000), it is calculated using the equation above.

= 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.

이고,

이므로,

로 계산된다.Also,

ego,

Because of,

.

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 sensor according to the present invention. In particular, FIG. 7 shows only the first auxiliary transmitting sensor and has the same shape as that of the first auxiliary receiving sensor, the second auxiliary transmitting sensor, and the second auxiliary receiving sensor. A description with reference to FIG. 7 is as follows.

In the first auxiliary transmission sensor 30 according to the present invention, the piezoelectric vibrator 34 is installed on the wedge 32, and the BNC connector connection part 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 sensor 20, the first auxiliary transmission sensor 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 flow sensor to the circular pipe, and to form a fixing jig hole (not shown) on one side of the wedge 32 so that the ultrasonic wave is incident on 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 중심에서 이어지는 선(①)은 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, the bottom surface of the wedge and the line (①) extending from the center are perpendicular to each other, so that the inclination angle of the contact surface is the wedge incident angle (

You can see the same as).

On the other hand, the present invention further comprises a fixing device 200 so that the center and the auxiliary transmitting sensor and the receiving sensor having the above-described characteristics can be firmly and easily attached to the outer wall of the pipe (10).

9 is a front view of the fixing device of the present invention mounted on a pipe, FIG. 10 is a plan view, FIG. 11 is a side view, and FIG. 12 is a perspective view of a jig.

In more detail, the fixing device 200 includes a jig 300 detachably mounted to an outer wall of the pipe 10, a strap 400 for fixing the jig 300 to the pipe 10, and the strap. A strap fixing part 500 for fixing the 400 is provided.

Here, the jig 300 is provided in plural as the number of sensors to be mounted on the pipe 10, the shape of the jig 300 can be appropriately modified according to the shape of the sensor attached to the pipe (10).

In the present embodiment, in order to easily understand the convenience and technical idea of the description, the fixing device 200 is shown around the two jig 300 and the strap 400 so that two sensors are installed in the pipe 10. Embodiment of 200 is not limited to this.

Although not specifically illustrated, the sensor may correspond to the above-described center and auxiliary transmission sensors, center and auxiliary reception sensors. Therefore, it should be noted that the term 'sensor' referred to below is a term including the aforementioned sensors.

The jig 300 is provided with a receiving groove 305 for accommodating the sensor so that the sensor is detachably mounted, and a strap support groove 310 for supporting the strap 400 on the outer surface.

Accordingly, as shown in FIG. 10, the receiving groove 305 may be provided in the jig 300 in a form in which one side of the receiving groove 305 is opened and a seating bar 320 on which the sensor is mounted. The receiving groove 305 is a connector recessed in the jig 300 in a semicircular shape so that the protruding portion of the BNC connector 28 of the sensor described above is supported at one side where the receiving groove 305 is formed according to the shape of the sensor. The groove 330 may be included.

The strap support groove 310 is provided on the outer surface of the jig 300, as in the present embodiment is provided in a shape recessed in both corner regions of the outer surface of the jig 300, the strap 400 is wrapped around the pipe 10 When the distance between the strap 400 and the jig 300 can be reduced.

The strap support groove 310 may be formed in each of four corner regions of one jig 300, and may be implemented in four, and the four strap support grooves 310 may be wrapped by two straps 400, and then jig ( 300 may be secured to pipe 10.

Of course, the strap support groove 310 may be implemented in various ways without being limited to the above-described embodiment. For example, the strap 400 may be formed long along the transverse direction of the outer surface of the jig 300 so that the strap 400 may be entirely seated on the outer surface of the jig 300, and the strap 400 and the jig 300 are integrally coupled to each other. It may be implemented in the form.

Since the jig 300 is in contact with the outer circumferential surface of the pipe 10, the shape of the part in contact with the pipe 10 is appropriately changed to correspond to the shape of the outer circumferential surface of the pipe 10 as shown in FIG. 10. Can be.

On the other hand, the strap 400 may be made of a steel (steel) material, it may be made of a band shape with a plurality of through grooves 410 formed on the inside. For example, the strap 400 may have a thickness of about 1 cm to about 2 cm and a length of about 1 cm to about 2 cm. The length of the strap 400 may be about 1 to 2 times between the jig 300 and the pipe 10.

Since the strap 400 is installed to surround the outer circumferential surface of the pipe 10 to pressurize the plurality of jigs 300 attached to the pipe 10, the plurality of jigs 300 may be formed with one strap 400. It can be fixed to the pipe 10 at one time. Of course, two straps 400 may be provided to surround both side edge regions of the jig 300 and to fix the jig 300 more firmly.

When the strap 400 surrounds the jig 300 and the pipe 10, the strap 400 fixes the position through the strap fixing part 500. The strap fixing part 500 may be implemented as a fixing screw that is separately coupled to the strap 400 in the edge region where the strap 400 is overlapped. Of course, the strap fixing portion 500 can be modified by welding or a separate coupling means.

When the jig 300 is fixed to the pipe 10 by the strap 400, the above-described sensors may be fixed to the pipe 10. Here, the sensors may be fixed to the jig 300 while being pressed by the strap 400 while being inserted into the jig 300, or inserted into the jig 300 after the jig 300 is fixed to the strap 400. Can be fixed.

In addition, a bolt hole 340 penetrating an outer surface of the jig 300 is formed so that the sensor can be more firmly fixed to the jig 300, and a bolt (not shown) is inserted into the bolt hole 340. To pressurize one side of the sensor.

As such, the plurality of center and auxiliary transmission sensors and the reception sensors may be detached from the outer wall of the pipe 10 through a fixing device 200 having a jig 300 and a strap 400 detachably mounted to the pipe 10. The external multi-line ultrasonic flow sensor may be installed in such a manner as to be attached thereto.

The jig 300 receives the sensor so that the respective sensors are detachably mounted, and the strap 400 presses the pipe 10 to press the plurality of jig 300 attached to the pipe 10. It wraps around the outer circumferential surface of) so that the installation structure is simpler and several sensors can be fixed at once.

In addition, since the sensor can be fixed to the pipe 10 through the fixing device 200, the wedge shape of the sensor can be simply configured as described above, so that the sensor can be easily processed.

Meanwhile, instead of the jig 300 described above, a strap support groove 310 may be formed in which the strap 400 is seated in the sensor. The sensor on which the strap support groove 310 is formed may be fixed to the pipe 10 while being immediately wrapped by the strap 400 without the above-described jig 300. Of course, in this case, the jig 300 may be manufactured so that the shape of the surface in contact with the pipe 10 corresponds to the outer circumferential surface of the pipe 10.

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 is a view showing an ultrasonic flow sensor according to the prior art,

2 is a conceptual diagram of an ultrasonic flow sensor according to the present invention,

3 is a perspective view showing a state in which a multi-line outer wall type ultrasonic flow rate sensor is installed in a circular pipe according to the present invention;

4 is an exploded perspective view showing a center transmission sensor according to the present invention,

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

FIG. 6 is a conceptual diagram for describing a wedge incident angle in FIG. 5.

7 is an exploded perspective view showing an auxiliary transmission sensor according to the present invention,

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

9 is a front view of the fixing device of the present invention mounted on a pipe, FIG. 10 is a plan view, FIG. 11 is a side view, and FIG. 12 is a perspective view of a jig.

<Description of Signs for Main Parts of Drawings>

10: circular pipe 20: center transmission sensor 30: first auxiliary transmission sensor

40: second auxiliary transmission sensor 120: center receiving sensor 130: first auxiliary receiving sensor

140: second auxiliary receiving sensor 200: fixing device 300: jig

310: strap support groove 400: strap

Claims (10)

A center transmission sensor and a center reception sensor for measuring the amount of fluid flowing in the circular pipe using ultrasonic waves passing through the center of the circular pipe; An auxiliary transmitting sensor and an auxiliary receiving sensor measuring an amount of fluid flowing in the circular pipe by using ultrasonic waves having a path deviating from the center of the circular pipe; And a fixing device having a jig and a strap detachably mounted to the pipe to attach the center and auxiliary transmitting sensors and the receiving sensors to the outer wall of the pipe. The auxiliary transmitting sensor and the auxiliary receiving sensor A wedge in which the contact surface in contact with the circular pipe is inclined with respect to the bottom surface; And A piezoelectric vibrator installed in the wedge; The inclination of the contact surface and the bottom surface is an external multi-line ultrasonic flow rate sensor, characterized in that the same as the wedge incident angle of the ultrasonic wave incident from the wedge to the circular pipe. The method of claim 1, The plurality of sensors are provided with a plurality of the auxiliary transmission sensor and the corresponding auxiliary receiving sensor, the external multi-line ultrasonic flow rate sensor, characterized in that mounted in the range of a semi-circle based on the cross section of the circular pipe. 3. The method of claim 2, The plurality of auxiliary transmission sensors are external multi-line ultrasonic flow rate sensor, characterized in that mounted to be symmetrical with respect to the center transmission sensor, respectively. delete The method according to any one of claims 1 to 3, An external multi-line ultrasonic flow sensor is formed in the jig of the fixing device, and a receiving groove for accommodating the sensor so that the respective sensors are detachably mounted, and a strap support groove for allowing the strap to rest on the outer surface. . The method of claim 5, The external multi-line ultrasonic flow sensor, characterized in that the strap wraps around the outer circumferential surface of the pipe to press the plurality of jigs attached to the pipe. The method of claim 6, The fixing device is an external multi-line ultrasonic flow rate sensor further comprises a strap fixing portion for fixing the strap mounted on the pipe and the jig. delete delete delete

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