Throttling type flow meter

Abstract

The utility model relates to a throttling type flowmeter which comprises a measuring pipeline, a trapezoidal throttling piece and a differential pressure gauge. The side wall, provided with the trapezoidal lower bottom, of the throttling element is fixed to the inner wall of the measuring pipeline, the included angle between one waist, close to the first pressure tapping opening, of the trapezoidal structure of the throttling element and the lower bottom ranges from 20 degrees to 45 degrees, and the included angle between the other waist and the lower bottom ranges from 8 degrees to 18 degrees. A first pressure tap and a second pressure tap are adjacently formed in the pipe wall of the measuring pipeline in the axial direction, the second pressure tap sequentially penetrates through the pipe wall of the measuring pipeline and the throttling element, an opening of the second pressure tap is located on one side of the trapezoid upper bottom of the throttling element, the area of the opening of the second pressure tap is smaller than that of the side wall, and the two pressure measuring ends of the differential pressure gauge are connected with the first pressure tap and the second pressure tap respectively. Therefore, the pressure difference between the first pressure tap and the second pressure tap can be detected, and the abrasion of the throttling wedge block of the wedge-shaped flow meter can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of flow meters, and in particular to a throttling flow meter. Background Art

[0002] Among various flow measurement instruments, throttling flowmeters are widely used. Throttling flowmeters usually consist of a throttling device that can convert fluid flow into a differential pressure signal and a differential pressure gauge that measures the differential pressure and displays the flow. The flow beam in the measuring pipeline will form a local contraction at the throttling point, thereby increasing the flow velocity and reducing the static pressure, thus generating a static pressure difference before and after the throttling device. Based on the Bernoulli theorem and the flow continuity equation as the basic principles, the flow rate is obtained by measuring the pressure difference generated by the fluid in the pipeline flowing through the throttling element and combining it with known working conditions.

[0003] Among them, the wedge flowmeter has a wide Reynolds number range (500-10 6 ), the flow rate and differential pressure always maintain a square root relationship, and the flow coefficient is linear. The throttling piece of the wedge flowmeter is a V-shaped wedge with the arc top angle facing downward, which is conducive to the passage of fluids containing suspended particles and high-viscosity liquids. Generally, there will be no stagnation and accumulation on the upstream side of the throttling piece. Therefore, it is very suitable for high viscosity in a wide Reynolds number range and the measurement of fluids containing suspended particles, and is widely used. However, the top angle of the V-shaped wedge of the wedge flowmeter is concentrated, directly bearing the scouring of the fluid, and the top angle is more easily worn, causing the wedge to deform, which directly affects the flow measurement accuracy.

[0004] Therefore, how to reduce the adverse effects of throttling wedge wear on flow measurement accuracy has become an urgent problem to be solved by those skilled in the art. Utility Model Content

[0005] In order to reduce the wear of a throttling wedge of a wedge-shaped flowmeter, the present application provides a throttling flowmeter.

[0006] A throttling flow meter provided to achieve the purpose of the utility model comprises:

[0007] Measuring pipes, throttles and differential pressure gauges;

[0008] The inner wall of the measuring pipe is provided with a throttling member, the throttling member is trapezoidal in shape as a whole, the throttling member is provided with side walls of its trapezoidal upper bottom and lower bottom which are parallel to the axial direction of the measuring pipe, the throttling member is provided with a side wall of its trapezoidal lower bottom which is fixed to the inner wall of the measuring pipe, one waist of the trapezoidal structure of the throttling member and the lower bottom have an angle of preset angle A, and the other waist and the lower bottom have an angle of preset angle B, the preset angle A is 20° to 45°, and the preset angle B is 8° to 18°;

[0009] The side wall of the measuring pipe is provided with a first pressure port and a second pressure port, the first pressure port and the second pressure port are adjacently distributed along the axial direction of the measuring pipe, the opening direction of the second pressure port is consistent with the height direction of the trapezoidal structure of the throttling device, the second pressure port sequentially penetrates the pipe wall of the measuring pipe and the throttling device, one end opening of the second pressure port is located on a side wall of the throttling device with its trapezoidal upper bottom, the opening area of ​​the second pressure port is smaller than the side area of ​​the throttling device with its trapezoidal structure upper bottom, along the axial direction of the measuring pipe, the end of the throttling device with a preset angle A is located between the first pressure port and the second pressure port,

[0010] The two pressure measuring ends of the differential pressure gauge are respectively connected to the first pressure port and the second pressure port to detect the pressure difference between the first pressure port and the second pressure port.

[0011] In a possible implementation, the measuring pipe is a cylindrical pipe.

[0012] In a possible implementation, along the axial direction of the measuring pipe, a side wall of the trapezoidal upper bottom of the throttling member is provided with a preset length L, and the preset length L is greater than or equal to the inner diameter of the measuring pipe.

[0013] In a possible implementation, the throttling element is provided with a preset height H along the height direction of its trapezoidal structure, and the preset height H is 1 / 3 to 2 / 3 times the inner diameter of the measuring pipe.

[0014] In a possible implementation, the preset height H is 1 / 2 times the inner diameter of the measuring pipe.

[0015] In a possible implementation, the opening ends of the first pressure port and the second pressure port located outside the measuring pipe both protrude out of the side wall of the measuring pipe, the protruding end of the first pressure port is connected to one pressure measuring end of the differential pressure gauge, and the protruding end of the second pressure port is connected to the other pressure measuring end of the differential pressure gauge.

[0016] In a possible implementation, a protruding end of the first pressure port is provided with a pressure flange to be connected to one pressure measuring end of a differential pressure gauge, and a protruding end of the second pressure port is provided with a pressure flange to be connected to the other pressure measuring end of the differential pressure gauge.

[0017] In a possible implementation, a side wall of a protruding end of the first pressure tapping port is welded to a pressure tapping flange, and a protruding end of the second pressure tapping port is welded to a pressure tapping flange.

[0018] In a possible implementation, connecting flanges are provided on the side walls of the openings at both axial ends of the measuring pipe.

[0019] In this application, a measuring pipe is set up for the flow of the fluid to be detected, and the flow direction is as follows Figure 1 As shown by the arrow. The first pressure port is set as the positive pressure port of the measuring pipeline, and the pressure port is set as the negative pressure port. A throttling device is set to form a local contraction of the fluid between the first pressure port and the second pressure port to generate a pressure difference. A differential pressure gauge is set to detect the pressure difference between the first pressure port and the second pressure port to calculate the fluid flow rate connected to the measuring pipeline.

[0020] Among them, the throttling piece was modified based on the wedge-shaped throttling piece as the prototype, and the V-shaped wedge was changed into a trapezoidal wedge to increase the contact area between the lowest point of contraction and the fluid. Even if the front end is worn along the flow direction, the position of the lowest point remains unchanged, reducing the influence of fluid wear on the local contraction of the wedge, thereby reducing the adverse effect of wedge wear on the accuracy of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram showing the structure of a measuring pipeline according to an embodiment of the present application;

[0022] Figure 2 A schematic diagram showing the structure of a measuring pipeline of an existing throttling flowmeter is shown;

[0023] Figure 3 A schematic diagram showing the structure of a throttling flow meter according to an embodiment of the present application is shown;

[0024] Figure 4 A partially enlarged view of a throttling flow meter according to an embodiment of the present application is shown.

[0025] Measuring pipeline 100, first pressure tapping port 110, second pressure tapping port 120, connecting flange 130, throttling element 200, differential pressure gauge 300, pressure tapping flange 310, sealing ring 311, temperature sensor 400. DETAILED DESCRIPTION

[0026] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0027] Among them, it should be understood that the directions or positional relationships indicated by terms such as "length", "width", "height", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0028] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0029] The present application provides a throttling flowmeter, comprising a measuring pipe 100, a throttling element 200 and a differential pressure gauge 300. The inner wall of the measuring pipe 100 is provided with a throttling element 200, and the throttling element 200 is trapezoidal in shape as a whole. The throttling element 200 is provided with side walls of its trapezoidal upper and lower bottoms which are parallel to the axial direction of the measuring pipe 100, and the throttling element 200 is provided with a side wall of its trapezoidal lower bottom which is fixed to the inner wall of the measuring pipe 100, and a preset gap is provided between one side wall of the throttling element 200 having its trapezoidal upper bottom and the inner wall of the measuring pipe 100, and one waist of the trapezoidal structure of the throttling element 200 has an angle of preset angle A with the lower bottom, and the other waist has an angle of preset angle B with the lower bottom, and the preset angle A is 20° to 45°, and the preset angle B is 8° to 18°;

[0030] The side wall of the measuring pipe 100 is provided with a first pressure port 110 and a second pressure port 120. The first pressure port 110 and the second pressure port 120 are adjacently distributed along the axial direction of the measuring pipe 100 and are located at the same end of the measuring pipe 100 along its axial direction. The opening direction of the second pressure port 120 is consistent with the height direction of the trapezoidal structure of the throttling device 200. The second pressure port 120 sequentially penetrates the pipe wall of the measuring pipe 100 and the throttling device 200. One end of the second pressure port 120 is opened on a side wall of the throttling device 200 where its trapezoidal upper bottom is provided. The opening area of ​​the second pressure port 120 is smaller than the side area of ​​the throttling device 200 where its trapezoidal structure upper bottom is provided. Along the axial direction of the measuring pipe 100, one end of the throttling device 200 where a preset angle A is provided is located between the first pressure port 110 and the second pressure port 120.

[0031] Two pressure measuring ends of the differential pressure gauge 300 are respectively connected to the first pressure port 110 and the second pressure port 120 to detect the pressure difference between the first pressure port 110 and the second pressure port 120 .

[0032] In the present application, a measuring pipe 100 is provided for the flow of the fluid to be detected, and the flow direction is along Figure 1 From left to right in the horizontal direction, the rest are analogous. By setting the first pressure port 110 as the positive pressure port of the measuring pipeline 100, the pressure port is set to be the negative pressure port, and the throttling member 200 is set to form a local contraction of the fluid between the first pressure port 110 and the second pressure port 120 to generate a pressure difference; by setting a differential pressure gauge 300 to detect the pressure difference between the first pressure port 110 and the second pressure port 120, the fluid flow rate connected to the measuring pipeline 100 is calculated.

[0033] Among them, the throttling piece 200 is modified based on the wedge-shaped throttling piece as the prototype, and the V-shaped wedge is changed into a trapezoidal wedge, so as to increase the contact area between the lowest point of contraction and the fluid. Even if the front end is worn along the flow direction, the position of the lowest point remains unchanged, thereby reducing the influence of fluid wear on the local contraction of the wedge, thereby reducing the adverse effect of wedge wear on the accuracy of the measurement results.

[0034] In a possible implementation, the measuring pipe 100 is a cylindrical pipe. Further, along the axial direction of the measuring pipe 100, a side wall of the throttling member 200 having a trapezoidal upper bottom is provided with a preset length L, and the preset length L is greater than or equal to the inner diameter D of the measuring pipe 100. Preferably, the preset length L is equal to the inner diameter D of the measuring pipe 100.

[0035] In a possible implementation, the throttling member 200 is provided with a preset height H along the height direction of its trapezoidal structure, and the preset height H is 1 / 3 to 2 / 3 times the inner diameter D of the measuring pipe 100, that is, the preset height H is 1 / 3D to 2 / 3D. Further, the preset height H is 1 / 2 times the inner diameter of the measuring pipe 100.

[0036] In a possible implementation, the opening ends of the first pressure port 110 and the second pressure port 120 located outside the measuring pipe 100 both protrude out of the side wall of the measuring pipe 100, the protruding end of the first pressure port 110 is connected to one pressure measuring end of the differential pressure gauge 300, and the protruding end of the second pressure port 120 is connected to the other pressure measuring end of the differential pressure gauge 300. Compared with flush openings, it is easier to perform connection operations, and the stability and sealing of the connection can be better guaranteed.

[0037] In a possible implementation, a pressure-taking flange 310 is provided at one end of the first pressure-taking port 110 to be connected to one pressure-measuring end of the differential pressure gauge 300, and a pressure-taking flange 310 is provided at one end of the second pressure-taking port 120 to be connected to the other pressure-measuring end of the differential pressure gauge 300. Further, the side wall of the protruding end of the first pressure-taking port 110 is welded to the pressure-taking flange 310, and the protruding end of the second pressure-taking port 120 is welded to the pressure-taking flange 310.

[0038] In a possible implementation, the side walls of the openings at both ends of the axial direction of the measuring pipe 100 are provided with connection flanges 130 , which are communicated with an external device in a sealed manner and allow fluid to pass therethrough.

[0039] It should be noted that the differential pressure gauge 300 is provided with a controller and a display screen, and the differential pressure data measured by the differential pressure gauge 300 is uploaded to its controller for calculation to obtain flow data, and the differential pressure and flow measurement results are displayed on the display screen. Alternatively, the differential pressure gauge 300 uses a differential pressure transmitter, the output end of the pressure transmitter is electrically connected to the input end of the computing device, and the computing device is provided with a display screen to display the input differential pressure data and the flow data calculated accordingly in real time.

[0040] In a possible implementation, a temperature sensor is further included, and the temperature measuring end of the temperature sensor is located in the measuring pipe 100 to detect the temperature. Along the axial direction of the measuring pipe 100, the temperature measuring end of the temperature sensor is located between the first pressure port 110 and the second pressure port 120. The output end of the temperature sensor is electrically connected to the differential pressure gauge 300 or the computing device for communication, and the pressure difference result is temperature compensated and corrected using the real-time monitored fluid temperature to ensure the accuracy of the flow measurement. The temperature measurement result can be displayed in real time through its own display screen, the display screen of the differential pressure gauge 300, or the display screen of the computing data.

[0041] In a possible implementation, a sealing ring 311 is provided on the side wall of the axial end of the pressure-taking flange 310 away from the measuring pipe 100, and the axial direction of the sealing ring 311 is consistent with the axial direction of the pressure-taking flange 310 and the opening direction of the first and second pressure-taking ports 120. The pressure-taking flange 310 and the pressure differential flange at the pressure measuring end of the differential pressure gauge 300 are sealed and connected via the sealing ring 311.

[0042] In a possible implementation, the throttle 200 is in the shape of a quadrangular prism as a whole, and the radial cross section along the quadrangular prism structure is trapezoidal. Among the four sides of the quadrangular prism structure of the throttle 200, two side edges between the two sides with two waists of the trapezoidal structure and the side with the upper bottom are chamfered or rounded.

[0043] Further, the side wall where the waist forms a preset angle A with the lower bottom is a front bevel, and the side wall where the other waist is located is a rear bevel, and the angle p of the front bevel is greater than the angle q of the rear bevel. The angle p of the front bevel is 20° to 45°, and the angle q of the rear bevel is 8° to 18°. The plane where the upper bottom is located is rectangular. The front bevel of the rectangular throttling member 200 with a smaller angle is similar to the front bevel of the Venturi, and the fluid can shrink smoothly, accelerate slowly, and pass evenly, greatly reducing the energy loss caused by the sharp contraction, and greatly reducing the resistance to the fluid. The elongated rectangular platform is a lengthened flow guide channel, so that the fluid can maintain uniform rectification, so that the flow velocity and static pressure of the fluid through the rectangular platform remain stable, so that extremely high measurement accuracy and good repeatability can be obtained. The small-angle rear bevel is similar to the role of the diffusion section at the tail of the Venturi, which can delay the separation of the accelerated fluid from the boundary layer of the pipe wall in the rear bevel diffusion section and decelerate and increase the pressure, reducing the generation of fluid vortices and eddies, thereby reducing the resistance and pressure loss of fluid flow. The angle between the front bevel and the side where the upper bottom is located is an obtuse angle, which can withstand the scouring of high-speed fluid or dirty fluid and fluid containing solid particles, thereby ensuring that the stability of the β value and the discharge coefficient C value will not change. Compared with the existing wedge flowmeter, the flowmeter of the present invention has the characteristics of safe and reliable structure, not easy to wear, good long-term stability, high measurement accuracy, small pressure loss, and lower straight pipe section. Furthermore, the throttling member 200 is a hyperbolic wedge block, and its front bevel and rear bevel adopt slightly convex arc surfaces.

[0044] In a possible implementation, a pressure relief port is also provided on the wall of the measuring pipe 100, and a valve is provided on the pressure relief port. Along the axial direction of the measuring pipe 100, the pressure relief port is located between the first pressure port 110 and the second pressure port 120. This prevents fluid blockage and excessive pressure, and has an explosion-proof effect. Furthermore, the output end of the differential pressure gauge 300 is electrically connected to the control end of the valve. When the measurement result of the differential pressure gauge 300 exceeds the safety threshold, the valve opens to divert the high-pressure fluid.

[0045] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A throttling flow meter, characterized in that: include: Measuring pipes, throttles and differential pressure gauges; The inner wall of the measuring pipe is provided with a throttling member, the throttling member is trapezoidal in shape as a whole, the throttling member is provided with side walls of its trapezoidal upper bottom and lower bottom which are parallel to the axial direction of the measuring pipe, the throttling member is provided with a side wall of its trapezoidal lower bottom which is fixed to the inner wall of the measuring pipe, one waist of the trapezoidal structure of the throttling member and the lower bottom have an angle of preset angle A, and the other waist and the lower bottom have an angle of preset angle B, the preset angle A is 20° to 45°, and the preset angle B is 8° to 18°; The side wall of the measuring pipe is provided with a first pressure-taking port and a second pressure-taking port, the first pressure-taking port and the second pressure-taking port are adjacently distributed along the axial direction of the measuring pipe, the opening direction of the second pressure-taking port is consistent with the height direction of the trapezoidal structure of the throttling device, the second pressure-taking port sequentially penetrates the pipe wall of the measuring pipe and the throttling device, one end of the second pressure-taking port is opened on a side wall of the throttling device provided with its trapezoidal upper bottom, the opening area of ​​the second pressure-taking port is smaller than the area of ​​one side of the throttling device provided with its trapezoidal structure upper bottom, and along the axial direction of the measuring pipe, one end of the throttling device provided with a preset angle A is located between the first pressure-taking port and the second pressure-taking port; The two pressure measuring ends of the differential pressure gauge are respectively connected to the first pressure port and the second pressure port to detect the pressure difference between the first pressure port and the second pressure port.

2. The throttling flow meter according to claim 1, characterized in that: The measuring pipe is a cylindrical pipe.

3. The throttling flow meter according to claim 2, characterized in that: Along the axial direction of the measuring pipe, a side wall of the trapezoidal upper bottom of the throttling member is provided with a preset length L, and the preset length L is greater than or equal to the inner diameter of the measuring pipe.

4. The throttling flow meter according to claim 2, characterized in that: The throttling element is provided with a preset height H along the height direction of its trapezoidal structure, and the preset height H is 1 / 3 to 2 / 3 times the inner diameter of the measuring pipe.

5. The throttling flow meter according to claim 4, characterized in that: The preset height H is 1 / 2 times the inner diameter of the measuring pipe.

6. The throttling flow meter according to claim 1, characterized in that: The first pressure port and the second pressure port have openings located outside the measuring pipe and both protrude out of the side wall of the measuring pipe. The protruding end of the first pressure port is connected to one pressure measuring end of the differential pressure gauge, and the protruding end of the second pressure port is connected to the other pressure measuring end of the differential pressure gauge.

7. The throttling flow meter according to claim 6, characterized in that: A protruding end of the first pressure port is provided with a pressure flange to be connected to one pressure measuring end of the differential pressure gauge, and a protruding end of the second pressure port is provided with a pressure flange to be connected to the other pressure measuring end of the differential pressure gauge.

8. The throttling flow meter according to claim 7, characterized in that: The side wall of the protruding end of the first pressure-taking port is welded to the pressure-taking flange, and the protruding end of the second pressure-taking port is welded to the pressure-taking flange.

9. The throttling flow meter according to claim 1, characterized in that: The side walls of the openings at both axial ends of the measuring pipeline are provided with connecting flanges.

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