Venturi flowmeter and method of manufacturing same

Abstract

The present application relates to flow meter technical field, propose a kind of venturi flowmeter and its processing method, including pipe body, two equalizing ring and multiple pressure lead pipe;The pipe body is equipped with multiple first connecting hole, the equalizing ring is equipped with multiple second connecting hole, and the first connecting hole, the second connecting hole and the pressure lead pipe are one-to-one correspondence;The pressure lead pipe includes sleeve and elbow pipe, the sleeve is welded and fixed in the second connecting hole;The one end of the elbow pipe is rotationally arranged in the sleeve, and is welded and sealed with the sleeve, the other end of the elbow pipe is inserted in the first connecting hole, and is welded and sealed with the pipe body, the axis of the two ends of the elbow pipe is not collinear.The sleeve, elbow pipe and the first connecting hole and second connecting hole matched with the two ends are arranged, and the axis of the two ends of the elbow pipe is not collinear, not only can simplify assembly process, improve processing efficiency, but also can avoid interference and collision in assembly process, improve processing quality.

Description

Technical Field

[0001] This invention relates to the field of flow meter technology, and in particular to a Venturi flow meter and its manufacturing method. Background Technology

[0002] A Venturi flow meter is an instrument that measures flow rate by utilizing the pressure difference generated when fluid flows through a throttling device. It is widely used in media conveying pipelines in industries such as petroleum, chemical, and power.

[0003] Traditional Venturi flow meters typically consist of a tube body, pressure taps, and a differential pressure transmitter. To eliminate the influence of local flow field disturbances on the measurement results and improve measurement accuracy, multiple pressure taps are usually installed along the circumference of the tube body, and the multiple pressure signals are averaged through an equalizing ring before being transmitted to the differential pressure transmitter.

[0004] To achieve high-precision spatial positioning of multiple pressure taps in the circumferential direction of the pipe body and ensure the measurement accuracy of the flow meter, the flow meter manufacturing process requires special welding fixtures to constrain and unify the reference of the pressure taps, pipe body and equalizing ring. This process is not only costly but also has a long commissioning cycle, which is not conducive to improving the manufacturing efficiency of Venturi flow meters. Summary of the Invention

[0005] In view of this, the present invention proposes a Venturi flow meter and its processing method, which can improve the processing efficiency and processing quality of the flow meter.

[0006] The technical solution of this invention is implemented as follows: This invention provides a Venturi flow meter, including a tube body, two equalizing rings, and multiple pressure-sensing tubes; the outer diameter of the tube body remains constant along its axial direction, and the inner diameter of the tube body gradually decreases and then gradually increases along its axial direction; both equalizing rings are sleeved on the tube body; the tube body is provided with multiple first connecting holes, and the equalizing rings are provided with multiple second connecting holes, and the first connecting holes and the second connecting holes correspond one-to-one with the pressure-sensing tubes; the pressure-sensing tube includes a sleeve and a bend, the sleeve is welded and fixed in the second connecting hole; one end of the bend is rotatably disposed in the sleeve and welded and sealed with the sleeve, the other end of the bend is inserted into the first connecting hole and welded and sealed with the tube body, and the axes of the two ends of the bend are not collinear.

[0007] Based on the above technical solutions, preferably, it also includes two flange plates, which are respectively welded and fixed to both ends of the pipe body; the projection of the bend along the axial direction of the pipe body is the pipe projection, and the minimum inner diameter of the cavity formed by the enclosed space of the multiple pipe projections is greater than the outer diameter of the flange plate.

[0008] Based on the above technical solutions, preferably, it also includes two connecting pipes and a differential pressure transmitter, wherein the equalizing ring is connected to the differential pressure transmitter through the connecting pipes.

[0009] Based on the above technical solutions, preferably, the axes of the two ends of the bend are parallel to each other, and the axis of the end of the bend away from the sleeve intersects and is perpendicular to the axis of the pipe body.

[0010] Based on the above technical solutions, preferably, multiple bends connected to the same equalizing ring are arranged in a circular array around the axis of the pipe body.

[0011] Based on the above technical solutions, preferably, the bent pipe includes a first branch pipe, a second branch pipe, a third branch pipe, and a fourth branch pipe; the second branch pipe is sleeved on the first branch pipe and slidably connected to the first branch pipe; the third branch pipe is connected to the first branch pipe and inserted into the first connecting hole, and the third branch pipe is perpendicular to the first branch pipe; the fourth branch pipe is connected to the second branch pipe and rotatably disposed in the sleeve, and the fourth branch pipe is perpendicular to the second branch pipe.

[0012] Based on the above technical solutions, preferably, the bent pipe further includes a retaining spring, the sleeve is provided with a first retaining groove, the fourth branch pipe is provided with a second retaining groove, the retaining spring is disposed between the first retaining groove and the second retaining groove, and the ring width of the retaining spring is less than the opening depth of the second retaining groove and greater than the opening depth of the first retaining groove.

[0013] Based on the above technical solutions, preferably, the second connecting hole includes a large hole and a small hole; the large hole and the small hole are coaxially connected, and the large hole is opened on the side of the equalizing ring near the tube body, and the small hole is opened inside the equalizing ring; the end of the large hole near the small hole is inclined to the axis of the sleeve and flush with one end of the sleeve.

[0014] Based on the above technical solutions, preferably, the axis of one end of the bend is parallel to the axis of the pipe body, and the axis of the other end is perpendicular to the axis of the pipe body.

[0015] The present invention also provides a method for processing a Venturi flow meter, comprising the following steps: S1, welding and fixing the connecting pipe to the equalizing ring, and welding and fixing the plurality of sleeves in the second connecting hole; S2, installing the fourth branch pipe and the retaining ring in the sleeve, and adjusting the length of the bend; S3, rotating the bend away from the center line of the equalizing ring, and inserting the pipe body into the equalizing ring; S4, rotating the bend, and inserting the end of the bend away from the sleeve into the first connecting hole; S5, installing two connecting pipes on the differential pressure transmitter, and welding the connection positions of the bend and the sleeve and the connection positions of the bend and the pipe body.

[0016] The Venturi flowmeter and its processing method of the present invention have the following advantages over the prior art: by setting a sleeve, a bend, and a first connecting hole and a second connecting hole that cooperate with the two, and by making the axes of the two ends of the bend non-collinear, not only can the assembly process be simplified and the processing efficiency improved, but also interference and collision during the assembly process can be avoided, thereby improving the processing quality; by setting the bend to an adjustable length structure, and by coordinating the number and distribution of the bends, the fixed position and fixed angle of the equalizing ring can be adjusted according to the actual working conditions, thereby improving the adaptability of the flowmeter to the installation environment and the interface spacing of the differential pressure transmitter. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a front view of a Venturi flow meter according to the present invention.

[0019] Figure 2 This is a cross-sectional view of the tube body in a Venturi flowmeter according to the present invention.

[0020] Figure 3 This is a cross-sectional view of the equalizing ring in a Venturi flowmeter according to the present invention.

[0021] Figure 4 This is a perspective view of a Venturi flow meter according to the present invention.

[0022] Figure 5 This is a perspective view of the equalizing ring in a Venturi flowmeter according to the present invention, showing the state of adjusting the distance between the two equalizing rings.

[0023] Figure 6This is a front view of the equalizing ring in a Venturi flowmeter according to the present invention, showing the state of adjusting the distance between the two equalizing rings.

[0024] Figure 7 This is a perspective view of the equalizing ring in a Venturi flowmeter according to the present invention, showing the state of adjusting the relative angle of the two equalizing rings.

[0025] Figure 8 This is a front view of the equalizing ring in a Venturi flowmeter according to the present invention, showing the state of adjusting the relative angle of the two equalizing rings.

[0026] Figure 9 This is a side view of the bend and flange plate in a Venturi flowmeter according to the present invention.

[0027] Figure 10 This is an exploded view of the sleeve in a Venturi flowmeter according to the present invention.

[0028] Figure 11 This is a cross-sectional view of the bend in a Venturi flowmeter according to the present invention.

[0029] Figure 12 This is a perspective view of the bend in a Venturi flowmeter according to the present invention.

[0030] The components are as follows: 1. Pipe body; 101. First connecting hole; 2. Flange plate; 3. Equalizing ring; 301. Second connecting hole; 3011. Large hole; 3012. Small hole; 4. Pressure tapping pipe; 41. Sleeve; 42. Bend; 421. First branch pipe; 422. Second branch pipe; 423. Third branch pipe; 424. Fourth branch pipe; 425. Snap ring; 401. First snap groove; 402. Second snap groove; 5. Connecting pipe; 6. Differential pressure transmitter. Detailed Implementation

[0031] The technical solutions of this invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0032] The present invention discloses a Venturi flow meter comprising a pipe body 1, two flange plates 2, two equalizing rings 3, two sets of pressure taps 4, two connecting pipes 5, and a differential pressure transmitter 6, for installation on a medium conveying pipeline to detect the flow rate of the medium.

[0033] like Figure 2As shown, the pipe body 1 is divided into five sections along its axial direction, sequentially arranged as an inlet section, a contraction section, a throat section, a diffuser section, and an outlet section along the fluid flow direction. The inlet section, throat section, and outlet section all use circular pipes of equal inner diameter, with the inner diameter of the inlet and outlet sections being consistent and larger than that of the throat section. The inner walls of the contraction and diffuser sections are designed as smoothly transitioning conical structures, with the inner diameter of the contraction section gradually decreasing along the fluid flow direction and the inner diameter of the diffuser section gradually increasing along the fluid flow direction. The continuous arrangement of the inner walls of the inlet, contraction, throat, diffuser, and outlet sections effectively reduces fluid resistance and ensures the stability of the flow field.

[0034] One end of each of the two sets of pressure tapping pipes 4 is fixed to the pipe body 1 and directly connected to the interior of the inlet section and the throat section, respectively. The other end is connected to two equalizing rings 3 sleeved on the outside of the pipe body 1. The two ends of the connecting pipe 5 are connected to the equalizing rings 3 and the differential pressure transmitter 6, respectively, forming a complete pressure transmission path. When the fluid flows through the pipe body 1, the flow velocity increases significantly and the static pressure decreases relatively due to the reduced flow area at the throat section, thus forming a pressure differential zone at the throat section that is lower than that at the inlet section. The differential pressure transmitter 6 captures this pressure differential signal in real time through the connecting pipe 5, the equalizing rings 3, and the pressure tapping pipes 4, and converts it into flow information, which is then transmitted to the detection system, realizing automated monitoring of flow data.

[0035] To further eliminate the influence of local flow field disturbances on the measurement results and significantly improve measurement accuracy, multiple pressure taps 4 are installed in each group of pressure taps 4, and the multiple pressure taps 4 in the same group are arranged in a circular array around the axis of the pipe body 1. This multi-point pressure tapping and equalization mechanism can effectively average the pressure fluctuations in the circumferential direction, significantly improve the representativeness and accuracy of pressure sampling, and ensure the reliability of flow measurement under complex operating conditions.

[0036] With the increase in the number of pressure taps 4, it is necessary to strictly ensure the consistency of the position of each pressure tap 4 in the circumferential direction of the pipe body 1, which leads to problems such as high positioning accuracy requirements, complex welding tooling, and easy generation of assembly stress. In order to overcome the processing difficulties brought about by the multi-pressure tap structure, this flowmeter sets the pressure tap 4 to include a sleeve 41 and a bend 42.

[0037] Specifically, the tube body 1 adopts a tubular structure with a uniform outer diameter, and its sidewalls are evenly provided with multiple first connecting holes 101 along the circumference; the pressure equalizing ring 3 is a hollow annular structure, and its sidewalls are provided with multiple second connecting holes 301; both the first connecting holes 101 and the second connecting holes 301 are stepped holes, and the pressure-guiding tube 4, the first connecting holes 101 and the second connecting holes 301 correspond one-to-one, forming a spatial matching relationship. Among them, one end of the bend 42 is rotatably set inside the sleeve 41, and the axes of the two ends of the bend 42 are not collinear. When one end of the bend 42 rotates around the axis of the sleeve 41, the other end of the bend 42 moves along a circular trajectory.

[0038] When assembling this flow meter, firstly, the sleeve 41 is welded and fixed into the corresponding second connecting hole 301 to complete the initial positioning and mechanical connection of the bend 42 and the equalizing ring 3; then, the bend 42 is rotated so that its free end is away from the center line of the equalizing ring 3, and after freeing up more installation space in the equalizing ring 3, the pipe body 1 is inserted into the equalizing ring 3 axially; after the pipe is inserted, each bend 42 is rotated so that its free end is inserted into the corresponding first connecting hole 101 to achieve the positioning of the pipe body 1, the equalizing ring 3 and the pressure tapping pipe 4; finally, the connection positions of the sleeve 41 and the bend 42 and the connection positions of the bend 42 and the pipe body 1 are welded and sealed to ensure the airtightness and structural strength of the pressure tapping channel.

[0039] In the above assembly process, one end of the pressure-sensing tube 4 is first connected to the equalizing ring 3 separately, and then connected to the tube body 1. It is not necessary to first position the tube body 1 and the equalizing ring 3 with a fixture, which simplifies the assembly process, reduces the assembly difficulty and tooling cost in the mass production process, and improves the assembly efficiency. During the tube insertion process, the bend 42 can be kept away from the outer wall of the tube body to avoid collision and interference. The first connecting hole 101 and the second connecting hole 301 are both stepped holes. During the assembly process, the slight deflection change of the bend 42 can be used to connect the bend 42 to the tube body 1 to achieve axial positioning of both ends of the pressure-sensing tube 4.

[0040] This design utilizes the spatial adjustability of the bend 42 and improves the installation consistency and repeatability of the pressure system through the assembly logic of "pre-fixing, pipe insertion, positioning, and final welding". At the same time, it enhances the structural robustness of the whole machine under service conditions such as vibration and thermal expansion and contraction.

[0041] Flange 2 is a circular plate structure with multiple through holes evenly distributed along its circumference for connecting bolts to pass through. The two flange plates 2 are welded and fixed to the inlet and outlet ends of the pipe body 1, respectively, forming an interface that matches the end flange of the external medium conveying pipeline, ensuring that the flow meter can be conveniently and reliably integrated into the industrial fluid pipeline system.

[0042] like Figure 9 As shown, the orthogonal projection of the bend 42 along the axial direction of the pipe body 1 is defined as the pipe projection. The pipe projection is determined by the spatial orientation of the bend 42, which can be adjusted by rotating the bend 42 and coordinating the optimization of the specifications and installation positions of the sleeve 41 and the bend 42. Through the adjustment of the spatial orientation, when the minimum inner diameter of the cavity formed by multiple pipe projections is greater than the outer diameter of the flange plate 2, after the pressure tapping pipe 4 is pre-assembled with the equalizing ring 3, the entire section of the pipe body 1 with the welded flange plate 2 can be integrally inserted into the equalizing ring 3 along the axial direction, thereby avoiding the risk of spatial interference or mechanical collision between the bend 42 and the flange plate 2. This design is suitable for situations where it is impossible to insert the pipe before welding the flange due to reasons such as the short axial length of the pipe body 1 and the weak structural strength of the equalizing ring 3.

[0043] In some embodiments, such as Figure 3 and Figure 4 As shown, the axes at both ends of the bend 42 are parallel to each other; specifically, the sleeve 41 is set on the inner ring sidewall of the equalizing ring 3, and the axis of the end of the bend 42 away from the sleeve 41 intersects and is perpendicular to the axis of the pipe body 1; this design makes the span of the pressure-sensing pipe 4 in the axial direction of the pipe body 1 smaller than the thickness of the equalizing ring 3, compressing the structural extension of the pressure-sensing pipe 4 in the axial direction. Under the premise of ensuring the reliability of pressure transmission, it effectively reduces the axial dimension of the whole machine and the installation envelope space, and improves the integration adaptability in narrow pipe racks or compact equipment interfaces.

[0044] like Figure 5 and Figure 6 As shown, in embodiments where the pressure taps 4 are configured with three or more on each equalizing ring 3, after the pipe body 1 is inserted into the equalizing ring 3 and the free end of the bend 42 is inserted into the corresponding first connecting hole 101, the equalizing ring 3 can be driven to undergo controllable displacement along the axial direction of the pipe body 1 by adjusting the length of the bend 42. This displacement characteristic allows the center distance between the two equalizing rings 3 to be dynamically adapted, especially to accurately match the standard spacing between the high-pressure input interface and the low-pressure input interface of the differential pressure transmitter 6, thereby avoiding the problems of increased flow resistance, sealing hazards, and stress concentration caused by forcibly bending, flexing, or adding flexible compensation sections to the connecting pipe 5 to adapt to the interface spacing in traditional solutions. In addition, this axial displacement capability can also be used to actively avoid adjacent equipment, supports, insulation layers, or other pipeline accessories, significantly enhancing the installation flexibility and engineering fault tolerance of this flowmeter in complex field environments.

[0045] like Figure 7 and Figure 8 As shown, in an embodiment where two pressure-equalizing pipes 4 are configured on each pressure-equalizing ring 3, when the pipe body 1 is inserted into the pressure-equalizing ring 3 and the free end of the bend 42 is inserted into the corresponding first connecting hole 101, in addition to achieving the aforementioned axial displacement function, the pressure-equalizing ring 3 can also rotate around the axis of the inner end of the pressure-equalizing pipe 4. This combined motion further expands the degree of freedom of spatial attitude adjustment and greatly improves the compatibility of the device with diverse installation references.

[0046] In summary, the modular and adjustable structural design of the pressure tapping tube 4 not only solves the high-precision assembly problem caused by multi-point pressure tapping, but also generates multiple process and installation advantages such as flange front integration, axial spacing self-adaptation, and spatial attitude dynamic calibration, comprehensively covering the entire chain of technical needs from precision manufacturing to field deployment.

[0047] To enable dynamic adaptation of the equalizing ring 3 to spatial constraints at the installation site, such as differential pressure transmitter 6 interface spacing deviation, interference from adjacent equipment, flange face tilt or pipeline axis offset, it is preferable to construct the bend 42 as an adjustable telescopic structure, thereby giving the equalizing ring 3 stepless displacement capability along the axial direction of the pipe body 1.

[0048] like Figure 5 , Figure 10 and Figure 11 As shown, the bend 42 includes a first branch pipe 421, a second branch pipe 422, a third branch pipe 423, a fourth branch pipe 424, and a retaining ring 425. The third branch pipe 423 is vertically connected to one end of the first branch pipe 421, and the two together form an L-shaped pipe structure. The third branch pipe 423 is inserted into the first connecting hole 101. The fourth branch pipe 424 is vertically connected to one end of the second branch pipe 422, and also forms an L-shaped pipe structure. The fourth branch pipe 424 is rotatably disposed in the sleeve 41. The second branch pipe 422 is sleeved outside the first branch pipe 421 and is slidably connected to the first branch pipe 421. By sliding the first branch pipe 421 and the second branch pipe 422 axially, the overall length of the bend 42 can be continuously adjusted, thereby driving the equalizing ring 3 to move axially along the pipe body 1.

[0049] To ensure the airtightness and long-term reliability of the pressure channel in the expansion and contraction state, sealing components such as sealing rings and locking rings can be installed between the second branch pipe 422 and the first branch pipe 421; alternatively, after the length of the bend pipe 42 is adjusted, the connection position between the second branch pipe 422 and the first branch pipe 421 can be welded and sealed to form a rigid connection and sealing barrier.

[0050] like Figure 10 As shown, the sleeve 41 has a first retaining groove 401, and the outer wall of the fourth branch pipe 424 has a second retaining groove 402. Both the first retaining groove 401 and the second retaining groove 402 are annular groove structures. The retaining spring 425 is an arc-shaped ring plate component with radial elastic deformation function. Its thickness is equal to the groove width of the first retaining groove 401 and the second retaining groove 402. Its ring width is less than the opening depth of the second retaining groove 402, but greater than the opening depth of the first retaining groove 401. During assembly, the retaining spring 425 is first radially compressed and embedded into the second retaining groove 402, so that it is completely contained in the groove and does not protrude outward. Then, the fourth branch pipe 424 together with the retaining spring 425 is inserted into the sleeve 41. When the retaining spring 425 moves with the fourth branch pipe 424 to the first retaining groove 401, it is pushed outward under its own elastic restoring force and locked between the first retaining groove 401 and the second retaining groove 402, thereby realizing the rotational connection between the fourth branch pipe 424 and the sleeve 41.

[0051] Furthermore, such as Figure 10As shown, the second connecting hole 301 includes a large hole 3011 and a small hole 3012. The large hole 3011 and the small hole 3012 are coaxially connected. The large hole 3011 is opened on the side of the equalizing ring 3 near the tube body 1, and the small hole 3012 is opened inside the equalizing ring 3. The sleeve 41 is inserted from the side of the large hole 3011, and after being axially pushed into place, its bottom end face abuts against the inner end face of the large hole 3011, thereby realizing the axial positioning and stopping of the sleeve 41.

[0052] Furthermore, the end of the large hole 3011 near the small hole 3012 is inclined to the axis of the sleeve 41, and this inclined surface is flush with and fits against the outer end face of the sleeve 41. When installing the sleeve 41, axial pressing of the sleeve 41 can make the sleeve 41 rotate adaptively and achieve circumferential limiting, which greatly improves the installation accuracy and welding concentricity of the sleeve 41 on the equalizing ring 3, and fundamentally ensures the spatial consistency of multiple pressure taps 4 and the uniformity of the pressure acquisition benchmark.

[0053] In other embodiments, the axis of one end of the bend 42 is parallel to the axis of the tube body 1 and is located on one side of the equalizing ring 3 along the axial direction of the tube body 1, while the axis of the other end of the bend 42 intersects and is perpendicular to the axis of the tube body 1; a portion of the bend 42 is located on one side of the equalizing ring 3 along the axial direction of the tube body 1. This offset arrangement allows the free end of the bend 42 to have a larger motion envelope space and a better insertion guide angle during rotational alignment; after the tube body 1 is inserted into the equalizing ring 3, it only needs to rotate a small angle around its own axis to drive the free end of the bend 42 to naturally align vertically with the center of the first connecting hole 101 and smoothly insert it along the normal direction, significantly reducing the risk of hole edge scratching and the probability of positioning deviation during the insertion process.

[0054] The manufacturing method of a Venturi flow meter according to the present invention is as follows: S1, weld and fix the two flange plates 2 to both ends of the pipe body 1 respectively; weld and fix one end of the two connecting pipes 5 to the outer side wall of the two equalizing rings 3 respectively; install multiple sleeves 41 in the corresponding second connecting holes 301 respectively, and weld and fix the connection position of the sleeves 41 and the equalizing rings 3.

[0055] S2, insert multiple fourth branch pipes 424 together with snap rings 425 pre-installed in the second slot 402 into the corresponding sleeves 41. Utilize the snap rings 425 to engage with the first slot 401 to form a rotating pair between the fourth branch pipes 424 and the sleeves 41. Adjust the relative positions of the first branch pipe 421 and the second branch pipe 422 according to the target installation conditions, set the overall length of the bend 42, and lock the first branch pipe 421 and the second branch pipe 422 through a locking structure.

[0056] S3, rotate the bend 42 so that the end of the bend 42 away from the sleeve 41 is away from the center line of the equalizing ring 3, and insert the pipe body 1 into the equalizing ring 3 axially.

[0057] S4, rotate the bend 42 in the opposite direction, and with the slight flexible bending of the bend 42, insert the end of the bend 42 away from the sleeve 41 into the corresponding first connecting hole 101 to achieve the pre-fixation of the equalizing ring 3 and the tube body 1.

[0058] S5, install the other ends of the two connecting pipes 5 on the two ports of the differential pressure transmitter 6 respectively, and weld the connection positions of the bend 42 and the sleeve 41 and the bend 42 and the pipe body 1.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A Venturi flow meter, characterized in that: It includes a tube body (1), two equalizing rings (3) and multiple pressure-sensing tubes (4); the outer diameter of the tube body (1) remains constant along its axial direction, and the inner diameter of the tube body (1) gradually decreases and then gradually increases along its axial direction; the two equalizing rings (3) are both sleeved on the tube body (1); the tube body (1) is provided with multiple first connecting holes (101), and the equalizing rings (3) are provided with multiple second connecting holes (301), and the first connecting holes (101), the second connecting holes (301) and the pressure-sensing tubes (4) correspond one-to-one; The pressure-sensing tube (4) includes a sleeve (41) and a bend (42). The sleeve (41) is welded and fixed in the second connecting hole (301). One end of the bend (42) is rotatably disposed in the sleeve (41) and welded and sealed with the sleeve (41). The other end of the bend (42) is inserted into the first connecting hole (101) and welded and sealed with the tube body (1). The axes of the two ends of the bend (42) are not collinear. Multiple bends (42) connected to the same equalizing ring (3) are arranged in a circular array around the axis of the pipe body (1); The bend (42) includes a first branch pipe (421), a second branch pipe (422), a third branch pipe (423), and a fourth branch pipe (424); the second branch pipe (422) is sleeved on the first branch pipe (421) and slidably connected to the first branch pipe (421); the third branch pipe (423) is connected to the first branch pipe (421) and inserted into the first connecting hole (101), and the third branch pipe (423) is perpendicular to the first branch pipe (421); the fourth branch pipe (424) is connected to the second branch pipe (422) and rotatably disposed in the sleeve (41), and the fourth branch pipe (424) is perpendicular to the second branch pipe (422); by sliding the first branch pipe (421) and the second branch pipe (422) axially, the overall length of the bend (42) can be continuously adjusted, thereby driving the equalizing ring (3) to move axially along the pipe body (1).

2. The Venturi flow meter as described in claim 1, characterized in that: It also includes two flange plates (2), which are respectively welded and fixed to both ends of the pipe body (1); The projection of the bend (42) along the axial direction of the pipe body (1) is the pipe projection, and the minimum inner diameter of the cavity formed by the enclosed space of the multiple pipe projections is greater than the outer diameter of the flange plate (2).

3. A Venturi flow meter as described in claim 1, characterized in that: It also includes two connecting pipes (5) and a differential pressure transmitter (6), wherein the equalizing ring (3) is connected to the differential pressure transmitter (6) through the connecting pipes (5).

4. A Venturi flow meter as described in claim 3, characterized in that: The axes at both ends of the bend (42) are parallel to each other, and the axis of the end of the bend (42) away from the sleeve (41) intersects and is perpendicular to the axis of the tube body (1).

5. A Venturi flow meter as described in claim 4, characterized in that: The bend (42) also includes a retaining ring (425). The sleeve (41) is provided with a first retaining groove (401), and the fourth branch pipe (424) is provided with a second retaining groove (402). The retaining ring (425) is disposed between the first retaining groove (401) and the second retaining groove (402), and the ring width of the retaining ring (425) is smaller than the opening depth of the second retaining groove (402) and larger than the opening depth of the first retaining groove (401).

6. A Venturi flow meter as described in claim 5, characterized in that: The second connecting hole (301) includes a large hole (3011) and a small hole (3012); the large hole (3011) and the small hole (3012) are coaxially connected, and the large hole (3011) is opened on the side of the equalizing ring (3) near the tube body (1), and the small hole (3012) is opened inside the equalizing ring (3); The end of the large hole (3011) near the small hole (3012) is inclined to the axis of the sleeve (41) and is flush with one end of the sleeve (41).

7. A Venturi flow meter as described in claim 1, characterized in that: The axis of one end of the bend (42) is parallel to the axis of the pipe body (1), and the axis of the other end is perpendicular to the axis of the pipe body (1).

8. A method for manufacturing a Venturi flowmeter as described in claim 6, characterized in that, Includes the following steps: S1, the connecting pipe (5) is welded and fixed on the equalizing ring (3), and the multiple sleeves (41) are welded and fixed in the second connecting hole (301); S2, install the fourth branch pipe (424) and the snap ring (425) inside the sleeve (41) and adjust the length of the bend pipe (42); S3, rotate the bend (42) so that the bend (42) is away from the center line of the equalizing ring (3), and insert the tube body (1) into the equalizing ring (3); S4, rotate the bent tube (42) and insert the end of the bent tube (42) away from the sleeve (41) into the first connecting hole (101); S5, install the two connecting pipes (5) on the differential pressure transmitter (6), and weld the connection position of the bend (42) to the sleeve (41) and the connection position of the bend (42) to the pipe body (1).

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