A dual Venturi flowmeter purging device

Abstract

This utility model discloses a dual Venturi flowmeter purging device, including a main Venturi tube, a secondary Venturi tube, a main purging ring, a secondary purging ring, and an intelligent control unit. The main and secondary Venturi tubes are arranged coaxially in series, with the main Venturi tube fitted over the secondary Venturi tube. The main purging ring is sleeved on the downstream throat of the main Venturi tube, and a nozzle is provided on the main purging ring. A main pressure tap is connected to the main Venturi tube. The secondary purging ring is sleeved on the downstream throat of the secondary Venturi tube, and a swirling nozzle is provided on the secondary purging ring. A secondary pressure tap is connected to the secondary Venturi tube. A differential pressure sensing module and a pneumatic execution module are electrically connected to a logic controller. The differential pressure sensing module monitors the differential pressure change rate between the main and secondary pressure taps in real time, and the logic controller controls the staged purging mode of the pneumatic execution module. This utility model can accurately remove dust blockage in the throttling element, effectively reduce nitrogen consumption, has a reasonable overall structural design, is easy to use, and is highly practical.

Description

Technical Field

[0001] This utility model relates to the technical field of gas pipeline measuring equipment, and in particular to a purging device for a dual Venturi flowmeter. Background Technology

[0002] The dust concentration in the gas pipeline has been consistently between 200-500 mg / m³ 3 The high value of the flow meter throat throttling device causes dust to accumulate continuously during operation, resulting in the following problems: (1) the differential pressure signal drifts, causing the measurement error to exceed ±5%, while the industry standard requires the measurement error to be ≤ ±2.5%; (2) the throat cross-sectional area shrinks, causing permanent flow field distortion; (3) manual cleaning requires gas shutdown, increasing annual maintenance costs by more than 30%.

[0003] Traditional purging devices have the following shortcomings: (1) Single-point purging device: only a direct-blowing nozzle is set upstream of a single venturi tube, which cannot cover the complex flow channel of the double throat structure, resulting in a purging efficiency of less than 40%; (2) Mechanical scraping device: the scraper is easy to jam and destroys the stability of the flow field during operation; (3) Timed pulse purging: lacks a blockage feedback mechanism, and the nitrogen waste rate is as high as 50% or more. Utility Model Content

[0004] The purpose of this invention is to provide a purging device for a dual Venturi flowmeter, thereby solving the aforementioned problems in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This utility model discloses a purging device for a dual Venturi flowmeter, comprising a main Venturi tube, a secondary Venturi tube, a main purging ring, a secondary purging ring, and an intelligent control unit. The main Venturi tube and the secondary Venturi tube are arranged coaxially in series. The main Venturi tube is fitted over the secondary Venturi tube. The downstream end of the throat of the main Venturi tube is fitted with the main purging ring. The main purging ring is provided with several nozzles, the spray direction of which is opposite to the flow direction of the medium in the pipeline. The angle between the nozzle orifice axis and the axis of the main Venturi tube is 25°-35°. A main pressure tap is connected to the main Venturi tube. The secondary Venturi tube... The downstream end of the throat of the inner tube is fitted with the auxiliary purge ring, which is provided with several swirling nozzles. The angle between the nozzle orifice axis and the axis of the auxiliary venturi tube is 15°-25°. The auxiliary venturi tube is connected to an auxiliary pressure tapping tube. The intelligent control unit includes a differential pressure sensing module, a logic controller, and a pneumatic path execution module. The differential pressure sensing module and the pneumatic path execution module are electrically connected to the logic controller. The differential pressure sensing module monitors the differential pressure change rate of the main pressure tapping tube and the auxiliary pressure tapping tube in real time. The logic controller controls the staged purging mode of the pneumatic path execution module.

[0007] Furthermore, the differential pressure sensing module includes a high-precision differential pressure transmitter, which is connected to the main pressure pipe and the auxiliary pressure pipe respectively, and the high-pressure end and the low-pressure end of the high-precision differential pressure transmitter are electrically connected to the logic controller through solenoid valves respectively.

[0008] Furthermore, the pneumatic execution module includes a main backflush pipe, a secondary backflush pipe, a solenoid valve, and a pressure reducing and stabilizing valve. The main backflush pipe and the secondary backflush pipe are respectively connected to the pressure reducing and stabilizing valve through the solenoid valve. The main backflush pipe is connected to the main purge ring, and the secondary backflush pipe is connected to the secondary purge ring. The two solenoid valves are respectively electrically connected to the logic controller.

[0009] Furthermore, the logic controller adopts a PLC or embedded controller and has a built-in dynamic adjustment algorithm. When ΔP / Δt ≥ 0.3 kPa / min, the main purge ring is started for purging. When ΔP / Δt ≥ 0.5 kPa / min, the main purge ring and the auxiliary purge ring are started for coordinated purging.

[0010] Furthermore, the diameter ratio of the main venturi throat to the secondary venturi throat is 1:0.6-0.8.

[0011] Furthermore, the secondary purge ring is located 40mm-60mm downstream of the throat of the secondary venturi tube.

[0012] Furthermore, the ratio of the number of nozzles in the main purge ring to the number of nozzles in the auxiliary purge ring is 3:2, and the nozzle orifice diameter is Φ2mm-Φ3mm.

[0013] Furthermore, the secondary purging ring is provided with four radially symmetrically distributed swirling nozzles, and the total number of nozzles is six.

[0014] Furthermore, the main purge ring is fixed to the throat of the main venturi tube by a stainless steel clamp.

[0015] Furthermore, the secondary purge ring is welded to the downstream end of the throat of the secondary venturi tube.

[0016] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0017] This utility model's dual Venturi flowmeter purging device, through the configuration of a main purging ring, a secondary purging ring, and an intelligent control unit, utilizes layered directional purging and closed-loop control technology to precisely remove dust blockages from the throttling element and effectively reduce nitrogen consumption. It is particularly suitable for flowmeter maintenance in high-dust, high-humidity gas environments. This utility model features a reasonable overall structural design, is easy to use, and highly practical. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the dual Venturi flowmeter purging device of this utility model;

[0020] Figure 2 This is a side view of the main Venturi tube and the auxiliary Venturi tube in the purging device of the dual Venturi flowmeter of this utility model.

[0021] Figure 3 This is a schematic diagram of the intelligent control unit in the dual Venturi flowmeter purging device of this utility model.

[0022] Explanation of reference numerals in the attached diagram: 101, Main Venturi tube; 102, Secondary Venturi tube; 201, Main purge ring; 201a, Nozzle; 202, Secondary purge ring; 202a, Swirl nozzle; 104, Main pressure tapping tube; 105, Secondary pressure tapping tube; 301, Differential pressure sensing module; 301a, High-precision differential pressure transmitter; 302, Logic controller; 303, Pneumatic circuit execution module; 303a, Main backflush tube; 303b, Secondary backflush tube; 303c, Solenoid valve; 303d, Pressure reducing and regulating valve. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0024] In the description of this utility model, it should be understood that the terms "length," "width," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] like Figures 1 to 3 As shown, the dual Venturi flowmeter purging device of this utility model embodiment includes an upstream main Venturi tube 101, a downstream auxiliary Venturi tube 102, a main purging ring 201, an auxiliary purging ring 202, and an intelligent control unit. The main Venturi tube 101 and the auxiliary Venturi tube 102 are arranged coaxially in series. The main Venturi tube 101 is fitted outside the auxiliary Venturi tube 102. The downstream end of the throat of the main Venturi tube 101 is fitted with a main purging ring 201. The main purging ring 201 is provided with a plurality of nozzles 201a. The spray direction of the nozzles 201a is opposite to the flow direction of the medium in the pipeline. The angle between the spray hole axis of the nozzles 201a and the axis of the main Venturi tube 101 is 25°-35°. A main pressure pipe 104 is connected to 101, and a secondary purge ring 202 is sleeved at the downstream end of the throat of the secondary venturi tube 102. Specifically, the secondary purge ring 202 is located 40mm-60mm downstream of the throat of the secondary venturi tube 102. Preferably, the secondary purge ring 202 is located 50mm downstream of the throat of the secondary venturi tube 102. A plurality of swirling nozzles 202a are provided on the secondary purge ring 202. The angle between the nozzle orifice axis of the swirling nozzle 202a and the axis of the secondary venturi tube 102 is 15°-25°. Preferably, the angle between the nozzle orifice axis of the swirling nozzle 202a and the tangent of the tube wall is 15°. A secondary pressure pipe 105 is connected to the secondary venturi tube 102.

[0027] In this embodiment, as Figure 3 As shown, the intelligent control unit includes a differential pressure sensing module 301, a logic controller 302, and a pneumatic path execution module 303. The differential pressure sensing module 301 and the pneumatic path execution module 303 are electrically connected to the logic controller 302. The differential pressure sensing module 301 monitors the rate of change of differential pressure between the main pressure pipe 104 and the auxiliary pressure pipe 105 in real time. The logic controller 302 controls the graded purging mode of the pneumatic path execution module 303.

[0028] Specifically, the differential pressure sensing module 301 includes a high-precision differential pressure transmitter 301a, which is connected to the main pressure pipe 104 and the auxiliary pressure pipe 105 respectively. The high-pressure end and the low-pressure end of the high-precision differential pressure transmitter 301a are electrically connected to the logic controller 302 through the solenoid valve 303c respectively. Preferably, the range of the high-precision differential pressure transmitter 301a is 0-10 kPa and the accuracy is 0.5 grade.

[0029] Furthermore, the pneumatic execution module 303 includes a main backflush pipe 303a, a secondary backflush pipe 303b, a solenoid valve 303c, and a pressure reducing and regulating valve 303d. The main backflush pipe 303a and the secondary backflush pipe 303b are respectively connected to the pressure reducing and regulating valve 303d via the solenoid valve 303c. The main backflush pipe 303a is connected to the main purge ring 201, and the secondary backflush pipe 303b is connected to the secondary purge ring 202. The two solenoid valves 303c are electrically connected to the logic controller 302. The operating pressure of the pneumatic execution module 303 is 0.4MPa-0.6MPa.

[0030] Preferably, the logic controller 302 adopts a PLC or an embedded controller and has a built-in dynamic adjustment algorithm. When ΔP / Δt≥0.3kPa / min, the main purge ring 201 is started for purging, and when ΔP / Δt≥0.5kPa / min, the main purge ring 201 and the auxiliary purge ring 202 are started for coordinated purging.

[0031] In this embodiment, the diameter ratio of the throat of the main venturi tube 101 to the throat of the secondary venturi tube 102 is 1:0.6-0.8.

[0032] The ratio of the number of nozzles in the main purge ring 201 to the auxiliary purge ring 202 is 3:2, and the nozzle orifice diameter is Φ2mm-Φ3mm. Preferably, the auxiliary purge ring 202 is provided with four radially symmetrically distributed swirl nozzles 202a, and the number of nozzles 201a is six.

[0033] Specifically, the main purge ring 201 is fixed to the throat of the main venturi tube 101 by a stainless steel clamp, and the auxiliary purge ring 202 is welded to the downstream end of the throat of the auxiliary venturi tube 102.

[0034] During installation of the dual Venturi flowmeter purging device in this embodiment, the main purging ring 201 is first fixed to the throat of the main Venturi tube 101 with a stainless steel clamp, ensuring that the spray direction of the nozzle 201a is opposite to the flow direction of the medium in the pipeline, and that the angle between the nozzle orifice axis of the nozzle 201a and the axis of the main Venturi tube 101 is 25°-35°. Then, the auxiliary purging ring 202 is welded to the downstream of the auxiliary Venturi tube 102, so that the angle between the nozzle orifice axis of the swirl nozzle 202a and the axis of the auxiliary Venturi tube 102 is 15°-25°. The high-precision differential pressure transmitter 301a is connected to the main pressure pipe 104 and the auxiliary pressure pipe 105 through a three-valve manifold.

[0035] During use, the high-precision differential pressure transmitter 301a in the differential pressure sensing module 301 works continuously, monitoring the differential pressure change between the main pressure pipe 104 and the auxiliary pressure pipe 105 in real time, and transmitting the data to the logic controller 302. The logic controller 302 calculates the differential pressure change rate ΔP / Δt based on the data transmitted from the differential pressure sensing module 301. The basic value of ΔP is 2.5 kPa, and the alarm value of ΔP / Δt is 0.3 kPa / min. When ΔP / Δt ≥ 0.3 kPa / min, it is determined that the throat throttling element of the dual Venturi flowmeter is blocked, triggering the purging program and starting the main purging ring 201 for purging.

[0036] When the purging procedure is triggered, the solenoid valve 303c in the gas path execution module 303 opens. Nitrogen gas, after being regulated to a working pressure of 0.4MPa-0.6MPa by the pressure reducing and regulating valve 303d, enters the main purging ring 201 through the main backflush pipe 303a. Since the injection direction of the nozzle 201a on the main purging ring 201 is opposite to the flow direction of the pipeline medium, and the angle between the nozzle orifice axis of 201a and the axis of the main venturi tube 101 is 25°-35°, the reverse injection of nitrogen gas through the main purging ring 201 can strip away large... For particulate fouling (particle size > 50 μm), depending on the degree of clogging, when ΔP / Δt ≥ 0.5 kPa / min, the main purge ring 201 and the auxiliary purge ring 202 are activated for coordinated purging. Nitrogen gas enters the auxiliary purge ring 202 through the auxiliary backflush pipe 303b. Since the angle between the nozzle orifice axis of the swirling nozzle 202a on the auxiliary purge ring 202 and the axis of the auxiliary venturi tube 102 is 15°-25°, the swirling spray of the swirling nozzle 202a can remove the adhesive fine powder (particle size < 10 μm), thus achieving two-stage coordinated purging.

[0037] The logic controller 302 has a built-in dynamic adjustment algorithm that can automatically adjust the purging parameters according to the differential pressure change rate. When ΔP / Δt is 0.3kPa / min-0.5kPa / min, the main ring is started for a single purging, which lasts for 8-12 seconds. When ΔP / Δt ≥ 0.5kPa / min, the main purging ring 201 and the auxiliary purging ring 202 purge alternately, with the duration being 10 seconds for the main purging ring, 5 seconds for the auxiliary purging ring, and an interval of 3 seconds.

[0038] In practical applications, when ΔP is detected to rise from 2.5 kPa to 3.1 kPa (ΔP / Δt = 0.4 kPa / min), the logic controller 302 triggers the main purge ring 201 to work for 10 seconds. After purging, ΔP drops back to 2.6 kPa, and the system enters standby mode. If ΔP does not return to normal after three consecutive purgings, the fault alarm module is activated.

[0039] Specifically, the response time of solenoid valve 303c is ≤0.5 seconds, the nitrogen pressure is set to 0.5MPa, and the nitrogen consumption is ≤0.8m³. 3 / h, while the nitrogen consumption of traditional equipment is ≥2m³ / h. 3 / h, through the Venturi effect, enhances airflow disturbance, reduces purging frequency, and saves energy.

[0040] This utility model discloses a nitrogen purging device for a dual Venturi flowmeter, which is used in gas pipelines. It addresses the problem of blockage in the throttling element of the dual Venturi flowmeter by using layered directional purging and closed-loop control technology to accurately remove dust blockage in the throttling element and effectively reduce nitrogen consumption. It is particularly suitable for flowmeter maintenance in high-dust and high-humidity gas environments.

[0041] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A dual venturi flow meter purge apparatus, characterized by, The system includes a main Venturi tube (101), a secondary Venturi tube (102), a main purge ring (201), a secondary purge ring (202), and an intelligent control unit. The main Venturi tube (101) and the secondary Venturi tube (102) are arranged coaxially in series. The main Venturi tube (101) is fitted over the secondary Venturi tube (102). The main purge ring (202) is sleeved on the downstream end of the throat of the main Venturi tube (101). 1) The main purge ring (201) is provided with a plurality of nozzles (201a). The spray direction of the nozzles (201a) is opposite to the flow direction of the medium in the pipeline. The angle between the spray hole axis of the nozzles (201a) and the axis of the main venturi tube (101) is 25°-35°. The main venturi tube (101) is connected to a main pressure tap (104). The downstream end of the throat of the auxiliary venturi tube (102) is outside The auxiliary purge ring (202) is fitted with a plurality of swirling nozzles (202a) on which a plurality of swirling nozzles (202a) are provided. The angle between the nozzle orifice axis of the swirling nozzles (202a) and the axis of the auxiliary venturi tube (102) is 15°-25°. The auxiliary venturi tube (102) is connected to an auxiliary pressure-sensing tube (105). The intelligent control unit includes a differential pressure sensing module (301), a logic controller (302), and a pneumatic path execution module (303). The differential pressure sensing module (301) and the pneumatic path execution module (303) are electrically connected to the logic controller (302). The differential pressure sensing module (301) monitors the differential pressure change rate of the main pressure-sensing tube (104) and the auxiliary pressure-sensing tube (105) in real time. The logic controller (302) controls the graded purging mode of the pneumatic path execution module (303).

2. The purging device for a dual Venturi flowmeter according to claim 1, characterized in that, The differential pressure sensing module (301) includes a high-precision differential pressure transmitter (301a), which is connected to the main pressure pipe (104) and the auxiliary pressure pipe (105) respectively. The high-pressure end and the low-pressure end of the high-precision differential pressure transmitter are electrically connected to the logic controller (302) through a solenoid valve (303c).

3. The purging device for a dual Venturi flowmeter according to claim 1, characterized in that, The pneumatic execution module (303) includes a main backflush pipe (303a), a secondary backflush pipe (303b), a solenoid valve (303c), and a pressure reducing and regulating valve (303d). The main backflush pipe (303a) and the secondary backflush pipe (303b) are respectively connected to the pressure reducing and regulating valve (303d) through the solenoid valve (303c). The main backflush pipe (303a) is connected to the main purge ring (201), and the secondary backflush pipe (303b) is connected to the secondary purge ring (202). The two solenoid valves (303c) are respectively electrically connected to the logic controller (302).

4. The purging device for a dual Venturi flowmeter according to claim 1, characterized in that, The logic controller (302) adopts a PLC or embedded controller and has a built-in dynamic adjustment algorithm. When ΔP / Δt≥0.3kPa / min, the main purging ring (201) is started to purge. When ΔP / Δt≥0.5kPa / min, the main purging ring (201) and the auxiliary purging ring (202) are started to purge together.

5. The purging device for a dual Venturi flowmeter according to claim 1, characterized in that, The diameter ratio of the throat of the main Venturi tube (101) to the throat of the secondary Venturi tube (102) is 1:0.6-0.

8.

6. The purging device for a dual Venturi flowmeter according to claim 1, characterized in that, The secondary purge ring (202) is located 40mm-60mm downstream of the throat of the secondary venturi tube (102).

7. The purging device for a dual Venturi flowmeter according to claim 1, characterized in that, The ratio of the number of nozzles in the main purge ring (201) to the number of nozzles in the auxiliary purge ring (202) is 3:2, and the nozzle orifice diameter is Φ2mm-Φ3mm.

8. A purging device for a dual Venturi flowmeter according to claim 7, characterized in that, The secondary purge ring (202) is provided with four radially symmetrically distributed swirling nozzles (202a), and the number of nozzles (201a) is six.

9. A purging device for a dual Venturi flowmeter according to any one of claims 1-8, characterized in that, The main purge ring (201) is fixed to the throat of the main venturi tube (101) by a stainless steel clamp.

10. A purging device for a dual Venturi flowmeter according to any one of claims 1-8, characterized in that, The secondary purge ring (202) is welded to the downstream end of the throat of the secondary venturi tube (102).

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