Mass flow meter with pre-droplet trapping and self-discharging structure

Abstract

The utility model provides a mass flow meter with a front droplet trapping and self-discharging structure. The mass flow meter comprises a vibrating tube, an outlet connecting tube, an inlet connecting tube and a liquid discharging assembly. A rectifying cavity and a centrifugal separation cavity are arranged in the inlet connecting pipe, the inner diameter of the rectifying cavity is smaller than that of the centrifugal separation cavity, a spiral guide vane is arranged in the rectifying cavity, and a drainage hole is formed in the cavity wall of the centrifugal separation cavity. The liquid discharging assembly comprises a liquid discharging shell, a first electromagnetic valve and a second electromagnetic valve, a liquid collecting cavity, a buffering cavity and a sewage draining opening are formed in the liquid discharging shell, and the first electromagnetic valve and the second electromagnetic valve are used for controlling on-off in a grading mode. Liquid drops are efficiently captured through the front structure, automatic liquid discharging is achieved in cooperation with the liquid discharging assembly, the liquid drops are effectively prevented from entering the vibration pipe, the problem that the metering precision is reduced due to wet gas is solved, the stability of equipment is improved, and the service life of the equipment is prolonged. The integrated structure does not need an external steam-water separator, the equipment size is greatly reduced, and the compact type installation requirement of the modern industry is met.

Description

Technical Field

[0001] This utility model relates to the field of mass flow meter technology, specifically to a mass flow meter with a pre-droplet trapping and self-draining structure. Background Technology

[0002] In typical gas-phase processes such as LNG vaporization tail gas, compressed air, and chemical reaction tail gas, the gas medium often contains micron-sized droplets. If such liquid-containing humid gases are directly introduced into the vibrating tube of a Coriolis mass flow meter for measurement, it will cause a series of serious problems: the droplets will accumulate locally in the vibrating tube, causing drastic changes in the flow meter's density reading and significantly reducing the measurement accuracy; the presence of droplets will cause a sudden increase in fluid damping, leading to an abnormal increase in the flow meter's drive current, and in extreme cases, the vibrating tube may even stop vibrating, causing measurement interruption; the high-speed moving droplets will also continuously impact the vibrating tube wall, causing erosion and wear, and significantly shortening the service life of the equipment.

[0003] To address these issues, existing technologies often employ external gas-water separators to pre-treat the humid gas before introducing the dried gas into the mass flow meter. However, this solution has several drawbacks: it is bulky, occupying significant industrial installation space; the pressure loss as the gas flows through the separator is high, affecting the normal transport of process fluids; the installation process is complex, requiring additional connecting pipelines and fixing structures; and it cannot accommodate the installation requirements of compact flow meters, failing to meet the core demands of modern industry for high-precision metering, compact layout, and low maintenance costs. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of this utility model is to provide a mass flow meter with a pre-droplet trapping and self-draining structure, so as to solve or at least alleviate one or more of the above-mentioned technical problems or other problems existing in the prior art.

[0005] To achieve the above objectives, this utility model provides a mass flow meter with a pre-drip trap and self-draining structure, comprising two vibrating tubes; an outlet pipe with its inlet end connected to the two vibrating tubes; an inlet pipe with its outlet end connected to the two vibrating tubes, wherein the inlet pipe has a rectifier chamber and a centrifugal separation chamber connected sequentially along its inlet end toward its outlet end, the inner diameter of the rectifier chamber being smaller than the inner diameter of the centrifugal separation chamber, the cavity wall of the rectifier chamber having multiple spiral guide vanes, and the cavity wall of the centrifugal separation chamber having multiple drain holes; and a drain assembly, comprising a drain housing, a first solenoid valve and a second solenoid valve, wherein the drain housing has a collection chamber, a buffer chamber and a drain outlet connected sequentially from top to bottom, the collection chamber being connected to each of the drain holes, the first solenoid valve being configured to control the opening and closing of the collection chamber and the buffer chamber, and the second solenoid valve being configured to control the opening and closing of the buffer chamber and the drain outlet.

[0006] Preferably, the centrifugal separation chamber is a cylindrical chamber, and the plurality of drainage holes are distributed within the lower half circumference of the wall of the centrifugal separation chamber.

[0007] Preferably, the inlet end of each drain hole is inclined toward the rectifier cavity, and the acute angle between the axis of each drain hole and the axis of the centrifugal separation cavity is 70° to 85°.

[0008] Preferably, the drain hole is arranged on the axial downstream section of the centrifugal separation chamber wall, and the axial upstream section of the centrifugal separation chamber wall is provided with a plurality of coalescing turbulence nails, which are distributed within the upper half circumference of the centrifugal separation chamber wall.

[0009] Preferably, the centrifugal separation chamber has a flow field recovery section on the side opposite to the rectifier chamber, the inner diameter of the flow field recovery section is smaller than the inner diameter of the centrifugal separation chamber, the flow field recovery section is provided with a rectifier mesh, and the inlet end of the vibrating tube is connected to the outlet end of the flow field recovery section.

[0010] Preferably, the inlet pipe is provided with a pressure balancing return pipe, one end of which is connected to the top of the centrifugal separation chamber, and the other end of which is connected to the top of the rectifier chamber near its inlet end.

[0011] Preferably, a liquid level sensor is provided inside the liquid collection chamber.

[0012] The beneficial effects of this utility model are:

[0013] This utility model discloses a mass flow meter with a pre-positioned droplet capture and self-draining structure. It achieves efficient droplet capture through a pre-positioned rectifier chamber and centrifugal separation chamber, and automatically drains the droplets with the help of a draining component. This effectively prevents droplets from entering the vibrating tube and solves problems such as decreased metering accuracy, abnormal drive current, and erosion and wear of the vibrating tube caused by humid gas. It improves the adaptability and stability of the mass flow meter in humid gas scenarios and extends the service life of the vibrating tube and the flow meter as a whole.

[0014] Meanwhile, the drainage assembly employs a first and second solenoid valve to control the opening and closing of the collection chamber and buffer chamber, as well as the buffer chamber and drain outlet, in a tiered manner. This enables the collection, temporary storage, and automatic discharge of droplets, eliminating the need for frequent manual cleaning and reducing subsequent maintenance costs. The tiered on / off design also effectively prevents gas leakage from the drain outlet, ensuring the sealing of the gas-liquid separation process and the stability of the metering system.

[0015] This mass flow meter integrates droplet capture and self-draining functions into the inlet pipe, eliminating the need for an external gas-water separator, significantly reducing equipment size, lowering gas pressure loss, simplifying the installation process, adapting to the compact installation requirements of modern industry, and reducing industrial production costs. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 A schematic diagram of a mass flow meter with a pre-droplet trapping and self-draining structure provided in an embodiment of the present invention;

[0018] Figure 2 This is a cross-sectional schematic diagram of the inlet pipe and drainage assembly;

[0019] Figure 3 This is a schematic diagram of the internal structure of the inlet pipe;

[0020] Figure 4 This is a schematic diagram of the drainage assembly.

[0021] Figure label:

[0022] 10. Outlet pipe; 20. Inlet pipe; 21. Rectifying chamber; 22. Centrifugal separation chamber; 23. Spiral guide vane; 24. Drain hole; 25. Aggregating turbulence pin; 26. Flow field recovery section; 27. Rectifying net; 30. Drain assembly; 31. Drain housing; 32. First solenoid valve; 33. Second solenoid valve; 34. Collection chamber; 35. Buffer chamber; 36. Drain outlet; 37. Liquid level sensor; 40. Housing; 50. Pressure balancing return pipe. Detailed Implementation

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0024] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0025] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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.

[0026] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical 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.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] like Figure 1-4As shown, in one embodiment of this utility model, a mass flow meter with a pre-droplet trap and self-draining structure is provided, including two vibrating tubes, an outlet pipe 10, an inlet pipe 20, and a drainage assembly 30. The two vibrating tubes, not shown in the drawings, are installed inside a housing 40. The inlet end of the outlet pipe 10 is connected to the outlet ends of the two vibrating tubes, and the outlet end of the inlet pipe 20 is connected to the inlet ends of the two vibrating tubes. The inlet pipe 20 has a rectifier chamber 21 and a centrifugal separation chamber 22 connected sequentially along its inlet end toward the outlet end. The inner diameter of the rectifier chamber 21 is smaller than the inner diameter of the centrifugal separation chamber 22. The cavity wall of the rectifier chamber 21 is provided with four to six spiral guide vanes 23 (preferably four in this embodiment). The cavity wall of the centrifugal separation chamber 22 is provided with multiple drainage holes 24.

[0030] The drainage assembly 30 includes a drainage housing 31, a first solenoid valve 32, and a second solenoid valve 33. The drainage housing 31 is installed on the inlet pipe 20. The drainage housing 31 is provided with a collection chamber 34, a buffer chamber 35, and a drain outlet 36 connected from top to bottom. The collection chamber 34 is connected to each drainage hole 24. The first solenoid valve 32 is configured to control the opening and closing of the collection chamber 34 and the buffer chamber 35. The second solenoid valve 33 is configured to control the opening and closing of the buffer chamber 35 and the drain outlet 36.

[0031] After entering the rectifier chamber 21 of the inlet connector 20 from the upstream pipeline, the turbulent humid gas is guided by the spiral guide vanes 23, causing the turbulent humid gas to form a stable spiral flow. At the same time, the droplet agglomerates are initially broken up, laying the foundation for subsequent centrifugal separation. Subsequently, the spiral flow enters the centrifugal separation chamber 22 with a larger inner diameter. The fluid velocity decreases and the centrifugal force increases. According to the principle of centrifugal separation, droplets with a density greater than that of gas are thrown towards the wall of the centrifugal separation chamber 22 under the action of centrifugal force, achieving efficient separation of droplets and gas.

[0032] After separation, the droplets are discharged into the collection chamber 34 through the drain hole 24. When the liquid volume in the collection chamber 34 reaches a certain amount, the first solenoid valve 32 is opened to allow the liquid to enter the buffer chamber 35. After the first solenoid valve 32 is closed, the second solenoid valve 33 is opened to discharge the liquid from the drain port 36. This effectively prevents gas from being discharged along with the liquid during the discharge process, thereby avoiding a sudden drop in the internal pressure of the flow meter and ensuring stable metering accuracy.

[0033] This embodiment discloses a mass flow meter with a pre-positioned droplet capture and self-draining structure. It achieves efficient droplet capture through a pre-positioned rectifier chamber 21 and centrifugal separation chamber 22, and automatically drains the droplets in conjunction with the draining component 30. This effectively prevents droplets from entering the vibrating tube and solves problems such as decreased metering accuracy, abnormal drive current, and erosion and wear of the vibrating tube caused by humid gas. It improves the adaptability and stability of the mass flow meter in humid gas scenarios and extends the service life of the vibrating tube and the flow meter as a whole.

[0034] Meanwhile, the drainage assembly 30 employs a first solenoid valve 32 and a second solenoid valve 33 to control the opening and closing of the collection chamber 34 and the buffer chamber 35, as well as the buffer chamber 35 and the drain port 36. This enables the collection, temporary storage, and automatic discharge of droplets, eliminating the need for frequent manual cleaning and reducing subsequent maintenance costs. The staged on / off design also effectively prevents gas leakage from the drain port 36, ensuring the sealing of the gas-liquid separation process and the stability of the metering system.

[0035] This mass flow meter integrates droplet capture and self-draining functions into the inlet pipe 20, eliminating the need for an external gas-water separator, significantly reducing equipment size, lowering gas pressure loss, simplifying the installation process, adapting to the compact installation requirements of modern industry, and reducing industrial production costs.

[0036] In one embodiment, the centrifugal separation chamber 22 is a cylindrical chamber, and multiple drainage holes 24 are distributed within the lower half of the circumference of the chamber wall. The lower half of the circumference refers to the circumferential region in a cross-section perpendicular to the axis of the centrifugal separation chamber 22, with the geometric center of the chamber as the origin, encompassing the lowest point in the direction of gravity (i.e., the 6 o'clock position) and covering a central angle of 180°. Specifically, it is the arc segment from the 3 o'clock position through the 6 o'clock position to the 9 o'clock position.

[0037] The centrifugal separation chamber 22 adopts a cylindrical chamber design, which makes the humid gas form a uniform spiral flow field in the centrifugal separation chamber 22 and the centrifugal force is evenly distributed. This avoids the flow field disturbance caused by the irregular shape of the chamber, ensures that the droplets can be stably and evenly thrown towards the chamber wall, improves the droplet separation efficiency, and reduces the probability of unseparated droplets entering the vibrating tube.

[0038] After being thrown against the cavity wall by centrifugal force, the droplets will flow downward along the cavity wall under the action of gravity and gather in the lower half of the centrifugal separation cavity 22. The drain holes 24 are distributed in the lower half of the cavity, which can accurately connect with the gathered droplets, so that the droplets can flow into the collection cavity 34 quickly and smoothly through the drain holes 24. This avoids the droplets from being stuck on the cavity wall and being entrained by gas again, thus improving the droplet discharge efficiency and gas-liquid separation effect.

[0039] In one embodiment, the inlet end of each drain hole 24 is inclined toward the rectifier cavity 21, and the acute angle between the axis of each drain hole 24 and the axis of the centrifugal separation cavity 22 is 70° to 85°. In this embodiment, the acute angle is preferably 75°. The inlet end of the drain hole 24 is inclined toward the rectifier cavity 21, which is compatible with the spiral flow direction of the humid gas in the centrifugal separation cavity 22. This can guide the droplets thrown toward the cavity wall to enter the drain hole 24 along the flow field direction, avoiding the accumulation of droplets on the cavity wall due to the impact of the flow field, thus further improving the smoothness and efficiency of droplet discharge.

[0040] Simultaneously, this angle range ensures that the droplets flow smoothly into the drain hole 24 under the combined action of gravity and flow field forces, while avoiding the problem of the drain hole 24 being too tilted due to an excessively small angle, which could cause gas to easily enter the drain hole 24 along with the droplets. It also avoids the increased resistance to the droplets entering the drain hole 24 due to an excessively large angle. Under the premise of ensuring drainage efficiency, it minimizes the leakage of gas from the drain hole 24, ensuring stable internal pressure of the flow meter and further improving measurement accuracy.

[0041] In one embodiment, the drain hole 24 is arranged on the downstream section of the centrifugal separation chamber 22, and a plurality of coalescing turbulence-inducing nails 25 are fixedly installed on the upstream section of the centrifugal separation chamber 22. The plurality of coalescing turbulence-inducing nails 25 are distributed within the upper half circumference of the centrifugal separation chamber 22. The upper half circumference refers to the circumferential area covering a 180° central angle, defined vertically upward from the 12 o'clock position in the cross-section perpendicular to the axis of the centrifugal separation chamber 22, with the geometric center of the chamber as the origin. Specifically, it is the arc segment from the 9 o'clock position through the 12 o'clock position to the 3 o'clock position.

[0042] When the humid gas enters the upstream section of the centrifugal separation chamber 22 from the rectifier chamber 21, the coalescence turbulence pins 25 on the upper half of the wall of the centrifugal separation chamber 22 will cause slight disturbance to the spiral flow, causing the tiny droplets in the airflow to collide and coalesce to form larger droplets. The larger droplets are more likely to be thrown towards the chamber wall in the subsequent centrifugal separation process, which effectively solves the problem that tiny droplets are difficult to separate due to their small mass and insufficient centrifugal force, and greatly improves the thoroughness and efficiency of droplet separation.

[0043] The coalescing turbulence pins 25 are distributed on the upper half of the wall of the centrifugal separation chamber 22. They can create moderate turbulence for the swirling gas without disrupting the stability of the overall spiral flow field, ensuring the normal operation of the centrifugal separation process. After the droplets coalesce into larger droplets in the upstream section, they will move and settle in the axial downstream section under the action of the swirling flow. The drain hole 24 is set in the downstream section to accurately collect the coalesced large droplets, achieving efficient discharge of the droplets and further improving the thoroughness of gas-liquid separation.

[0044] In one embodiment, a flow field recovery section 26 is provided on the side of the centrifugal separation chamber 22 away from the rectifier chamber 21. The inner diameter of the flow field recovery section 26 is smaller than the inner diameter of the centrifugal separation chamber 22. A rectifier mesh 27 is fixedly installed inside the flow field recovery section 26, and the inlet end of the vibrating tube is connected to the outlet end of the flow field recovery section 26. After the wet gas passes through the centrifugal separation chamber 22 to separate the liquid droplets, a small amount of swirling flow will still remain in the gas flow. If the gas with residual swirling flow directly enters the vibrating tube, it will cause uneven distribution of fluid velocity in the vibrating tube, which will affect the stable generation of the Coriolis force and lead to a decrease in measurement accuracy.

[0045] Therefore, by designing the flow field recovery section 26 and the rectifier net 27, the inner diameter of the flow field recovery section 26 is smaller than the inner diameter of the centrifugal separation chamber 22, which can play a contraction role on the airflow. After the gas enters the flow field recovery section 26, the flow velocity is moderately increased. With the help of the internal rectifier net 27, the residual swirling flow can be effectively dispersed, so that the airflow is transformed into a stable axial flow, ensuring that the airflow enters the two vibrating tubes evenly.

[0046] In one embodiment, the inlet pipe 20 is provided with a pressure balancing return pipe 50, one end of which is connected to the top of the centrifugal separation chamber 22, and the other end of which is connected to the top of the rectifier chamber 21 near its inlet end.

[0047] When the flow meter starts up or stops, the airflow velocity in the inlet pipe 20 changes abruptly, causing a momentary pressure difference between the centrifugal separation chamber 22 and the rectifier chamber 21. If the pressure difference is too large, it will disrupt the stability of the flow field. The pressure balancing return pipe 50 connects the top of the centrifugal separation chamber 22 with the top of the rectifier chamber 21 near the inlet end, enabling pressure conduction between the two chambers. This quickly balances the momentary pressure difference during startup / shutdown, preventing pressure changes from damaging the equipment and ensuring the stability of the flow meter during startup and shutdown.

[0048] Meanwhile, trace amounts of non-condensable gases (such as air) tend to accumulate at the top of the centrifugal separation chamber 22. If these gases accumulate over a long period, they can affect the flow field distribution within the centrifugal separation chamber 22, reduce droplet separation efficiency, and potentially lead to measurement data deviations. The pressure balance return pipe 50 can guide these trace amounts of non-condensable gases from the top of the centrifugal separation chamber 22 back to the rectifying chamber 21, where they flow with the main airflow into the subsequent flow channels and are ultimately discharged from the flow meter, thus avoiding the negative impacts of non-condensable gas accumulation.

[0049] In one embodiment, a liquid level sensor 37 is provided in the liquid collection chamber 34. The liquid level sensor 37 is used to detect the liquid level in the liquid collection chamber 34. The liquid level sensor 37 can be a capacitive liquid level switch. Of course, the drainage assembly 30 also includes a control unit. The control unit is configured to perform the following operations in sequence when the liquid level sensor 37 outputs a liquid level that reaches a preset threshold: open the first solenoid valve 32 to allow liquid to flow into the intermediate buffer chamber 35; close the first solenoid valve 32; open the second solenoid valve 33 to drain the liquid; and close the second solenoid valve 33. The control unit is prior art and will not be described in detail in this embodiment.

[0050] The liquid level sensor 37 can accurately determine the liquid level in the collection chamber 34, preventing liquid overflow and backflow due to untimely drainage. When the liquid level reaches the preset upper limit, it can trigger the linkage action of the first solenoid valve 32 and the second solenoid valve 33 to realize the automatic drainage of liquid.

[0051] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A mass flow meter with a pre-liquid droplet trapping and self-draining structure, characterized by, The utility model relates to a kind of centrifugal liquid separator, comprising: Two vibrating tubes; Outlet connecting pipe (10), inlet end is communicated with two vibrating tubes; Inlet connecting pipe (20), outlet end is communicated with two vibrating tubes, inlet connecting pipe (20) is sequentially provided with communication rectifier cavity (21) and centrifugal separation cavity (22) along the direction of its inlet end towards outlet end, the inner diameter of rectifier cavity (21) is less than the inner diameter of centrifugal separation cavity (22), the cavity wall of rectifier cavity (21) is provided with multiple spiral guide vanes (23), the cavity wall of centrifugal separation cavity (22) is provided with multiple liquid discharge holes (24);And Liquid discharge assembly (30), including liquid discharge shell (31), first electromagnetic valve (32) and second electromagnetic valve (33), the liquid discharge shell (31) is sequentially provided with communication liquid collection cavity (34), buffer cavity (35) and blowdown (36) from top to bottom, the liquid collection cavity (34) is communicated with each liquid discharge hole (24), the first electromagnetic valve (32) is configured to control the on-off of the liquid collection cavity (34) and the buffer cavity (35), the second electromagnetic valve (33) is configured to control the on-off of the buffer cavity (35) and the blowdown (36).

2. The mass flow meter with pre-liquid droplet trapping and self-draining structure of claim 1, wherein, The centrifugal separation cavity (22) is a cylindrical chamber, and the plurality of liquid discharge holes (24) are distributed in the lower half of the circumference of the cavity wall of the centrifugal separation cavity (22).

3. The mass flow meter with pre-liquid droplet trapping and self-draining structure of claim 2, wherein, The inlet end of each liquid discharge hole (24) is inclined towards the rectifier cavity (21), and the acute angle between the axis of each liquid discharge hole (24) and the axis of the centrifugal separation cavity (22) is 70°-85°.

4. The mass flow meter with pre-liquid droplet trapping and self-discharge structure of any one of claims 1 to 3, wherein, The liquid discharge holes (24) are arranged on the cavity wall of the downstream axial section of the centrifugal separation cavity (22), and the cavity wall of the upstream axial section of the centrifugal separation cavity (22) is provided with a plurality of coalescence turbulence pins (25), and the plurality of coalescence turbulence pins (25) are distributed in the upper half of the circumference of the cavity wall of the centrifugal separation cavity (22).

5. The mass flow meter with pre-liquid droplet trapping and self-draining structure of claim 1, wherein, The side of the centrifugal separation cavity (22) away from the rectifier cavity (21) is provided with a flow field recovery section (26), the inner diameter of the flow field recovery section (26) is less than the inner diameter of the centrifugal separation cavity (22), the flow field recovery section (26) is provided with a flow straightener (27) therein, and the inlet end of the vibrating tube is communicated with the outlet end of the flow field recovery section (26).

6. The mass flow meter with pre-liquid droplet trapping and self-discharge structure of claim 1, wherein, The inlet connecting pipe (20) is provided with a pressure balance return pipe (50), one end of the pressure balance return pipe (50) is communicated with the top of the centrifugal separation cavity (22), and the other end of the pressure balance return pipe (50) is communicated with the top of the rectifier cavity (21) close to the inlet end thereof.

7. The mass flow meter with pre-liquid droplet trapping and self-discharge structure of claim 1, wherein, The liquid level sensor (37) is arranged in the liquid collection cavity (34).

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