Mass flow meter of non-circular section measuring tube

Abstract

The utility model provides a mass flow meter with non-circular section measuring tubes, which relates to the field of Coriolis mass flow meters and comprises a support provided with a flange, a shunt tube serving as an extension part of the support and communicated with the flange and two measuring tubes butted with the shunt tube, a gap is arranged between the two measuring tubes, a first vibration pickup is arranged in the gap, and a second vibration pickup is arranged in the gap. According to the Coriolis mass flow meter using the measuring tube with the oval section, under the condition that the sensitivity is basically unchanged, the flowable volume of a pipeline can be greatly improved, pressure loss is further reduced, in addition, the flow rate of the pipeline can be greatly increased, and the flow rate of the pipeline can be greatly increased. The rectangular section or the semicircular section can also achieve similar functions.

Description

Technical Field

[0001] The utility model relates to the field of Coriolis mass flowmeters, in particular to a mass flowmeter with a non-circular cross-section measuring tube. Background Art

[0002] The Coriolis mass flowmeter is a device that directly measures the mass flow rate by using the Coriolis principle that is proportional to the mass flow rate when the fluid flows in a vibrating pipe. The Coriolis mass flowmeter consists of a mass flow sensor and a mass flow transmitter, wherein the mass flow sensor is mainly composed of inlet and outlet flanges, a flow divider, a measuring tube, a drive and receiving assembly, and a housing. When the mass flowmeter is working, the fluid flows into the flange, and the fluid flows into the measuring tube after being diverted by the flow divider, and then flows out of the flange after being merged by the flow divider. When the fluid passes through the vibrating measuring tube, the Coriolis effect is generated, and the mass flow rate is measured at this time. Therefore, the measuring tube is the core component of the mass flowmeter. The mass flowmeter usually works by the resonance of the double measuring tube. Its resonant frequency is negatively correlated with the sensitivity of the mass flowmeter, that is, the higher the resonant frequency, the lower the Coriolis effect generated under the same flow rate, and vice versa. Therefore, the mass flowmeter should try to reduce the resonant frequency when designing to ensure good sensitivity. At present, the cross-sectional design of the measuring tube of the mass flowmeter is circular, and the reduction of the resonant frequency is achieved by reducing the inner and outer diameters of the measuring tube. The disadvantages brought about by this include: first, reducing the inner and outer diameters of the measuring tube will greatly reduce the flow cross-section, reduce the flowability of the mass flowmeter, bring about great pressure loss, and cause a huge waste of resources; second, the circular measuring tube structure is easily disturbed by non-resonant frequencies, reducing measurement reliability; for this reason, this paper intends to design a mass flowmeter with a non-circular cross-section measuring tube, which greatly improves the flowability of the mass flowmeter and reduces pressure loss while ensuring sensitivity. Utility Model Content

[0003] The utility model aims to provide a mass flow meter with a non-circular cross-section measuring tube to solve the above technical problems.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A mass flow meter with a non-circular cross-section measuring tube includes a bracket equipped with a flange, a shunt tube which is an extension of the bracket and connected to the flange, and two measuring tubes connected to the shunt tube. There is a gap between the two measuring tubes, and a first vibration pickup, a second vibration pickup, and a driver are arranged in the gap. The cross-section of the measuring tube is a non-circular cross-section.

[0006] Preferably, the non-circular cross-section has a first axis corresponding to the dimension of the cross-section at its narrowest point, and a second axis corresponding to the dimension of the cross-section at its widest point.

[0007] Preferably, the axial direction of the first axis lies in the resonant direction of the measuring tube, and the axial direction of the second axis is perpendicular to the resonant direction of the measuring tube.

[0008] Preferably, the non-circular cross-section is one of an elliptical cross-section, a rectangular cross-section, and a semi-circular cross-section.

[0009] Preferably, the first pick-up and the second pick-up detect the amplitudes of the two measuring tubes on both sides of the driver.

[0010] Preferably, it further includes a housing covering the two measuring tubes.

[0011] Preferably, there is also a restraint clip for clamping the measuring tubes between the two measuring tubes.

[0012] Preferably, it further includes a transmitter. The transmitter has a wire harness, and the wire harness is connected to the first pick-up, the second pick-up, and the driver.

[0013] The beneficial effects of the present utility model are:

[0014] In the present utility model, for the Coriolis mass flowmeter using a measuring tube with an elliptical cross-section, the flow capacity of the pipeline can be greatly improved under the condition that the sensitivity remains basically unchanged, thereby reducing the pressure loss. In addition, a rectangular cross-section or a semi-circular cross-section can also achieve a similar function. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of a mass flowmeter with a non-circular cross-section measuring tube;

[0016] Figure 2 It is Figure 1 a cross-sectional view of the mass flowmeter with the non-circular cross-section measuring tube shown;

[0017] Figure 3 It is Figure 2 a cross-sectional view of the measuring tube and the shunt tube in ;

[0018] Figure 4 It is a cross-sectional dimension diagram of the comparative example;

[0019] Figure 5 It is a cross-sectional dimension diagram of the shunt tube and the elliptical measuring tube;

[0020] Figure 6 It is Figure 4 a modeling diagram and a second-order resonance frequency diagram constructed from the pipeline dimension data shown;

[0021] Figure 7 It is Figure 4 a modeling diagram and a sixth-order resonance frequency diagram constructed from the pipeline dimension data shown;

[0022] Figure 8 It is Figure 5The modeling diagram and the second-order resonance frequency diagram constructed from the shown pipeline dimension data;

[0023] Figure 9 For Figure 5 the modeling diagram and the sixth-order resonance frequency diagram constructed from the shown pipeline dimension data;

[0024] Reference numerals: 1, support; 2, housing; 3, shunt pipe; 4, flange; 5, transmitter; 6, wire harness; 7, restraint clip; 8, first measuring pipe; 9, second measuring pipe; 10, first pickup; 11, second pickup; 12, driver. Detailed implementation manners

[0025] In order to make the technical means, creative features, achieved purposes and functions of the present utility model easy to understand, the present utility model will be further described below in conjunction with specific embodiments and the accompanying drawings. However, the following embodiments are only the preferred embodiments of the present utility model and not all of them. Based on the embodiments in the implementation manners, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present utility model.

[0026] The specific embodiments of the present utility model will be described below in conjunction with the accompanying drawings.

[0027] Embodiment 1

[0028] In this embodiment, a mass flowmeter with a non-circular cross-section measuring pipe is proposed. Please refer to Figures 1-3 , the mass flowmeter with a non-circular cross-section measuring pipe includes a support 1 equipped with a flange 4, a shunt pipe 3 that is an extension part of the support 1 and communicates with the flange 4, and also includes two measuring pipes docked with the shunt pipe 3.

[0029] Please refer to Figure 1 and Figure 2 , there are two of the above-mentioned flanges 4, and the two flanges 4 are arranged at the ends of the support 1. There is a channel in the support 1, and this channel communicates the flange 4 with the shunt pipe 3.

[0030] Please refer to Figure 2 and Figure 3 , the two measuring pipes are respectively the first measuring pipe 8 and the second measuring pipe 9 in Figure 2 . The first measuring pipe 8 and the second measuring pipe 9 are preferably U-shaped pipes. Further, the pipe orifices of the first measuring pipe 8 and the second measuring pipe 9 are docked with the corresponding pipe orifices of the shunt pipe 3, and after docking, they form the style shown in Figure 3 .

[0031] Please continue to refer to Figure 2 and Figure 3 , there is a gap between the first measuring pipe 8 and the second measuring pipe 9, and a first pickup 10, a second pickup 11, and a driver 12 are arranged in the gap.

[0032] Please refer to Figure 2 , the driver 12 is at the center of the first measuring tube 8 and the second measuring tube 9, and the first pickup 10 and the second pickup 11 are located on both sides of the driver 12. Among them, the first pickup 10 and the second pickup 11 are located on the driver 12 to detect the amplitude of the fluid passing through the first measuring tube 8 and the second measuring tube 9.

[0033] Please continue to refer to Figure 2 , the mass flowmeter with a non-circular cross-section measuring tube further includes a housing 2 covering the first measuring tube 8 and the second measuring tube 9. Specifically, the housing 2 is a U-shaped housing adapted to the first measuring tube 8 and the second measuring tube 9. The U-shaped housing has a receiving space for covering the first measuring tube 8 and the second measuring tube 9. The U-shaped housing also has two ports, and the two ports respectively clamp the corresponding shunt tubes 3. There are also two restraint clips 7 in the housing 2, and the two restraint clips 7 are close to the corresponding shunt tubes 3 to hoop the first measuring tube 8 and the second measuring tube 9.

[0034] Please refer to Figure 1 , in this embodiment, the mass flowmeter with a non-circular cross-section measuring tube also has a transmitter 5. The transmitter 5 is equipped with a wire harness 6, and the wire harness 6 is connected to the first pickup 10, the second pickup 11 and the driver 12.

[0035] The core of the mass flowmeter with a non-circular cross-section measuring tube proposed in this embodiment lies in adjusting the tube shape of the measuring tube (the tube shapes of the first measuring tube 8 and the second measuring tube 9). Please refer to Figure 2 and Figure 3 , the cross-sections of the first measuring tube 8 and the second measuring tube 9 are non-circular cross-sections, and this cross-section is preferably an elliptical cross-section in this embodiment. Of course, the cross-section can also be a rectangular cross-section or a semi-circular cross-section, etc.

[0036] Further explanation, the non-circular cross-section has a first axis corresponding to the dimension at the narrowest part of the cross-section, and a second axis corresponding to the dimension at the widest part of the cross-section. Specifically, the axial direction of the first axis is located in the resonant direction of the measuring tube, and the axial direction of the second axis is perpendicular to the resonant direction of the measuring tube. Taking Figure 3 as an example, the first axis is marked as b in Figure 3 , and the second axis is marked as a in Figure 3 . It should be emphasized that b / a < 1.

[0037] In order to better elaborate on the advantages of the non-circular cross-section measuring tube compared with the circular cross-section measuring tube, please refer to Figure 4 and Figure 5 , taking the design of a measuring tube with an elliptical cross-section for a mass flowmeter with a DN80 caliber as an example, the flowability and sensitivity are analyzed and explained.

[0038] First, the analysis of flowability

[0039] Since the cross-section from the shunt tube 3 to the measurement tube cross-section is a variable cross-section, the fluid pressure loss is positively correlated with the ratio of the cross-section change. Therefore, by comparing the cross-section change ratios of the two, the size of the flowability can be known.

[0040] Please refer to Figure 4 and Figure 5 , the cross-sectional area of the shunt tube 3: A = πR 2 = 6400π = 5026.5482mm 2 ;

[0041] In this embodiment, a measurement tube with a circular cross-section is used as a comparative example of this embodiment, and its data is as follows:

[0042] Please refer to Figure 4 , the flow cross-sectional areas of the two circular measurement tubes: A1 = 2208.9323mm 2 , the change rate of the flow cross-sectional area of the circular measurement tube: α1 = 1 - A1 / A = 56.5%.

[0043] The cross-sectional data of the elliptical measurement tube in this embodiment is as follows:

[0044] Please refer to Figure 5 , the flow cross-sectional areas of the two elliptical measurement tubes: A2 = 2208.9323mm 2 , the change rate of the flow cross-sectional area of the elliptical measurement tube: α2 = 1 - A2 / A = 36.7%.

[0045] From the above data, it can be seen that the flow cross-sectional area of the elliptical measurement tube is increased by 19.35% compared with the circular measurement tube, and its flowability is significantly improved.

[0046] Second, the analysis of sensitivity

[0047] Please refer to Figures 6-9 , by modeling, analyzing and comparing the above data, the results are as follows:

[0048] Please refer to Figure 6 and Figure 7 , the second-order resonance frequency of the circular measurement tube: F2 = 71.903Hz, the sixth-order resonance frequency: F6 = 177.600Hz; Please refer to Figure 8 and Figure 9 , the second-order resonance frequency of the elliptical measurement tube: f2 = 74.025Hz, the sixth-order resonance frequency: f6 = 184.309Hz.

[0049] From the above data, it can be seen that the sensitivity of the elliptical measurement tube and the circular measurement tube is basically unchanged, but the flow rate is significantly increased, and the pressure loss can be greatly reduced.

[0050] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0051] The foregoing has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present utility model and are not used to limit the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and all such changes and improvements fall within the scope of the present utility model claimed. The scope of protection claimed for the present utility model is defined by the appended claims and their equivalents.

Claims

1. A mass flow meter with a non-circular cross-section measuring tube, comprising a bracket equipped with a flange, a shunt tube as an extension of the bracket and connected to the flange, and two measuring tubes connected to the shunt tube, a gap between the two measuring tubes, a first vibration pickup, a second vibration pickup, and a driver, characterized in that: The cross section of the measuring tube is a non-circular cross section.

2. A mass flowmeter with a non-circular cross-section measuring tube according to claim 1, characterized in that: A non-circular cross-section has a first axis corresponding to the dimension of the cross-section at its narrowest point and a second axis corresponding to the dimension of the cross-section at its widest point.

3. A mass flowmeter with a non-circular cross-section measuring tube according to claim 2, characterized in that: The axial direction of the first axis is located in the resonance direction of the measuring tube, and the axial direction of the second axis is perpendicular to the resonance direction of the measuring tube.

4. A mass flowmeter with a non-circular cross-section measuring tube according to claim 3, characterized in that: The non-circular cross section is one of an elliptical cross section, a rectangular cross section and a semicircular cross section.

5. A mass flowmeter with a non-circular cross-section measuring tube according to claim 1, characterized in that: The first vibration pickup and the second vibration pickup detect the vibration amplitudes of the two measuring tubes on both sides of the driver.

6. A mass flowmeter with a non-circular cross-section measuring tube according to claim 1, characterized in that: Also included is a housing that covers the two measuring tubes.

7. A mass flowmeter with a non-circular cross-section measuring tube according to claim 6, characterized in that: There is also a restraining clamp for hooping the measuring tubes between the two measuring tubes.

8. A mass flowmeter with a non-circular cross-section measuring tube according to claim 1, characterized in that: The utility model also comprises a transmitter, which has a wiring harness connected with the first vibration pickup, the second vibration pickup and the driver.

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