Bullet-nosed tube insertable electromagnetic flow sensor

Abstract

The application discloses a bullet-head-shaped pipe-inserted electromagnetic flow sensor, and belongs to the technical field of liquid flow measurement. The sensor comprises a bullet-head-shaped pipe, a magnetic circuit assembly and electrodes. The magnetic circuit assembly is composed of an I-shaped core and a cylindrical coil wound on the central column of the I-shaped core. The bullet-head-shaped pipe is a combined structure of a semi-elliptical body and a cylindrical body. The I-shaped core is fixed in the pipe by a high-molecular adhesive. The electrodes are fixed on the pipe wall and in the magnetic field range. The I-shaped core is formed by laminating silicon steel sheets or industrial pure iron. The cylindrical coil is optimized in terms of wire diameter, number of turns and other parameters and is excited by direct current. The electrodes are made of corrosion-resistant and wear-resistant materials and are fixed by screw connection. The application can generate a uniform and stable magnetic field, promote the smooth flow of fluid to reduce turbulence and vortex, has the advantages of high measurement precision, reliable structure, simple installation and maintenance, and can meet the requirements of high-precision flow measurement for production control and trade settlement.

Description

Technical Field

[0001] This invention belongs to the field of liquid flow measurement technology, and in particular relates to a bullet-shaped tube-type insertion electromagnetic flow sensor. Background Technology

[0002] In the field of liquid flow measurement, insertion electromagnetic flowmeters are widely used for liquid flow monitoring in various pipelines due to their advantages such as convenient installation and relatively low cost. Currently, conventional insertion electromagnetic flowmeters on the market all operate based on Faraday's law of electromagnetic induction. They collect the induced electromotive force generated on the electrodes when the fluid flows in a magnetic field, and then process the data through secondary instruments to finally obtain the fluid's flow velocity and flow rate.

[0003] Structurally, existing insertion electromagnetic flowmeters typically use a cylindrical or elliptical tube. To generate the magnetic field required for measurement, they are mostly equipped with a cylindrical or rectangular coil and an iron core. When energized, they form a closed magnetic field. At the same time, a pair of electrodes are set on the tube wall within the magnetic field range for collecting the induced electromotive force.

[0004] However, existing technologies have the following obvious drawbacks: 1. Non-uniform magnetic field leads to unstable measurement signal: The closed magnetic field generated by the cylindrical or rectangular coil and the iron core exhibits a non-uniform distribution around the electrodes. According to Faraday's law of electromagnetic induction, the magnitude of the induced electromotive force is related to parameters such as magnetic field strength and fluid flow velocity. A non-uniform magnetic field causes the induced electromotive force generated at the electrodes to fluctuate continuously during the measurement process, failing to stably reflect the true flow velocity of the fluid and directly affecting the measurement accuracy.

[0005] 2. Tube shape causes flow turbulence: When using circular or elliptical tubes with similar major and minor axes, turbulence and eddies are easily generated during fluid flow outside the tube. Turbulent flow leads to uneven distribution of fluid velocity outside the tube, further aggravating fluctuations in induced electromotive force, resulting in a large deviation between the velocity (flow rate) data obtained from secondary instruments and the actual value.

[0006] 3. Low overall measurement accuracy: The combination of the above-mentioned problems of uneven magnetic field and turbulent flow state results in the generally low measurement accuracy of existing insertion electromagnetic flowmeters, which is difficult to meet the needs of production control and trade settlement scenarios with high requirements for flow measurement accuracy. Summary of the Invention

[0007] This invention aims to overcome the shortcomings of existing insertion electromagnetic flowmeters, which suffer from low measurement accuracy due to non-uniform magnetic fields and turbulent flow. By innovating the magnetic circuit structure and device shape, it provides a liquid velocity (flow rate) measuring device that can generate a uniform magnetic field and ensure stable fluid flow, thereby significantly improving measurement accuracy, reducing usage costs, and meeting the high-precision measurement needs of production control and trade settlement scenarios.

[0008] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to a bullet-shaped tube insertion electromagnetic flow sensor, comprising a bullet-shaped tube, a magnetic circuit assembly, and electrodes. The magnetic circuit assembly includes an I-shaped iron core and a cylindrical coil wound around the central column of the I-shaped iron core. The bullet-shaped tube is a combination structure of an ellipse and a cylinder. The I-shaped iron core is fixed inside the elliptical tube, and the electrodes are fixed to the tube wall and are within the magnetic field range generated by the I-shaped iron core.

[0009] In one embodiment, the I-shaped core is made of silicon steel sheets or industrial pure iron and employs a laminated structure. This structure helps improve the magnetic permeability of the core, ensuring the uniformity and stability of the magnetic field.

[0010] In one embodiment, the cylindrical coil is wound with enameled wire of diameter 0.1-0.35mm, has 600-3500 turns, and a resistance of 30-120 ohms. The coil is excited by DC current with an excitation current of 100-250mA, an excitation supply voltage of 12-36V, and an excitation frequency of 2.5-25Hz. By optimizing the coil parameters and excitation method, the magnetic field strength is ensured to meet the measurement requirements, while also guaranteeing the stability and reliability of the coil operation.

[0011] In one embodiment, the cross-section of the bullet-shaped tube is composed of a semi-ellipse and a cylinder. The major axis of the ellipse is 10-100mm, the diameter of the cylinder is 5-50mm, and the total length of the bullet-shaped tube is 90-120mm. The bullet-shaped tube is made of stainless steel or engineering plastic. Stainless steel has good strength and corrosion resistance, while engineering plastic can reduce the cost of the device while ensuring a certain strength. Appropriate materials can be selected according to different application scenarios.

[0012] In one embodiment, the electrode is made of 316 or 304 stainless steel or a special corrosion-resistant and wear-resistant material, and is fixed to the wall of the bullet-shaped tube by a threaded connection. The sensing end of the electrode protrudes 0.2-3 mm from the tube wall. This design ensures full contact between the electrode and the fluid, improving the efficiency of induced electromotive force acquisition, while the threaded connection ensures the firmness and sealing of the electrode installation.

[0013] In one embodiment, the I-shaped iron core is fixed inside the bullet-shaped tube by a polymer adhesive to ensure the stability of the iron core installation and avoid the iron core position shift caused by fluid flow or device vibration, which would affect the magnetic field distribution.

[0014] The present invention has the following beneficial effects: This invention uses an I-shaped iron core and a cylindrical coil to form a closed magnetic circuit, which can generate a uniform and stable magnetic field in the electrode area. This effectively overcomes the signal fluctuation problem caused by uneven magnetic field distribution in traditional insertion electromagnetic flowmeters, and significantly improves the stability and measurement accuracy of induced electromotive force.

[0015] The bullet-shaped tube design of this invention is composed of a semi-elliptical body and a cylinder, which can effectively promote the smooth flow of fluid, reduce the generation of eddies and turbulence, make the flow velocity distribution more uniform, and thus reduce the impact of flow disturbance on measurement.

[0016] In this invention, the I-shaped iron core is made of laminated silicon steel sheets, the coil parameters and excitation method are optimized, and the bullet-shaped tube can be made of stainless steel or engineering plastic according to actual needs. The overall structure is sturdy and corrosion-resistant. The electrodes are fixed by threaded connection process, the assembly process is mature, the sealing is good, the service life is long, and it is suitable for long-term stable use in industrial sites.

[0017] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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.

[0019] Figure 1 A schematic diagram of the overall structure of a bullet-shaped tube-type insertion electromagnetic flow sensor; Figure 2 A front view of a bullet-shaped tube-type insertion electromagnetic flow sensor; Figure 3 for Figure 2 Sectional view of AA in the middle; Figure 4 This is a schematic diagram of the structure of the present invention 90. Figure 5 This is a schematic diagram of the vertically installed structure of the present invention.

[0020] The attached diagram lists the components represented by each number as follows: 1. I-shaped iron core; 2. Cylindrical coil; 3. Bullet-shaped tube; 4. Electrode. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "inside," "outside," "inside," etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, terms such as installation, setting, and connection should be interpreted broadly. For example, connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Example 1 Please see Figures 1-5 As shown, this embodiment illustrates the detailed structure of a liquid flow rate measuring device: I. Component Parameter Selection I-shaped core 1: Made of Baosteel B35A230 silicon steel sheets, the central column is 5mm wide, 25mm high, and 20mm thick. The upper and lower yokes are matched with the central column to ensure a closed magnetic circuit and a uniform magnetic field. Cylindrical coil 2: 0.2mm diameter self-adhesive enameled wire, wound with 2350 turns, with a coil resistance of 89 ohms, wound around the central column of the I-shaped core 1. The two ends of the coil are connected to an external excitation power supply via wires. The excitation current is 100-250mA, the excitation voltage is 12-36V, and the excitation frequency is 2.5-25Hz. Bullet-shaped tube 3: Made of engineering plastic, the cross-section consists of a semi-ellipse (major axis 60mm) and a cylinder (diameter 50mm). The total length of the tube is 120mm, and the wall thickness is 3mm, ensuring structural strength and corrosion resistance. Electrode 4: Made of 316 or 304 stainless steel or special corrosion-resistant and wear-resistant materials, 5mm in diameter, fixed to the tube wall via threaded connection, with the electrode sensing end protruding 0.3mm from the tube wall. Sealing and Fixing: The I-shaped iron core 1 is fixed inside the tube body with the same type of adhesive to ensure a firm assembly and no liquid leakage.

[0025] II. Assembly Process First, the I-shaped iron core 1 is pre-treated by stacking Baosteel B35A230 silicon steel sheets according to the design dimensions to ensure that the core dimensional accuracy meets the requirements. A winding machine is used to wind 2350 turns of 0.2mm self-adhesive enameled wire onto the central column of the I-shaped iron core 1. During winding, the winding tension is controlled to be uniform to avoid loosening of the coil. After winding, the coil resistance is measured to ensure it is approximately 78. Next, the bullet-shaped tube 3 is processed, including tube forming, electrode mounting hole drilling, and welding (using laser welding technology to ensure a firm tube connection). Finally, the electrode 4 is installed on the tube using a threaded connection process. At the electrode mounting holes, ensure that electrode 4 is tightly connected to the tube body without any looseness; use epoxy resin polymer adhesive to fix the assembled coil-shaped iron core 1 inside the bullet-shaped tube body 3, ensuring that the magnetic field generated by the coil can completely cover the electromagnetic induction area; apply epoxy resin adhesive to the joints of the tube body shell for sealing treatment, and place it in an environment of 80℃ for 2 hours to ensure the sealing effect; after assembly, perform visual inspection, dimensional verification and sealing test on the device (using water pressure test, test pressure 1.6MPa, pressure held for 30 minutes, no leakage is qualified).

[0026] It should be further noted that this device is installed within an insertion-type electromagnetic flowmeter and is connected and debugged with other components of the flowmeter. The electrodes of the liquid flow rate measuring device are reliably connected to the secondary instrument of the flowmeter via wires to ensure stable signal transmission. During connection, attention should be paid to the insulation of the wires to avoid signal interference. Simultaneously, the cylindrical coil is connected to the external excitation power supply, and the connection is checked for secureness to prevent unstable excitation due to poor contact.

[0027] After connection, power on the entire insertion electromagnetic flowmeter for testing. Observe the display of the secondary instrument to check whether it can normally acquire the electromotive force signal induced by the electrodes and accurately calculate the fluid velocity and flow rate. If any abnormality is found in the display, promptly check the connection of each component of the device, the excitation parameters of the coil, and the induction status of the electrodes.

[0028] After successful testing, the insertion electromagnetic flowmeter with the liquid flow rate measurement device installed is then installed on the pipeline where liquid flow monitoring is required. During installation, ensure a tight seal between the device and the pipeline to prevent liquid leakage. Simultaneously, ensure the device is correctly positioned within the pipeline so that the fluid can flow smoothly through the bullet-shaped tube for optimal measurement results.

[0029] After installation, the device undergoes comprehensive commissioning and calibration again. Based on the actual measured liquid characteristics and pipeline conditions, the parameters of the secondary instruments are adjusted to ensure more accurate and reliable measurement results. Regular maintenance and inspection of the device are also essential, including checking electrode wear, coil insulation performance, and pipe corrosion, to promptly identify and resolve potential problems and ensure long-term stable operation, providing accurate liquid flow measurement data for production control and trade settlement scenarios.

[0030] In the description of this specification, references to terms such as "an embodiment," "an example," and "a specific example" indicate that a particular feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A bullet-shaped tube insertion electromagnetic flow sensor, comprising a bullet-shaped tube (3), a magnetic circuit assembly, and electrodes (4), characterized in that: The magnetic circuit assembly includes an I-shaped iron core (1) and a cylindrical coil (2) wound on the central column of the I-shaped iron core (1). The bullet-shaped tube (3) is a combination structure of an ellipse and a cylinder. The I-shaped iron core (1) is fixed inside the bullet-shaped tube (3). The electrode (4) is fixed on the tube wall of the bullet-shaped tube (3) and is within the magnetic field range generated by the I-shaped iron core (1).

2. The bullet-shaped tube-type insertion electromagnetic flow sensor according to claim 1, characterized in that, The I-shaped iron core (1) is made of silicon steel sheet or industrial pure iron material and adopts a stacked molding structure.

3. The bullet-shaped tube-type insertion electromagnetic flow sensor according to claim 1, characterized in that, The cylindrical coil (2) is made of enameled wire with a wire diameter of 0.1-0.35mm, a coil number of 600-3500 turns, and a coil resistance of 30-120. The coil is excited by DC excitation with an excitation current of 100-250mA, an excitation power supply voltage of 12-36V, and an excitation frequency of 2.5-25Hz.

4. The bullet-shaped tube-type insertion electromagnetic flow sensor according to claim 1, characterized in that, The cross-section of the bullet-shaped tube (3) consists of a half-ellipse and a cylinder. The major axis of the ellipse is 10-100mm, the diameter of the cylinder is 5-50mm, and the total length of the bullet-shaped tube (3) is 90-120mm. The bullet-shaped tube (3) is made of stainless steel or engineering plastic.

5. A bullet-shaped tube-type insertion electromagnetic flow sensor according to claim 1, characterized in that, The electrode (4) is made of 316 or 304 stainless steel or special corrosion-resistant and wear-resistant materials and is fixed to the tube wall of the bullet-shaped tube body (3) by a threaded connection process. The sensing end of the electrode (4) protrudes 0.2-3mm from the tube wall.

6. The bullet-shaped tube-type insertion electromagnetic flow sensor according to claim 1, characterized in that, The I-shaped iron core (1) is fixed inside the bullet-shaped tube (3) by a polymer adhesive.

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