Coriolis flow meter

Abstract

The utility model provides a Coriolis flowmeter, the upstream end and the downstream end of a flow guide pipe in a chamber of a meter shell are respectively connected with an opening and closing valve and a liquid outlet pipe, a sensing device is arranged at the position close to the free end of a vibration rod in the flow guide pipe, a magnet is arranged on the middle section or the free end of the vibration rod, and a magnetic induction coil is arranged on the pipe wall close to the magnet. The magnet is arranged on the vibration rod, the magnet vibrates along with vibration of the vibration rod, the magnet in vibration cuts magnetic induction lines of the magnetic induction coil to generate electricity, and therefore the flowmeter can automatically supply energy in the measuring process.

Description

Technical Field

[0001] The utility model relates to the technical field of fluid measurement, in particular to a Coriolis flowmeter. Background Art

[0002] A flow meter is an instrument used to measure the flow rate of a fluid in a pipeline. A flow meter designed using the Coriolis force principle has the advantages of being able to directly measure the flow rate and having high measurement accuracy. The Coriolis flow meter in the prior art is usually designed as a measuring tube with an electromagnetic vibrator and two vibration sensors, which measures the vibration signal when the fluid passes through the measuring tube to feedback its flow rate.

[0003] The patent named "Fluid Oscillation Flowmeter" (US3698245A) discloses a technical solution, in which a reed assembly 17 is provided in a flow channel 16. When the fluid passes through the flow channel, the reed assembly 17 generates elastic oscillations, and the sensor responds to the output, thereby calculating the flow rate of the fluid. However, the above solution requires an external power supply for measurement, which is not convenient for application in places where it is difficult to provide power. Utility Model Content

[0004] The utility model aims to provide a Coriolis flowmeter, which uses its own measuring structure to set a self-generating module to improve the convenience of using the flowmeter.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a Coriolis flowmeter, the downstream end of the liquid inlet pipe is connected to the inner cavity of a tube box-shaped case, a flow guide pipe is arranged in the case chamber, the downstream end of the flow guide pipe is connected to the liquid outlet pipe, a valve plate of an opening and closing valve is arranged at the pipe mouth of the upstream end of the liquid outlet pipe, and when the valve plate is displaced, the chamber of the case and the upstream end of the flow guide pipe are cut off or connected, a vibration rod is arranged in the flow guide pipe, and a sensing device is arranged on the shell wall of the case near the free end of the vibration rod to collect vibration signals of the vibration rod and output the collected vibration signals, a magnet is arranged on the middle section or free end of the vibration rod, and a magnetic induction coil is arranged on the tube wall near the magnet.

[0006] The utility model mainly arranges a flow guide tube in the chamber of the meter case, arranges a magnet on the middle section or free end of the vibrating rod in the flow guide tube, and arranges a magnetic induction coil on the tube wall adjacent to the magnet. Whenever the vibrating rod is affected by the fluid in the flow guide tube and vibrates, the magnet on the middle section or free end also vibrates with the vibration of the vibrating rod, and the vibrating magnet cuts the magnetic induction line of the magnetic induction coil to generate electricity, so that the flow meter can supply energy by itself during the measurement process. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of a Coriolis flow meter case;

[0008] Figure 2 , Figure 3They are cross-sectional views of two embodiments of a Coriolis flow meter. DETAILED DESCRIPTION

[0009] See also Figures 1-2 In the Coriolis flowmeter shown, the downstream end of the liquid inlet pipe 1 is connected to the inner cavity of the tube box-shaped case 3, a flow guide pipe 22 is arranged in the chamber of the case 3, the downstream end of the flow guide pipe 22 is connected to the liquid outlet pipe 2, a valve plate 211 of an opening and closing valve 21 is arranged at the pipe mouth of the upstream end of the liquid outlet pipe 2, and the valve plate 211 is displaced to cut off or connect the chamber of the case 3 and the upstream end of the flow guide pipe 22, a vibration rod 30 is arranged in the flow guide pipe 22, and a sensor device 40 is arranged on the shell wall of the case 3 near the free end of the vibration rod 30 to collect vibration signals of the vibration rod 30 and output the collected vibration signals, a magnet 50 is arranged on the middle section or free end of the vibration rod 30, and a magnetic induction coil 51 is arranged on the tube wall near the magnet 50.

[0010] In the above scheme, a spring 5 is provided in the cavity of the opening and closing valve 21, and the valve plate 211 is a rubber sheet pre-stressed by the spring 5 and sealing the upstream end of the outlet pipe 2. The pre-stressed pressure of the spring 5 can be adjusted and set on the opening and closing valve 21. Preferably, the opening and closing valve 21 can adopt a pilot valve, and the opening or closing of the opening and closing valve 21 is controlled by other control mechanisms. The vibration rod 30 in the flow guide tube 22 can be fixed at one end and freely suspended at the other end. The vibration rod 30 can be made of elastic materials, such as stainless steel sheets, phosphor copper sheets and plastic sheets, etc. The free end of the vibration rod 30 vibrates when the fluid passes through, and at this time, the magnet 50 on the middle section or free end of the vibration rod 30 also vibrates with the vibration of the vibration rod 30. The vibrating magnet cuts the magnetic induction line of the magnetic induction coil and generates current to charge the capacitor and battery in the flow meter, which is controlled by the processor of the flow meter and supplies power to other modules, so that the flow meter can be self-powered during the measurement process, which improves the convenience of the flow meter measurement and enables it to still work in an environment without an external power supply.

[0011] In order to obtain the vibration signal of the vibration rod 30 more accurately, the vibration rod 30 is in a strip shape, and the length direction of the vibration rod 30 is consistent with the core line direction of the guide tube 22.

[0012] Preferably, the rod core line of the vibration rod 30 coincides with the tube core line of the guide tube 22. The midstream section of the guide tube 22 is provided with a reduced diameter section 221, and the middle section of the vibration rod 30 is located in the reduced diameter section 221. In the above scheme, the strip-shaped vibration rod 30 has a larger force-bearing area during the oscillation of the fluid, which is conducive to the vibration of the free end of the vibration rod 30. The rod core line of the vibration rod 30 coincides with the tube core line of the guide tube 22, so that the tube cavities on both sides of the vibration rod 30 are symmetrical. After the fluid passes through the reduced diameter section 221 in the guide tube 22, the vortex oscillation generated by the fluid is more intense, which is convenient for the sensor device 40 to collect vibration signals.

[0013] According to the different fixing positions of the magnet 50 on the vibration rod 30, there are two embodiments as follows:

[0014] 1) If Figure 1 As shown, the magnet 50 is fixed to the middle section of the vibration rod 30, and the magnetic induction coil 51 is arranged on the inner wall or outer wall of the tube of the reduced diameter section 221. The sensing device 40 includes a second magnet 401 fixed at the free end of the vibration rod 30 and a Wiegand sensor 402 arranged adjacent to the second magnet 401. The Wiegand sensor 402 is fixed on the shell wall of the watch case 3 at the downstream end of the guide tube 22. In the above scheme, there is a relatively large space at the tube wall of the reduced diameter section 221, which is convenient for the arrangement of the magnetic induction coil 51. If the magnetic induction coil 51 is arranged on the inner wall of the tube, the magnetic induction coil 51 also serves as the throat of the guide tube 22, further enhancing the eddy current oscillation generated by the fluid passing through the throat. The Wiegand sensor 402 has the advantages of no need for an external power supply and accurate measurement. The vibration signal can be measured by using the magnet 401 in combination with the Wiegand sensor 402, and high-precision measurement of large and small flows can be achieved through algorithms.

[0015] 2) If Figure 2 As shown, the magnet 50 is fixed at the free end of the vibration rod 30, and the magnetic induction coil 51 is arranged on the wall of the watch case 3 at the downstream end of the guide tube 22. The sensing device 40 includes a Wiegand sensor 402 arranged adjacent to the magnet 50, and the Wiegand sensor 402 is fixed on the wall of the downstream end of the guide tube 22. In the above scheme, the magnet 50 has two functions: one is to serve as a power generation component, cutting the magnetic flux lines of the magnetic induction coil 51 to generate current for energy supply, and the other is to serve as a measuring component, and the magnet 50 cooperates with the Wiegand sensor 402 to measure the vibration signal transmitted by the vibration rod 30. Compared with the previous embodiment, the magnet 50 in this scheme is fixed at the free end of the vibration rod 30, and its vibration amplitude as the vibration rod 30 vibrates is obviously larger, so the electric energy generated by cutting the magnetic flux lines is larger, and it is more convenient for the sensing device 40 to collect vibration signals.

[0016] In order to improve the range ratio of the Coriolis flowmeter, a pulse ejector 11 is arranged on the tube wall of the flow guide tube 22, and the liquid inlet end of the pulse ejector 11 is connected to the chamber of the case 3, and the jet of the pulse ejector 11 is directed to the free end or segment of the vibration rod 30. In the above scheme, after the fluid enters from the liquid inlet end of the pulse ejector 11, it is divided into two paths at its downstream end, one path along the inner cavity of the tube box-shaped case 3 to reach the valve plate 211 of the on-off valve 21, and the other path enters the inner cavity of the case 3 from the liquid inlet end of the pulse ejector 11 on the tube wall. There are two possible situations here:

[0017] 1. When the fluid flow is small, the fluid pressure is small, and the fluid pressure flowing from the inner cavity of the case 3 to the valve plate 211 is not enough to open the valve plate 211. The fluid can only enter the downstream end of the inner cavity of the flow guide tube 22 from the pulse ejector 11 on the wall of the flow guide tube 22, and flow out from the liquid outlet pipe 2. Since the jet of the pulse ejector 11 points to the free end or segment of the vibration rod 30, the free end of the vibration rod 30 will vibrate under the impact of the jet. After the sensor device 40 collects the vibration signal of the vibration rod 30, the processor collects the vibration signal and processes it through the corresponding algorithm to obtain the flow rate of the fluid.

[0018] Second, when the fluid flow rate is large, the fluid pressure flowing from the inner cavity of the case 3 to the valve plate 211 is sufficient to open the valve plate 211, and the fluid enters the guide tube 22 through the on-off valve 21, forming a vortex in the guide tube 22 to vibrate the vibration rod 30. In this process, part of the fluid still enters through the liquid inlet 111 of the pulse ejector 11, and the two fluids merge at the downstream end of the guide tube 22 and flow out from the liquid outlet pipe 2. At this time, the measurement of the flow meter is based on the Coriolis force principle. The vortex in the guide tube 22 and the jet of the pulse ejector 11 merge and act on the vibration rod 30 to produce resonance. The sensor device 40 collects the vibration signal synthesized by the above two vibrations. The vibration signal obtains the magnitude of the Coriolis force generated by the fluid through the corresponding algorithm, and then measures the flow rate.

[0019] Therefore, the Coriolis flowmeter of the present solution can measure both flow conditions mentioned above, and can measure both large flow and small flow fluids, and both have high measurement accuracy. Compared with the traditional flowmeter, the flowmeter of the present solution obviously has a larger range ratio. In the present invention, when the flowmeter measures different fluid media, it can select the corresponding vibration rod 30 with different Young's modulus according to the medium with different densities. For example, when measuring water flow and air flow with similar flow rates, the Young's modulus of the vibration rod 30 used to measure the water flow is greater than the Young's modulus of the vibration rod 30 used to measure the fluid.

[0020] The outer surface of the tube wall at the downstream end of the flow guide tube 22 is connected with a partition 8 that separates the liquid inlet tube 1 and the liquid outlet tube 2. The partition 8 is annular as a whole and is obliquely placed in the chamber of the watch case 3 so that the liquid outlet tube 2 is only connected to the downstream end of the flow guide tube 22. The outer edge of the partition 8 abuts against the inner wall of the watch case 3 and a groove for accommodating a sealing ring is provided on the outer edge of the partition 8.

[0021] The sensor device 40 includes a second magnet 401 fixed at the free end of the vibration rod 30 and a Wiegand sensor 402 arranged adjacent to the second magnet 401 . The Wiegand sensor 402 is fixed on the wall of the watch case 3 directly facing the downstream end of the flow guide tube 22 .

[0022] More specifically, a bracket 311 connected to the pipe wall is provided in the guide pipe 22 . The bracket is in an I-shape or a X-shape and is horizontally placed in the pipe. The middle section or one end of the vibration rod 30 is fixedly connected to the bracket 311 .

[0023] The flow meter of the present invention can be used on a water meter or a gas meter. Preferably, an independent shell that can accommodate the electronic components of the smart water meter or gas meter is attached to the outside of the shell of the opening and closing valve 21. The shell is provided with a liquid crystal display device such as an LCD display to indicate water usage information such as the operating status of the water meter or gas meter, and a communication device for providing information to a remote management system is provided in the cavity of the shell.

[0024] When used as a smart water meter, the signal lines of the vibrating rod 30 and the sensor device 40 of the present invention are connected to the electronic circuit, and the working status of the vibrating rod 30 and the sensor device 40, and the information of the water flow flowing through the water meter can be monitored by electronic components. Through the control of the electronic circuit, the sensor device and the built-in operating software, the information such as the water flow speed and flow rate in the pipeline, whether the pipeline is leaking, whether the pipeline is overloaded, whether the water meter is working, etc. can be collected and displayed on the liquid crystal display, and provided to the remote meter reading system through wired or wireless communication.

Claims

1. A Coriolis flowmeter, characterized in that: The downstream end of the liquid inlet pipe (1) is connected to the inner cavity of a tube box-shaped case (3); a flow guide pipe (22) is arranged in the chamber of the case (3); the downstream end of the flow guide pipe (22) is connected to the liquid outlet pipe (2); a valve plate (211) of an opening and closing valve (21) is arranged at the pipe mouth of the upstream end of the liquid outlet pipe (2); when the valve plate (211) is displaced, the chamber of the case (3) and the upstream end of the flow guide pipe (22) are cut off or connected; a vibration rod (30) is arranged in the flow guide pipe (22); a sensor device (40) is arranged on the shell wall of the case (3) adjacent to the free end of the vibration rod (30); the sensor device (40) collects vibration signals of the vibration rod (30) and outputs the collected vibration signals; a magnet (50) is arranged on the middle section or free end of the vibration rod (30); a magnetic induction coil (51) is arranged on the tube wall adjacent to the magnet (50).

2. The Coriolis flowmeter according to claim 1, characterized in that: A pulse jet (11) is arranged on the tube wall of the flow guide tube (22), the liquid inlet end of the pulse jet (11) is connected to the chamber of the watch case (3), and the jet of the pulse jet (11) is directed to the free end or section of the vibration rod (30).

3. The Coriolis flowmeter according to claim 1, characterized in that: The vibration rod (30) is in the shape of a strip, and the length direction of the vibration rod (30) is consistent with the direction of the core line of the flow guide tube (22).

4. The Coriolis flowmeter according to claim 3, characterized in that: A reduced diameter section (221) is provided at the midstream section of the flow guide pipe (22), and the middle section of the vibration rod (30) is located at the reduced diameter section (221).

5. The Coriolis flowmeter according to claim 4, characterized in that: The magnet (50) is fixed to the middle section of the vibration rod (30), and the magnetic induction coil (51) is arranged on the inner wall or outer wall of the tube of the reduced diameter section (221).

6. The Coriolis flowmeter according to any one of claims 1 to 4, characterized in that: The magnet (50) is fixed at the free end of the vibration rod (30), and the magnetic induction coil (51) is arranged on the shell wall of the watch case (3) at the downstream end of the flow guide tube (22).

7. The Coriolis flowmeter according to claim 6, characterized in that: The sensing device (40) comprises a Wiegand sensor (402) arranged adjacent to the magnet (50), and the Wiegand sensor (402) is fixed on the pipe wall at the downstream end of the flow guide pipe (22).

8. The Coriolis flowmeter according to claim 5, characterized in that: The sensing device (40) comprises a second magnet (401) fixed at the free end of the vibration rod (30) and a Wiegand sensor (402) arranged adjacent to the second magnet (401); the Wiegand sensor (402) is fixed on the wall of the meter case (3) directly facing the downstream end of the flow guide tube (22).

9. The Coriolis flowmeter according to claim 3, characterized in that: The rod core line of the vibration rod (30) coincides with the tube core line of the flow guide tube (22).

10. The Coriolis flowmeter according to claim 1, characterized in that: A support (311) connected to the pipe wall is provided in the flow guide pipe (22). The support is in the shape of a letter "I" or a letter "X" and is horizontally placed in the pipe. The middle section or one end of the vibration rod (30) is fixedly connected to the support (311).

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