Transducer for a vibratory fluid meter

Abstract

A transducer assembly (300) for a vibratory meter having meter electronics (20) is provided. The transducer assembly (300) includes a holder portion (401) including a holder plate (402). A magnet portion (301) includes a coil bobbin (305) and a coil (309) wound around the coil bobbin (305). A magnet (313) is coupled with the coil bobbin (305). The holder plate (402) is prevented from contacting the coil bobbin (305).

Description

Technical Field

[0001] The embodiments described below relate to vibratory meters, and more specifically to transducers for vibratory fluid meters. Background Technology

[0002] Vibratory meters, such as vibratory densitometers and Coriolis flow meters, are commonly known and used to measure the mass flow rate and other information of materials within conduits. The material can be flowing or stationary. Typical Coriolis flow meters are disclosed in U.S. Patents 4,109,524, 4,491,025, and Re. 31,450, all attributed to J.E. Smith et al. These flow meters comprise one or more conduits with straight or curved configurations. Each conduit configuration in a Coriolis mass flow meter has a set of natural vibration modes, which can be simple bending, torsional, or coupled types. Each conduit can be driven to oscillate in a preferred mode.

[0003] Material flows into the flowmeter from the connecting pipe on the inlet side, is guided through the conduit, and exits the flowmeter through the outlet side. The natural vibration mode of the vibrating material-filled system is partially defined by the combined mass of the conduit and the material flowing within it.

[0004] When no flow passes through the flow meter, the driving force applied to the conduit causes all points along the conduit to oscillate with the same phase or a small “zero offset,” which is the time delay measured at zero flow. When material begins to flow through the flow meter, the Coriolis force causes each point along the conduit to have a different phase. For example, the phase at the inlet end of the flow meter lags behind the phase at the centralized actuator location, while the phase at the outlet leads the phase at the centralized actuator location. Detection sensors on the conduit generate sinusoidal signals representing the conduit's motion. The signals output from the detection sensors are processed to determine the time delay between the detection sensors. The time delay between two or more detection sensors is proportional to the mass flow rate of the material flowing through the conduit.

[0005] Metering electronics connected to the actuator generate a drive signal for operating the actuator and determine the mass flow rate and other properties of the material based on signals received from the detection sensor. The actuator can include one of many well-known devices; however, magnets and opposing drive coils have achieved great success in the vibratory metering industry. Examples of suitable drive coil and magnet arrangements are provided in U.S. Patents 7,287,438 and 7,628,083, both of which are nominally assigned to Micro Motion, Inc., and are incorporated herein by reference. Alternating current is supplied to the drive coil to cause the conduit to vibrate at the desired flow rate amplitude and frequency. It is also known in the art to provide the detection sensor as a magnet and coil arrangement very similar to the actuator arrangement. However, when the actuator receives a current that induces motion, the detection sensor can use the motion provided by the actuator to sense a voltage. This voltage is proportional to the conduit displacement. The magnitude of the time delay measured by the detection sensor is very small; typically measured in nanoseconds. Therefore, the transducer output must be very accurate.

[0006] Figure 1 illustrates an example of a prior art vibratory meter 5 in the form of a Coriolis flow meter, which includes a sensor assembly 10 and metering electronics 20. The metering electronics 20 is in electrical communication with the sensor assembly 10 to measure properties of the flowing material, such as density, mass flow rate, volumetric flow rate, total mass flow rate, temperature, and other information.

[0007] The sensor assembly 10 includes a pair of flanges 101 and 101', manifolds 102 and 102', and conduits 103A and 103B. Manifolds 102 and 102' are attached to opposite ends of conduits 103A and 103B. In prior art Coriolis flow meters, flanges 101 and 101' are attached to opposite ends of spacer 106. Spacer 106 maintains the spacing between manifolds 102 and 102' to prevent unwanted vibrations in conduits 103A and 103B. Conduits 103A and 103B extend outward from the manifolds in a generally parallel manner. When the sensor assembly 10 is inserted into a piping system (not shown) that carries a flowing material, the material enters the sensor assembly 10 through the flange 101, passes through the inlet manifold 102—the total amount of material is directed at the inlet manifold 102 to enter conduits 103A and 103B, flows through conduits 103A and 103B and returns to the outlet manifold 102', and the material exits the sensor assembly 10 through the flange 101' at the outlet manifold 102'.

[0008] The prior art sensor assembly 10 includes an actuator 104. For example, the actuator 104 is attached to conduits 103A and 103B at locations where it can cause the conduits 103A and 103B to vibrate in a driven mode. More specifically, the actuator 104 includes a first actuator component 104A attached to conduit 103A and a second actuator component 104B attached to conduit 103B. The actuator 104 can include one of many well-known arrangements, such as a coil mounted to conduit 103A and an opposing magnet mounted to conduit 103B.

[0009] In the current example of a prior art Coriolis flowmeter, the drive mode is a first out-of-phase bending mode, and conduits 103A and 103B are selected and properly mounted to inlet manifold 102 and outlet manifold 102' to provide a balancing system having substantially the same mass distribution, moment of inertia, and elastic modulus about bending axes WW and W'-W', respectively. In this example, with the drive mode being the first out-of-phase bending mode, conduits 103A and 103B are driven by driver 104 in opposite directions about their respective bending axes WW and W'-W'. The drive signal, in alternating current form, can be provided by metering electronics 20, for example via path 110 and through a coil, to cause the two conduits 103A and 103B to oscillate. Those skilled in the art will understand that prior art Coriolis flowmeters can use other drive modes.

[0010] The illustrated sensor assembly 10 includes a pair of detectors 105, 105' attached to conduits 103A, 103B. More specifically, first detector components 105A and 105'A are located on the first conduit 103A, and second detector components 105B and 105'B are located on the second conduit 103B. In the described example, detectors 105, 105' may be electromagnetic detectors, such as detector magnets and detector coils that generate detector signals representing the velocity and position of conduits 103A, 103B. For example, detectors 105, 105' may provide detector signals to metering electronics 20 via paths 111, 111'. It will be understood by those skilled in the art that the movement of conduits 103A, 103B is generally proportional to certain properties of the flowing material, such as the mass flow rate and density of the material flowing through conduits 103A, 103B. However, the movement of catheters 103A and 103B also includes a zero-flow delay or offset that can be measured at detectors 105 and 105'. Zero-flow offset can be caused by many factors, such as non-proportional damping, residual flexible response, electromagnetic crosstalk, or phase delay in the instrument.

[0011] In the prior art, sensor assemblies 103, 104, and 105 are aligned on the coil axis to minimize the air gap in the magnetic circuit and maximize the coupling between the magnet and the coil field. Typically, the retainer assembly is mounted to the first conduit, while the coil assembly is mounted to the second conduit (the arrangement differs for single-conduit instruments). The retainer and coil must be carefully installed to maximize the clearance between components.

[0012] Unfortunately, the coil and retainer assemblies can come into contact under certain conditions, resulting in damage to the flow meter and potential malfunction. For example, manufacturing deviations can cause axial misalignment. In another case, fluid traveling through a conduit beyond the mating conduit can cause inertial forces and relative lateral movement between the pipes, leading to contact between the magnet / coil / retainer and resulting in assembly damage. In yet another example, temperature differences can cause contact between the coil and retainer assemblies. Hot fluid flowing through a conduit significantly earlier than the time it would have flowed through the mating conduit can cause uneven conduit expansion exceeding the coil / retainer clearance limits, resulting in contact.

[0013] Therefore, as can be understood, conventional transducer assemblies are susceptible to damage due to misalignment in many situations that may occur during normal instrument operation. There is a need in the art for a transducer assembly that is unaffected by misalignment and the resulting damage. The embodiments described below overcome these and other problems and represent an advancement in the art. Summary of the Invention

[0014] A transducer assembly for a vibratory meter with metering electronics is provided. The transducer assembly includes a retainer portion comprising a retainer plate. The transducer assembly also includes a magnet portion comprising a coil spool, a coil wound around the coil spool, and a magnet coupled to the coil spool, wherein the retainer plate is prevented from contacting the coil spool.

[0015] A method is provided for forming a vibratory meter including a sensor assembly having one or more flow conduits. The method includes the steps of: forming a retainer portion including a retainer plate and coupling the retainer portion to a first component of the vibratory meter; forming a magnet portion including a coil spool and coupling the magnet portion to a second component of the vibratory meter; winding a coil around the coil spool; coupling a magnet to the coil spool; placing the retainer plate adjacent to the magnet; and electrically connecting the coil to meter electronics.

[0016] In terms of invention

[0017] According to one aspect, a transducer assembly for a vibratory meter with metering electronics includes a retainer portion comprising a retainer plate. The transducer assembly also includes a magnet portion comprising a coil spool, a coil wound around the coil spool, and a magnet coupled to the coil spool, wherein the retainer plate is prevented from contacting the coil spool.

[0018] Preferably, a flux loop is provided that surrounds at least a portion of the coil bobbin.

[0019] Preferably, a flux loop is provided that surrounds at least a portion of the coil.

[0020] Preferably, the magnet is connected to the coil spool using pole pieces.

[0021] Preferably, the magnet is a permanent magnet.

[0022] Preferably, the coil spool, coil, and magnet are fixed in place relative to each other.

[0023] Preferably, the metering electronics supply an oscillating current to the coil, which induces movement in the retainer plate.

[0024] Preferably, the retainer portion and the magnet portion are respectively connected to the first portion and the second portion of the vibratory meter, wherein at least one of the first portion and the second portion of the vibratory meter includes a flow conduit.

[0025] According to one aspect, a method for forming a vibratory meter including a sensor assembly having one or more flow conduits includes the following steps: forming a retainer portion including a retainer plate and connecting the retainer portion to a first component of the vibratory meter; forming a magnet portion including a coil spool and connecting the magnet portion to a second component of the vibratory meter; winding a coil around the coil spool; connecting a magnet to the coil spool; placing the retainer plate adjacent to the magnet and electrically connecting the coil to meter electronics.

[0026] Preferably, the first component and the second component include at least one flow conduit.

[0027] Preferably, the method includes the step of surrounding at least a portion of the coil spool with a flux loop.

[0028] Preferably, the method includes the step of connecting a magnet to a coil using pole pieces.

[0029] Preferably, the method includes the step of fixing the coil spool, coil, and magnet in place relative to each other.

[0030] Preferably, the method includes the step of providing an oscillating current to the coil, which induces movement of the retainer plate.

[0031] Preferably, the method includes the step of receiving an oscillating current from the coil, wherein the oscillating current is induced by the movement of the retainer plate. Attached Figure Description

[0032] Figure 1 shows a fluid meter of the prior art.

[0033] Figure 2 shows a cross-sectional view of a prior art transducer assembly.

[0034] Figure 3 The magnet portion of a transducer assembly according to an embodiment is shown.

[0035] Figure 4 The retainer portion of a transducer assembly according to an embodiment is shown.

[0036] Figure 5 A cross-sectional view of a transducer assembly according to an embodiment is shown. Detailed Implementation

[0037] Figures 3 to 5 The following description illustrates specific examples to teach those skilled in the art how to manufacture and use the best mode of implementation for the transducer. Some conventional aspects have been simplified or omitted for the purpose of teaching the principles of the invention. Those skilled in the art will understand variations arising from these examples falling within the scope of this specification. Those skilled in the art will understand that the features described below can be combined in various ways to form multiple variations of the fluid meter. Therefore, the embodiments described below are not limited to the specific examples described below, but are limited only by the claims and their equivalents.

[0038] Figure 2 shows a cross-sectional view of a prior art transducer assembly 200. This transducer assembly 200 can be coupled to a first flow conduit 103A and a second flow conduit 103B. The prior art transducer assembly 200 includes a coil portion 204A and a magnet portion 204B. The magnet portion 204B includes a magnet 211. The magnet 211 can be positioned within a magnet holder 213 that helps guide the magnetic field. The magnet portion 204B may also include pole pieces 215. The magnet portion 204B includes a typical magnet portion of a prior art sensor assembly. The magnet portion 204B can be coupled to the second flow conduit 103B via a mounting bracket (not shown for clarity). The mounting bracket can be coupled to the flow conduit 103B using well-known techniques such as welding, brazing, or joining.

[0039] The coil portion 204A can be connected to the first flow conduit 103A via a mounting bracket (not shown for clarity). The mounting bracket can be connected to the flow conduit 103A using well-known techniques such as welding, brazing, or joining.

[0040] The coil portion 204A also includes a coil spool 220. The coil spool 220 may include a magnet receiving portion 220' for receiving at least a portion of the magnet 211. The coil spool 220 includes a coil 222. The coil spool 220 may be secured to the mounting bracket 210 by a fastening device.

[0041] Figure 3 A transducer assembly 300 according to an embodiment is shown (in Figure 5 The magnet portion 301 (shown in cross-section) is shown. A bracket 303 is attached to a coil spool 305. The bracket 303 can be joined to the coil spool 305 using mechanical fasteners, adhesives, welding / brazing, or other methods known in the art. The specific methods used to join the coil spool 305 to the bracket 303 should not limit the scope of this embodiment. In this embodiment, the bracket 303 and the coil spool 305 are formed from the same material. The bracket 303 and the coil spool 305 can be formed by machining operations, casting / forming operations, 3D printing, or similar additive manufacturing methods.

[0042] The coil spool 305 can be made of plastic, ceramic, polymer, or other non-magnetic materials. In one embodiment, the coil spool 305 can be made of ferrous material. A flux ring 307 can surround a portion of the coil spool 305. The flux ring 307 can also surround the coil 309 (see...). Figure 5 Part or all of the coil 309 is wound around the coil spool 305. The flux ring 307 may be formed of carbon steel or other metal and helps to isolate the electric field associated with the various wires in the system. The pole piece 311 is attached to the inner diameter of the coil spool 305 and moves with the coil spool 305 to form part of the magnetic circuit. The magnet 313 is attached to the pole piece 311 and moves with the pole piece 311 / spool 305 to form part of the magnetic circuit.

[0043] The axial position of the pole is optimized to maximize the coupling between the coil and the pole, and the thickness of the spool hub is minimized to maximize the coupling between the coil and the pole. As those skilled in the art will understand, the precise dimensions used to achieve these optimizations vary depending on the size of the component, the size of the spool, the number of coil windings, the strength of the magnet, the slew rate of the transducer, etc.

[0044] Figure 4 and Figure 5 It shows ( Figure 5 The transducer assembly 300 (shown) includes a retainer portion 401. A retainer plate 402 is attached to a bracket 403. The bracket 403 can be attached to the retainer plate 402 using mechanical fasteners, adhesives, welding / brazing, or other methods known in the art. The specific methods used to attach the retainer plate 402 to the bracket 403 should not limit the scope of this embodiment.

[0045] Therefore, it will be understood that this is significantly different from prior art transducers, as almost all components of the proposed transducer assembly 300 are arranged on a single side / support. That is, the magnet 313 and pole piece 311, which interact magnetically with the coil 309 / coil spool 305, are not only located on the same support 303, but are also fixed in place relative to each other.

[0046] In this embodiment, magnet 313 is a permanent magnet, but an electromagnet could also be considered. The magnet in the proposed invention will generate a magnetic circuit through adjacent components and attract the retainer plate 402. The oscillating current through coil 309 will increase / decrease the force on retainer plate 402 that causes it to oscillate. Transducer assembly 300 is configured such that it can function as both an actuator and a detection sensor. The transducer circuit will operate in the same mechanical manner as in the prior art, but with an output voltage proportional to the magnet / retainer plate gap. Thus, the present invention will function as in existing actuator and detection circuits, but eliminates the aforementioned problems related to coil / retainer positioning issues and sources of misalignment and lateral movement.

[0047] Transducer assembly 300 is typically coupled to a dual-flow duct transducer assembly. In other embodiments, one of portions 303, 403 may be coupled to, for example, a fixed component, a dummy tube, a counterweight, or a housing component. This may also be the case when the combined transducer assembly 300 is used in a single-flow duct sensor assembly.

[0048] Although not shown for clarity, it should be understood that the metering electronics 20 can communicate with a wire similar to wire 110 shown in FIG. 1. Therefore, when communicating electrically with the metering electronics 20, a drive signal can be provided to the transducer assembly 300 to generate movement between the magnet portion 301 and the holder portion 401. Similarly, the transducer assembly 300 can communicate with the metering electronics 20 using a wire similar to one of wires 111, 111' shown in FIG. 1. Therefore, when communicating electrically with the metering electronics, the transducer assembly 300 can sense movement between the magnet portion 301 and the holder portion 401.

[0049] Vibratory meters, such as the one shown in Figure 1, may include a transducer assembly 300. The vibratory meter may include a Coriolis flow meter or some other vibratory meter. The vibratory meter can accept flowing or stationary fluids. The fluid may include gases, liquids, gases with suspended particles, liquids with suspended particles, multiphase fluids, or combinations thereof.

[0050] The detailed description of the above embodiments is not an exhaustive description of all embodiments that the inventors intended to fall within the scope of this specification. In fact, those skilled in the art will recognize that certain elements in the above embodiments can be combined differently or removed to produce other embodiments, and such other embodiments fall within the scope and teachings of this specification. It will also be apparent to those skilled in the art that the above embodiments can be combined, in whole or in part, to produce other embodiments within the scope and teachings of this specification.

[0051] Therefore, although specific embodiments have been described herein for illustrative purposes, various equivalent modifications are possible within the scope of this specification, as will be recognized by those skilled in the art. The teachings provided herein can be applied to other fluid gauges, not only those described above and shown in the accompanying drawings. Therefore, the scope of the embodiments should be determined by the appended claims.

Claims

1. A transducer assembly (300) for a vibration meter having metering electronics (20), the transducer assembly (300) comprising: The retainer portion (401) includes a retainer plate (402). The magnet portion (301) includes: Coil spool (305); A coil (309) is wound around a coil bobbin (305); A magnet (313) is connected to the coil spool (305), wherein the magnet (313) is connected to the coil spool (305) by means of a pole piece (311). A flux ring (307) is positioned between the coil spool (305) and the retainer plate (402), the flux ring (307) preventing the retainer plate (402) from contacting the coil spool (305). The retainer plate (402) is prevented from contacting the coil spool (305), the magnet (313), and the pole piece (311).

2. The transducer assembly (300) according to claim 1, wherein, The flux ring (307) is configured to surround at least a portion of the coil bobbin (305).

3. The transducer assembly (300) according to claim 1, wherein, The flux ring (307) is configured to surround at least a portion of the coil (309).

4. The transducer assembly (300) according to claim 1, wherein, The magnet (313) is a permanent magnet.

5. The transducer assembly (300) according to claim 1, wherein, The coil spool (305), the coil (309), and the magnet (313) are fixed in place relative to each other.

6. The transducer assembly (300) according to claim 1, wherein, The metering electronics (20) provides an oscillating current to the coil (309), which induces movement in the retainer plate (402).

7. The transducer assembly (300) according to claim 1, wherein, The retainer portion (401) and the magnet portion (301) are respectively connected to the first portion and the second portion of the vibrating meter, wherein at least one of the first portion and the second portion of the vibrating meter includes a flow conduit (103A, 103B).

8. A method for forming a vibratory meter including a sensor assembly having one or more flow conduits, the method comprising the steps of: Forming a retainer portion including a retainer plate; Connect the retainer portion to the first component of the vibratory meter; Forming a magnetic portion including a coil spool; Connect the magnet portion to the second component of the vibratory meter; The coil is wound around the coil spool; Connect the magnet to the coil spool; The magnet is connected to the coil using pole pieces; The retainer plate is positioned adjacent to the magnet; A flux loop is provided, the flux loop being positioned between the coil bobbin and the retainer plate. The flux ring is used to prevent the retainer plate from contacting the coil spool, the magnet, and the pole pieces; and The coil is electrically connected to the metering electronics.

9. The method according to claim 8, wherein, The first component and the second component include at least one flow conduit.

10. The method of claim 8, further comprising the step of surrounding at least a portion of the coil spool with the flux loop.

11. The method of claim 8, further comprising the step of fixing the coil spool, the coil, and the magnet in place relative to each other.

12. The method of claim 8, further comprising the step of providing an oscillating current to the coil, the oscillating current inducing movement of the retainer plate.

13. The method of claim 8, further comprising the step of receiving an oscillating current from the coil, wherein, The oscillating current is induced by the movement of the retainer plate.

Images