Variable mass balance bar

Abstract

A variable mass balance rod (120-320, 520-820) is provided. The variable mass balance rod (120-320, 520-820) includes a balance body (122-322b, 522-822) containing a balance fluid (124-324b, 524-824), wherein the mass of the balance fluid (124-324b, 524-824) is selected to balance a measurement conduit (110-310, 510-810) containing a process material.

Description

Technical Field

[0001] The embodiments described below relate to balance poles, and more particularly to variable mass balance poles. Background Art

[0002] Vibration sensors, such as vibrating densitometers and Coriolis vibrometers, are well known and are used to measure mass flow and other information about a material flowing through a measuring conduit in the vibrator. Exemplary Coriolis vibrometers are disclosed in U.S. Patents 4,109,524, 4,491,025, and Re. 31,450, all to J.E. Smith et al. These vibrators have one or more measuring conduits in straight or curved configurations. For example, each measuring conduit configuration in a Coriolis mass vibrator has a set of natural vibration modes; each measuring conduit configuration can be a simple bending, torsional, or coupled type. Each measuring conduit can be driven to oscillate in a preferred mode.

[0003] Material flows into the vibrating meter from a connecting pipe on the inlet side of the vibrating meter, is guided through a measuring conduit, and exits the vibrating meter through the outlet side of the vibrating meter. The natural vibration modes of the vibrating system are defined in part by the combined mass of the measuring conduit and the material flowing within the measuring conduit.

[0004] When there is no flow through the vibrometer, the driving force applied to the measuring conduit causes all points along the measuring 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 vibrometer, the Coriolis force causes each point along the measuring conduit to have a different phase. For example, the phase at the inlet end of the vibrometer lags the phase at the centered driver position, while the phase at the outlet leads the phase at the centered driver position. Detectors on the measuring conduit produce sinusoidal signals representing the movement of the measuring conduit. The signals output from the detectors are processed to determine the time delay between the detectors. The time delay between two or more detectors is proportional to the mass flow rate of the material flowing through the measuring conduit.

[0005] Meter electronics connected to the driver generate drive signals to operate the driver and determine the mass flow rate and other properties of the material based on the signals received from the detector. The driver can include one of many known arrangements; however, magnets and counter-drive coils have been used with great success in the vibrometer industry. Alternating current is delivered to the drive coil to cause the measuring conduit to vibrate at the desired measuring conduit amplitude and frequency. It is also known in the art to set up the detector with a magnet and coil arrangement that is very similar to the driver arrangement. However, when the driver receives a current that induces motion, the detector can use the motion provided by the driver to induce a voltage.

[0006] Figure 1 A cross-section of a prior art vibrating meter 1 is disclosed. The vibrating meter 1 includes a housing 6 enclosing a balance bar 2 with an end 4, and a measuring conduit 101. The ends of the measuring conduit 101 extend beyond housing ends 7 and 8 of the housing 6 to flanges (not shown), which enable the vibrating meter 1 to be connected to a pipeline whose material flow is to be measured. The flow of the process material to be measured is illustrated by arrows 111 and 112. Meter electronics 5 are connected to the vibrating meter 1 via conductors 22, 23, and 24 to control its operation and receive output signals from detectors (velocity sensors) LPO and RPO. The meter electronics processes the received information and transmits output information representing the material flow via conductor 26 to application circuitry (not shown). The meter electronics 5 applies a signal to a driver D (having a corresponding magnet M) via conductor 23. Driver D vibrates the measuring conduit 101 and the balance bar 2 in anti-phase in a known manner. The vibrations of the measuring conduit 101 and the material flow induce a Coriolis response in the measuring conduit 101. The amplitude of the Coriolis response represents the material flow rate and is detected by the detectors LPO and RPO (detectors LPO and RPO have magnets M). The detectors LPO and RPO transmit their output signals via conductors 22 and 24 to the meter electronics 5, which determines the phase difference between the output signals of the two detectors. This phase difference is proportional to the flow rate.

[0007] However, for a given density of the material in the measurement conduit 101, the measurement conduit 101 of the prior art vibrator 1 can be balanced by the balance bar 2. That is, the prior art vibrator 1 is designed to provide accurate measurements of materials with a density within a design density range. If the density of the material is substantially greater than or less than the design density, the measurement result may be inaccurate. For example, if the density of the material is outside the tolerance range of the design density, the measurement result of the material density may be inaccurate. The design density and the corresponding tolerance range may have a constant mass due to the balance bar 2. Therefore, a variable-mass balance bar is required. Summary of the Invention

[0008] A variable mass balance rod is provided. According to an embodiment, the variable mass balance rod comprises a balancing body containing a balancing fluid, wherein the mass of the balancing fluid is selected to balance a measuring conduit containing a process material.

[0009] A vibrating meter having a variable mass balance bar is provided. According to an embodiment, the vibrating meter includes a measuring conduit and a variable mass balance bar mechanically coupled to the measuring conduit. The mass of the variable mass balance bar is selected to balance the measuring conduit containing process material.

[0010] A system is provided that includes a vibrating meter including a variable-mass balance bar. According to an embodiment, the system includes a vibrating meter that includes a measurement conduit and a variable-mass balance bar mechanically coupled to the measurement conduit. The mass of the variable-mass balance bar is selected to balance the measurement conduit containing a process material.

[0011] A method for balancing a measurement conduit with a variable mass balancing rod is provided. According to an embodiment, the method comprises selecting a mass of a balancing fluid to balance a measurement conduit containing a process material and providing the balancing fluid to a balancing body.

[0012] All aspects

[0013] According to one aspect, a variable mass balance bar (120-320, 520-820) includes a balance body (122-322b, 522-822) containing a balance fluid (124-324b, 524-824), wherein the mass of the balance fluid (124-324b, 524-824) is selected to balance a measurement conduit (110-310, 510-810) containing a process material.

[0014] Preferably, the mass of the balancing fluid (124-324b, 524-824) is selected by selecting the density of the balancing fluid (124-324b, 524-824).

[0015] Preferably, the resonance frequency of the balancing body (122-322b, 522-822) containing the balancing fluid (124-324b, 524-824) is equal to the resonance frequency of the measuring conduit (110-310, 510-810) containing the process material.

[0016] Preferably, the mass of the balancing body (122~322b, 522~822) is equal to the mass of the measuring catheter (110~310, 510~810) and is not equal to the mass of the measuring catheter (110~310, 510~810), and the stiffness of the balancing body is equal to the stiffness of the measuring catheter (110~310, 510~810) and is not equal to the stiffness of the measuring catheter (110~310, 510~810).

[0017] Preferably, the balancing body (122-322b, 522-822) is configured to be mechanically coupled to the measuring conduit (110-310, 510-810).

[0018] Preferably, the balancing fluid (124-324b, 524-824) is a non-process material.

[0019] Preferably, the balancing body (122-322b, 522-822) includes: at least one inlet configured to receive the balancing fluid (124-324b, 524-824); and at least one outlet configured to provide the balancing fluid (124-324b, 524-824).

[0020] Preferably, the mass of the balance fluid (124-324b, 524-824) is between the at least one inlet and the at least one outlet.

[0021] According to one aspect, a vibrating meter (100-300, 500-800) having a variable-mass balance bar (120-320, 520-820) includes a measuring conduit (110-310, 510-810) and a variable-mass balance bar (120-320, 520-820) mechanically coupled to the measuring conduit (110-310, 510-810). The mass of the variable-mass balance bar (120-320, 520-820) is selected to balance the measuring conduit (110-310, 510-810) containing a process material.

[0022] Preferably, the mass of the variable mass balance bar (120-320, 520-820) is selected by selecting the mass of the balance fluid (124-324b, 524-824) of the variable mass balance bar (120-320, 520-820).

[0023] Preferably, the resonant frequency of the variable mass balance bar (120-320, 520-820) is equal to the resonant frequency of the measurement conduit (110-310, 510-810) containing the process material.

[0024] Preferably, the mass of the variable mass balance rod (120-320, 520-820) is equal to or not equal to the mass of the measuring conduit (110-310, 510-810) accommodating the process material, and the stiffness of the variable mass balance rod (120-320, 520-820) is equal to or not equal to the stiffness of the measuring conduit (110-310, 510-810) accommodating the process material.

[0025] Preferably, the variable mass balance rod (120-320, 520-820) comprises at least one inlet and at least one outlet, wherein the mass of the variable mass balance rod (120-320, 520-820) is between the inlet and the outlet.

[0026] Preferably, the mass of the variable mass balance rod (120-320, 520-820) is selected by selecting the density of the variable mass balance rod (120-320, 520-820).

[0027] Preferably, the vibrating meter (700, 800) further includes at least one balance sensor (780, 880) mechanically coupled to the variable mass balance bar (720, 820) and the reference structure (760, 860b) of the vibrating meter (700, 800).

[0028] Preferably, the vibrating meter (700, 800) further includes meter electronics (750, 850) communicatively coupled to the at least one balance sensor (780, 880), the meter electronics (750, 850) configured to determine whether the variable mass balance bar (720, 820) balances the measurement conduit (710, 810) containing the process material.

[0029] Preferably, the meter electronics (750, 850) configured to determine whether the variable mass balance bar (720, 820) balances the measurement conduit (710, 810) containing the process material includes the meter electronics (750, 850) configured to determine whether a resonant frequency of the measurement conduit (710, 810) containing the process material is equal to a resonant frequency of the variable mass balance bar (720, 820).

[0030] According to one aspect, a system (400, 900) including a vibrating meter (100') having a variable mass balance bar (120) includes a vibrating meter (100, 100') including a measurement conduit (110) and a variable mass balance bar (120) mechanically coupled to the measurement conduit (110), wherein the mass of the variable mass balance bar (120) is selected to balance the measurement conduit (110) containing a process material.

[0031] Preferably, the mass of the variable mass balance bar (120) is selected by selecting the mass of the balance fluid (124) of the variable mass balance bar (120).

[0032] Preferably, the resonant frequency of the variable mass balance bar (120) is equal to the resonant frequency of the measurement conduit (110) containing the process material.

[0033] Preferably, the mass of the variable mass balance rod (120) is equal to or unequal to the mass of the measuring conduit (110) containing the process material, and the stiffness of the variable mass balance rod (120) is equal to or unequal to the stiffness of the measuring conduit (110).

[0034] Preferably, the variable mass balance bar (120) comprises at least one inlet and at least one outlet, wherein the mass of the variable mass balance bar (120) is between the inlet and the outlet.

[0035] Preferably, the mass of the variable mass balance bar (120) is selected by selecting the density of the variable mass balance bar (120).

[0036] Preferably, the system (400, 900) further comprises at least one balance sensor (980), the at least one balance sensor (980) being mechanically coupled to the variable mass balance bar (120) and the reference structure (160, 160a, 160b).

[0037] Preferably, the system (900) further includes metrology electronics (150) communicatively coupled to the at least one balance sensor (980), the metrology electronics (150) configured to at least one of determine whether the variable mass balance bar (120) balances the measurement conduit (110) containing the process material and select a mass of the variable mass balance bar (120).

[0038] Preferably, the meter electronics (150) is configured to determine whether the variable mass balance bar (120) balances the measurement conduit (110) containing the process material includes the meter electronics (150) being configured to determine whether a resonant frequency of the measurement conduit (110) containing the process material is equal to a resonant frequency of the variable mass balance bar (120).

[0039] Preferably, the meter electronics (150) being configured to select the mass of the variable mass balance bar (120) includes the meter electronics (150) being configured to select the mass of the balancing fluid (124) of the variable mass balance bar (120) by at least one of controlling the density of the balancing fluid (124) of the variable mass balance bar (120) and controlling the volume of the balancing fluid (124) of the variable mass balance bar (120).

[0040] Preferably, the system (900) further includes an accelerometer (990) coupled to the reference structure (160, 160a, 160b) and communicatively coupled to the meter electronics (150), wherein the accelerometer (990) is configured to sense vibrations of the reference structure (160, 160a, 160b).

[0041] Preferably, the meter electronics (150) configured to determine whether the variable mass balance bar (120) balances the measurement conduit (110) includes the meter electronics (150) configured to determine whether a reference structure (160, 160a, 160b) of the vibrating meter (100) is vibrating due to the variable mass balance bar (120) not balancing the measurement conduit (110) containing the process material.

[0042] Preferably, the system (400, 900) further comprises a mixer (402, 902) fluidly coupled to the variable mass balancing rod (120), the mixer (402, 902) being configured to mix the plurality of balancing fluid components into a balancing fluid (124) and provide the balancing fluid (124) to the variable mass balancing rod (120).

[0043] According to one aspect, a method of balancing a measurement conduit with a variable mass balance bar includes selecting a mass of a balancing fluid to balance a measurement conduit containing a process material; and providing the balancing fluid to a balancing body.

[0044] Preferably, selecting the mass of the balancing fluid to balance the measurement conduit containing the process material comprises selecting the density of the balancing fluid.

[0045] Preferably, the resonance frequency of the balancing body containing the balancing fluid is equal to the resonance frequency of the measuring conduit containing the process material.

[0046] Preferably, the mass of the balancing body is one of equal to and unequal to the mass of the measuring tube, and the stiffness of the balancing body is one of equal to and unequal to the stiffness of the measuring tube.

[0047] Preferably, the method further comprises configuring the balancing body to be mechanically coupled to the measuring conduit.

[0048] Preferably, the balancing fluid is a non-process material.

[0049] Preferably, providing the balancing fluid to the balancing body comprises providing the balancing fluid to at least one inlet configured to receive the balancing fluid.

[0050] Preferably, the method further comprises coupling at least one balance sensor to the variable mass balance bar and the reference structure of the vibrating meter.

[0051] Preferably, the method further comprises using a balance sensor to determine whether the variable mass balance rod balances the measurement conduit containing the process material.

[0052] Preferably, using the balance sensor to determine whether the variable mass balance bar balances the measurement conduit containing the process material comprises using the balance sensor to determine whether a resonant frequency of the measurement conduit is equal to a resonant frequency of the variable mass balance bar.

[0053] Preferably, the method further comprises coupling an accelerometer to the reference structure and sensing vibrations of the reference structure with the accelerometer.

[0054] Preferably, the method further comprises determining whether the reference structure is vibrating due to the variable mass balance bar not balancing the measurement conduit containing the process material.

[0055] Preferably, providing the balancing fluid to the balancing body comprises mixing a plurality of balancing fluid components into the balancing fluid and providing the balancing fluid to the balancing body. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The same reference numerals represent the same elements throughout the drawings.It should be understood that the drawings are not necessarily drawn to scale.

[0057] Figure 1 A cross section of a prior art vibrating meter 1 is disclosed, which has a housing 6 enclosing a balance bar 2 and a measuring duct 101 .

[0058] Figure 2 A vibrating meter 100 including a variable mass balance bar 120 is shown.

[0059] Figure 3A and Figure 3B An alternative variable mass balance bar in a vibrating meter is shown, for clarity, Figure 3A and Figure 3B No metering electronics or detection sensors are depicted.

[0060] Figure 4 A system 400 is shown having a vibrating meter 100 including a variable mass balance bar 120 .

[0061] Figure 5 A vibrating meter 500 including a variable mass balance bar 520 is shown.

[0062] Figure 6A and Figure 6B A vibrating meter 600 having a variable mass balance bar 620 is shown.

[0063] Figure 7 and Figure 8 A vibrating meter including a variable mass balance bar and a balance sensor is shown.

[0064] Figure 9 A system 900 is shown having a vibrating meter 100 ′ including a variable mass balance bar 120 .

[0065] Figure 10 A method 1000 of balancing a measurement catheter using a variable mass balance bar is shown. DETAILED DESCRIPTION

[0066] Figures 1 to 10 The following description depicts specific examples to teach those skilled in the art how to make and use the best mode of implementing a variable-mass balance beam. For the purpose of teaching the inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate that variations from these examples fall within the scope of this description. Those skilled in the art will appreciate that the features described below can be combined in various ways to form numerous variations of the variable-mass balance beam. Therefore, the embodiments described below are not limited to the specific examples described below, but are limited only by the claims and their equivalents.

[0067] Vibration meter

[0068] Figure 2 A vibrating meter 100 is shown including a variable mass balance bar 120. Figure 2 As shown in FIG, the variable mass balance rod 120 is adjacent to the measurement conduit 110, which is shown to have a Figure 1 The measuring tube 101 shown in FIG has different dimensions. Although not shown in FIG. Figure 2 , but the end of the measurement conduit 110 and the end of the variable mass balance rod 120 may be rigidly coupled together by a coupling which in turn is coupled to the housing, which is not shown for clarity. Figure 2As shown in FIG, the flow of process material measured by the measuring conduit 110 is illustrated by arrows 111 , 112 .

[0069] The left pickoff sensor 130a, the right pickoff sensor 130b, and the driver 140 are disposed between and coupled to the measurement conduit 110 and the variable mass balance rod 120. The left pickoff sensor 130a, the right pickoff sensor 130b, and the driver 140 are shown as being communicatively coupled to meter electronics 150. As will be described in more detail below, the meter electronics 150 can provide drive signals to the driver 140 and receive sensor signals from the left pickoff sensor 130a and the right pickoff sensor 130b to measure properties of the material in the measurement conduit 110, such as density, mass flow rate, etc. As will also be described below with reference to Figure 9 To describe in more detail, meter electronics 150 may be communicatively coupled to other devices.

[0070] like Figure 2 As shown in FIG, measurement conduit 110 is a straight cylindrical tube, but any suitable shape may be employed. For example, alternative measurement conduits may be arcuate, curved, or the like. Measurement conduit 110 is shown as having an outer diameter. As illustrated by the dashed lines, measurement conduit 110 also has an inner diameter. Measurement conduit 110 is configured to oscillate when subjected to a vibration force, such as provided by driver 140. The vibration oscillates at a resonant frequency and is balanced by variable mass balance bar 120.

[0071] The variable mass balance rod 120 has a mass that can be selected to balance the measurement conduit 110. For example, the density of the variable mass balance rod 120 can be selected to balance the measurement conduit 110. The variable mass balance rod 120 includes a balancing body 122. Figure 2 As shown in FIG, the balancing body 122 has the shape of a straight cylindrical tube, the wall thickness of which is defined by the cylindrical inner surface. The balancing body 122 can be made of the same, similar or different material as the measuring conduit 110 and / or have the same, similar or different shape as the measuring conduit 110. Figure 2 As shown in FIG, balancing body 122 has approximately the same length as measurement conduit 110 and has an outer diameter smaller than that of measurement conduit 110. Balancing body 122 also includes an inner diameter (illustrated by dashed lines) of a cylindrical inner surface extending along the length of variable mass balancing rod 120.

[0072] The variable-mass balance bar 120 also includes a balancing fluid 124. The balancing fluid 124 is shown by arrows as entering and exiting the variable-mass balance bar 120. More specifically, the balancing fluid 124 is shown as entering the balancing body 122 at an inlet near the inlet arrow, being delivered by the balancing body 122, and being provided by the balancing body 122 at an outlet near the outlet arrow. Thus, the balancing fluid 124 can fill the space formed by the cylindrical inner surface of the balancing body 122. The balancing fluid 124 has properties that can ensure that the variable-mass balance bar 120 balances the measurement conduit 110. Therefore, even if the density of the process material may vary, the measurement of the properties of the process material in the measurement conduit 110 can be accurate.

[0073] Although Figure 2 The variable mass balance rod 120 shown in the figure is a single straight cylindrical tube arranged adjacent to the measuring conduit 110, but alternative shapes and / or configurations can be used. For example, other variable mass balance rods can include two or more variable mass balance rods arranged around the measuring tube, one or more variable mass balance rods partially or completely surrounding the measuring tube, etc. Additionally or alternatively, other variable mass balance rods can have non-circular cross-sectional shapes, such as oval, triangular, square, etc. cross-sectional shapes. Other variable mass balance rods can also have different geometric structures, such as bow-shaped, curved, U-shaped, etc. Geometric structures. Refer to the following Figure 3A and Figure 3B Some exemplary alternative configurations are discussed.

[0074] Variable mass balance bar

[0075] Figure 3A and Figure 3B An alternative variable mass balance bar in a vibrating meter is shown, for clarity, Figure 3A and Figure 3B No metering electronics or detection sensors are depicted. Figure 3A A first alternative vibration meter 200 is shown including a measurement conduit 210 disposed within and surrounded by a cylindrical variable-mass balance bar 220. The cylindrical variable-mass balance bar 220 includes a cylindrical balancing body 222 and a balancing fluid 224 contained within the cylindrical balancing body 222. The balancing fluid 224 is shown entering the cylindrical balancing body 222 at an inlet near the inlet arrow, being conveyed by the cylindrical balancing body 222, and being provided by the cylindrical balancing body 222 at an outlet near the outlet arrow.

[0076] Figure 3BA second alternative vibration meter 300 is shown, including a measurement conduit 310 disposed within a dual variable mass balance bar 320. The dual variable mass balance bar 320 includes a first half variable mass balance bar 320a and a second half variable mass balance bar 320b. The first half variable mass balance bar 320a includes a first half balancing body 322a and a first half balancing fluid 324a. The second half variable mass balance bar 320b includes a second half balancing body 322b and a second half balancing fluid 324b. Therefore, the balancing fluid includes a first half balancing fluid 324a and a second half balancing fluid 324b contained within the first half balancing body 322a and the second half balancing body 322b, respectively. The first half balancing fluid 324a and the second half balancing fluid 324b are shown as entering the first half balancing body 322a and the second half balancing body 322b at the inlet near the inlet arrow, being transported by the first half balancing body 322a and the second half balancing body 322b, and being provided by the first half balancing body 322a and the second half balancing body 322b at the outlet near the outlet arrow.

[0077] Variable mass balance bar

[0078] A variable mass balance bar, such as the variable mass balance bars 120, 220, 320 described above, may include an inlet and an outlet. Figures 2 to 3B In the embodiment of the present invention, the variable mass balancing rod 120, 220, 320 receives its respective balancing fluid 124, 224, 324a, 324b at an inlet near arrow 111. The received balancing fluid 124, 224, 324a, 324b is delivered by the balancing body 122, 222, 322a, 322b to an outlet near arrow 112. The balancing fluid 124, 224, 324a, 324b is contained by the respective inner surfaces of the balancing body 122, 222, 322a, 322b. As can be appreciated, the inlet and outlet of the variable mass balancing rod 120, 220, 320 are located at the ends of the variable mass balancing rod 120, 220, 320 and the balancing body 122, 222, 322a, 322b.

[0079] The end of the variable mass balance rod can be connected to the end of the measuring conduit. Figures 2 to 3B The ends of the variable mass balancing rods 120, 220, and 320 can be coupled to the ends of the measurement conduits 110, 210, and 310 using a coupling. The coupling can define a vibration node of the variable mass balancing rod and the measurement conduit. Therefore, the ends of the variable mass balancing rod and the measurement conduit can be vibration nodes.

[0080] The mass of a variable mass balance rod, such as the variable mass balance rods 120, 220, 320 described above, can be the portion of the variable mass balance rod between the ends of the variable mass balance rod. For example, the mass can be between nodes defined by a coupler coupled to the ends of the variable mass balance rod and the ends of the measurement conduit. Figure 5 An exemplary coupling is described. As can be appreciated, the mass is determined by the mass of the balancing fluid 124-324b between the ends of the variable mass balancing rod 120, 220, 320.

[0081] Balanced fluid

[0082] Balancing fluids, such as balancing fluids 124, 224, 324a, and 324b described above, can be composed of either process material or non-process material. Non-process material can be advantageous in situations where, for example, the process material is susceptible to deterioration. Additionally, the non-process material can have a different density than the process material, thereby allowing the variable-mass balance bar to balance the conduit even if the balancing body of the variable-mass balance bar is different from the measurement conduit. Additionally or alternatively, the density of the non-process material can be varied to ensure that the variable-mass balance bar balances the conduit containing the process material even when the density of the process material can vary.

[0083] Therefore, prior to use in a vibrating meter, the properties of the balancing fluid may be known or selected to balance the measurement conduit containing the process material. That is, the balancing fluid may not be the process material to be measured by the vibrating meter, and thus, the vibrating meter itself is not balanced due to the same process material being distributed between two similarly sized conduits under the same process conditions. However, for example, the density of the balancing fluid may be known or controlled to ensure that the variable-mass balance bar balances the measurement conduit.

[0084] As explained in more detail below, the density of the balancing fluid can be equal to, greater than, or less than the density of the process material contained by the measurement conduit. The balancing fluid can be considered part of the vibrating meter, while the process material to be measured by the vibrating meter may not be considered part of the vibrating meter. For example, the vibrating meter or variable-mass balancing bar can be sold to a customer already containing the balancing fluid. Alternatively, the customer can select and configure the balancing fluid. Thus, in this example, the balancing fluid may not be part of the vibrating meter or the variable-mass balancing bar.

[0085] The balancing fluid can have a selected density. For example, the balancing fluid can include known fluids with corresponding known densities. The fluids can be selected to select the density. Alternatively, balancing fluid components with corresponding component densities can be mixed together to select the density of the balancing fluid. One or more of the balancing fluid components can be a fluid, a non-fluid such as a solid, a gas, etc.

[0086] Balanced Vibration Meter

[0087] The variable mass balance bar and the measurement conduit containing the process material, such as the variable mass balance bar 120, 220, 320 and the measurement conduit 110, 210, 310 described above, can be balanced when their respective resonant frequencies are equal. The resonant frequencies can be equal if the relationship of the following formula [3] is satisfied. To explain formula [3], we first note that the measurement conduit containing the process material can operate according to formula [1]:

[0088]

[0089] in:

[0090] f 处理 is the resonant frequency of the measurement conduit containing the process material;

[0091] m 导管 It is a measure of the quality of the catheter;

[0092] m 处理材料 is the mass of process material contained by the measuring conduit; and

[0093] k1 is the spring constant of the measuring conduit containing the process material.

[0094] Similarly, a variable mass balancing rod comprising a balancing body containing a balancing fluid may operate according to the following equation [2]:

[0095]

[0096] in:

[0097] f 平衡 is the resonant frequency of a variable mass balancing bar including a balancing body containing a balancing fluid;

[0098] m 平衡 It is the mass of the balancing body;

[0099] m 平衡流体 is the mass of the balancing fluid contained by the balancing body; and

[0100] k2 is the spring constant of the balancing body containing the balancing fluid.

[0101] For a variable mass balancing rod used to balance the measuring conduit, the resonant frequency f of the measuring conduit containing the process material is 处理 can be equal to the resonant frequency f of the variable mass balance bar including the balance body and the balance fluid 平衡 :f 处理 =f 平衡From the above formulas [1] and [2], it can be concluded that for a variable mass balance rod, the following formula [3] can be satisfied to balance the measuring conduit containing the process material:

[0102]

[0103] The spring constant and mass of the conduit and the balance body can be measured by a vibration meter, such as the one referenced above. Figures 2 to 3B The design of the vibrating meters 100, 200, and 300 described herein is determined and established. For example, the geometry, dimensions, and material of the measuring conduit and balancing body can be selected to achieve a desired spring constant. In one example, the measuring conduit and balancing body can have a cylindrical shape with a length, inner diameter, outer diameter, and material selected to achieve a desired mass and spring constant for the measuring conduit and balancing body.

[0104] As can be understood from formula [3], if the spring constant of the measuring conduit is equal to or different from the spring constant of the balancing body containing the balancing fluid, the variable mass balancing rod can balance the measuring conduit containing the process material. For example, if the spring constant of the measuring conduit is different from the spring constant of the balancing body, the masses of the measuring conduit, the balancing body, the process material, and / or the balancing fluid can be different to ensure that the design satisfies formula [3].

[0105] Still referring to formula [3], the spring constant and mass of the measuring conduit and the balancing body can be determined during the design of the vibrating meter. Additionally, the mass of the process material can change sufficiently that the vibrating meter is no longer balanced. That is, the vibrating meter may not comply with formula [3] due to changes in the mass of the process material. However, by changing the mass of the balancing fluid, compliance with formula [3] can be achieved. For example, if the mass of the process material increases significantly due to an increase in the density of the process material, then correspondingly increasing the density of the balancing fluid can ensure that the vibrating meter still complies with formula [3].

[0106] Therefore, a variable-mass balancing rod, such as variable-mass balancing rods 120, 220, and 320 described above, can include a balancing body containing a balancing fluid, wherein the mass of the balancing fluid is selected to balance the measurement conduit containing the process material. The mass of the balancing fluid can be selected by selecting the density of the balancing fluid. Thus, the resonant frequency of the balancing body containing the balancing fluid can be equal to the resonant frequency of the measurement conduit containing the process material.

[0107] The resonant frequency can be equal in various configurations of the balancing body and the balancing fluid. For example, the mass of the balancing body may be equal to or different from the mass of the measuring conduit. Additionally or alternatively, the stiffness of the balancing body may be equal to or different from the stiffness of the measuring conduit. The balancing body can be configured to be mechanically coupled to the measuring conduit. In addition, the balancing fluid can be a non-processing material. Although the balancing fluid can be fully contained (for example, the ends of the balancing body are sealed), the properties of the balancing fluid, such as temperature, can preferably be controlled by causing the balancing fluid to flow. Therefore, the balancing body may include at least one inlet configured to receive the balancing fluid and at least one outlet configured to provide the balancing fluid. The mass of the balancing fluid can therefore be the mass of the balancing fluid between the inlet and the outlet.

[0108] As can be appreciated, the mass of the variable mass balancing rod can be controlled by controlling the properties of the balancing fluid. For example, as discussed above, the density of the balancing fluid can be selected. To control the mass, the density of the balancing fluid, once selected, can be controlled by, for example, controlling other properties of the balancing fluid, such as the composition, temperature, etc. Controlling the properties of the balancing fluid can be manual, such as simply selecting an appropriate fluid with a selected density. However, the mass of the balancing fluid can be automatically controlled. Hereinafter, reference will be made to Figure 4 An exemplary system for automatically controlling the density of a balancing fluid, and thereby controlling the mass of a variable mass balancing rod, is described.

[0109] Controlling the mass of a variable mass balance bar

[0110] Figure 4 A system 400 is shown having a vibrating meter 100 including a variable mass balance bar 120. Figure 2 Same, Figure 4 The vibrating meter 100 shown in FIG. 1 includes a variable mass balance bar 120. Figure 4 As shown in FIG, the measurement conduit 110 is adjacent to the variable mass balance rod 120. Although Figure 4 The ends of the measurement conduit 110 and the variable mass balance rod 120 may be rigidly coupled together by a coupling, which in turn may be coupled to a housing, which is not shown for clarity. The flow of process material measured by the measurement conduit 110 is illustrated by arrows 111, 112.

[0111] The left pickoff sensor 130a, the right pickoff sensor 130b, and the driver 140 are disposed between and coupled to the measurement conduit 110 and the variable mass balance rod 120. The left pickoff sensor 130a, the right pickoff sensor 130b, and the driver 140 are shown as being communicatively coupled to meter electronics 150. As will be described in greater detail below, the meter electronics 150 can provide drive signals to the driver 140 and receive sensor signals from the left pickoff sensor 130a and the right pickoff sensor 130b to measure properties of the material in the measurement conduit 110, such as density, mass flow rate, and the like.

[0112] like Figure 4 As shown in , the metering electronics 150 is communicatively coupled to the mixer 402. The mixer 402 is shown as receiving a plurality of balancing fluid components, each balancing fluid component having a corresponding component density ρ1, ρ2, ... ρn. The mixer 402 can receive the plurality of balancing fluid components, mix the plurality of balancing fluid components into the balancing fluid 124, and provide the balancing fluid 124 to the balancing body 122. The mixer 402 can also be configured to regulate the balancing fluid 124. For example, the mixer 402 can heat and / or cool the balancing fluid 124. Although the mixer 402 is shown as a single integral device, the mixer 402 can include different sub-devices, each of which has a control circuit. As Figure 4 As shown in FIG, the mixer 402 may include control circuitry that may control the mass of the balancing fluid 124 by controlling the density of the balancing fluid 124, as described in more detail below.

[0113] The mixer 402 is shown to include multiple inlets, each of which is fluidically coupled to a corresponding balancing fluid component. The mixer 402 may also include a valve, such as a flow valve, for regulating the flow rate of the corresponding balancing fluid component. The mixer 402 may also select one of the multiple balancing fluid components or mix two or more of the multiple balancing fluid components into the balancing fluid 124. For example, the mixer 402 may include a control circuit having a memory for storing component densities p1, p2, ... pn of the multiple balancing fluid components. The control circuit may store and / or receive other values, such as the volume of the measurement conduit 110, the density of the process material in the measurement conduit 110, the volume of the balancing body 120, etc.

[0114] Thus, if, for example, the density of the process material in the measuring conduit 110 and the volume of the measuring conduit 110 are known, the mixer can be operated without feedback from the meter electronics 150. Assuming substantially equal stiffness, the dosage of any equilibrium fluid component to bring the measuring conduit 110 into equilibrium can thus be approximated as:

[0115]

[0116] in:

[0117] i is the index of the equilibrium fluid component;

[0118] n is the total number of equilibrium fluid components;

[0119] x i is the mass fraction of one of the equilibrium fluid components; and

[0120] ρ is the density of the equilibrium fluid components.

[0121] The above formula may assume that there are no reactions between any of the equilibrium fluid components that would change the composition and density of the equilibrium fluid 124 .

[0122] The mixer 402 may include a density meter that measures the density of the balancing fluid components and / or the balancing fluid 124 provided to the balancing body 122. The measured density may be used to adjust the density of the balancing fluid 124 provided to the balancing body 122. For example, referring to the above formula [4], the density of the balancing fluid 124 may be equal to Therefore, the control circuit in the mixer 402 can adjust the mass fraction x of one or more of the balancing fluid components. i Adjustments are made (eg, increased or decreased) so that the measured density results in the balancing fluid 124 satisfying the requirements of equation [4].

[0123] The mixer 402 can be used to provide the balancing fluid 124 so that the variable mass balancing rod 120 can balance the measurement conduit 110 containing the process material without controlling the volume of the balancing fluid 124. For example, the system 400 can balance the measurement conduit 110 without controlling the flow rate of the balancing fluid 124 provided to the balancing body 122. However, other systems can control the volume of the balancing fluid in the balancing body. To control the flow of the balancing fluid to the exemplary system, a valve, such as described below with reference to Figure 5 Those valves described.

[0124] Controlling the volume of the balancing fluid

[0125] Figure 5A vibrating meter 500 is shown including a variable mass balance bar 520. Figure 5 As shown in FIG, the vibrating meter 500 includes a measuring conduit 510. A variable mass balance bar 520 is adjacent to the measuring conduit 510, which can be connected to the measuring conduit 510. Figure 1 The measurement conduits 510 shown in FIG. 5 may be the same or different. Figure 5 As shown in FIG, the ends of the measurement conduit 510 and the variable mass balance rod 520 may be coupled together with, for example, a first coupler 570a and a second coupler 570b. The first coupler 570a and the second coupler 570b are further coupled to the housing 560.

[0126] The left pickoff sensor 530a, the right pickoff sensor 530b, and the driver 540 are disposed between and coupled to the measurement conduit 510 and the variable mass balance rod 520. The left pickoff sensor 530a, the right pickoff sensor 530b, and the driver 540 are shown as being communicatively coupled to meter electronics 550. As will be described in greater detail below, the meter electronics 550 can provide drive signals to the driver 540 and receive sensor signals from the left pickoff sensor 530a and the right pickoff sensor 530b to measure properties of the process material in the measurement conduit 510, such as density, mass flow rate, etc. The meter electronics 550 can also be communicatively coupled to other devices, such as a mixer, such as the mixer 402 described above.

[0127] like Figure 5 As shown in FIG, meter electronics 550 is also communicatively coupled to an inlet valve 520a and an outlet valve 520b. Inlet valve 520a is fluidly coupled to the inlet of variable mass balancing rod 520. Inlet valve 520a is configured to receive balancing fluid 524 from a source, such as a mixer, and to control the flow rate, such as the volumetric or mass flow rate, of balancing fluid 524 provided to balancing body 522. Outlet valve 520b is fluidly coupled to the outlet of variable mass balancing rod 520. Outlet valve 520b is configured to receive balancing fluid 524 from balancing body 522 and to control the flow rate of balancing fluid 524 out of balancing body 522. Thus, the mass of balancing fluid 524 in balancing body 522 can be controlled. For example, by controlling the flow rate of balancing fluid 524 into and out of balancing body 522, the temperature and / or volume of balancing fluid 524 can be controlled.

[0128] The foregoing discloses a variable mass balance bar for balancing a measurement conduit having a straight tube configuration. In addition, the vibrating meter 500 includes an inlet valve 520a and an outlet valve 520b. Other configurations using alternative measurement conduit geometries and more or fewer balancing fluid valves may be employed. Figure 6A and Figure 6B Exemplary vibrating meters having alternative configurations are described.

[0129] Figure 6A and Figure 6B A vibrating meter 600 is shown having a variable mass balance bar 620. Figure 6A and Figure 6B As shown in FIG, the vibrating meter 600 includes a measuring conduit 610. Figure 6B As shown in FIG, a measuring conduit 610 is disposed adjacent to a variable mass balance rod 620. The variable mass balance rod 620 includes a balancing body 622 and a balancing fluid 624. The vibrating meter 600 is shown to include a detection sensor 630 disposed between the measuring conduit 610 and the variable mass balance rod 620 and coupled to the measuring conduit 610 and the variable mass balance rod 620. The detection sensor 630 includes a left detection sensor 630a and a right detection sensor 630b. The vibrating meter 600 also includes a driver 640 disposed between the measuring conduit 610 and the variable mass balance rod 620 and coupled to the measuring conduit 610 and the variable mass balance rod 620.

[0130] like Figure 6A and Figure 6B As shown in FIG, the vibrating meter 600 includes an inlet valve 620a. The vibrating meter 600 does not include an outlet valve. The inlet valve 620a is fluidly coupled to the inlet of the variable mass balancing rod 620. The inlet valve 620a can be configured to receive a balancing fluid 624 from a source, such as a mixer, and to control the flow rate, such as the volumetric flow rate or the mass flow rate, of the balancing fluid 624 provided to the balancing body 622. Thus, the mass of the balancing fluid 624 in the balancing body 622 can be controlled. For example, by controlling the flow rate of the balancing fluid 624 into the balancing body 622, the temperature and / or volume of the balancing fluid 624 can be controlled.

[0131] like Figure 6A and Figure 6BAs shown in , the vibrometer 600 includes a housing 660. The housing 660 is mechanically coupled to a base 660a. The measuring conduit 610 extends through the base 660a into the space formed by the housing 660. The housing 660 and the base 660a can be substantially rigid structures. Thus, the base 660a can coincide with the vibration nodes of the measuring conduit 610 and the variable mass balance bar 620. Furthermore, the housing 660 and the base 660a can be reference structures or reference surfaces. For example, it can be assumed that a surface on the housing 660 and / or the base 660a has zero displacement with respect to time when the measuring conduit 610 and / or the variable mass balance bar 620 vibrates. Thus, the displacement of the measuring conduit 610 and / or the variable mass balance bar 620 relative to a reference surface or reference structure can be measured, and the reference surface or reference structure can be the housing 660, such as the reference surface Figure 7 and Figure 8 discussed.

[0132] As mentioned above Figure 5 、 Figure 6A 、 Figure 6B As discussed, the mixer can be used to provide the balancing fluid 524, 624 so that the variable mass balancing rod 520, 620 balances the measurement conduit 510, 610 containing the process material without determining whether the measurement conduit 510, 610 is balanced. However, the vibrating meter or a system employing the vibrating meter can also determine whether the balancing fluid balances the measurement conduit containing the process material. Figure 7 and Figure 8 Exemplary systems and vibrating meters are discussed.

[0133] Determine if the balancing fluid balances the measuring conduit

[0134] Figure 7 and Figure 8 A vibrating meter including a variable mass balance bar and a balance sensor is shown. Figure 7 As shown in FIG, the vibrating meter 700 includes a variable mass balance bar 720 adjacent to the measuring conduit 710. The variable mass balance bar 720 includes a balance body 722 and a balance fluid 724. Figure 7As shown in the figure, the vibration meter 700 includes a detection sensor 730, which is arranged between the measurement conduit 710 and the housing 760 and is connected to the measurement conduit 710 and the housing 760, and the housing 760 is mechanically connected to the base 760a. The detection sensor 730 includes a left detection sensor (not shown in the figure) and a right detection sensor 730b. The vibration meter 700 also includes a balance sensor 780, which is arranged between the variable mass balance rod 720 and the housing 760 and is connected to the variable mass balance rod 720 and the housing 760. The balance sensor 780 includes a first balance sensor (not shown in the figure) and a second balance sensor 780b. The vibration meter 700 also includes a driver 740, which is arranged between the measurement conduit 710 and the variable mass balance rod 720 and is connected to the measurement conduit 710 and the variable mass balance rod 720.

[0135] like Figure 7 As shown in FIG, balance sensor 780 is mechanically coupled to housing 760. A first balance sensor is also mechanically coupled to variable mass balance rod 720. A second balance sensor 780b is also mechanically coupled to measurement conduit 710. Balance sensor 780 can be configured to measure the displacement of variable mass balance rod 720 relative to housing 760. Balance sensor 780 is also configured to provide a balance sensor signal to meter electronics 750.

[0136] like Figure 8 As shown in FIG, the vibrating meter 800 includes a variable mass balance bar 820 adjacent to a plate 860b. The plate 860b is disposed between the variable mass balance bar 820 and the measuring conduit 810. The plate 860b is mechanically coupled to the base 860a, and the base 860a is mechanically coupled to the housing 860. The detection sensor 830 is disposed between the measuring conduit 810 and the reference plate 860b and is coupled to the measuring conduit 810 and the reference plate 860b. The detection sensor 830 includes a left detection sensor (not shown in the drawing) and a right detection sensor 830b. The driver 840 is disposed between the measuring conduit 810 and the variable mass balance bar 820 and is coupled to the measuring conduit 810 and the variable mass balance bar 820.

[0137] Balance sensor 880 is disposed between plate 860b and variable-mass balance bar 820 and is coupled to both plate 860b and variable-mass balance bar 820. Balance sensor 880 includes a first balance sensor (not shown) and a second balance sensor 880b. Balance sensor 880 can be configured to measure the displacement of variable-mass balance bar 820 relative to housing 860. Balance sensor 880 is also configured to provide a balance sensor signal to meter electronics 850.

[0138] like Figure 7 and Figure 8As shown in FIG, the vibrating meters 700, 800 include inlet valves 720a, 820a. The vibrating meters 700, 800 do not include outlet valves. The inlet valves 720a, 820a are fluidly coupled to the inlets of the variable mass balancing bars 720, 820. The inlet valves 720a, 820a are configured to receive a balancing fluid 724, 824 from their respective sources, such as mixers, and to control the flow rate, such as the volumetric flow rate or mass flow rate, of the balancing fluid 724, 824 provided to the balancing bodies 722, 822. Thus, the mass of the balancing fluid 724, 824 in the balancing bodies 722, 822 can be controlled. For example, by controlling the flow rate of the balancing fluid 724, 824 into and out of the balancing bodies 722, 822, the temperature and / or volume of the balancing fluid 724, 824 can be controlled.

[0139] like Figure 7 and Figure 8 As shown in FIG, the vibrating meter 700, 800 includes a housing 760, 860. The housing 760, 860 is mechanically coupled to a base 760a, 860a, which can be coupled to a reference structure, such as a Figure 8 The measurement conduits 710, 810 extend through the bases 760a, 860a into the space formed by the housings 760, 860. The housings 760, 860, the bases 760a, 860a, and the plates 860b can be substantially rigid structures. Thus, the bases 760a, 860a can coincide with the vibration nodes of the measurement conduits 710, 810 and the variable mass balance rods 720, 820. Furthermore, the housings 760, 860 and the plates 860b can be reference structures or reference surfaces. For example, it can be assumed that a surface on the housings 760, 860 and / or the plates 860b has zero displacement with respect to time when the measurement conduits 710, 810 and / or the variable mass balance rods 720, 820 vibrate. Thus, the displacement of the measurement conduits 710, 810 and / or the variable mass balance rods 720, 820 relative to a reference surface or structure, which may be the housing 760, 860 and / or the plate 860b, may be measured.

[0140] Because housing 760, 860 and plate 860b are reference structures or surfaces, the displacements of measurement conduits 710, 810 and variable-mass balance rods 720, 820 relative to a common reference structure or surface can be measured. In these examples, it is assumed that housing 760, 860 and plate 860b are not vibrating, and therefore any displacements of conduits 710, 810 and variable-mass balance rods 720, 820 can be measured and compared to one another.

[0141] As discussed above, when the resonant frequency of the measurement conduits 710, 810 containing the process material is equal to the resonant frequency of the variable-mass balance bars 720, 820, the measurement conduits 710, 810 can be balanced. Therefore, by measuring the displacement of the measurement conduits 710, 810 containing the process material with the pickoff sensors 730, 830 and the displacement of the variable-mass balance bars 720, 820 with the balance sensors 780, 880, the frequencies of the measurement conduits 710, 810 and the variable-mass balance bars 720, 820 can be calculated. The frequencies can be determined by the metrology electronics 750, 850 based on the sensor signals provided by the pickoff sensors 730, 830 and the balance sensors 780, 880. When the frequencies of the measurement conduits 710, 810 containing the process material are equal to the frequencies of the variable-mass balance bars 720, 820, respectively, the measurement conduits 710, 810 are balanced by the variable-mass balance bars 720, 820.

[0142] Systems for balancing measuring tubes

[0143] Figure 9 A system 900 is shown having a vibrating meter 100' that includes a variable mass balance bar 120. Figure 9 As shown in FIG, the variable mass balance rod 120 is adjacent to the measuring conduit 110. The ends of the measuring conduit 110 and the ends of the variable mass balance rod 120 are rigidly coupled to the first housing end 160a and the second housing end 160b of the housing 160. Figure 9 , the flow of process material to be measured by the measurement conduit 110 is illustrated by arrows 111, 112. The inlet valve 920a is communicatively coupled to the meter electronics 150 and fluidically and mechanically coupled to the balancing body 122. The inlet valve and the outlet valve 920a are configured to control the flow of the balancing fluid 124 provided to the balancing body 122.

[0144] Left and right pickoff sensors 130a, 130b are disposed between and mechanically coupled to the measurement conduit 110 and the housing 160. Left and right pickoff sensors 130a, 130b are configured to measure displacement of the measurement conduit 110 relative to the housing 160. Driver 140 is disposed between and coupled to the measurement conduit 110 and the variable-mass balance bar 120. Left and right pickoff sensors 130a, 130b, and driver 140 are shown as being communicatively coupled to meter electronics 150. Meter electronics 150 can provide drive signals to driver 140 and receive sensor signals from left and right pickoff sensors 130a, 130b to measure properties of the material in the measurement conduit 110, such as density, mass flow rate, and the like. As will be described in greater detail below, meter electronics 150 can also be communicatively coupled to other devices.

[0145] like Figure 9 As shown in FIG, measurement conduit 110 is a straight cylindrical tube, but any suitable shape may be employed. Measurement conduit 110 is shown as having an outer diameter. As illustrated by the dashed lines, measurement conduit 110 also has an inner diameter. Measurement conduit 110 is configured to vibrate when subjected to a vibration force, such as provided by driver 140. The vibration may oscillate at a resonant frequency. Measurement conduit 110 is balanced by a variable mass balance bar 120.

[0146] The variable mass balance rod 120 has a mass that can be selected to balance the measurement conduit 110. For example, the density of the variable mass balance rod 120 can be selected to balance the measurement conduit 110. The variable mass balance rod 120 is shown to include a balancing body 122. Figure 9 As shown in FIG, the balancing body 122 has the shape of a hollow cylindrical tube having a wall thickness. The balancing body 122 may be made of the same or similar material as the measuring conduit 110 and / or have the same or similar shape as the measuring conduit 110. Figure 9 As shown in FIG, balancing body 122 has approximately the same length as measurement conduit 110, but any suitable diameter may be employed. Balancing body 122 has an outer diameter that is smaller than the outer diameter of measurement conduit 110. Balancing body 122 also has an inner diameter (illustrated by dashed lines) that extends along the length of variable mass balancing rod 120, forming a cylindrical inner surface.

[0147] The variable-mass balancing rod 120 also includes a balancing fluid 124. The balancing fluid 124 is shown by arrows as entering and exiting the variable-mass balancing rod 120. More specifically, the balancing fluid 124 is shown as entering the balancing body 122 at an inlet near the inlet arrow, being delivered by the cylindrical balancing body 122, and being provided by the cylindrical balancing body 122 at an outlet near the outlet arrow. Thus, the balancing fluid 124 can fill the space formed by the cylindrical inner surface of the balancing body 122. The balancing fluid 124 has properties that can ensure that the variable-mass balancing rod 120 balances the measurement conduit 110. Therefore, even if the density of the process material in the measurement conduit 110 may vary, the measurement of the process material's properties can be accurate.

[0148] like Figure 9 As shown in FIG, at least one balance sensor 980 includes a first balance sensor 980a and a second balance sensor 980b mechanically coupled to the housing 160 and the variable mass balance bar 120. A single balance sensor may be employed in other systems or vibrating meters. Figure 9 As shown in FIG, first and second balance sensors 980a, 980b are communicatively coupled to meter electronics 150. First and second balance sensors 980a, 980b are configured to measure displacement of variable mass balance bar 120 relative to housing 160. First and second balance sensors 980a, 980b are further configured to provide balance sensor signals to meter electronics 150.

[0149] Housing 160 and first and second housing ends 160a, 160b may be a reference structure or surface. For example, housing 160 and / or surfaces on housing ends 160a, 160b may be assumed to have zero displacement relative to time when measurement conduit 110 and / or variable-mass balance bar 120 vibrate. Thus, the displacement of measurement conduit 110 and / or variable-mass balance bar 120 relative to a reference surface or structure may be measured, which may be housing 160.

[0150] Because housing 160 and housing ends 160a, 160b are reference structures or surfaces, the displacements of measurement conduit 110 and variable-mass balance rod 120 relative to a common reference structure or surface can be measured. In this example, it is assumed that housing 160 does not vibrate or that the surfaces of housing 160 do not vibrate relative to each other, and therefore any displacements of measurement conduit 110 and variable-mass balance rod 120 can be measured and compared.

[0151] System 900 also includes an accelerometer 990 mechanically coupled to second housing end 160b. Accelerometer 990 is communicatively coupled to meter electronics 150. Accelerometer 990 is configured to detect acceleration. For example, if accelerometer 990 vibrates, accelerometer 990 will generate an acceleration signal that may be proportional to the acceleration at that location. Accelerometer 990 may provide the acceleration signal to meter electronics 150 accordingly.

[0152] System 900 includes a mixer 902. Mixer 902 is fluidically coupled to variable mass balancing rod 120 and communicatively coupled to meter electronics 150. Mixer 902 is shown as receiving a plurality of balancing fluid components, each having a corresponding component density ρ1, ρ2, ρ3, ..., ρn. Mixer 902 can receive the plurality of balancing fluid components, mix the plurality of balancing fluid components into a balancing fluid 124, and provide the balancing fluid 124 to balancing body 122. Mixer 902 is also configured to receive balancing fluid 124 from vibrating meter 100' in a semi-closed loop system.

[0153] The mixer 902 can also be configured to condition the balancing fluid 124. For example, the mixer 902 can heat and / or cool the balancing fluid 124. Although the mixer 902 is shown as a single, integral device, the mixer 902 can include different sub-devices, each of which has a control circuit. Figure 9 As shown in FIG, the mixer 902 may include control circuitry that may control the mass of the balancing fluid 124 by controlling the density of the balancing fluid 124, as described in more detail below.

[0154] The mixer 902 is shown to include multiple inlets, each of which is fluidically coupled to a corresponding balancing fluid component. The mixer 902 may also include a valve, such as a flow valve, for regulating the flow rate of the corresponding balancing fluid component. The mixer 902 may also select one of the multiple balancing fluid components or mix two or more of the multiple balancing fluid components into the balancing fluid 124. For example, the mixer 402 may include a control circuit having a memory for storing component densities p1, p2, p3, ... pn of the multiple balancing fluid components. The control circuit may store and / or receive other values, such as the volume of the measurement conduit 110, the density of the process material in the measurement conduit 110, the volume of the balancing body 122, etc.

[0155] System 900 also includes a density sensor 904 disposed between and fluidically coupled to mixer 902 and vibrating meter 100'. Density sensor 904 is communicatively coupled to meter electronics 150. Density sensor 904 is configured to measure the density of balancing fluid 124 provided to vibrating meter 100'. The measured density is provided to meter electronics 150, which can perform calculations using the measured density. Some of these calculations may include calculating the mass of variable mass balancing rod 120. By calculating the mass of variable mass balancing rod 120 and knowing the spring constant of variable mass balancing rod 120, meter electronics 150 can analytically determine whether variable mass balancing rod 120 balances measurement conduit 110.

[0156] If the meter electronics 150 analyzes and determines that the variable mass balancing rod 120 is not balancing the measurement conduit 110, then the meter electronics 150 can provide a signal indicating the measured density, the equilibrium density, or the difference between the equilibrium density (e.g., the density value that would be analyzed to cause the variable mass balancing rod 120 to balance the measurement conduit 110) and the measured density to the mixer 902. The mixer 902 can use these values ​​to select, adjust, etc. one or more of the balancing fluid components so that the density of the balancing fluid 124 is approximately the same as the equilibrium density.

[0157] Additionally or alternatively, the meter electronics 150 can determine whether the measurement conduit 110 is balanced by using the acceleration signal provided by the accelerometer 990, the balance sensor signal provided by the at least one balance sensor 980, the standard deviation of the zero offset, and / or the drive gain of the driver 140. For example, if the variable-mass balance bar 120 balances the measurement conduit 110 containing the process material, any vibrations detected by the accelerometer 990 will not be due to an unbalanced vibration meter 100'. Vibrations detected in the balanced vibration meter 100' may be due to other sources, such as vibrations from the process material, piping connected to the vibration meter 100', ambient noise / vibration, etc. These other sources can be filtered using, for example, a bandpass filter centered around the resonant frequency of the variable-mass balance bar 120 and / or the measurement conduit 110 containing the process material.

[0158] At least one balance sensor 980 can also be used to determine whether the variable-mass balance bar 120 balances the measurement conduit 110 containing the process material. For example, as described above, when the resonant frequency of the variable-mass balance bar 120 is equal to the resonant frequency of the measurement conduit 110, the variable-mass balance bar 120 can balance the measurement conduit 110 containing the process material. The at least one balance sensor 980 can detect the displacement (e.g., distance, velocity, and / or acceleration) of the variable-mass balance bar 120 and provide a balance bar displacement signal to the meter electronics 150. The meter electronics 150 can determine whether the resonant frequency of the variable-mass balance bar 120 is equal to the resonant frequency of the measurement conduit 110 containing the process material.

[0159] The resonant frequency of the variable mass balancing rod 120 can be measured by varying the density / mass of the balancing fluid and / or the frequency of the drive signal provided to the driver 140. For example, the mixer 902 can increase or decrease the density of the balancing fluid 124. While the density of the balancing fluid 124 is being scanned to determine the equilibrium density value, the meter electronics 150 can measure the amplitude of the accelerometer signal provided by the accelerometer 990. The equilibrium density value can correspond to when the amplitude of the accelerometer signal is minimum within the density scan range of the balancing fluid 124.

[0160] Additionally or alternatively, one or more frequencies of the drive signal provided to driver 140 can be varied to minimize the drive gain or other variable corresponding to the amplitude of the drive signal. The one or more frequencies of the drive signal can include component frequencies of the drive signal. In other words, the drive signal can include one or more components having different sinusoidal frequencies. For example, the drive signal can include a component at or tracking the resonant frequency of measurement conduit 110 containing the process material and a component at or tracking the resonant frequency of variable-mass balance bar 120. Thus, the amplitude of the component corresponding to the resonant frequency of variable-mass balance bar 120 can be minimized. Tracking the component corresponding to the resonant frequency of variable-mass balance bar 120 can be achieved by minimizing the drive gain while varying the frequencies of the components.

[0161] The meter electronics 150 can determine that the variable-mass balance bar 120 balances the measurement conduit 110 containing the process material in other ways in addition to or in lieu of the ways described above. For example, the meter electronics 150 can monitor the drive gain of the drive signal provided to the driver 140 and, if the drive gain is too high, the meter electronics 150 can determine that the vibrating meter 100' is unbalanced. Additionally or alternatively, the meter electronics 150 can determine that the variable-mass balance bar 120 balances the measurement conduit 110 containing the process material when the frequency of the component corresponding to the variable-mass balance bar 120 is equal to the frequency of the component corresponding to the measurement conduit 110 containing the process material (e.g., when their respective drive gains are minimized).

[0162] The drive gain can be a measure of the drive signal power required to maintain the amplitude of the measurement conduit 110 containing the process material. For example, the drive gain can be a ratio of the drive signal amplitude to one or more signal amplitudes of the signal provided by the at least one balance sensor 980 and / or the sensor signals provided by the left pickoff sensor 130a and the right pickoff sensor 130b. In other words, the drive gain can be determined for and corresponding to the variable mass balance rod 120 and / or the measurement conduit 110 containing the process material.

[0163] Meter electronics 150 can also determine whether vibrating meter 100' is balanced by monitoring the zero point. When vibrating meter 100' is balanced, the zero point will be equal to the equilibrium zero point. That is, when process material is not flowing through the measurement conduit, the time or phase delay can be equal to the previously determined time or phase delay measured when vibrating meter 100' was balanced. For example, the equilibrium zero point can be determined using accelerometer 990, density sensor 904, at least one balance sensor 980, etc. For example, accelerometer 990 can be used to balance vibrating meter 100' to minimize vibration, and the corresponding zero point can then be stored as the equilibrium zero point. The equilibrium zero point can also be related to process conditions, such as process material, temperature, density reading, pressure, etc.

[0164] Balancing the Vibration Meter

[0165] Figure 10 A method 1000 of balancing a measurement catheter using a variable mass balance rod is shown. Figure 10As shown in , method 1000 includes step 1010, in which method 1000 selects a mass of a balancing fluid to balance the measurement conduit. The balancing fluid may be balancing fluids 124-324b, 524-824 described above. In step 1020, method 1000 provides the balancing fluid to a balancing body. The balancing body may be balancing bodies 122-322b, 522-822 described above, but any suitable balancing body may be used. Method 1000 may include other steps. For example, selecting the mass of the balancing fluid to balance the measurement conduit may include selecting a density of the balancing fluid. The density may be selected in any suitable manner, such as selecting a specific fluid, a mixed fluid component, etc. The fluid or fluid component may or may not be a process material. Non-process materials may be advantageous because the balancing temperature can be controlled, rather than being determined by the process material to be measured. Method 1000 may also include providing the balancing fluid to at least one inlet configured to receive the balancing fluid. Providing the balancing fluid to the balancing body may further comprise mixing a plurality of balancing fluid components into the balancing fluid and providing the balancing fluid to the balancing body.Thus, the variable mass balancing rod may balance the measurement conduit containing the process material.

[0166] The resonant frequency of the balancing body that contains the balancing fluid can be equal to the resonant frequency of the measuring conduit that contains the processing material. Therefore, the resonant frequency of the variable mass balancing rod can be equal to the resonant frequency of the measuring conduit that contains the processing material. According to the above formulas [1] to [3], the frequencies can be equal to each other. In one example, the mass of the balancing body can be equal to the mass of the measuring conduit. Therefore, the stiffness of the balancing body can be the same as the stiffness of the measuring conduit. Alternatively, the mass of the balancing body may not be equal to the mass of the measuring conduit. Therefore, the stiffness of the measuring conduit may not be equal to the stiffness of the measuring conduit. For example, if the mass of the balancing body is less than the mass of the measuring conduit, the stiffness of the balancing body can be greater than the stiffness of the measuring conduit. However, the above depends on the mass of the processing material, as explained in the above formula [3].

[0167] Method 1000 may also include other steps, such as configuring the balancing body to be mechanically coupled to the measuring conduit. For example, a connector or housing end may be attached to an end of the balancing body and an end of the measuring conduit. However, any suitable mechanical coupling may be employed. Additionally or alternatively, at least one balancing sensor may be coupled to the variable mass balancing bar and the reference structure of the vibrometer. The balancing sensor may be used to determine whether the variable mass balancing bar balances the measuring conduit. For example, as described above, the balancing sensor may be used to determine whether the resonant frequency of the measuring conduit is equal to the resonant frequency of the variable mass balancing bar. Additionally or alternatively, an accelerometer may be coupled to the reference structure to, for example, sense vibrations of the reference structure using the accelerometer. The accelerometer and / or the balancing sensor may be used to determine whether the reference structure is vibrating because the variable mass balancing bar is not balancing the measuring conduit containing the process material.

[0168] Balancing a vibrating meter, such as the vibrating meters 100-300, 500-800 described above, may include monitoring one or more variables. For example, referring to Figure 9 As the mixer 902 changes the density of the balancing fluid 124 provided to the balancing body 122, the drive gain signal provided to the driver 140 and the acceleration signal from the accelerometer 990 can be monitored. If the frequency of the component of the drive signal corresponding to the variable mass balancing rod 120 and the frequency of the component of the drive signal corresponding to the measurement conduit 110 containing the process material are approximately equal and minimize the acceleration signal from the accelerometer 990, then the meter electronics 150 can determine that the vibrating meter 100' is balanced.

[0169] As can be appreciated, each variable can have a corresponding threshold. These thresholds can also be associated with processing conditions. For example, the frequencies of the components of the drive signal can be within a threshold of each other and the amplitude of the acceleration can be less than a threshold before meter electronics 150 can determine that vibrating meter 100' is balanced. The determination that vibrating meter 100' is balanced can be used in various ways, such as indicating that method 1000 is terminated, indicating that the measured mass flow rate is likely accurate, etc. Variables can also be quantized to provide a measure of the accuracy of the measured mass flow rate, etc.

[0170] The vibrating meters 100-300, 500-800 including the variable mass balancing bar 120-320, 520-820, and the systems 400, 900 having the vibrating meters 100, 100' including the variable mass balancing bar 120 are described above. The variable mass balancing bar 120 can be used to balance the measuring conduits 110-310, 510-810. By balancing the vibrating meters 100-300, 500-800 instead of using a fixed mass balancing bar, the vibrating meters 100-300, 500-800 can accurately measure the properties of the processed material.

[0171] Even though the properties of the process material may vary, the balanced vibrating meters 100-300, 500-800 may not vibrate. Thus, for example, a single straight conduit configuration can be used for a wide range of process materials. This allows the benefits of the straight conduit configuration, such as higher frequency operating modes, to be realized in a wider range of process measurement applications. Other configurations may have specific benefits that can be similarly realized, such as very low frequency operation, desired flow capacity, etc.

[0172] Balancing the vibrating meter 100-300, 500-800 can also compensate for variations in the measuring conduit 110-310, 510-810. For example, the mass of the measuring conduit 110-310, 510-810 can increase or decrease due to erosion, corrosion, coating, adjustments (e.g., adjustments to the detection sensors 130a, 130b), maintenance such as replacement of part or all of the measuring conduit 110-310, 510-810, etc. This can reduce lifecycle costs by extending the operating life of the vibrating meter 100-300, 500-800, allowing for part-level repairs where component-level repairs might previously have been required.

[0173] The detailed description of the above embodiments is not an exhaustive description of all embodiments contemplated by the inventors within the scope of this specification. Indeed, those skilled in the art will recognize that certain elements of the above embodiments may be variously combined or eliminated to create additional embodiments, and such additional embodiments fall within the scope and teachings of this specification. It will be apparent to those skilled in the art that the above embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of this specification.

[0174] Therefore, although specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of this specification, as those skilled in the relevant art will recognize. The teachings provided herein can be applied to other variable mass balance bars, vibrating meters including variable mass balance bars, or systems and methods for balancing a measurement pipeline using a variable mass balance bar, and not only to the embodiments described above and shown in the accompanying drawings. Therefore, the scope of the embodiments described above should be determined by the appended claims.

Claims

1. A vibrating meter (100-300, 500-800) having a variable mass balance bar (120-320, 520-820), the vibrating meter (100-300, 500-800) comprising: Measuring catheter (110-310, 510-810); as well as The variable mass balance rod (120-320, 520-820), the variable mass balance rod (120-320, 520-820) is mechanically coupled to the measurement conduit (110-310, 510-810); wherein the mass of the variable mass balance bar (120-320, 520-820) is selected to balance the measurement conduit (110-310, 510-810) containing the process material, so that the resonant frequency of the variable mass balance bar (120-320, 520-820) is equal to the resonant frequency of the measurement conduit (110-310, 510-810); and The mass of the variable mass balance bar (120-320, 520-820) is selected by selecting the mass of the balance fluid (124-324b, 524-824) of the variable mass balance bar (120-320, 520-820).

2. The vibrating meter (100-300, 500-800) according to claim 1, wherein: The mass of the variable mass balance bar (120-320, 520-820) is one of equal to the mass of the measurement conduit (110-310, 510-810) containing the process material and not equal to the mass of the measurement conduit (110-310, 510-810) containing the process material; and The stiffness of the variable mass balance rod (120-320, 520-820) is one of equal to the stiffness of the measurement catheter (110-310, 510-810) and not equal to the stiffness of the measurement catheter (110-310, 510-810).

3. The vibrating meter (100-300, 500-800) according to claim 1, wherein: The variable mass balance bar (120-320, 520-820) comprises at least one inlet and at least one outlet, wherein the mass of the variable mass balance bar (120-320, 520-820) is between the inlet and the outlet.

4. The vibrating meter (100-300, 500-800) according to claim 1, wherein: The mass of the variable mass balance bar (120-320, 520-820) is selected by selecting the density of the variable mass balance bar (120-320, 520-820).

5. The vibrating meter (700, 800) of claim 1, further comprising at least one balance sensor (780, 880) mechanically coupled to the variable mass balance bar (720, 820) and a reference structure (760, 860b) of the vibrating meter (700, 800).

6. The vibrating meter (700, 800) of claim 5, further comprising meter electronics (750, 850) communicatively coupled to the at least one balance sensor (780, 880), the meter electronics (750, 850) configured to determine whether the variable mass balance bar (720, 820) balances the measurement conduit (710, 810) containing the process material.

7. The vibrating meter (700, 800) according to claim 6, wherein The meter electronics (750, 850) is configured to determine whether the variable mass balance bar (720, 820) balances the measurement conduit (710, 810) containing the process material, including the meter electronics (750, 850) being configured to determine whether the resonant frequency of the measurement conduit (710, 810) containing the process material is equal to the resonant frequency of the variable mass balance bar (720, 820).

8. A system (400, 900) comprising a vibrating meter (100'), the vibrating meter (100') comprising a variable mass balance bar (120), the system (400, 900) comprising: The vibrating meter (100, 100'), the vibrating meter (100, 100') comprising: a measuring catheter (110); and The variable mass balance rod (120), the variable mass balance rod (120) being mechanically coupled to the measurement conduit (110); wherein the mass of the variable mass balance bar (120) is selected to balance the measurement conduit (110) containing the process material so that the resonant frequency of the variable mass balance bar (120-320, 520-820) is equal to the resonant frequency of the measurement conduit (110-310, 510-810); and The mass of the variable mass balance bar (120) is selected by selecting the mass of the balance fluid (124) of the variable mass balance bar (120).

9. The system (400, 900) of claim 8, wherein: The mass of the variable mass balance bar (120) is one of equal to the mass of the measurement conduit (110) containing the process material and not equal to the mass of the measurement conduit (110) containing the process material; and The stiffness of the variable mass balance bar (120) is one of equal to the stiffness of the measurement tube (110) and unequal to the stiffness of the measurement tube (110).

10. The system (400, 900) of claim 8, wherein: The variable mass balance bar (120) includes at least one inlet and at least one outlet, wherein the mass of the variable mass balance bar (120) is between the inlet and the outlet.

11. The system (400, 900) of claim 8, wherein: The mass of the variable mass balance bar (120) is selected by selecting the density of the variable mass balance bar (120).

12. The system (400, 900) of claim 8, further comprising at least one balance sensor (980) mechanically coupled to the variable mass balance bar (120) and a reference structure (160, 160a, 160b).

13. The system (900) of claim 12, further comprising metrology electronics (150) communicatively coupled to the at least one balance sensor (980), the metrology electronics (150) configured to at least one of determine whether the variable mass balance bar (120) balances the measurement conduit (110) containing the process material and select the mass of the variable mass balance bar (120).

14. The system (900) of claim 13, wherein: The meter electronics (150) is configured to determine whether the variable mass balance bar (120) balances the measurement conduit (110) containing the process material, including the meter electronics (150) being configured to determine whether the resonant frequency of the measurement conduit (110) containing the process material is equal to the resonant frequency of the variable mass balance bar (120).

15. The system (900) of claim 13, wherein: The meter electronics (150) being configured to select the mass of the variable mass balance bar (120) includes the meter electronics (150) being configured to select the mass of the balancing fluid (124) of the variable mass balance bar (120) by at least one of controlling a density of the balancing fluid (124) of the variable mass balance bar (120) and controlling a volume of the balancing fluid (124) of the variable mass balance bar (120).

16. The system (900) of claim 13, further comprising an accelerometer (990) coupled to the reference structure (160, 160a, 160b) and communicatively coupled to the meter electronics (150), wherein The accelerometer (990) is configured to sense vibrations of the reference structure (160, 160a, 160b).

17. The system (900) of claim 13, wherein: The meter electronics (150) is configured to determine whether the variable mass balance bar (120) balances the measurement conduit (110) including the meter electronics (150) being configured to determine whether a reference structure (160, 160a, 160b) of the vibrating meter (100) is vibrating due to the variable mass balance bar (120) not balancing the measurement conduit (110) containing the process material.

18. The system (400, 900) of claim 13, further comprising a mixer (402, 902) fluidly coupled to the variable mass balancing rod (120), the mixer (402, 902) configured to mix a plurality of balancing fluid components into the balancing fluid (124) and provide the balancing fluid (124) to the variable mass balancing rod (120).

19. A method of balancing a measurement conduit using a variable mass balance bar, the method comprising: selecting a mass of a balancing fluid to balance a measurement conduit containing a process material so that a resonant frequency of the variable mass balancing rod is equal to a resonant frequency of the measurement conduit; as well as The balancing fluid is provided to a balancing body.

20. The method according to claim 19, wherein Selecting the mass of the balancing fluid to balance the measurement conduit containing the process material includes selecting a density of the balancing fluid.

21. The method of claim 19, wherein: The mass of the balancing body is one of equal to the mass of the measuring conduit and not equal to the mass of the measuring conduit; and The stiffness of the balancing body is one of equal to and not equal to the stiffness of the measuring tube.

22. The method of claim 19, further comprising configuring the balancing body to be mechanically coupled to the measurement conduit.

23. The method according to claim 19, wherein The balancing fluid is a non-process material.

24. The method according to claim 19, wherein Providing the balancing fluid to the balancing body includes providing the balancing fluid to at least one inlet configured to receive the balancing fluid.

25. The method of claim 19, further comprising coupling at least one balance sensor to the variable mass balance bar and a reference structure of a vibrating meter.

26. The method of claim 25, further comprising using the balance sensor to determine whether the variable mass balance bar balances the measurement conduit containing the process material.

27. The method according to claim 26, wherein Using the balance sensor to determine whether the variable mass balance bar balances the measurement conduit containing the process material includes using the balance sensor to determine whether the resonant frequency of the measurement conduit is equal to the resonant frequency of the variable mass balance bar.

28. The method of claim 27, further comprising coupling an accelerometer to the reference structure and sensing vibrations of the reference structure with the accelerometer.

29. The method of claim 28, further comprising determining whether the reference structure is vibrating due to the variable mass balance bar not balancing the measurement conduit containing the process material.

30. The method of claim 19, wherein Providing the balancing fluid to the balancing body includes mixing a plurality of balancing fluid components into the balancing fluid and providing the balancing fluid to the balancing body.

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