KR100898639B1 - Low mass coriolis mass flowmeter having a low mass drive system - Google Patents

Abstract

A Coriolis mass flow meter 300 with a low mass drive system includes a drive coil D for vibrating the flow tube means 102. The Coriolis mass flowmeter does not use a magnet attached to the flow tube means. Instead, the flow tube means is coated with a magnetic material 103 that is responsive to the magnetic field generated by the driver coil that vibrates the flow tube means, or is formed integrally with the magnetic material. The flow tube means may comprise more than one (102) flow tubes 1402C1, 1402C2. The magnetic material may be an iron material having no internal magnetic field. Alternatively, the magnetic material may be steel or stainless steel with an internal magnetic field.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a low mass cooriente mass flow meter having a low mass drive system,

The present invention relates to a Coriolis mass flow meter, and more particularly to a lightweight Coriolis mass flow meter having a low mass drive system. The present invention also relates to a lightweight Coriolis mass flow meter having a small diameter flow tube. The present invention also relates to a lightweight Coriolis mass flow meter suitable for measuring a low volume mass flow rate.

problem

Coriolis mass flow meters are available in a variety of sizes and flow rates to measure material flow and generate information about material flow, such as mass flow, density, and so on. Generally, a Coriolis mass flow meter has one or more straight or irregular shaped flow tubes that are vibrated laterally by an electromagnetic driver. The material flow through the flow tube causes Coriolis deflection of the flow tube, and the Coriolis deflection is detected by one or more pick-offs. The pick-off generates an output signal and sends the output signal to an associated meter electronics for generating material flow information. The resultant output signals generated by Coriolis deflection and pick-off are proportional to the mass of the flow through the flow tube. The composite output signal generated by the Coriolis deflection and pick-off becomes large when the material filled in the flow tube has a relatively large mass relative to the mass of the associated driver and pick-off.

Conventional dual curved tube Coriolis flowmeters have flow rates ranging from about 100 to 700,000 kg / h and have flow tubes with an inner diameter in the range of about 0.3 to 11 cm. Typically, the preferred ratio of the mass of the flow tube filled with material to the mass of the driver and pick-off is 10: 1 or greater. This ratio can be obtained in a conventional Coriolis flowmeter because the mass of the flow tube filled with material is relatively large compared to the relatively small mass of the associated driver and pick-off.
It is a problem to obtain an acceptable mass ratio in a lightweight Coriolis mass flow meter using an associated mounting device attached to a vibrating flow tube structure and conventional magnets. In general, the driver used to vibrate the material-filled metal flow tube is a magnet and coil combination structure, typically the magnet is attached to the flow tube and the coil is attached to another flow tube or support structure. The mass of the magnet is problematic in providing a lightweight flowmeter because of the metallurgical consideration that the effective minimum size of the magnet is limited to about 5 mg. The combined mass of the associated hardware used to attach the magnet to the flow tube is about 7 mg. To obtain a desired mass ratio of 10 to 1, the mass of the flow tube filled with the material should be at least 70 mg. The problem is to provide a Coriolis mass flow meter having a material-filled, oscillating flow tube structure having a mass of about 70 mg or less to measure a low mass mass flow rate.

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solution

The above and other problems are solved by the present invention as the Coriolis mass flowmeter is small and lightweight and is provided theoretically suitable for measurement of density information for mass flow and small amount of material flow. The flow meter of the present invention is compact and has a flow tube having a flow rate of about 10 kg / h or less and an inner diameter of about 2 mm or less. For example, the flow tube itself may be as small as a human hair with a proportional wall thickness.

In the present invention, the flow tube may be formed of any suitable material and is coated with a magnetic material. The magnetic material may be formed on the flow tube by spraying or vapor deposition. The magnetic material may alternatively be made in one piece with the flow tube, or the flow tube may be made of the magnetic material itself. The present invention allows for the removal of separate magnets to prevent manufacturing problems associated with the attachment and alignment of magnets to the flow tube as well as physical problems due to excessive mass.

Both the driver and sensor magnets can be removed with the present invention. Generally, a Coriolis sensor uses a magnet and a coil as a phase-sensing "pick-off" assembly that provides information about the Coriolis deflection in the flow tube. According to the present invention, the magnet for the pick-off assembly is constructed in the same manner as the magnet for the driver. Therefore, the driver or pick-off magnets, or both, can be configured in the manner disclosed in the present invention.

An alternative implementation of a very light flow tube has a driver of the structure as described and a pick-off signal generated by optical measurements. A suitable pick-off is a light device having a light emitter and a light collector disposed across the flow tube. The curvature of the flow tube controls the transmitted light, which is received and converted into an output signal indicative of the vibrations of the flow tube including the Coriolis reaction.

An important advantage of the Coriolis mass flowmeter of the present invention is the magnetic plating or coating of the flow tube. Such plating may be applied through a plating bath, vapor deposition, plasma deposition or other plating system. This is advantageous in that a very thin layer can be deposited on the flow tube or a thin layer can be integrally formed on the flow tube. This causes a very small amount of mass to be distributed over the length of the specified tube and is used to drive the flow tube with proper vibration with the drive coil. If the plated mass is small as well as distributed, the effect of the density change on the generated output information can be reduced. Also, a low plating mass causes the Coriolis mass flow meter to resonate at an acceptable frequency that allows for improved density accuracy.

According to one possible embodiment of the present invention, a magnet coating is used in the flow tube to act like a magnet with an internal N / S magnetic field. According to another embodiment of the present invention, a plating bath is used to deposit a soft magnetic material ("ferrous" or "permeable") in the flow tube. The iron material is attracted by the driver coil. The drive system using this material with a single driver coil is a "full-on" type rather than the standard "push-pull system" of conventional Coriolis mass flow meters. However, the opposing drive coils driven by each half of the drive waveform will be able to alternately pull the flow tubes in the opposite direction at the drive frequency. According to another embodiment, the flow tube itself may be formed of a magnetic material having an internal N / S magnetic field.

Plating of the magnetic material may be manufactured continuously on the entire flow tube, or may be made only in the axial portion by selective etching to be used to form the final plating pattern. The iron material may also be fabricated from a composite flow tube, wherein the iron material of the synthesis flow tube is co-extruded outside the flow tube and selectively etched.

According to one embodiment of the present invention, the flow tube has a magnetic material that is linear and is deposited in the axial center portion of the flow tube. Another embodiment is a U-shaped flow tube having left and right legs, and a central portion connected to the upper portions of the left and right legs. The central portion of the U-shaped flow tube has a layer of magnetic material deposited at the center.

The straight tube embodiment and the U-shaped flow tube embodiment both include a flow meter that utilizes an optical pick-off to detect the Coriolis reaction of the flow tube when the flow tube is vibrated by a magnet close to the deposition layer of magnetic material . According to another embodiment, the magnetic layer is formed of a ferrous material and is oscillated in a full-on mode by a single drive coil. Another embodiment is a flow tube having a layer of soft, magnetic ferrous material, wherein the flow tube is vibrated in a push-pull mode using a pair of coils disposed across the flow tube. Another embodiment has a magnetic material disposed only in the axial center of the flow tube. Another embodiment includes a flow tube having a magnetic material deposition layer in its entire axial length. Another embodiment has a flow tube entirely formed of a magnetic material. Another embodiment has a magnetic material applied to the entire axial length of the flow tube.

According to another embodiment, the flow meter has a pair of U-shaped flow tubes to which a magnetic material is applied at the top center, an optical detector on each leg of the flow tube, and a drive magnet disposed between the flow tubes. In another embodiment, the Coriolis mass flow meter has a pair of linear flow tubes with a magnetic material deposited, along with an optical detector and a driver coil disposed in the middle of the flow tubes. In another embodiment, the pair of linear flow tubes are oriented parallel to each other and are vibrated by a magnet disposed outside the flow tube. In another embodiment, a Coriolis mass flow meter has parallel flow tubes formed of a magnetic material having a magnetic and drive magnet and a pair of pick-off magnets disposed between the flow tubes.

It can thus be seen that the Coriolis mass flowmeter of the present invention can be developed in technology by providing a Coriolis mass flowmeter that is smaller in size and smaller in mass than the current Coriolis mass flowmeter formed of metal. While the present invention is directed to a small Coriolis mass flow meter, the benefits described by the above described solutions are equally applicable to large sensors.

According to an aspect of the present invention,

Flow tube means for receiving a material flow and generating Coriolis deflection by oscillating with said material flow,

Driver coil,

A meter electronics for applying a drive signal to the driver coil to vibrate the flow tube means with a material flow,

Off means coupled to said flow tube means for generating a pick-off signal indicative of said Coriolis deflection of said flow tube means, and

And means for applying the pick-off signal to the meter electronics for generation of an output signal indicative of the material flow, the Coriolis flowmeter comprising:

Said flow tube means being made of a magnetic material,

Wherein the driver coil generates a magnetic field that interacts with the magnetic material to vibrate the flow tube means filled with the material in response to application of the drive signal.

The magnetic material preferably comprises a layer of iron material contained in at least a portion of the outer surface of the flowtube means.

Preferably, the magnetic material is shorter than the entire axial length of the flow tube means.

The magnetic material is preferably present in the entire axial length of the flow tube means.

Said magnetic material comprising an iron material integrally formed in at least an outer radial portion of said flow tube,

The iron material preferably has no internal magnetic field.

The magnetic material is preferably applied in a shorter length than the entire axial length of the flow tube means.

The magnetic material is preferably applied to the entire axial length of the flow tube means.

The magnetic material preferably comprises a ferromagnetic material having a self-contained magnetic field.

The magnetic material preferably comprises an outer layer that is shorter than the entire axial length of the flow tube means.

The magnetic material preferably comprises an outer layer present in the entire axial length of the flow tube means.

The magnetic material is preferably integrally formed at least in the outer radial portion of the flow tube means.

Preferably, the magnetic material is integrally formed to be shorter than the entire axial length of the flow pipe means.

The magnetic material is preferably integrally formed in the entire axial length of the flow tube means.

The flow tube means is preferably straight.

Preferably, the flow tube means has an irregular shape.

The flow tube means is preferably U-shaped.

Preferably, the pick-off means includes first and second optical pick-offs, each of which includes a light emitter and an optical receiver that convert received light into an electrical signal.

The driver coil vibrates the flow tube means in a full-ONE mode, and when current is applied, in the full-ONE mode the material of the flow tube means is magnetically attached to the driver coil, It is preferable that the elastic force inherent to the flow tube means restores the flow tube means to a rest state.

The driver coil forming a first driver coil,

Wherein the Coriolis flowmeter further comprises a second driver coil,

The first driver coil and the second driver coil being disposed opposite the flow tube means,

Wherein the meter electronics generates a periodically varying magnetic field by applying an opposing sinusoidal current to the first driver coil and the second driver coil, wherein the periodically varying magnetic field causes the flow tube means to contact the first driver coil It is desirable to periodically oscillate between the second driver coils in a push-pull mode.

The mass flow rate of the material flow is preferably less than 10,000 g / h.

The flow tube means preferably has an inner diameter of less than 2 mm.

The flow tube means has an inner diameter of less than 2 mm, and the mass flow rate of the material flow is preferably less than 10,000 g / h.

The mass flow rate of the material flow is preferably less than 10 g / h.

The flow tube means preferably has an inner diameter of less than 0.2 mm.

The flow tube means has an inner diameter of less than 0.2 mm, and the mass flow rate of the material flow is preferably less than 10 g / h.

The flow tube means preferably has an inner diameter of less than 0.9 mm.

The flow tube means has an inner diameter of less than 0.9 mm, and the mass flow rate is preferably less than 10,000 g / h.

The flow tube means preferably comprises a single flow tube.

The flow tube means comprising a first flow tube and a second flow tube parallel to the first flow tube,

The driver coil is preferably disposed between the first flow tube and the second flow tube to vibrate the first flow tube and the second flow tube in opposite phases.

Wherein the first flow pipe and the second flow pipe are U-shaped with a left leg and a right leg connected by an upper central element, respectively,

The pick-off means preferably includes first and second optical pick-offs adjacent the flow tube for generating the pick-off signal indicative of the Coriolis bias of the flow tube.

The driver coil is preferably disposed close to the axial central portion of the upper central element.

Wherein the magnetic material comprises a ferromagnetic material having an internal magnetic field,

The magnetic material extends along the axial length of the flow tube such that a magnetic field of the magnetic material is applied to the pick-off,

The pick-off preferably generates the pick-off signal indicative of the Coriolis deflection in response to the magnetic field of the magnetic material and the Coriolis deflection of the U-shaped flow tube.

The pick-off means preferably includes first and second optical pick-offs adjacent the flow tube for generating the output signal indicative of the Coriolis bias of the flow tube.

The flow pipe is preferably formed of stainless steel.

Said flow tube means being formed of a ferromagnetic material having an internal N / S magnetic field,

Wherein the pick-off means is a magnetic transducer,

Said magnetic material extending axially to said drive coil and said flow tube means adjacent said magnetic transducer,

The vibration of the material filled in the flow tube means preferably causes a magnetic field indicative of the Coriolis deflection in the magnetic transducer.

The flow tube means comprises a double linear flow tube,

The driver coils are preferably disposed midway between the flow tubes and are effective to vibrate the double flow tubes in opposite phase.

Said flow tube comprising a double parallel flow tube,

The Coriolis flowmeter preferably further comprises a pair of driver coils disposed on the outer side of the flow tube and effective to vibrate the double flow tubes in opposite phase.

The pick-off is preferably an optical pick-off.

The pick-off is preferably a magnetic transducer.

The driver coil is effective to vibrate the flow tube means in opposite phase to a push-pull mode,

Preferably, the pick-off means comprises a magnetic transducer that interacts with the magnetic field of the oscillating flow tube means to generate the pick-off signal.

Said flow tube means comprising a pair of said linear flow tubes,

The driver coil being disposed in the middle of the flow tubes adjacent the axial center of the flow tube to vibrate the flow tube in a transverse direction in opposite phase,

The transducer is preferably disposed in the middle of the flow tube opposite to the driver coil.

Said flow tube means comprising a pair of U-shaped flow tubes,

The driver coil is disposed between the flow tubes close to the upper axial center of the flow tube,

The transducer is preferably disposed between the flow tubes opposite the driver coils.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other features of the present invention are better understood with reference to the following detailed description when taken in conjunction with the drawings, wherein: FIG.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a detailed illustration of a possible exemplary embodiment of a straight flow tube,

2 is a detailed view of an example of a U-shaped flow pipe,

Figures 3 and 4 show a detailed view of a Coriolis mass flow meter including the straight flow tube of Figure 1,

FIGS. 5 and 6 are views showing a Coriolis mass flow meter including the U-shaped flow pipe of FIG. 2 in detail;

FIG. 7 is a detailed view of a light-emitting diode and an optical receiver including the pick-offs of FIGS. 3 to 6,

Figure 8 shows the flow tube of Figure 1 connected to a single "full-on" driver coil,

Figure 9 shows the flow tube of Figure 1 connected to a "push-pull" type driver,

Figures 10-13 illustrate another embodiment of a straight flow tube,

Figure 14 shows an embodiment of a double U-shaped flow tube of the present invention, and

15 to 17 are views showing a double linear flow tube of the present invention.

Detailed description of Figure 1

Figure 1 shows in detail a straight flow tube 101 comprising a hollow tube 102 having a shaft surrounded by a magnetic material, which may comprise a hard magnetic material or a soft ferrous magnetic material. The hollow tube 102 has a left end 104L and a right end 104R. The magnetic element 103 may be a plating metal used on the surface of the straight tube 102. The metal for plating is a thin layer having a thickness of about 0.0013 cm. The plated element 103 may be applied to the entire axial length of the flow tube 102 as shown in Figure 11 or may be concentrated in the middle of the shaft portion of the flow tube 102 as shown in Figures 1 and 10 have. In one possible embodiment, the element 103 may be a magnetic coating that reacts exactly like a magnet. The magnetic cladding material may be deposited with a plasma deposition system. With the use of a magnetic covering material, the element 103 can react exactly like a magnet with an N or S magnetic field. The magnetic wrapping material also allows the flow tube 101 to vibrate by a single driver coil during a "push-pull" operation.

According to a possible second embodiment, the element 103 may comprise a wrought iron magnetic material that does not have a unique N / S magnetic field but can be operated on a single coil that can only pull the element 103 towards the coil . This type of drive system is referred to as "pull-only" since the driver coil can only pull the ferrous material 103. The iron material 103 is attracted toward the excited coil regardless of the direction of the current passing through the coil. The flow tube 101 is vibrated during use by applying a voltage to the associated driver coil so as to pull the soft iron 103 toward the coil. The inherent elasticity of the flow tube 101 is used to cause the flow tube to bend again in a stopped state when the current through the driver coil is cut off. This type of flow tube and associated coil is shown in Fig.

Alternatively, the flow tube 101 may include two driver coils (not shown) that vibrate the flow tube 102 and the element 103 when alternating voltages are applied to the coils D1 and D2, Lt; / RTI >

2,

Fig. 2 shows a U-shaped flow pipe 201 similar to the flow pipe 101. Fig. The U-shaped flow tube 201 includes a tubular element 202 having a left side 202L and a right side 202R with a magnetic element 203 connected to the upper central portion 202C of the tube 202. [ The U-shaped tube 202 has a lower left end 204L and a lower right end 204R. When in use, the flow tube 202 is vibrated by magnetic interaction between the magnetic element 203 and the associated driver coil, as shown in Figs. 5 and 6.

3 and 4

Figs. 3 and 4 show the flow pipe 101 included in the Coriolis mass flow meter 300. Fig. Coriolis mass flow meter 300 includes a flow tube assembly 101 that includes a flow tube 102, a magnetic material 103, a driver coil D, a left pick-off LP0, Off process (RPO), left flange or left process connection 105, and right flange or right process connection 106. The coriolis mass flow meter 300 further includes meter electronics 321 that conductors 306 and 307 control the driver coil D to vibrate the flow tube 101 in a full- And the current flowing through the coil D applied in the full-ONE mode is the elastic force of the flow tube 101 that restores the flow tube 101 to the stop state when the current through the driver coil D is cut off, Thereby deflecting the flow pipe 101 toward the driver coil.

The material flow to be treated is received by the process connection 105 from a source of material not shown. The material flows right through the flow tube 102 toward the process connection 106 outgoing from the Coriolis mass flow meter. Vibration of the flow tube 102 by the driver coil D along with the material flow causes Coriolis deflections in the flow tube 102. These deflections are detected by the pick-offs LP0 and RP0 and converted into electric signals. An electrical signal is applied to the meter electronics 321 via paths 304, 305, 308, and 309, which processes the signal to generate information about the material flow. The information is used via output path 322 to an unshown utilization circuit. The meter electronics 321 is shown only in Fig. 3 to minimize the complexity of the figure.

The driver coil D oscillates the flow tube 102 in a " full-only "mode in which the applied coil D intermittently pulls the flow tube 102 when intermittently applied by the leads 306 and 307 . The flow tube 102 is returned to the stopped state due to the inherent elastic force when the current through the coil D is stopped, respectively. The driver coil D oscillates the flow tube up and down as shown in Fig. The flow pipe 102 shown in Fig. 3 vibrates in and out with respect to the plane of Fig. As shown in FIG. 7, it is advantageous that the pick-off LP0, RP0 is an optical pick-off comprising a light emitting diode (LED) 701 and an optical receiver 702. The flow tube 102 vibrates under the influence of the driver coil D to block and adjust the light beam 703 transmitted from the LED 701 towards the optical receiver 702. The optical receiver 702 converts the pattern of the received light wave into an output signal and the output signal is transmitted to the meter electronics 321 via paths 304, 305, 308 and 309.

5 and 6

Figs. 5 and 6 show a front view and a perspective view of the flow pipe 201 of Fig. 2 implemented in the Coriolis mass flow meter 500, respectively. The legs 202L and 202R of the U-shaped flow pipe 202 are attached to the manifold 503 that receives material flow at the process connection 501 and extend the flow received through the legs 202L, And the right leg 202R in the course of which the material flow is received by the output end of the manifold 503 and applied to the right process connection 502. The driver coil D oscillates the flow tube 202C in a "full-on" mode in a manner similar to that described with respect to the Coriolis mass flow meter 300 of FIGS. The oscillation of the flow tube 202 with the material flow causes the Coriolis deflection of the flow tube 202 where the Coriolis deflection is detected by the pick offs LPO and RPO and is detected by the meter electronics 321 through the leads 304, 305, And the meter electronics processes the signal to generate output information about the material flow. This output information arrives via path 322 to a utilization circuit not shown.

The Coriolis mass flowmeters of FIGS. 5 and 6 are manufactured and manufactured to satisfy the ratio of the mass of the flow pipe filled with the material to the mass of the driver and the pick-off of 10: 1. One such embodiment includes a flow tube having an inner diameter of 0.2 mm and a flow rate of 10 g / h. The second embodiment includes a flow tube having an inner diameter of 0.9 mm and a flow rate of 10,000 g / h.

8 and 9

Flow tube 102 is operated in a "full-on" vibration mode using a single driver coil D coupled to the flow tube as shown in FIG. In the "full-on" mode, the current through the driver coil D pulls the flow tube 102 from its original stationary state. When the flow stops, the flow tube is restored to the stopped state by the elastic force inherent to the flow tube 102. Alternatively, as shown in Fig. 9, the flow tube 102 may be vibrated in a "push-pull" mode using a pair of driver coils D1 and D2. In the "push-pull" mode, the current through the coil D1 deflects the element 103 and the flow tube 102 upward. The stop of the current passing through the driver coil D2 together with the current passing through the driver coil D1 deflects the element 103 and the flow tube 102 downward. As shown in Fig. 9, energization and de-energization of these alternating currents of the driver coils D1 and D2 generate an alternating magnetic field that oscillates the flow tube 102 in the transverse direction. The embodiment of FIG. 8 may be used when the original elastic force of the flow tube 102 structure is suitable to restore the flow tube 102 to a rest state when the driver coil D is not applied. The "push-pull" embodiment of Fig. 9 may be used where it is desired to be vibrated under the influence of a magnetic field in each direction across the longitudinal outlet of the flow tube. U-shaped flow tube 202 may be similarly operated in a "full-on" or "push-pull" mode. The leads 306A, 307A of FIG. 9 are connected to the meter electronics 321.

10 To  13 detailed description

10-13 illustrate different alternative structures that may be used to apply the flow tubes 101,202. 10 shows a flow pipe in which a magnetic material is integrally formed in the axial center portion 1002 of the flow pipe 1000. Fig. The ends 1001 and 1003 do not include a magnetic material. The embodiment of FIG. 11 differs from the embodiment of FIG. 10 in that the entire flow tube 1100 is darkened to indicate that the magnetic material is integrally formed with respect to the total flow tube length. 11 The magnetic material of the flow tube 1100 may be of a soft or hard type. The flow tube 1100 may also be entirely formed of a material such as steel or stainless steel 400 having an internal N / S magnetic field. Figure 12 shows an embodiment in which the magnetic material is applied as a film to the surface of the flow tube. In Fig. 12, the magnetic material 1202 is applied to the center portion of the flow tube, but the ends 1201 and 1203 have no magnetic material. The embodiment of Figure 13 differs from the embodiment of Figure 12 in that the flow tube has a magnetic material 1301 applied to the surface of the entire flow tube length. The magnetic material of the flow tubes of Figs. 10-13 may be of the soft or hard type.

Figs. 10-13 illustrate an alternative embodiment to the straight tube 101 of Fig. The U-shaped tube 203 may have similar embodiments within a range where the magnetic material can be integrally formed with less than all or a portion of the flow tube. Alternatively, the magnetic material may be deposited on a surface of a length shorter than the length or the entire length of the U-shaped pre-set flow tube 203 of FIG. Alternatively, the U-shaped flow tube of FIG. 2 may be formed of a material such as steel or stainless steel 400 having an internal N / S magnetic field.

The "magnetic material" used in the present invention is used as a "soft" soft iron material having no inherent N / S magnetic field. But may also be used as a ferromagnetic material having a permanent N / S magnetic field.

14,

Figure 14 shows a dual U-shaped flow tube Coriolis mass flow meter 1400 embodying the present invention. The Coriolis mass flow meter 1400 is similar to the single U-shaped flow tube Coriolis flowmeter of FIG. 6, except that the Coriolis flowmeter of FIG. 14 has a pair of U-shaped flow tubes 1402-1 and 1402-2. The driver coil D is disposed between the two flow tubes. The magnetic material in the axial center portion of the flow tube upper element is indicated by 1403-1 and 1403-2. The magnetic material may be of a hard or soft type. When the magnetic material is a soft type, the driver coil D vibrates the two flow tubes in opposite phases to the flow tubes drawn to the driver coil D when the current flows, and when the current does not flow, And is returned to the normal stop state. If the magnetic material is a rigid type with an internal N / S magnetic field, the driver coil D can vibrate the two flow tubes in opposite directions in opposite phases. The pick-offs LP0 and RP0 include a light emitter and an optical receiver. The light emitter and the optical receiver operate in a known manner to generate an output signal indicative of the oscillation of the two flow tubes. The output signal is adjusted according to the amount of light received by the optical receiver in response to the oscillating condition of the flow tubes. The output conductors 304, 305, 308, 309, 306, and 307 extending to the meter electronics 321 are displayed as shown in FIG. The function of the leads is to control the driver (D) to vibrate the two flow tubes at the resonant frequency of the flow tubes through which the material flows. The function of the leads is also to extend the pick-off output signal to the meter electronics 321 to generate information about the material flow and extend this information via path 322 to a utilization circuit not shown. Manifold 503 operates in the same manner as described with respect to FIG. The left legs of the U-shaped flow pipe are indicated as 1402L1 and 1402L2. The right legs are indicated as 1402R1 and 1402R2. The upper elements of the flow tubes are indicated as 1402C1 and 1402C2.

15 and 16

15 and 16 show a dual linear tube coriolis mass flow meter (1500, 1600). The embodiment of FIG. 15 uses a single driver coil D disposed between two oscillating tubes to vibrate flow tubes in opposite phases. When the flow tube elements 1503-1 and 1503-2 include a soft magnetic material, the driver coil D is effective to vibrate the flow tubes in opposite phases using the full-on-one mode. In the full-on mode, flow tubes are attracted to the driver coil D only when current is applied. When the current flow stops, the flow tubes return to the stop state due to the inherent elastic force. When the magnetic material is a rigid type with an internal N / S magnetic field, it is efficient for the driver coil D to vibrate the flow tubes in a "push-pull" mode. The pick-off (LP0 top and LP0 bottom), as well as the pick-off (RP0 top and RP0 bottom), is an optical type as shown and described in Figure 14 to generate a pick- Lt; / RTI > The pick-off signal is transmitted to the meter electronics 321 in the same manner as described with reference to Fig.

The embodiment of FIGS. 15 and 16 includes a left input manifold 1505 that receives material flow into an opening 1508. The embodiment of Figures 10 and 15 further includes an output manifold 1506 connected to the right side of the flow tube and having an output 1509 through which material is discharged by a Coriolis mass flow meter.

Fig. 16 differs from the embodiment of Fig. 15 only in the provision of a pair of driver coils denoted D1 and D2. These driver coils D1 and D2 function to vibrate the two flow tubes in opposite phases under the control of the meter electronics 321. [ The "full-only" mode is used when the magnetic material is a soft type. The "push-pull" mode is used when the magnetic material is a hard type.

17,

17 shows a dual linear tube coriolis mass flow meter in which the flow tube is made of magnetic steel with an internal N / S magnetic field. This type of steel may be stainless steel 400 or a conventional steel which may have an internal magnetic field. With the above-described steel, a separate magnetic coating or magnetic material is unnecessary inside or outside. Instead, the internal magnetic field of the flow tube made of the aforementioned steel can be used. As shown in Fig. 17, the single driver coil D is controlled by the meter electronics 321 to vibrate the two flow tubes 1703-1 and 1703-2 in opposite phases. The vibrational states of the two flow tubes are detected by the magnetic pick-off (LPO, RPO), and the magnetic pick-off represents the vibration of the flow tube including Coriolis deflection generated by oscillating the flow tube with the material flow And sends a signal to the meter electronics 321. The advantage of the Coriolis mass flowmeter of Figure 17 is that it does not require the use of a special manufacturing technique for depositing an external magnetic coating or adding a magnetic material to the flow tube because the flow tube is made of a material having its own magnetic field . As shown in FIGS. 5, 6 and 14, a Coriolis mass flow meter with a U-shape can be provided to form flow tubes / flow tubes using magnet steel instead of rigid or soft magnetic coatings. As shown in Figure 17, an embodiment of a dual U-shaped tube includes a "push-pull" system that uses magnetic transducers as pick-offs to detect deflection of a flow tube including Coriolis deflection from a material flow, Mode using a driver coil to vibrate the flow tubes / flow tubes.

It is clearly understood that the claimed invention is not limited to the description of specific embodiments, but includes other modifications and variations within the spirit and scope of the invention. A "soft magnetic material" or "iron material" will be understood as a characteristic material that is attracted by a magnetic field but does not have its own internal N / S magnetic field.

"Ductile" or "hard magnetic material" may all be applied to a flow tube that has already been formed, such as a coating, film or outer layer, or combined with a flow tube when manufactured to form an integral structure that functions as a soft or hard magnetic material It is possible.

As used herein, "material" and "material flow" will be understood to include materials such as liquids as well as any materials that flow, such as flurries, plasma, It will also be appreciated that although the present invention is particularly advantageous for use with small flow tubes and small Coriolis mass flow meters with low flow rates, the principles of the present invention are advantageously applicable to flow meters of any size and any material.

Claims (42)

Flow tube means (102) for receiving a material flow and generating a Coriolis deflection by oscillating with said material flow, The driver coils (D), A meter electronics 321 for applying a drive signal to the driver coil D to vibrate the flow tube means with the material flow, Off means (LP0, RP0) connected to said flow tube means for generating a pick-off signal indicative of said Coriolis deflection of said flow tube means, and And means (304,305,308,309) for applying the pick-off signal to the meter electronics for generation of an output signal indicative of the material flow, the Coriolis flowmeter comprising: Said flow tube means comprising magnetic material (103, 203) Wherein the driver coil generates a magnetic field that interacts with the magnetic material to vibrate the flow tube means filled with the material in response to application of the drive signal. Coriolis flowmeter. The method according to claim 1, Characterized in that the magnetic material (103,203) comprises a layer of iron material contained in at least a portion of the outer surface of the flowtube means, Coriolis flowmeter. 3. The method of claim 2, Characterized in that the magnetic material (103,203) is present in a length less than the entire axial length of the flow tube means, Coriolis flowmeter. 3. The method of claim 2, Characterized in that the magnetic material (103,203) is present in the entire axial length of the flow tube means, Coriolis flowmeter. The method according to claim 1, Wherein the magnetic material (103, 203) comprises an iron material formed integrally in at least an outer radial portion of the flow tube, Characterized in that the iron material has no internal magnetic field. Coriolis flowmeter. delete delete The method according to claim 1, Characterized in that the magnetic material (103,203) comprises a ferromagnetic material having a self-magnetic field. Coriolis flowmeter. delete delete Claim 11 has been abandoned due to the set registration fee. 9. The method of claim 8, Characterized in that the magnetic material (103,203) is integrally formed at least in the outer radial portion of the flow tube means, Coriolis flowmeter. delete delete delete delete delete Claim 17 has been abandoned due to the setting registration fee. The method according to claim 1, Wherein the pick-off means comprises first and second optical pick-offs (700) each comprising a light emitter and an optical receiver for converting the received light into an electrical signal, Coriolis flowmeter. The method according to claim 1, The driver coil D vibrates the flow tube means in a full-ONE mode and the material of the flow tube means is magnetically attached to the driver coil when current is applied in the full-ONE mode, Characterized in that the resilient force inherent in said flow tube means, when interrupted, returns said flow tube means to a rest state. Coriolis flowmeter. The method according to claim 1, The driver coil forms the first driver coil D1, Wherein the Coriolis flowmeter further comprises a second driver coil (D2) Said first driver coil and said second driver coil being disposed opposite said flow tube means, Wherein the meter electronics generates a periodically varying magnetic field by applying an opposing sinusoidal current to the first driver coil and the second driver coil, the periodically varying magnetic field causing the flow tube means to contact the first driver coil And oscillates periodically in a push-pull mode between the second driver coils. Coriolis flowmeter. delete delete delete delete delete delete delete delete delete Claim 29 has been abandoned due to the setting registration fee. The method according to claim 1, Said flow tube means comprising a first flow tube (1402C1) and a second flow tube (1402C2) parallel to said first flow tube, Wherein said driver coil is disposed intermediate said first flow tube and said second flow tube to vibrate said first flow tube and said second flow tube in opposite phase, Coriolis flowmeter. Claim 30 has been abandoned due to the set registration fee. 30. The method of claim 29, Wherein said first flow pipe and said second flow pipe are U-shaped with a left leg and a right leg connected by an upper central element, respectively, Characterized in that the pick-off means comprises first and second optical pick-offs adjacent the flow tube for generating the pick-off signal indicative of the Coriolis deflection of the flow tube. Coriolis flowmeter. delete Claim 32 is abandoned due to the set registration fee. 30. The method of claim 29, Wherein the magnetic material comprises a ferromagnetic material having an internal magnetic field, The magnetic material extends along the axial length of the flow tube such that a magnetic field of the magnetic material is applied to the pick-offs LP0, RP0, Characterized in that the pick-off (LP0, RP0) is responsive to the magnetic field of the magnetic material and the Coriolis deflection of the U-shaped flow tube to generate the pick-off signal indicative of the Coriolis deflection. Coriolis flowmeter. Claim 33 is abandoned due to the set registration fee. 30. The method of claim 29, Characterized in that the pick-off means comprises first and second optical pick-off (700) adjacent the flow tube for generating the output signal indicative of the Coriolis bias of the flow tube. Coriolis flowmeter. delete The method according to claim 1, Said flow tube means being formed of a ferromagnetic material having an internal N / S magnetic field, The pick-off means LP0 and RP0 are magnetic converters, Said magnetic material extending axially in said flow tube means adjacent said driver coil and said magnetic transducer, Wherein vibrations of the material filled in said flow tube means cause a magnetic field indicative of said Coriolis deflection of said magnetic transducer, Coriolis flowmeter. delete delete delete delete The method according to claim 1, The driver coil D is effective to vibrate the flow tube means 1703-1, 1703-2 in opposite phases in a push-pull mode, Characterized in that the pick-off means comprises a magnetic transducer which interacts with the magnetic field of the oscillating flow tube means to generate the pick-off signal. Coriolis flowmeter. delete delete

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