CA1298487C - Coriolis mass flowmeter - Google Patents
Coriolis mass flowmeterInfo
- Publication number
- CA1298487C CA1298487C CA000539199A CA539199A CA1298487C CA 1298487 C CA1298487 C CA 1298487C CA 000539199 A CA000539199 A CA 000539199A CA 539199 A CA539199 A CA 539199A CA 1298487 C CA1298487 C CA 1298487C
- Authority
- CA
- Canada
- Prior art keywords
- mass flowmeter
- loops
- coriolis mass
- flowmeter according
- tubes
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/8409—Coriolis or gyroscopic mass flowmeters constructional details
- G01F1/8413—Coriolis or gyroscopic mass flowmeters constructional details means for influencing the flowmeter's motional or vibrational behaviour, e.g., conduit support or fixing means, or conduit attachments
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/8409—Coriolis or gyroscopic mass flowmeters constructional details
- G01F1/8431—Coriolis or gyroscopic mass flowmeters constructional details electronic circuits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/845—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits
- G01F1/8468—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits
- G01F1/8472—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having curved measuring conduits, i.e. whereby the measuring conduits' curved center line lies within a plane
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/845—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits
- G01F1/8468—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits
- G01F1/8472—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having curved measuring conduits, i.e. whereby the measuring conduits' curved center line lies within a plane
- G01F1/8477—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having curved measuring conduits, i.e. whereby the measuring conduits' curved center line lies within a plane with multiple measuring conduits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/845—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits
- G01F1/8468—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits
- G01F1/8481—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having loop-shaped measuring conduits, e.g. the measuring conduits form a loop with a crossing point
- G01F1/8486—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having loop-shaped measuring conduits, e.g. the measuring conduits form a loop with a crossing point with multiple measuring conduits
Abstract
?
ABSTRACT
CORIOLIS MASS FLOWMETERS
In a coriolis mass flowmeter a flexible tube structure for carrying the fluid to be measured comprises parallel tubes (1, 2) fixed at (7, 8) and formed with loops (5, 6). Electromagnetic means vibrate the loops in their own planes in directions normal to arms A, B of the tubes setting up torques on the loops sensed by two sensor pairs (14, 15). The signals from the two sensors are used to measure the mass flow rate (since the later is proportional to the time phase-shift of these signals).
Also the signals are used to drive and control the driving device for the electromagnetic means.
ABSTRACT
CORIOLIS MASS FLOWMETERS
In a coriolis mass flowmeter a flexible tube structure for carrying the fluid to be measured comprises parallel tubes (1, 2) fixed at (7, 8) and formed with loops (5, 6). Electromagnetic means vibrate the loops in their own planes in directions normal to arms A, B of the tubes setting up torques on the loops sensed by two sensor pairs (14, 15). The signals from the two sensors are used to measure the mass flow rate (since the later is proportional to the time phase-shift of these signals).
Also the signals are used to drive and control the driving device for the electromagnetic means.
Description
~2~ '7 CORIOLIS MASS FLOWMETERS
FIELD OF THE INVE~.ITION
This invention relates ~o coriolis mass flowmeters that can advantageously be used industrially.
DESCRIPTION OF THE PRIOR ART
A coriolis force is defined as a velocity dependent with respect to a rotating coordinate system and mass flowmeters involving this principle are known and commercially available.
OUTLINE OF THE IN~ENTION
An object of -the present invention is to provide a tube structure carrying the fluid to be measured arranged in such a way that the forces arising in the operation of the meter enable the structure to have reduced stiffness and consequently reduced risk of fatigue failure and economy in the power required to operate the meter.
The invention provides, in a broad aspect, a coriolis mass flowmeter comprising substantially parallel tubes for fluid of which the mass flow is to be measured when passing in the same direction therethrough; first means for adapting said tubes at one ~0 end thereof jointly to receive said fluid to pass therethrough:
second means for adapting said tubes at the other end thereof jointly to deliver said fluid after passing therethrough, each said tube being formed between its ends with a loop from which two arms, constituting portions of said tube, extend respectively to said first and second means, means remote from said loops holding said arms fixed in the flowmeter, means for vibra~ting said loops respectively in the planes thereof with equal frequency in opposite phases whereby coriolis forces are experienced by said .~
' ~29l~
la 72256-2 arms such as to exert vibratory torques on said loops having a phase-shift dependent on the mass of said fluid when passing through said tubes and sensing means responsive to said phase-shift for providing a measurement signal corresponding to the mass flow of said fluid through said tubes.
According to the present invention a coriolis mass flowmeter comprises substantially parallel tubes each arranged for Eluid to be measured to pass in the same direction through the tubes, each tube being formed between its ends with a loop so that arms forming parts of the tube project from the loop in opposite directions, the ends of the arms remote from the loops being fixed in ;;.~`
~ 9~
space, means for vibrating the loops in their planes with equal frequency in opposite phases whereby coriolis forces are experie.n~ed by the arms such as to exert vibratory torques on the loops having a phase-shift dependent on the 5 mass of fluid when flowing through the pipes and sensing means responsive to the phase-shift for providing a mass flow measurement signal.
DESCRIPTION OF THE D AWINGS
In order tha~ the invention may be clearly 10 understood and readily carried into effect, coriolis mass flowmeters in accordance therewith will now be described, by way of example, with reference to the accompanying drawings, in which:-Fiyure 1 is a plan of a mechanical assembly in a 15 coriolis mass flowmeter;
Figures 2a, 2b are side and end elevations of theassembly of Figure l;
Figures 3a, 3b and 3c show very diagrammatically plan, side and end elevations of a modification of the ~ arrangement shown in Fi~ures 1 and 2;
Figure 4 is a block diagram showing an electronic circuit for use with the assemblies of Figure 1 to 3c.
Figures 5, 6 and 7 are explanatory diagrams;
Figure 8 is a diagram showing a modification of the 25 assem~ly of Figures 1, ~a, 2b; and Figure 9 is a diagram showing a further modification of the assembly of Figures 1, 2a, '2b~
Figures 1, 2a, 2b show a tube configuration comprising two identical lengths 1, ~ of tube having a 30 circular cross-section throughout. Inlet ends of these tubes merge at 3 to receive the fluid whose mass flow is to be measured. At their opposite ends the tubes merge at for the discharge of the fluid.
The central portion of each tube is folded back on 35 itself to form a rectangular loop 5, ~-with rounded corners. The tubes 1, 2 are parallel and the similar loops 5, 6 are ~uxtaposed as shown in ~igure 1 with arms A
~z9~
and B projecting in opposite directions therefrom. The ends of the tu~es l, 2 are rigidly mounted in frame members 7, 8 upstream and downstream of the loops 5, 6 so that when the ioops are vibrated as described below, the 5 tubes are vibrated at their resonant frequency in the planes of the loops.
The vibration of the loops 5, 6 is in opposite phase so that one moves up as the other moves down. This is e~ected by electromagnets 9, lO allocated respectively to the loops and designed to provide sufficient amplitude of oscillation to vibrate the tubes in a flexural mode. In each electromagnet a pole piece ll is made from annealed low carbon steel which allows a high flux density without saturation to provide a sufficient field strength and is fixed to a cross-bar 13. The associated coils 12 which ~' are mounted on pole pieces ll in vertical alignment with these pole pieces ll each have 776 turns of 28 A5W wire.
In operation, when a mass of fluid is flowing in the direction of the arrows V, coriolis forces C are set up in the arms A, B as shown in Figures 6 and 7. These are due to the oscillatory rotation W (Figure 5) of these arms which is achieved by the reciprocating driving forces FD
of the electromagnets 9, lO. When the force FD due to one electromagnet is in one direction (Figure 6) the coriolis force C on the arm B of the associated loop is enhancing the driving force while the coriolis force C on the arm A
is opposing the driving force. With the force FD due to the electromagnet in the opposite direction (Figure 7~ the coriolis force C in the arm B is again enhancing the driving force while the coriolis force on the arm A is again opposing the driving force. This tends to slow down the deflection of the arm A while accelerating the deflection of the arm B. Because the electromagnets 9, lO
are 180 out of phase the corresponding actions of their pairs A, B of arms are out of phase and a time phase shift is developed between the pairs of arms. The mass flow-rate of the~flowing fluid is detected by measuring the qde -ma~ k ~,~g&~
ti~.e phase shift bet~een two sensors as described below.
When the mass flowrate of the flowing fluid varies this phase shift varies and the variation can be recorded.
~ach of the aforementioned sensors comprises a 5 double pole perma~ent magnet 14 mounted on a vertical limb o~ one coiled pipe and a search coil lS facing the magnet, the search coil being on the corresponding vertical limb of the other coiled pipe, the second vertical limb of which carries the permanent magnet 14 of the second sensor 10 faclng a search coil on the first coil. Each coil 15 has ~00 turns of 30 AWG wire.
The electromagnets 9, 10 for vibrating ~he loops 5, are driven in phase with the output of the sensor coils 15 by feedbac~ connections 16 (Figure 4) an amplifier 17, 15 an automatic gain controller 18 and a power amplifier 19.
The mass flow measurement signal is derived by detecting the time phase shift between the sensors. For this purpose each of the sensor coils 15 is connected by its own gain amplifier ~0 and zero crossing comparator ~1 20 to a common arrangement of gates 22 feeding an integrator 23.
The various electronic units shown in Figure 4 are believed to be very well known to those skilled in the art and so do not need any further elucidation in this 25 specification.
Figures 3a to 3c show very diagrammatically an alternative configuration of tubes using the same principle as in Figure 1 to 2b, corresponding reference numerals being used in this alternative. An advantage of 30 this design is that only one driving coil 24 is needed for the two loops and the pole pieces are fixed directly to the loops at the point where the loops cross over with the coil between them so that no cross-bar is required with consequent reduction in the effect of frame vibration.
35 Alternating voltage applied to the coil 21 cause the pole pieces to separate raising one loop while depressing the other and then to approach one another depressing the *~ Je-mo~h ~2~8~
first loop and simultaneously raislng the second.
In another modification the two ~ubes are merged into one another before they meet the supporting frame mem'Ders 7, ~ whieh are then spaced further apart, thereby cancelling or minimising v~bration ~efore it is tran~-mitted to the frame of the instrument.
In a further modification each loop is circular.
In yet a further modification shown in Fi~ure 8, each loop 5, 6 is not closed but is open between the associated coaxial ~rms A, B. The required reversal of momentum of the fluid in rela~ion to the reciprocation of the driving force FD still results from this arrangement.
Figure 9 shows a modification in which a node plate 25 is fixed to the inputs of the tubes 1, 2 just ahead of the frame member 7 and a node plate ~6 is fixed to the outputs of the tubes 1, 2 just before the frame member 8.
These node plates ~5, 26 are located a few diameters from the respective frame members 7, 8. One advantage of these node plates is that they maintain the resonant energy between the two loops. A second advantage is that they reduce the effect of vibration and noise to and from the meter. A third advantage is that they reduce the bending stresses at the joints between the pipes and frame members 7, 8.
FIELD OF THE INVE~.ITION
This invention relates ~o coriolis mass flowmeters that can advantageously be used industrially.
DESCRIPTION OF THE PRIOR ART
A coriolis force is defined as a velocity dependent with respect to a rotating coordinate system and mass flowmeters involving this principle are known and commercially available.
OUTLINE OF THE IN~ENTION
An object of -the present invention is to provide a tube structure carrying the fluid to be measured arranged in such a way that the forces arising in the operation of the meter enable the structure to have reduced stiffness and consequently reduced risk of fatigue failure and economy in the power required to operate the meter.
The invention provides, in a broad aspect, a coriolis mass flowmeter comprising substantially parallel tubes for fluid of which the mass flow is to be measured when passing in the same direction therethrough; first means for adapting said tubes at one ~0 end thereof jointly to receive said fluid to pass therethrough:
second means for adapting said tubes at the other end thereof jointly to deliver said fluid after passing therethrough, each said tube being formed between its ends with a loop from which two arms, constituting portions of said tube, extend respectively to said first and second means, means remote from said loops holding said arms fixed in the flowmeter, means for vibra~ting said loops respectively in the planes thereof with equal frequency in opposite phases whereby coriolis forces are experienced by said .~
' ~29l~
la 72256-2 arms such as to exert vibratory torques on said loops having a phase-shift dependent on the mass of said fluid when passing through said tubes and sensing means responsive to said phase-shift for providing a measurement signal corresponding to the mass flow of said fluid through said tubes.
According to the present invention a coriolis mass flowmeter comprises substantially parallel tubes each arranged for Eluid to be measured to pass in the same direction through the tubes, each tube being formed between its ends with a loop so that arms forming parts of the tube project from the loop in opposite directions, the ends of the arms remote from the loops being fixed in ;;.~`
~ 9~
space, means for vibrating the loops in their planes with equal frequency in opposite phases whereby coriolis forces are experie.n~ed by the arms such as to exert vibratory torques on the loops having a phase-shift dependent on the 5 mass of fluid when flowing through the pipes and sensing means responsive to the phase-shift for providing a mass flow measurement signal.
DESCRIPTION OF THE D AWINGS
In order tha~ the invention may be clearly 10 understood and readily carried into effect, coriolis mass flowmeters in accordance therewith will now be described, by way of example, with reference to the accompanying drawings, in which:-Fiyure 1 is a plan of a mechanical assembly in a 15 coriolis mass flowmeter;
Figures 2a, 2b are side and end elevations of theassembly of Figure l;
Figures 3a, 3b and 3c show very diagrammatically plan, side and end elevations of a modification of the ~ arrangement shown in Fi~ures 1 and 2;
Figure 4 is a block diagram showing an electronic circuit for use with the assemblies of Figure 1 to 3c.
Figures 5, 6 and 7 are explanatory diagrams;
Figure 8 is a diagram showing a modification of the 25 assem~ly of Figures 1, ~a, 2b; and Figure 9 is a diagram showing a further modification of the assembly of Figures 1, 2a, '2b~
Figures 1, 2a, 2b show a tube configuration comprising two identical lengths 1, ~ of tube having a 30 circular cross-section throughout. Inlet ends of these tubes merge at 3 to receive the fluid whose mass flow is to be measured. At their opposite ends the tubes merge at for the discharge of the fluid.
The central portion of each tube is folded back on 35 itself to form a rectangular loop 5, ~-with rounded corners. The tubes 1, 2 are parallel and the similar loops 5, 6 are ~uxtaposed as shown in ~igure 1 with arms A
~z9~
and B projecting in opposite directions therefrom. The ends of the tu~es l, 2 are rigidly mounted in frame members 7, 8 upstream and downstream of the loops 5, 6 so that when the ioops are vibrated as described below, the 5 tubes are vibrated at their resonant frequency in the planes of the loops.
The vibration of the loops 5, 6 is in opposite phase so that one moves up as the other moves down. This is e~ected by electromagnets 9, lO allocated respectively to the loops and designed to provide sufficient amplitude of oscillation to vibrate the tubes in a flexural mode. In each electromagnet a pole piece ll is made from annealed low carbon steel which allows a high flux density without saturation to provide a sufficient field strength and is fixed to a cross-bar 13. The associated coils 12 which ~' are mounted on pole pieces ll in vertical alignment with these pole pieces ll each have 776 turns of 28 A5W wire.
In operation, when a mass of fluid is flowing in the direction of the arrows V, coriolis forces C are set up in the arms A, B as shown in Figures 6 and 7. These are due to the oscillatory rotation W (Figure 5) of these arms which is achieved by the reciprocating driving forces FD
of the electromagnets 9, lO. When the force FD due to one electromagnet is in one direction (Figure 6) the coriolis force C on the arm B of the associated loop is enhancing the driving force while the coriolis force C on the arm A
is opposing the driving force. With the force FD due to the electromagnet in the opposite direction (Figure 7~ the coriolis force C in the arm B is again enhancing the driving force while the coriolis force on the arm A is again opposing the driving force. This tends to slow down the deflection of the arm A while accelerating the deflection of the arm B. Because the electromagnets 9, lO
are 180 out of phase the corresponding actions of their pairs A, B of arms are out of phase and a time phase shift is developed between the pairs of arms. The mass flow-rate of the~flowing fluid is detected by measuring the qde -ma~ k ~,~g&~
ti~.e phase shift bet~een two sensors as described below.
When the mass flowrate of the flowing fluid varies this phase shift varies and the variation can be recorded.
~ach of the aforementioned sensors comprises a 5 double pole perma~ent magnet 14 mounted on a vertical limb o~ one coiled pipe and a search coil lS facing the magnet, the search coil being on the corresponding vertical limb of the other coiled pipe, the second vertical limb of which carries the permanent magnet 14 of the second sensor 10 faclng a search coil on the first coil. Each coil 15 has ~00 turns of 30 AWG wire.
The electromagnets 9, 10 for vibrating ~he loops 5, are driven in phase with the output of the sensor coils 15 by feedbac~ connections 16 (Figure 4) an amplifier 17, 15 an automatic gain controller 18 and a power amplifier 19.
The mass flow measurement signal is derived by detecting the time phase shift between the sensors. For this purpose each of the sensor coils 15 is connected by its own gain amplifier ~0 and zero crossing comparator ~1 20 to a common arrangement of gates 22 feeding an integrator 23.
The various electronic units shown in Figure 4 are believed to be very well known to those skilled in the art and so do not need any further elucidation in this 25 specification.
Figures 3a to 3c show very diagrammatically an alternative configuration of tubes using the same principle as in Figure 1 to 2b, corresponding reference numerals being used in this alternative. An advantage of 30 this design is that only one driving coil 24 is needed for the two loops and the pole pieces are fixed directly to the loops at the point where the loops cross over with the coil between them so that no cross-bar is required with consequent reduction in the effect of frame vibration.
35 Alternating voltage applied to the coil 21 cause the pole pieces to separate raising one loop while depressing the other and then to approach one another depressing the *~ Je-mo~h ~2~8~
first loop and simultaneously raislng the second.
In another modification the two ~ubes are merged into one another before they meet the supporting frame mem'Ders 7, ~ whieh are then spaced further apart, thereby cancelling or minimising v~bration ~efore it is tran~-mitted to the frame of the instrument.
In a further modification each loop is circular.
In yet a further modification shown in Fi~ure 8, each loop 5, 6 is not closed but is open between the associated coaxial ~rms A, B. The required reversal of momentum of the fluid in rela~ion to the reciprocation of the driving force FD still results from this arrangement.
Figure 9 shows a modification in which a node plate 25 is fixed to the inputs of the tubes 1, 2 just ahead of the frame member 7 and a node plate ~6 is fixed to the outputs of the tubes 1, 2 just before the frame member 8.
These node plates ~5, 26 are located a few diameters from the respective frame members 7, 8. One advantage of these node plates is that they maintain the resonant energy between the two loops. A second advantage is that they reduce the effect of vibration and noise to and from the meter. A third advantage is that they reduce the bending stresses at the joints between the pipes and frame members 7, 8.
Claims (14)
1. A coriolis mass flowmeter comprising substantially parallel tubes for fluid of which the mass flow is to be measured when passing in the same direction therethrough;
first means for adapting said tubes at one end thereof jointly to receive said fluid to pass therethrough; second means for adapting said tubes at the other end thereof jointly to deliver said fluid after passing therethrough, each said tube being formed between its ends with a loop from which two arms, constituting portions of said tube, extend respectively to said first and second means, means remote from said loops holding said arms fixed in the flowmeter, means for vibrating said loops respectively in the planes thereof with equal frequency in opposite phases whereby coriolis forces are experienced by said arms such as to exert vibratory torques on said loops having a phase-shift dependent on the mass of said fluid when passing through said tubes and sensing means responsive to said phase-shift for providing a measurement signal corresponding to the mass flow of said fluid through said tubes.
first means for adapting said tubes at one end thereof jointly to receive said fluid to pass therethrough; second means for adapting said tubes at the other end thereof jointly to deliver said fluid after passing therethrough, each said tube being formed between its ends with a loop from which two arms, constituting portions of said tube, extend respectively to said first and second means, means remote from said loops holding said arms fixed in the flowmeter, means for vibrating said loops respectively in the planes thereof with equal frequency in opposite phases whereby coriolis forces are experienced by said arms such as to exert vibratory torques on said loops having a phase-shift dependent on the mass of said fluid when passing through said tubes and sensing means responsive to said phase-shift for providing a measurement signal corresponding to the mass flow of said fluid through said tubes.
2. A coriolis mass flowmeter according to Claim 1, in which said tubes are identical in length and diameter.
3. A coriolis mass flowmeter according to Claim 1, in which each said loop, as viewed in elevation, is in the form of a rectangle with rounded corners.
4. A coriolis mass flowmeter according to Claim 1, in which each said loop, as viewed in elevation, is in the form of a circle.
5. A coriolis mass flowmeter according to Claim 1, in which each said loop is an open loop consisting of a transverse limb and two substantially parallel limbs extending respectively from the ends of said transverse limb, said two arms associated with said loop being formed to extend in opposite directions respectively from the ends of said substantially parallel limbs remote from said transverse limb.
6. A coriolis mass flowmeter according to Claim 1, in which said loops are located respectively in parallel planes.
7. A coriolis-mass flowmeter according to Claim 1, in which said loops are located respectively in intersecting planes in positions such that they cross one another in the line of intersection of said planes, said vibrating means being unitary means located substantially at said line of intersection.
8. A coriolis mass flowmeter according to Claim 1, in which said vibrating means are electromagnetic means.
9. A coriolis mass flowmeter according to Claim 1, in which said vibrating means comprise spaced sensors each including a magnet mounted on one of said loops facing a search coil mounted on the other of said loops.
10. A coriolis mass flowmeter according to Claim 1, including means connecting said vibrating means and said sensing means and operative to maintain said frequency of vibration resonant with said vibratory torques.
11. A coriolis mass flowmeter according to Claim 1, including two node plates, one said node plate being mounted to bridge said tubes adjacent said first means and the second said node plate being mounted to bridge said tube adjacent said second means, said node plates being free from said means for holding said arms fixed and said means for holding said arms fixed being located to fix said arms at a first location between said first means and said one node plate and to fix said arms at a second location between said second means and said second node plate.
12 A coriolis mass flowmeter according to Claim 11, in which said node plates are arranged to maintain resonant energy between said two loops.
13. A coriolis mass flowmeter according to Claim 11, in which said node plates are arranged to reduce transmission of noise to and from the flowmeter.
14. A coriolis mass flowmeter according to Claim 11, in which said node plates are arranged to reduce bending of said tubes at said first and second locations.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB868614135A GB8614135D0 (en) | 1986-06-10 | 1986-06-10 | Coriolis mass flowmeters |
| GB8614135 | 1986-06-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1298487C true CA1298487C (en) | 1992-04-07 |
Family
ID=10599254
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000539199A Expired - Lifetime CA1298487C (en) | 1986-06-10 | 1987-06-09 | Coriolis mass flowmeter |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4934195A (en) |
| EP (1) | EP0311610B1 (en) |
| JP (1) | JPH01503483A (en) |
| AT (1) | ATE68261T1 (en) |
| AU (1) | AU7483387A (en) |
| CA (1) | CA1298487C (en) |
| DE (1) | DE3773674D1 (en) |
| GB (1) | GB8614135D0 (en) |
| WO (1) | WO1987007714A1 (en) |
Families Citing this family (35)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0333784A4 (en) * | 1987-07-27 | 1991-07-17 | Hyok Sang Lew | Convective inertia force flowmeter |
| US4843890A (en) * | 1988-07-08 | 1989-07-04 | Micro Motion, Incorporated | Coriolis mass flow rate meter having an absolute frequency output |
| US4879911A (en) * | 1988-07-08 | 1989-11-14 | Micro Motion, Incorporated | Coriolis mass flow rate meter having four pulse harmonic rejection |
| DE3829061A1 (en) * | 1988-08-26 | 1990-03-08 | Danfoss As | FLOW MEASURING DEVICE WORKING ACCORDING TO THE CORIOLIS PRINCIPLE (III) |
| US5115683A (en) * | 1988-09-27 | 1992-05-26 | K-Flow Division Of Kane Steel Co., Inc. | Coriolis mass flow meter adapted for low flow rates |
| DE3916285A1 (en) * | 1989-05-19 | 1990-11-22 | Krohne Messtechnik Massametron | MASS FLOW MEASURING DEVICE |
| US5060523A (en) * | 1990-01-19 | 1991-10-29 | Lew Hyok S | Vibrating looped conduit mass flowmeter |
| US5131280A (en) * | 1990-01-19 | 1992-07-21 | Lew Hyok S | Vibrating conduit mass flowmeter |
| US5373745A (en) * | 1991-02-05 | 1994-12-20 | Direct Measurement Corporation | Single path radial mode Coriolis mass flow rate meter |
| WO1992014123A1 (en) * | 1991-02-05 | 1992-08-20 | Donald Reed Cage | Improved coriolis mass flow rate meter |
| US5448921A (en) * | 1991-02-05 | 1995-09-12 | Direct Measurement Corporation | Coriolis mass flow rate meter |
| US5497665A (en) * | 1991-02-05 | 1996-03-12 | Direct Measurement Corporation | Coriolis mass flow rate meter having adjustable pressure and density sensitivity |
| US5604316A (en) * | 1994-10-19 | 1997-02-18 | Alonso; Joey G. | Multiple phase coriolis mass meter |
| US5753827A (en) * | 1995-10-17 | 1998-05-19 | Direct Measurement Corporation | Coriolis meteR having a geometry insensitive to changes in fluid pressure and density and method of operation thereof |
| US5907104A (en) * | 1995-12-08 | 1999-05-25 | Direct Measurement Corporation | Signal processing and field proving methods and circuits for a coriolis mass flow meter |
| US5926096A (en) * | 1996-03-11 | 1999-07-20 | The Foxboro Company | Method and apparatus for correcting for performance degrading factors in a coriolis-type mass flowmeter |
| US5827979A (en) * | 1996-04-22 | 1998-10-27 | Direct Measurement Corporation | Signal processing apparati and methods for attenuating shifts in zero intercept attributable to a changing boundary condition in a Coriolis mass flow meter |
| DE29609624U1 (en) * | 1996-05-30 | 1997-10-02 | Bopp & Reuther Messtech Gmbh | Measuring device for measuring the mass flow of a flowing medium |
| US20030216874A1 (en) | 2002-03-29 | 2003-11-20 | Henry Manus P. | Drive techniques for a digital flowmeter |
| US8467986B2 (en) * | 1997-11-26 | 2013-06-18 | Invensys Systems, Inc. | Drive techniques for a digital flowmeter |
| US7404336B2 (en) | 2000-03-23 | 2008-07-29 | Invensys Systems, Inc. | Correcting for two-phase flow in a digital flowmeter |
| US6311136B1 (en) * | 1997-11-26 | 2001-10-30 | Invensys Systems, Inc. | Digital flowmeter |
| US7124646B2 (en) * | 1997-11-26 | 2006-10-24 | Invensys Systems, Inc. | Correcting for two-phase flow in a digital flowmeter |
| US8447534B2 (en) | 1997-11-26 | 2013-05-21 | Invensys Systems, Inc. | Digital flowmeter |
| US7784360B2 (en) | 1999-11-22 | 2010-08-31 | Invensys Systems, Inc. | Correcting for two-phase flow in a digital flowmeter |
| GB2373336B (en) | 1997-12-19 | 2002-12-04 | Abb Ltd | Coriolis flow meter |
| BR9911805A (en) | 1998-07-02 | 2001-03-27 | Ind Res Ltd | Coriolis effect flowmeter |
| US6227059B1 (en) | 1999-01-12 | 2001-05-08 | Direct Measurement Corporation | System and method for employing an imaginary difference signal component to compensate for boundary condition effects on a Coriolis mass flow meter |
| JP2003528306A (en) * | 2000-03-23 | 2003-09-24 | インベンシス システムズ インコーポレイテッド | Correction for two-phase flow in digital flow meters. |
| US7127815B2 (en) * | 2001-11-26 | 2006-10-31 | Emerson Electric Co. | Method of manufacturing a Coriolis flowmeter |
| US7059199B2 (en) | 2003-02-10 | 2006-06-13 | Invensys Systems, Inc. | Multiphase Coriolis flowmeter |
| US7188534B2 (en) * | 2003-02-10 | 2007-03-13 | Invensys Systems, Inc. | Multi-phase coriolis flowmeter |
| US7065455B2 (en) * | 2003-08-13 | 2006-06-20 | Invensys Systems, Inc. | Correcting frequency in flowtube measurements |
| JP4254966B2 (en) * | 2006-03-14 | 2009-04-15 | 株式会社オーバル | Coriolis flowmeter with vibration direction regulating means |
| US7617055B2 (en) | 2006-08-28 | 2009-11-10 | Invensys Systems, Inc. | Wet gas measurement |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4491025A (en) * | 1982-11-03 | 1985-01-01 | Micro Motion, Inc. | Parallel path Coriolis mass flow rate meter |
| GB8304783D0 (en) * | 1983-02-21 | 1983-03-23 | Shell Int Research | Coriolis-type mass flow meter |
| JPH0663808B2 (en) * | 1984-07-11 | 1994-08-22 | イグザク・コ−ポレ−シヨン | Flowmeter for measuring mass flow rate in a flow of matter |
-
1986
- 1986-06-10 GB GB868614135A patent/GB8614135D0/en active Pending
-
1987
- 1987-06-02 AT AT87903714T patent/ATE68261T1/en not_active IP Right Cessation
- 1987-06-02 EP EP87903714A patent/EP0311610B1/en not_active Expired
- 1987-06-02 US US07/287,199 patent/US4934195A/en not_active Expired - Lifetime
- 1987-06-02 AU AU74833/87A patent/AU7483387A/en not_active Abandoned
- 1987-06-02 JP JP62503431A patent/JPH01503483A/en active Pending
- 1987-06-02 DE DE8787903714T patent/DE3773674D1/en not_active Expired - Fee Related
- 1987-06-02 WO PCT/GB1987/000378 patent/WO1987007714A1/en active IP Right Grant
- 1987-06-09 CA CA000539199A patent/CA1298487C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE3773674D1 (en) | 1991-11-14 |
| AU7483387A (en) | 1988-01-11 |
| ATE68261T1 (en) | 1991-10-15 |
| GB8614135D0 (en) | 1986-07-16 |
| US4934195A (en) | 1990-06-19 |
| EP0311610A1 (en) | 1989-04-19 |
| EP0311610B1 (en) | 1991-10-09 |
| WO1987007714A1 (en) | 1987-12-17 |
| JPH01503483A (en) | 1989-11-22 |
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