WO2012112030A2 - Rotor meter for measuring an amount of gas - Google Patents

Rotor meter for measuring an amount of gas Download PDF

Info

Publication number
WO2012112030A2
WO2012112030A2 PCT/NL2012/050019 NL2012050019W WO2012112030A2 WO 2012112030 A2 WO2012112030 A2 WO 2012112030A2 NL 2012050019 W NL2012050019 W NL 2012050019W WO 2012112030 A2 WO2012112030 A2 WO 2012112030A2
Authority
WO
WIPO (PCT)
Prior art keywords
rotor
coil
rotors
rotor meter
meter
Prior art date
Application number
PCT/NL2012/050019
Other languages
French (fr)
Other versions
WO2012112030A3 (en
Inventor
Paulus Josephus Adrianus Petrus HOEKS
Original Assignee
Flow Meter Group B.V.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Flow Meter Group B.V. filed Critical Flow Meter Group B.V.
Publication of WO2012112030A2 publication Critical patent/WO2012112030A2/en
Publication of WO2012112030A3 publication Critical patent/WO2012112030A3/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D4/00—Tariff metering apparatus
    • G01D4/02—Details
    • 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
    • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
    • G01F1/06—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects using rotating vanes with tangential admission
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F3/00—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow
    • G01F3/02—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement
    • G01F3/04—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having rigid movable walls
    • G01F3/06—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having rigid movable walls comprising members rotating in a fluid-tight or substantially fluid-tight manner in a housing
    • G01F3/10—Geared or lobed impeller meters

Definitions

  • the invention relates to a rotor meter for measuring the amount of gas flowing through a gas pipe, comprising a housing accommodating a measuring chamber an inlet opening and an outlet opening, the rotor meter furthermore comprising at least one rotor which is bearing-mounted in the housing and rotatable in the measuring chamber and during operation is present in the gas flow between the inlet opening and the outlet opening in such a way that the gas flow causes the rotor to rotate, and the rotor meter furthermore comprising a counter that counts the number of revolutions of the rotor.
  • a rotor meter of this type is generally known. Rotor meters are used for measuring gas flows and thus the gas consumption. Inside the housing of a rotor meter there are one or more rotors present in a measuring chamber. Through an inlet opening present in the housing gas flows into the measuring chamber and against the rotor which starts rotating as a result and allows an amount of gas to pass through to an outlet opening also present in the housing. The rotating rotor or rotors does not or do not contact the walls of the measuring chamber. If several rotors are present in the housing, the rotation of the rotors relative to each other is synchronized by means of a gear train between the shafts of the rotors and the rotors themselves do not contact each other.
  • the rotors are driven by the difference in pressure that evolves over the rotors as a result of flow through the rotor meter (in case of offtake).
  • the magnitude of the difference in pressure depends inter alia on the opposing torque of the rotors, mainly the friction of the rotating parts (bearings, shafts, counting mechanism).
  • the difference in pressure over the rotors at the same time provides that among the rotors mutually and the rotors and the side walls of the measuring chamber an amount of gas leaks out (after all the rotors rotate freely from each other and from the wall of the measuring chamber). The amount of gas that has leaked out is not recorded as such and leads to a measuring error. The more gas leaks out, the larger the measuring error.
  • a counting mechanism can be driven by means of a plurality of gear wheels to record the gas consumption.
  • the rotors are traditionally made of aluminium in view of the strength, dimensional stability and accuracy during processing. The accuracy of processing is essential for minimizing the clearance between the rotors mutually and the walls of the measuring chamber. For that matter, in case of a minor clearance (order of magnitude 0.1 - 0.1 mm) the leakage losses are smaller and, in consequence, the measuring error is smaller as well.
  • the rotor meter according to the invention is characterised in that the rotor comprises at least one coil as well as a transmitter to which both ends of the coil are connected and which transmits a signal the moment a current starts passing through the coil.
  • the coil extends over the entire or substantially entire axial length of the rotor.
  • the great advantage of the use of a coil over the entire length of the rotor is that it does not matter where the magnets are mounted. If the magnetic field of the magnets can influence the rotation of the rotor, the coil will start rotation as a result of this magnetic field and a current will start flowing.
  • An embodiment of the rotor meter according to the invention is characterised in that the rotor meter comprises a receiver which can receive the signal transmitted by the transmitter and is located inside or on top of the housing.
  • the transmitter may be a radio frequency transmitter and the receiver a radio frequency receiver.
  • the transmitter may also be a light source, for example an LED, and the receiver a light-sensitive cell. The lighting up of the LED is then detected by an optical sensor.
  • a light source for example an LED
  • the receiver a light-sensitive cell. The lighting up of the LED is then detected by an optical sensor.
  • the transmitter may be a coil having a ferromagnetic core and the receiver a magnetic sensor.
  • the coil with core may be installed in the heart of the rotor and generate a weak magnetic field. This magnetic field is then detected by a magnetic sensor that switches when a specific field strength is attained (Hall, Wiegand, Reed contact, GMR, etc.)
  • a further embodiment of the rotor meter according to the invention is characterised in that the rotor meter comprises a processor as well as a memory connected to this processor, the processor recording the received signals in a time-related manner.
  • the receiver At a certain voltage (depending on the magnetic field and the number of coil windings) the receiver is activated as a sign of manipulation.
  • the signal from the receiver is then processed by a microprocessor in the rotor meter and recorded in a non-volatile memory in a time- related manner. Based on these recordings structural manipulatory activities by means of magnets can be demonstrated.
  • Fig. 1 shows a cross- sectional view of a rotor meter according to the invention
  • Fig. 2 shows another cross- sectional view of the rotor meter according to the invention showing synchronizing gears
  • Fig. 3 shows one of the rotors of an embodiment of the rotor meter having a coil with ferromagnetic core as a transmitter
  • Fig. 4 shows one of the rotors of a further embodiment of the rotor meter having an LED as a transmitter.
  • Figs. 1 and 2 show two different cross-sectional views of an embodiment of the rotor meter according to the invention with synchronizing gears being indicated in the cross-sectional view shown in Fig. 2.
  • the rotor meter 1 has a housing 3 accommodating a measuring chamber 5 that has an inlet opening 7 and an outlet opening 9.
  • the rotor meter 1 further includes two rotors 11 and 13 which are bearing-mounted in the housing 3 and rotatable in the measuring chamber 5.
  • rotors 11 and 13 are present in the gas flow 15 between the inlet opening 7 and the outlet opening 9. The gas flow then causes the rotors to rotate.
  • the rotor meter further includes a counter (not shown) that counts the number of revolutions of the rotors.
  • This counter may be a mechanical counting mechanism that is driven via a gearwheel that meshes with either of the two synchronisation gears 17 and 19 (see Fig. 2) on the rotor shafts 21 and 23.
  • a coil 25 is present and a transmitter connected to it (see Figs. 3 and 4) which transmits a signal as soon as a current starts flowing through the coil.
  • Fig. 3 the rotor meter rotor 11 comprising the coil 25.
  • a further coil 27 with a ferromagnetic core 29 is connected to the coil 25.
  • This further coil 27 with core 29 is located in the shaft of the rotor and forms a transmitter which generates a signal in the form of a relatively weak magnetic field the moment a current starts flowing through the coil 25. The latter occurs if the rotor meter 1 is manipulated by holding a strong permanent magnet against the housing 3. This strong permanent magnet restrains the rotation of the rotors.
  • the coil 25 is located in the rotor 11, which starts rotating in a magnetic field in case of manipulatory activities, a current starts running through the coil 25.
  • a receiver is installed in the housing of the rotor meter. This receiver is arranged as a magnetic sensor 31 that switches at a certain field strength of the weak magnetic field generated by the transmitter.
  • the magnetic sensor may be, for example, a Hall element or a Reed contact.
  • the magnetic sensor 31 At a certain current level (depending on the external magnetic field and the number of windings of the coil 25) the magnetic sensor 31 is activated as a sign of manipulatory activities.
  • the signal from the magnetic sensor 31 is subsequently processed by a microprocessor 33 located in the rotor meter and then recorded in a lime-related manner (by utilizing a clock 35 that is connected to the microprocessor) in a non-volatile memory 37 coupled to the microprocessor. Based on this recording it is possible to demonstrate structural manipulatory activity by means of magnets.
  • FIG. 4 depicts one of the rotors 39 of a further embodiment of the rotor meter according to the invention.
  • This LED 41 functions as a transmitter that cooperates with an optical sensor 43 (for example a light-sentitive cell) which is located inside the housing of the rotor meter and detects the lighting up of the LED.
  • This sensor 43 in its turn is connected to a microprocessor 45 which processes the signals and records them in a memory 49 in a time-related manner (clock 47).

Abstract

A rotor meter comprises a housing that accommodates two rotatable rotors. Gas flowing through the housing causes the rotors to rotate. One of the rotors 11 accommodates a coil 25 and a transmitter (formed by a coil 27 with a ferromegnetic core 29) connected to this coil 25, which transmitter sends a signal the moment a current starts flowing through the coil. The latter occurs if the rotor meter 1 is manipulated by holding a strong permanent magnet against the housing 3. This strong permanent magnet restrains the rotation of the rotors, but at the same time a current starts flowing through the coil. A magnetic sensor 31 switches when a certain field strength of the magnetic field generated by the transmitter is monitored. The signal from the magnetic sensor 31 is subsequently processed by a microprocessor 33 and then recorded in a time-related manner in a memory 37. Based on this recording it is possible to demonstrate manipulatory activity.

Description

Rotor meter for measuring an amount of gas
DESCRIPTION Field of the invention. The invention relates to a rotor meter for measuring the amount of gas flowing through a gas pipe, comprising a housing accommodating a measuring chamber an inlet opening and an outlet opening, the rotor meter furthermore comprising at least one rotor which is bearing-mounted in the housing and rotatable in the measuring chamber and during operation is present in the gas flow between the inlet opening and the outlet opening in such a way that the gas flow causes the rotor to rotate, and the rotor meter furthermore comprising a counter that counts the number of revolutions of the rotor.
State of the art A rotor meter of this type is generally known. Rotor meters are used for measuring gas flows and thus the gas consumption. Inside the housing of a rotor meter there are one or more rotors present in a measuring chamber. Through an inlet opening present in the housing gas flows into the measuring chamber and against the rotor which starts rotating as a result and allows an amount of gas to pass through to an outlet opening also present in the housing. The rotating rotor or rotors does not or do not contact the walls of the measuring chamber. If several rotors are present in the housing, the rotation of the rotors relative to each other is synchronized by means of a gear train between the shafts of the rotors and the rotors themselves do not contact each other.
The rotors are driven by the difference in pressure that evolves over the rotors as a result of flow through the rotor meter (in case of offtake). The magnitude of the difference in pressure depends inter alia on the opposing torque of the rotors, mainly the friction of the rotating parts (bearings, shafts, counting mechanism). The difference in pressure over the rotors at the same time provides that among the rotors mutually and the rotors and the side walls of the measuring chamber an amount of gas leaks out (after all the rotors rotate freely from each other and from the wall of the measuring chamber). The amount of gas that has leaked out is not recorded as such and leads to a measuring error. The more gas leaks out, the larger the measuring error.
Since the stroke volume is known, a counting mechanism can be driven by means of a plurality of gear wheels to record the gas consumption. By means of extremely strong magnets it has been demonstrated that the meters are sensitive to manipulatory activities. The rotors are traditionally made of aluminium in view of the strength, dimensional stability and accuracy during processing. The accuracy of processing is essential for minimizing the clearance between the rotors mutually and the walls of the measuring chamber. For that matter, in case of a minor clearance (order of magnitude 0.1 - 0.1 mm) the leakage losses are smaller and, in consequence, the measuring error is smaller as well.
By holding a strong magnet on the rotor meter or in its vicinity, braking forces will evolve on the rotating (non-ferro) rotors (Eddy currents). These braking forces cause more difference in pressure over the rotors to be needed for continuation of rotation leading to the result that leakage losses increase and so do the measuring errors. Depending on the construction of the rotor meter and the strength of the magnets a measuring error may rise to dozens of per cents.
Seeing that the braking of the rotors by means of magnets can take place without permanent or visible indication, it is well-nigh impossible to record such manipulatory activities. Because strong magnets are easy to obtain, it may be assumed that manipulation of rotor gas meters will assume gigantic proportions.
Summary of the invention
It is an object of the invention to provide a rotor meter of the type defined in the opening paragraph by which manipulatory activities can be counteracted. To this end the rotor meter according to the invention is characterised in that the rotor comprises at least one coil as well as a transmitter to which both ends of the coil are connected and which transmits a signal the moment a current starts passing through the coil. Now, if the rotor meter were manipulated by holding a magnet close to it on the outside, a current would start running through the coil because the coil rotates as a result of the magnetic field. By connecting a transmitter to the coil and arranging this transmitter in such a way that it transmits a signal the moment a current starts passing through it and recording or monitoring this signal, manipulation can be demonstrated simultaneously or in hindsight. Preferably, the coil extends over the entire or substantially entire axial length of the rotor. The great advantage of the use of a coil over the entire length of the rotor is that it does not matter where the magnets are mounted. If the magnetic field of the magnets can influence the rotation of the rotor, the coil will start rotation as a result of this magnetic field and a current will start flowing.
An embodiment of the rotor meter according to the invention is characterised in that the rotor meter comprises a receiver which can receive the signal transmitted by the transmitter and is located inside or on top of the housing. The transmitter may be a radio frequency transmitter and the receiver a radio frequency receiver.
The transmitter may also be a light source, for example an LED, and the receiver a light-sensitive cell. The lighting up of the LED is then detected by an optical sensor.
Furthermore, the transmitter may be a coil having a ferromagnetic core and the receiver a magnetic sensor. The coil with core may be installed in the heart of the rotor and generate a weak magnetic field. This magnetic field is then detected by a magnetic sensor that switches when a specific field strength is attained (Hall, Wiegand, Reed contact, GMR, etc.)
A further embodiment of the rotor meter according to the invention is characterised in that the rotor meter comprises a processor as well as a memory connected to this processor, the processor recording the received signals in a time-related manner. At a certain voltage (depending on the magnetic field and the number of coil windings) the receiver is activated as a sign of manipulation. The signal from the receiver is then processed by a microprocessor in the rotor meter and recorded in a non-volatile memory in a time- related manner. Based on these recordings structural manipulatory activities by means of magnets can be demonstrated.
Brief description of the drawings
The following description relating to the appended drawings, the whole given by way of non-limiting example of the rotor meter according to the invention, will provide better understanding of how the invention can be realized, in which:
Fig. 1 shows a cross- sectional view of a rotor meter according to the invention; Fig. 2 shows another cross- sectional view of the rotor meter according to the invention showing synchronizing gears;
Fig. 3 shows one of the rotors of an embodiment of the rotor meter having a coil with ferromagnetic core as a transmitter; and
Fig. 4 shows one of the rotors of a further embodiment of the rotor meter having an LED as a transmitter.
Detailed description of the drawings Figs. 1 and 2 show two different cross-sectional views of an embodiment of the rotor meter according to the invention with synchronizing gears being indicated in the cross-sectional view shown in Fig. 2. The rotor meter 1 has a housing 3 accommodating a measuring chamber 5 that has an inlet opening 7 and an outlet opening 9. The rotor meter 1 further includes two rotors 11 and 13 which are bearing-mounted in the housing 3 and rotatable in the measuring chamber 5. During operation (that is to say. while gas is flowing through the rotor meter) rotors 11 and 13 are present in the gas flow 15 between the inlet opening 7 and the outlet opening 9. The gas flow then causes the rotors to rotate.
The rotor meter further includes a counter (not shown) that counts the number of revolutions of the rotors. This counter may be a mechanical counting mechanism that is driven via a gearwheel that meshes with either of the two synchronisation gears 17 and 19 (see Fig. 2) on the rotor shafts 21 and 23. In one of the rotors 11 a coil 25 is present and a transmitter connected to it (see Figs. 3 and 4) which transmits a signal as soon as a current starts flowing through the coil.
In Fig. 3 is shown the rotor meter rotor 11 comprising the coil 25. A further coil 27 with a ferromagnetic core 29 is connected to the coil 25. This further coil 27 with core 29 is located in the shaft of the rotor and forms a transmitter which generates a signal in the form of a relatively weak magnetic field the moment a current starts flowing through the coil 25. The latter occurs if the rotor meter 1 is manipulated by holding a strong permanent magnet against the housing 3. This strong permanent magnet restrains the rotation of the rotors. However, since the coil 25 is located in the rotor 11, which starts rotating in a magnetic field in case of manipulatory activities, a current starts running through the coil 25.
A receiver is installed in the housing of the rotor meter. This receiver is arranged as a magnetic sensor 31 that switches at a certain field strength of the weak magnetic field generated by the transmitter. The magnetic sensor may be, for example, a Hall element or a Reed contact.
At a certain current level (depending on the external magnetic field and the number of windings of the coil 25) the magnetic sensor 31 is activated as a sign of manipulatory activities. The signal from the magnetic sensor 31 is subsequently processed by a microprocessor 33 located in the rotor meter and then recorded in a lime-related manner (by utilizing a clock 35 that is connected to the microprocessor) in a non-volatile memory 37 coupled to the microprocessor. Based on this recording it is possible to demonstrate structural manipulatory activity by means of magnets.
It would also be possible to activate an LED with the voltage generated in the coil 25. This is illustrated in Fig. 4 which depicts one of the rotors 39 of a further embodiment of the rotor meter according to the invention. This LED 41 functions as a transmitter that cooperates with an optical sensor 43 (for example a light-sentitive cell) which is located inside the housing of the rotor meter and detects the lighting up of the LED. This sensor 43 in its turn is connected to a microprocessor 45 which processes the signals and records them in a memory 49 in a time-related manner (clock 47).
Albeit in the foregoing disclosure the invention has been explained with reference to the drawing figures, it should be pointed out that the invention is by no means restricted to the embodiments shown in the drawing figures. The invention also pertains to all embodiments deviating from the embodiments shown in the drawing figures within the spirit and scope defined by the claims. For example, coils may also be located in both rotors and in lieu of a single coil extending over the entire length of the rotor it is also possible for more than one coil to be present in the rotor side by side in axial direction.

Claims

CLAIMS:
1. A rotor meter for measuring the amount of gas flowing through a gas pipe, comprising a housing accommodating a measuring chamber an inlet opening and an outlet opening, the rotor meter furthermore comprising at least one rotor which is bearing-mounted in the housing and rotatable in the measuring chamber and during operation is present in the gas flow between the inlet opening and the outlet opening in such a way that the gas flow causes the rotor to rotate, and the rotor meter furthermore comprising a counter that counts the number of revolutions of the rotor, characterised in that the rotor comprises at least one coil as well as a transmitter to which both ends of the coil are connected and which transmits a signal the moment a current starts passing through the coil.
2. A rotor meter as claimed in claim 1, characterised in that the coil extends over the entire or substantially entire axial length of the rotor.
3. A rotor meter as claimed in claim 1 or 2, characterised in that the rotor meter comprises a receiver which can receive the signal transmitted by the transmitter and is located inside or on top of the housing.
4. A rotor meter as claimed in claim 3, characterised in that the rotor meter comprises a processor as well as a memory connected to this processor, the processor recording the received signals in a time-related manner.
PCT/NL2012/050019 2011-01-12 2012-01-12 Rotor meter for measuring an amount of gas WO2012112030A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL2005995 2011-01-12
NL2005995A NL2005995C2 (en) 2011-01-12 2011-01-12 ROTOR METER FOR MEASURING A QUANTITY OF GAS.

Publications (2)

Publication Number Publication Date
WO2012112030A2 true WO2012112030A2 (en) 2012-08-23
WO2012112030A3 WO2012112030A3 (en) 2014-01-16

Family

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Family Applications (1)

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PCT/NL2012/050019 WO2012112030A2 (en) 2011-01-12 2012-01-12 Rotor meter for measuring an amount of gas

Country Status (2)

Country Link
NL (1) NL2005995C2 (en)
WO (1) WO2012112030A2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015215115A (en) * 2014-05-09 2015-12-03 パナソニック株式会社 Gas shut-off device
EP3623774B1 (en) * 2018-09-11 2021-05-26 Common Spolka Akcyjna Rotary flow meter for measuring gas flow

Family Cites Families (4)

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Publication number Priority date Publication date Assignee Title
HU9402209D0 (en) * 1994-07-27 1994-10-28 Magyar Gazmeroe Technika Kft Device for consumption test and of permission gas-consumers
DE20216283U1 (en) * 2002-10-23 2003-01-16 Techem Dev Gmbh Volume flowmeter has pair of oppositely-magnetized wires arranged parallel to each other on housing to detect manipulation by magnets
IL158710A0 (en) * 2003-11-02 2004-05-12 S F M Sophisticated Water Mete A fluid consumption meter
US7948378B2 (en) * 2008-10-06 2011-05-24 Toptech Systems, Inc. Tamperproof non-contact switch

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015215115A (en) * 2014-05-09 2015-12-03 パナソニック株式会社 Gas shut-off device
EP3623774B1 (en) * 2018-09-11 2021-05-26 Common Spolka Akcyjna Rotary flow meter for measuring gas flow

Also Published As

Publication number Publication date
NL2005995C2 (en) 2012-07-16
WO2012112030A3 (en) 2014-01-16

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