WO2000014488A1 - Fault detector for pipings - Google Patents

Fault detector for pipings Download PDF

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Publication number
WO2000014488A1
WO2000014488A1 PCT/DK1999/000453 DK9900453W WO0014488A1 WO 2000014488 A1 WO2000014488 A1 WO 2000014488A1 DK 9900453 W DK9900453 W DK 9900453W WO 0014488 A1 WO0014488 A1 WO 0014488A1
Authority
WO
WIPO (PCT)
Prior art keywords
characterised
fault detector
detector according
device
element
Prior art date
Application number
PCT/DK1999/000453
Other languages
French (fr)
Inventor
Jørgen Seindal WIWE
Jørgen SEERUP
Arne Markvart
Jan S. Harling
Original Assignee
Danfoss A/S
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
Priority to DE1998139956 priority Critical patent/DE19839956C1/en
Priority to DE19839956.1 priority
Application filed by Danfoss A/S filed Critical Danfoss A/S
Publication of WO2000014488A1 publication Critical patent/WO2000014488A1/en

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow
    • G01F1/05Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects
    • G01F1/06Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects using rotating vanes with tangential admission
    • G01F1/065Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects using rotating vanes with tangential admission with radiation as transfer means to the indicating device, e.g. light transmission
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow
    • G01F1/05Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects
    • G01F1/20Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects by detection of dynamic effects of the fluid flow
    • G01F1/22Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects by detection of dynamic effects of the fluid flow by variable-area meters, e.g. rotameters
    • G01F1/26Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through the meter in a continuous flow by using mechanical effects by detection of dynamic effects of the fluid flow by variable-area meters, e.g. rotameters of the valve type
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F15/00Details of, or accessories for, apparatus of the preceding groups insofar as such details or appliances are not adapted to particular types of such apparatus
    • G01F15/12Cleaning arrangements; Filters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F7/00Volume-flow measuring devices with two or more measuring ranges; Compound meters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01MTESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00Investigating fluid-tightness of structures
    • G01M3/02Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/26Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
    • G01M3/28Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
    • G01M3/2807Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipes

Abstract

A fault detector for pipings, particularly leakage detector, with a main flow path (22) having a lifting valve (16), an auxiliary flow path (26) having a flowmeter (27), as well as a closing device activated on the occurence of a fault. At least the part of the flowmeter (27) carrying fluid is arranged in the movable element (19) of the lifting valve (16). This gives a more simple construction of the leakage detector. It can also have small dimensions.

Description

Fault detector for pipings

The invention concerns a fault detector for pipings, with a main flow path having a lifting valve, an auxiliary flow path having a flowmeter, as well as a closing device activated on the occurrence of a fault.

From DE 39 07 209 Cl a leakage detector of this kind is known, which in a main flow path has a main valve and in an auxiliary flow path has a volume flowmeter, a throttle and an auxiliary valve. The main valve opens in dependence of the pressure drop at the throttle, but not until the volume flow in the auxiliary flow path exceeds a predeter- mined value. Thus, small volume flows appearing in connection with small leakages, approximately in the range from 1 to 25 1/h, are sure to be detected, whereas in connection with large leakages or normal consumption, approximately between 30 and 2,500 1/h, an exact determination of the volume flow is no longer critical.

The task of the invention is to provide a flow measuring device of the kind described in the introduction, which has a simple construction and can have smaller dimensions.

According to the invention, this task is solved in that at least the part of the flowmeter carrying fluid is arranged in the movable element of the lifting valve.

As the channels required for the auxiliary flow path are arranged in the movable valve element, the valve housing has a very simple construction. As the second flowmeter is arranged in the movable valve element, it only requires little space. The most important fault to be detected is a leakage, be it a large leakage or a small leakage. However, also other faults may be concerned, for example excessive water consumption. In dependence of the detected fault, the closing device can block the flow completely or partially.

Advantageously, the movable valve element is loaded by a closing spring and closes against the flow direction, a lift measuring device determining the opening degree of the lifting valve and an evaluating circuit for evaluation of the lift measuring value and the flow measuring value are provided. In this construction the closing spring has two functions. Firstly it ensures the with low flow the main flow path is blocked and only the second flowmeter in the auxiliary flow path is active. Secondly, with larger flow, it determines the opening degree of the lifting valve, so that the measured lift is a unique measure for the flow in the main flow path. Thus, both very small and very large volume flows can be measured, meaning that a very large measuring area is available.

In a preferred embodiment it is provided that the flowmeter has a measuring rotor in the movable valve element and a speed measuring device, fixed on the housing, deter- mining the speed of said rotor. Thus, both flowmeters work mechanically. As measuring rotors with small dimensions are available, for example turbine wheels, the movable valve element does not have to be enlarged substantially.

It is advantageous that the measuring rotor has markings, which can be detected by a scanner, fixed on the housing, producing scanning signals. The scanning can be made optically, magnetically, or in any other desired way. Thus, the flow is reproduced by means of an pulse fre- quency. The lift of the movable valve element has no influence on this frequency. Therefore, the scanner can be fixed on the housing.

It is particularly advantageous that the markings have a radial extension, that for creating the speed measuring device the evaluating circuit evaluates the frequency of the scanning signals, and for creating the lift measuring device it measures the pulse-pause ratio of the scanning signals. Thus, one single scanner is sufficient to detect the flow in both auxiliary flow path and main flow path.

It is preferred that the measuring rotor is an impeller wheel and that an optic scanning device scans the impellers. An impeller wheel of this kind can be arranged in the movable valve element without problems.

Additionally, it is recommended that an optic scanning device is separated from the measuring rotor by a transparent separating wall, and that on the rotor side a cleaning device is provided for the separating wall. Thus, the separating wall is cleaned of impurities, for example calcification, to make sure that the measuring rotor is always ready for measuring.

Further, it is recommended to have a closing device closing the lifting valve when a leakage has been established. Thus the lifting valve can at the same time be part of the blocking device required when a leakage is established.

In particular it can be provided that from a first position in which a counter flange holds a second closing spring in an ineffective position, said counter flange is movable by means of an adjustment device to a second position, in which the second closing spring acts upon the movable valve element. When the counter flange is moved to the second position by an operation of the adjustment device, this adjusting movement is supported by the closing spring, so that the drive of the adjustment device requires only a little energy. When, additionally to the first closing spring also the second closing spring meets the valve element, the lifting valve is sure to be closed.

In this connection it is favourable that the closing device also closes the auxiliary path. Thus the whole flow is interrupted.

Advantageously, this can be made in that the counter flange is connected with a closure element, which acts upon an orifice in the auxiliary flow path. The closing of the orifice only requires small components, which is an advantage for the construction on a whole.

Further, it is recommended that an operating element is arranged on the housing of the lifting valve, which element comprises an operating motor, which adjusts an ad- justing element along the lifting axis. An adjusting element of this kind can serve the purpose of operating a closing device or a cleaning device.

Further, it is advantageous that a control device for the operating motor is provided, which device activates the motor on the occurrence of a leakage and of predetermined algorithms. These algorithms can cause zero point adjustments, cleaning processes, volume flow limitations for the purpose of sending signals etc.

Advantageously, a pressure sensor is also provided. By means of this sensor it can be established, if the volume flow registered by the second flowmeter is the result of dripping caused by a small leakage or of an increase of the supply pressure, which also causes a flow if the pipings are not 100 percent rigid. In the following the invention is described on the basis of preferred embodiments on the basis of the drawings, showing:

Fig. 1 a three-dimensional, partial view of a leakage detector according to the invention with a flow measuring arrangement Fig. 2 a longitudinal section through the leakage de- tector in Fig. 1

Fig. 3 a cross section through the leakage detector in

Fig. 1

The leakage detector has a housing 1, having an inlet connector 2 and an outlet connector 3, each with an internal thread, for building into a pipe of a piping to be monitored. An element 4 is fixed on the housing 1 by means of the nut 5 with external thread. The element has a cover 6 and a rotary knob 7 projecting towards the outside.

In the housing 1 an insert 10 is mounted using two sealing rings 8 and 9, which insert has an upper wall 11 for limiting an inlet chamber 12 and a lower wall 13 for separating an outlet chamber 14 from the inlet chamber 12 and for forming the valve seat 15 of a lifting valve 16.

This insert is also fixed in the housing 1 by means of the nut 5. The valve seat 15 is formed by an annular slot 17, which is connected with the inlet chamber 12 via bores 18. The locking piece is a movable valve element 19 provided with a sealing ring, which valve element is loaded by a first, weaker closing spring 20 against the flow direction, and - as will be explained in detail later - which can be loaded by a second, stronger closing spring 21. Thus, a main flow path 22 extends between the inlet cham- ber 12 and the outlet chamber 14, which path comprises the bores 18, the annular slot 17 and the lifting valve 16. As fluid can flow both radially inwards and radially outwards on lifting the sealing ring from the valve seat 15, also large flow quantities will cause a small pressure drop.

A measuring rotor 23 in the shape of an impeller wheel is supported in the movable valve element 19. It is fed with fluid via an orifice 24 arranged on the insert 10, which fluid can flow off through a channel 25 in the movable valve element 19. This gives an auxiliary flow path 26 between the inlet chamber 12 and the outlet chamber 14, which path comprises the orifice 24, the measuring rotor 23 and the channel 25.

The measuring rotor 23 is part of a flowmeter 27 having an optic scanning device 28. This device comprises an electro-optic transmitter 29, for example a light-emission diode, and on the opposite side of the measuring rotor 23 an electro-optic receiver 30, for example a photocell, a photo transistor or a photo resistor. Transmitter and receiver are separated from the fluid carrying chamber by means of transparent separating walls 31 and 32, and thus are mounted in protected surroundings. As shown, the separating walls 31, 32, can be made in one piece with the insert 10, provided that it is made completely of a trans- parent material. The impellers of the measuring rotor 23, extending radially with constant thickness, form markings 33, which temporarily interrupt the light beam transmitted by the transmitter 29, so that a pulse-shaped scanning signal occurs. The measuring rotor 23 can have very small dimensions, for example a diameter of 15 mm and a width of 1 mm.

In the position shown, a carrier 34 projects through openings in the movable valve element 19 by means of a counter flange 35, the second closing spring 21 being made inactive. The carrier 34 bears with an end stop 36 on a pin 37 extending sealingly outwards, which pin again is brought to bear on an end stop 38 of an adjusting element

39 by the force of the closing spring 21. A displacement of the adjusting element 39 in the outwards direction brings the carrier 34 to a second position, in which the second closing spring 21 acts upon the movable valve element 19.

Further, two cleaning elements 40 and 41 are connected with the carrier 34, which elements bear flexibly with a cleaning edge on the separating walls 31 and 32, respectively, and, on displacement of the carrier 34 cleans the working area of the optic scanning device 28 of impurities, for example calcification. Further, a closing and cleaning element 42 is arranged on the carrier 34, which element closes the orifice 24 on the upward movement of the carrier 34, that is, blocks the auxiliary flow path 26. Further, the orifice 24 can be cleaned, either through a pin (not shown) in the closing and cleaning element 42 being pushed into the orifice opening, or through the flexible material of the orifice 24 being deformed by the closing and cleaning element 42, so that any impurities stuck in the orifice are set free. To improve the closing and cleaning effect of the closing and cleaning element 42, a third spring can be provided, which presses the carrier 34 as far upwards as permitted by the end stop 38 on the adjusting element 39.

The element 4 comprises an evaluating and control circuit 43 supplied with the scanning signals, which circuit can, for example, be made on a printed circuit board, and an electrical battery 45. An electronic operating motor 46 controlled by the evaluating and control circuit 43 is able to adjust the adjusting element 39 axially via a gear 47. The rotary knob 7 permits an auxiliary displacement via a cam 48. Optionally, a pressure sensor 49 can also be provided in the inlet chamber 12, whose measuring signal can also be supplied to the evaluating and control circuit 43.

The scanning signals of the scanning device 28 are evaluated in two ways. Due to their frequency, which corresponds to the speed of the measuring rotor 23, the volume flow in the auxiliary flow path 26 is registered. Due to the pulse-pause relation, which increases with increasing downwards motion of the lifting valve 16, caused by the constant thickness of the impellers, the lift of the movable valve element 19 and thus the volume flow in the main flow path are registered.

With small volume flows the lifting valve 16 remains closed under the influence of the first closing spring 20, The total flow is registered by the flowmeter 27. Small volume flows can be measured very accurately. In this situation the pulse-pause relation is constant, whereas the frequency is proportional to the flow.

With larger flows, the lifting valve opens, the resulting lift depending exclusively on the flow and on the charac- teristic of the first spring 20. Thus, the lift is a direct measure for the flow through the main flow path 22. By means of the evaluating and control circuit 43, the total flow thus can be calculated by a conversion of the measured lift of the volume flow in the main flow path 22 added to the volume flow in the auxiliary flow path 26 registered by means of the flowmeter 27.

The device shown acts as blocking device, when the adjusting element 39 and thus the carrier 34 are moved upward, which only requires little motor power due to the load by the second closing spring 21. As soon as the second clos- ing spring 21 bears on the movable valve element 19, the valve element is pushed with large force into the closed position. At the same time the orifice 24 is closed by means of the closing and cleaning element 42. Thus main and auxiliary flow paths are blocked.

The same displacement of the carrier 34 can also be used to clean the separating walls 31 and 32 by means of the cleaning elements 40 and 41, and to clean the orifice 24 by inserting a pin in the orifice 24 opening and/or by squeezing the orifice 24. This can be made in dependence of time or of degree of impurification.

The movement of the carrier 34 over partial areas can be used to make a zero-point adjustment or to throttle the flow. The latter serves the signal transmission to a consumer, who is tapping water, to persuade him to change or end the tapping.

The blocking procedure is initiated when a leakage occurs. A small leakage, for example, is assumed, when small volume flows appear, without reports from the pressure sensor 49 about changes in the supply pressure. A large leakage is assumed when large volume flows appear and it is recognisable that no tapping is going on, which is, for example, established in that a random throttling of the flow at the leakage detector is not responded by a change of the volume flow with the tapping consumer.

To save energy, the field current of the opto-electrical transmitter 29 can be set at a minimum value, which is permissible due to the repeated cleaning processes, and the individual measurings of the leakage detection can be performed at larger intervals, for example 20 minutes. Although the embodiment described concerns the flow of water, it is obvious that equal or similar embodiments can also be used for other liquids or for gases.

Claims

Patent Claims
1. Fault detector for pipings, with a main flow path having a lifting valve, an auxiliary flow path having a flowmeter, as well as a closing device activated on the occurrence of a fault, characterised in that at least the part of the flowmeter (27) carrying fluid is arranged in the movable element (19) of the lifting valve (16) .
2. Fault detector according to claim 1, characterised in that the movable valve element (19) is loaded by a closing spring (20) and closes against the flow direc- tion, a lift measuring device determining the opening degree of the lifting valve (16) and an evaluating circuit (43) for evaluation of the lift measuring value and the flow measuring value are provided.
3. Fault detector according to claim 1 or 2, characterised in that the flowmeter (27) has a measuring rotor (23) in the movable valve element (19) and a speed measuring device, fixed on the housing, determining the speed of said rotor.
Fault detector according to claim 3, characterised in that the measuring rotor (23) has markings (33) , which can be detected by a scanner (28), fixed on the housing, producing scanning signals.
5. Fault detector according to claim 4, characterised in that the markings (33) have a radial extension, that for creating the speed measuring device the evaluating circuit (43) evaluates the frequency of the scanning signals, and for creating the lift measuring device it measures the pulse-pause ratio of the of the scanning signals .
6. Fault detector according to one of the claims 3 to 5, characterised in that the measuring rotor (23) is an impeller wheel and that an optic scanning device (28) scans the impellers.
7. Fault detector according to one of the claims 4 to 6, characterised in that an optic scanning device (28) is separated from the measuring rotor (23) by a transparent separating wall (31, 32) , and that on the rotor side a cleaning device for the separating wall (31, 32) is provided.
8. Fault detector according to one of the claims 1 to 7, characterised in a closing device closing the lifting valve (16) when a leakage has been established.
9. Fault detector according to claim 8, characterised in that from a first position in which a counter flange (35) holds a second closing spring (21) in an ineffective position, said counter flange is movable by means of an adjustment device to a second position, in which the second closing spring (21) acts upon the movable valve element (19) .
10. Fault detector according to claim 8 or 9, characterised in that the closing device also closes the auxiliary path (26) .
11. Fault detector according to claim 9 or 10, characterised in that the counter flange (35) is connected with a closure element (42), which acts upon an ori- fice (24) in the auxiliary flow path (26).
12. Fault detector according to one of the claims 7 to 11, characterised in that an operating element (4) is ar- ranged on the housing (1) of the lifting valve (16), which element comprises an operating motor (46), which adjusts an adjusting element (39) along the lifting axis .
13. Fault detector according to claim 12, characterised in that a control device (43) for the operating motor (46) is provided, which device activates the motor on the occurrence of a leakage and of predetermined algorithms .
14. Fault detector according to one of the claims 1 to 13, characterised in that a pressure sensor (49) is also provided.
PCT/DK1999/000453 1998-09-02 1999-08-30 Fault detector for pipings WO2000014488A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE1998139956 DE19839956C1 (en) 1998-09-02 1998-09-02 Fault detector for line systems
DE19839956.1 1998-09-02

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AU52794/99A AU5279499A (en) 1998-09-02 1999-08-30 Fault detector for pipings

Publications (1)

Publication Number Publication Date
WO2000014488A1 true WO2000014488A1 (en) 2000-03-16

Family

ID=7879539

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DK1999/000453 WO2000014488A1 (en) 1998-09-02 1999-08-30 Fault detector for pipings

Country Status (3)

Country Link
AU (1) AU5279499A (en)
DE (1) DE19839956C1 (en)
WO (1) WO2000014488A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2853963A1 (en) * 2003-04-16 2004-10-22 Andre Mabelly Water leakage detecting device, has pipe to permit passage of water to be distributed when pressure difference exceeds one threshold, lower than another threshold, and sensor to provide signal when water passes by pipe

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR670378A (en) * 1929-02-27 1929-11-28 Cfcmug Locking device of the liquid timer counter for receiving gas momentanémentun
DE1176885B (en) * 1962-08-30 1964-08-27 Bopp & Reuther Gmbh for flowing media od Geschwindigkeitszaehler with an impeller. like. As the measuring member
US3352155A (en) * 1964-09-30 1967-11-14 Schlumberger Instrumentation Valve and flowmeter assembly
US3813940A (en) * 1972-12-18 1974-06-04 Sperry Rand Corp Flow meter with a bypass
EP0656527A1 (en) * 1993-12-02 1995-06-07 S.F.M. Sophisticated Water Meters Ltd. Compound flow meter and leak detector system with a valve that is shut under abnormal flow conditions

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3907209C1 (en) * 1989-01-18 1990-03-01 Danfoss A/S, Nordborg, Dk
DE4418396A1 (en) * 1994-04-20 1995-10-26 Otto Muggenthaler Flow duration monitoring device for domestic water supply

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR670378A (en) * 1929-02-27 1929-11-28 Cfcmug Locking device of the liquid timer counter for receiving gas momentanémentun
DE1176885B (en) * 1962-08-30 1964-08-27 Bopp & Reuther Gmbh for flowing media od Geschwindigkeitszaehler with an impeller. like. As the measuring member
US3352155A (en) * 1964-09-30 1967-11-14 Schlumberger Instrumentation Valve and flowmeter assembly
US3813940A (en) * 1972-12-18 1974-06-04 Sperry Rand Corp Flow meter with a bypass
EP0656527A1 (en) * 1993-12-02 1995-06-07 S.F.M. Sophisticated Water Meters Ltd. Compound flow meter and leak detector system with a valve that is shut under abnormal flow conditions

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2853963A1 (en) * 2003-04-16 2004-10-22 Andre Mabelly Water leakage detecting device, has pipe to permit passage of water to be distributed when pressure difference exceeds one threshold, lower than another threshold, and sensor to provide signal when water passes by pipe
WO2004094978A2 (en) * 2003-04-16 2004-11-04 Mabelly Andre Detection of low-flow leaks in a water-distribution system, using two pressure difference thresholds
WO2004094978A3 (en) * 2003-04-16 2004-12-23 Andre Mabelly Detection of low-flow leaks in a water-distribution system, using two pressure difference thresholds

Also Published As

Publication number Publication date
AU5279499A (en) 2000-03-27
DE19839956C1 (en) 2000-05-04

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