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WO1998054559A1 - Fluid leakage detector - Google Patents

Fluid leakage detector Download PDF

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Publication number
WO1998054559A1
WO1998054559A1 PCT/DK1998/000201 DK9800201W WO9854559A1 WO 1998054559 A1 WO1998054559 A1 WO 1998054559A1 DK 9800201 W DK9800201 W DK 9800201W WO 9854559 A1 WO9854559 A1 WO 9854559A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
detector
base member
channel
electrical
Prior art date
Application number
PCT/DK1998/000201
Other languages
French (fr)
Inventor
Stine HØGHOLT
Original Assignee
Apv Fluid Handling Horsens 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
Application filed by Apv Fluid Handling Horsens A/S filed Critical Apv Fluid Handling Horsens A/S
Priority to AU74250/98A priority Critical patent/AU7425098A/en
Priority to DE19882365T priority patent/DE19882365T1/en
Publication of WO1998054559A1 publication Critical patent/WO1998054559A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/16—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/16—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means
    • G01M3/18—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators
    • G01M3/183—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators for pipe joints or seals

Definitions

  • the invention relates to a detector for detecting fluid leakage in hygienic processing plants or processing plant units, mainly pumps, homogenizers and the like apparatuses, in which shaft seals are used and in which falling drops of fluid occur in case of fluid leakage.
  • a detector for detecting fluid leakage in shaft seals in pumps is known.
  • the sensor is arranged in the bottom of a vessel for gathering the leakage fluid.
  • the detector is not activated until a certain fluid level in the vessel has been reached.
  • This detector is rather complicated, as a gathering vessel (maybe a collector container) is required which makes the construction fairly complex and thus expensive.
  • the detector is not hygienic, as bacteria may grow in the collector vessel.
  • the object of the invention is to provide a detector of the above type which is of a considerably simpler construction than the known constructions and at the same time more hygienic.
  • the detector according to the invention is characterised in that it is shaped as a base member provided with a drip-catcher and having an inclined fluid drainage channel without connection to a collector unit and that at least one electrical sensor is mounted in the drainage channel and adapted to detect each drop passing through the channel, said sensor forming part of a sensor circuit in or at the base member.
  • the detector is furthermore easily mounted on all types of processing plant or units thereof. Having passed the detector, the individual drops evaporate. An unhygienic collector vessel is thus rendered superfluous.
  • electrical sensors may form part of an electrical oscillating circuit for capacitive measurement of the passing drop, a first sensor being arranged slightly above the bottom wall of the channel and a second electrical sensor being inserted, eg embedded, in the base member. A particularly reliable detection of the drops is thus obtained.
  • the electrical sensors may be adapted for conductive measurement and be formed of two sensor bodies interspaced in the bottom wall of the channel, voltage being applied between said sensor bodies to generate an electrical signal when a drop passes the sensors. Accordingly a particularly simple manufacture of the detector is obtained.
  • the base member may have a substantially vertical rear wall or surface provided with fastening means for securing the detector to the processing plant, e.g. by gluing, fastening by screws or by magnetic fastening. A very reliable fixing of the detector in suitable distance below the possible leakage point in the processing plant or on the processing unit is thus obtained.
  • the base member may be of a electrically insulating material, such as plastics, in particular epoxy resin, in which at least one of the sensors is embed- ded or attached, whereby the detector is particular inexpensive to manufacture at the same time as the sensors or sensor bodies in electrical sense are better insulated.
  • the detector only reacts, when a drop passes by in the channel.
  • the sensor circuit of the detector may be coupled to one or more signal processing units, such as a PLC and/or a computer for generating one or several guide signals, when the signal or signals from the said sensor(s) or sensor bodies exceed(s) a predetermined threshold value.
  • the detector can be set to only generate an actual alarm, when said threshold value has been exceeded, for instance when the fluid leakage is so extensive that the number of drops per time unit flowing through the base member is so large that the fluid hitting the floor below the detector does not evaporate, before new drops reach the floor.
  • the change in frequency of the oscillating circuit can be used as a measure of whether a drop has passed the drainage channel.
  • Fig. 1 is a perspective view of an embodiment of the detector according to the invention.
  • Fig. 2 illustrates the same embodiment mounted below a shaft seal on a centrifugal pump
  • Fig. 3 illustrates an embodiment of the detector according to the invention in which the measurement of the drops is conductive
  • Fig. 4 illustrates an embodiment of the detector in which the measurement of the drops is capacitive
  • Fig. 5 illustrates a sensor circuit connected to a signal processing unit.
  • Fig. 1 The detector shown in Fig. 1 is intended for detecting fluid leakage in hygienic processing plants or processing plant units, such as centrifugal pumps and homogenizers, in particular in the shaft seals thereof.
  • Fig. 2 illustrates such a centrifugal pump 2 having a shaft seal indicated at reference numeral 3. In case of fluid leakage in this seal, the fluid drops 4 fall as indicated and are gathered by the detector 1 according to the invention.
  • the detector shown in Fig. 1 comprises a base member 5 having a drip-catcher 6 downwardly ending in a fluid drainage channel 7.
  • the detector is not connected to a collector unit such as a container or vessel.
  • the fluid drops passing through the channel thus fall onto the surface on which the centrifugal pump is placed. It is assumed that drops occur very rarely and furthermore are spread on the large floor space when hitting this, thus ensuring quick evaporation of the drops.
  • At least one electrical sensor 9a, 9b is mounted in the drainage channel and adapted to detect the individual drop 4 when this passes through the channel.
  • the sensor forms part of a sensor circuit 12 in or at the base member 1, an electrical voltage being applied to the circuit via a terminal 13.
  • the negative terminal of the sensor circuit is indicated at 13' .
  • the circuit is inserted or embedded in the base member 1.
  • the electrical sensors may form part of an electric oscillating circuit 12 for capacitive measurement of the passing drops of water, the first electrical sensor 19a being arranged slightly above the bottom of the channel, while the second electric sensor 19b being inserted, e.g. embedded in the base member 5.
  • the electrical sensors may be adapted for conductive measure- ment, the sensor bodies 9a and 9b being interspaced in the bottom wall of the channel 7.
  • the two sensor bodies may protrude upwardly out of the channel as illustrated in Fig. 3.
  • Fig. 3 illustrates how the substantially vertical rear wall or surface 15 of the base member 5 may be provided with fastening means 17a, 17b for securing the detector to the processing plant or the processing unit.
  • the fastening means may be adapted for fastening the detector by means of screws, but may also be in form of glue-fastening members or magnetic fastening members.
  • the base member 5 may be of an electrically insulating material such as plastics, in particular epoxy resin, in which or on which at least one of the sensors is embedded or attached.
  • Fig. 5 is a diagrammatic view of how the sensor circuit 12 in the base member 5 (only the terminals of the sensor circuit are shown) may be connected to a signal processing unit 20 such a PLC and/or a computer.
  • V is an applied DC or AC voltage.
  • One of the other terminals of the sensor circuit is earthed with the negative terminal of PLC.
  • the unit 20 may be adapted to generate a control signal, when the signal(s) from said sen- sor(s) 9a,9b, 19a, 19b exceed(s) a predetermined threshold value.
  • the signal processing unit 20 may for instance be adapted to only generate the control signal when/if the number of passing drops has reached a certain magnitude.
  • the signal processing unit 20 can be provided with a recognition function such that the unit is able to distinguish between a "pure" drop and any dirt particles.
  • the unit 20 may form part of an overall control with optional alarm functions (not shown).
  • the change in frequency of the oscillating circuit 12' can be used as a measure of whether a drop has passed the sensor.
  • the sensor circuit may be arranged on a printed circuit board which is either embedded or inserted into the base member 5.
  • the detector may be modified in many ways without thereby deviating from the scope of the invention.
  • the base member may thus be substantially wedge- shaped, the drip-catcher 6 and the channel 7 accordingly being provided in the upper inclined face of the wedge.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Examining Or Testing Airtightness (AREA)

Abstract

Dectector for detecting fluid leakages in shaft seals (3) of a hygienic centrifugal pump (2), in which the leakage occurs as falling drops (4). The detector comprises a base member (5) having a drip-catcher (6) and an inclined fluid drainage channel (7). In or at the latter at least one electrical sensor (19a) is mounted which can detect the individual drop, when this passes the channel (7). The sensor (19a) forms part of a sensor circuit (12) in or at the base member (5). In this manner a very simple and inexpensive and hygienic detector is obtained.

Description

Title: Fluid leakage detector
Technical Field
The invention relates to a detector for detecting fluid leakage in hygienic processing plants or processing plant units, mainly pumps, homogenizers and the like apparatuses, in which shaft seals are used and in which falling drops of fluid occur in case of fluid leakage.
Background Art
A detector for detecting fluid leakage in shaft seals in pumps is known. In this detector the sensor is arranged in the bottom of a vessel for gathering the leakage fluid. The detector is not activated until a certain fluid level in the vessel has been reached. This detector is rather complicated, as a gathering vessel (maybe a collector container) is required which makes the construction fairly complex and thus expensive. At the same time the detector is not hygienic, as bacteria may grow in the collector vessel.
Brief Description of the Invention
The object of the invention is to provide a detector of the above type which is of a considerably simpler construction than the known constructions and at the same time more hygienic.
The detector according to the invention is characterised in that it is shaped as a base member provided with a drip-catcher and having an inclined fluid drainage channel without connection to a collector unit and that at least one electrical sensor is mounted in the drainage channel and adapted to detect each drop passing through the channel, said sensor forming part of a sensor circuit in or at the base member. As a result a particularly simple and inexpensive construction is obtained. The detector is furthermore easily mounted on all types of processing plant or units thereof. Having passed the detector, the individual drops evaporate. An unhygienic collector vessel is thus rendered superfluous.
According to the invention electrical sensors may form part of an electrical oscillating circuit for capacitive measurement of the passing drop, a first sensor being arranged slightly above the bottom wall of the channel and a second electrical sensor being inserted, eg embedded, in the base member. A particularly reliable detection of the drops is thus obtained.
Moreover according to the invention the electrical sensors may be adapted for conductive measurement and be formed of two sensor bodies interspaced in the bottom wall of the channel, voltage being applied between said sensor bodies to generate an electrical signal when a drop passes the sensors. Accordingly a particularly simple manufacture of the detector is obtained.
Furthermore according to the invention the base member may have a substantially vertical rear wall or surface provided with fastening means for securing the detector to the processing plant, e.g. by gluing, fastening by screws or by magnetic fastening. A very reliable fixing of the detector in suitable distance below the possible leakage point in the processing plant or on the processing unit is thus obtained.
According to the invention the base member may be of a electrically insulating material, such as plastics, in particular epoxy resin, in which at least one of the sensors is embed- ded or attached, whereby the detector is particular inexpensive to manufacture at the same time as the sensors or sensor bodies in electrical sense are better insulated. The detector only reacts, when a drop passes by in the channel.
Finally according to the invention the sensor circuit of the detector may be coupled to one or more signal processing units, such as a PLC and/or a computer for generating one or several guide signals, when the signal or signals from the said sensor(s) or sensor bodies exceed(s) a predetermined threshold value. As a result, the detector can be set to only generate an actual alarm, when said threshold value has been exceeded, for instance when the fluid leakage is so extensive that the number of drops per time unit flowing through the base member is so large that the fluid hitting the floor below the detector does not evaporate, before new drops reach the floor.
Finally according to the invention the change in frequency of the oscillating circuit can be used as a measure of whether a drop has passed the drainage channel.
Brief Description of the Drawings
The invention is explained in detail below with reference to the drawings, in which
Fig. 1 is a perspective view of an embodiment of the detector according to the invention,
Fig. 2 illustrates the same embodiment mounted below a shaft seal on a centrifugal pump,
Fig. 3 illustrates an embodiment of the detector according to the invention in which the measurement of the drops is conductive,
Fig. 4 illustrates an embodiment of the detector in which the measurement of the drops is capacitive and
Fig. 5 illustrates a sensor circuit connected to a signal processing unit.
Best Mode for Carrying Out the Invention
The detector shown in Fig. 1 is intended for detecting fluid leakage in hygienic processing plants or processing plant units, such as centrifugal pumps and homogenizers, in particular in the shaft seals thereof. Fig. 2 illustrates such a centrifugal pump 2 having a shaft seal indicated at reference numeral 3. In case of fluid leakage in this seal, the fluid drops 4 fall as indicated and are gathered by the detector 1 according to the invention.
The detector shown in Fig. 1 comprises a base member 5 having a drip-catcher 6 downwardly ending in a fluid drainage channel 7. The detector is not connected to a collector unit such as a container or vessel. The fluid drops passing through the channel thus fall onto the surface on which the centrifugal pump is placed. It is assumed that drops occur very rarely and furthermore are spread on the large floor space when hitting this, thus ensuring quick evaporation of the drops. At least one electrical sensor 9a, 9b is mounted in the drainage channel and adapted to detect the individual drop 4 when this passes through the channel. The sensor forms part of a sensor circuit 12 in or at the base member 1, an electrical voltage being applied to the circuit via a terminal 13. The negative terminal of the sensor circuit is indicated at 13' . In Fig. 1 the circuit is inserted or embedded in the base member 1.
As illustrated in Fig. 4, the electrical sensors may form part of an electric oscillating circuit 12 for capacitive measurement of the passing drops of water, the first electrical sensor 19a being arranged slightly above the bottom of the channel, while the second electric sensor 19b being inserted, e.g. embedded in the base member 5.
As shown in Figs. 1 and 3 the electrical sensors may be adapted for conductive measure- ment, the sensor bodies 9a and 9b being interspaced in the bottom wall of the channel 7. Optionally, the two sensor bodies may protrude upwardly out of the channel as illustrated in Fig. 3.
Fig. 3 illustrates how the substantially vertical rear wall or surface 15 of the base member 5 may be provided with fastening means 17a, 17b for securing the detector to the processing plant or the processing unit. As shown the fastening means may be adapted for fastening the detector by means of screws, but may also be in form of glue-fastening members or magnetic fastening members. The base member 5 may be of an electrically insulating material such as plastics, in particular epoxy resin, in which or on which at least one of the sensors is embedded or attached.
Fig. 5 is a diagrammatic view of how the sensor circuit 12 in the base member 5 (only the terminals of the sensor circuit are shown) may be connected to a signal processing unit 20 such a PLC and/or a computer. V is an applied DC or AC voltage. One of the other terminals of the sensor circuit is earthed with the negative terminal of PLC. The unit 20 may be adapted to generate a control signal, when the signal(s) from said sen- sor(s) 9a,9b, 19a, 19b exceed(s) a predetermined threshold value. The signal processing unit 20 may for instance be adapted to only generate the control signal when/if the number of passing drops has reached a certain magnitude. The signal processing unit 20 can be provided with a recognition function such that the unit is able to distinguish between a "pure" drop and any dirt particles. The unit 20 may form part of an overall control with optional alarm functions (not shown).
With reference to Fig. 4 it should be noted that the change in frequency of the oscillating circuit 12' can be used as a measure of whether a drop has passed the sensor.
The sensor circuit may be arranged on a printed circuit board which is either embedded or inserted into the base member 5.
The detector may be modified in many ways without thereby deviating from the scope of the invention. As shown in Fig. 3 the base member may thus be substantially wedge- shaped, the drip-catcher 6 and the channel 7 accordingly being provided in the upper inclined face of the wedge.

Claims

Claims
1. Detector for detecting fluid leakages in hygienic processing plants or processing plant units (2), mainly pumps, homogenizers and the like apparatuses, in which shaft seals (3) are used and in which falling drops of fluid (4) occur in case of fluid leakage, characterised in that it is shaped as a base member (5) provided with a drip- catcher (6) and having an inclined fluid drainage channel (7) without connection to a collector unit and that at least one electrical sensor (9a,9b,19a,19b) is mounted in the drainage channel (7) and adapted to detect each drop (4) passing through the channel (7), said sensor (9a, 9b, 19a, 19b) forming part of a sensor circuit (12) in or at the base member (5).
2. Detector according to claim 1, characterised in that the electrical sensors (19a, 19b) form part of an electrical oscillating circuit (12) for capacitive measurement of the passing drop (4), a first sensor (19a) being arranged slightly above the bottom wall of the channel and a second electrical sensor (19b) being inserted, eg embedded, in the base member (5).
3. Detector according to claim 1, characterised in that the electrical sensors (9a,9b) are adapted for conductive measurement and formed of two sensor bodies (9a,9b) interspaced in the bottom wall of the channel, electric voltage being applied between said sensor bodies to generate an electrical signal when a drop (4) passes the sensors.
4. Detector according to one or more of the claims 1-3, characterised in that the base member (5) has a substantially vertical rear wall or surface (15) provided with fastening means (17, 17b) for securing the detector to the processing plant or processing unit (2), e.g. by gluing, fastening by screws or by magnetic fastening.
5. Detector according to one or more of the claims 1-4, characterised in that the base member (5) is of an electrically insulating material such as plastics, in particular epoxy resin in which or on which at least one of the sensors (9a,9b,19a,19b) is embedded or attached.
6. Detector according to one or more of the claims 1-5, characterised in that the sensor circuit (12) is coupled to one or more signal processing units (l╬╕)such as a PLC and/or a computer for generating one or more control signals, when the signal or signals from the one or more of said sensors (9a, 9b, 19a, 19b) exceed(s) a predetermined threshold value.
7. Detector according to claim 2, characterised in that the change in frequency of the oscillating circuit (12') is used as a measure of whether a drop has passed the channel (7).
PCT/DK1998/000201 1997-05-27 1998-05-20 Fluid leakage detector WO1998054559A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU74250/98A AU7425098A (en) 1997-05-27 1998-05-20 Fluid leakage detector
DE19882365T DE19882365T1 (en) 1997-05-27 1998-05-20 Liquid leakage detector

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DK0602/97 1997-05-27
DK60297A DK173785B1 (en) 1997-05-27 1997-05-27 Detector for detecting fluid leaks

Publications (1)

Publication Number Publication Date
WO1998054559A1 true WO1998054559A1 (en) 1998-12-03

Family

ID=8095441

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DK1998/000201 WO1998054559A1 (en) 1997-05-27 1998-05-20 Fluid leakage detector

Country Status (4)

Country Link
AU (1) AU7425098A (en)
DE (1) DE19882365T1 (en)
DK (1) DK173785B1 (en)
WO (1) WO1998054559A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1562031A2 (en) * 2004-02-04 2005-08-10 Rolls-Royce Plc Leakage drain
EP1621863A2 (en) 2004-07-26 2006-02-01 Carl Freudenberg KG Device for detecting a leakage
EP2492670A1 (en) * 2011-02-23 2012-08-29 Fujitsu Limited Condensation sensing device, electronic apparatus, and condensation sensing method
CN109519394A (en) * 2017-09-20 2019-03-26 格兰富控股联合股份公司 Pump seal leak detection system

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770002A (en) * 1971-11-01 1973-11-06 L Brown Automatic water shut-off system
US4502044A (en) * 1982-05-19 1985-02-26 Farris James R Moisture alarm system
US4520667A (en) * 1983-09-07 1985-06-04 Nelson Joseph A Nonmechanical digital raingauge
GB2157424A (en) * 1984-03-29 1985-10-23 Von Kernbrennstoffen Mbh Deuts Method and means for detecting drip leakage in an enclosed space
US4673926A (en) * 1985-02-12 1987-06-16 Gorman Walter T Liquid containment and leak detection system
GB2199436A (en) * 1986-11-28 1988-07-06 B & R Electrical Prod Ltd Detection of fluid leakage
US4827766A (en) * 1987-06-11 1989-05-09 Nelson Joseph A Dual filter, drop based, digital raingauge
GB2272553A (en) * 1992-11-13 1994-05-18 O Dea Francis Joseph Apparatus for controlling flooding from a water using appliance
US5339676A (en) * 1993-06-02 1994-08-23 Del Johnson Water leak detection, collection and support device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770002A (en) * 1971-11-01 1973-11-06 L Brown Automatic water shut-off system
US4502044A (en) * 1982-05-19 1985-02-26 Farris James R Moisture alarm system
US4520667A (en) * 1983-09-07 1985-06-04 Nelson Joseph A Nonmechanical digital raingauge
GB2157424A (en) * 1984-03-29 1985-10-23 Von Kernbrennstoffen Mbh Deuts Method and means for detecting drip leakage in an enclosed space
US4673926A (en) * 1985-02-12 1987-06-16 Gorman Walter T Liquid containment and leak detection system
GB2199436A (en) * 1986-11-28 1988-07-06 B & R Electrical Prod Ltd Detection of fluid leakage
US4827766A (en) * 1987-06-11 1989-05-09 Nelson Joseph A Dual filter, drop based, digital raingauge
GB2272553A (en) * 1992-11-13 1994-05-18 O Dea Francis Joseph Apparatus for controlling flooding from a water using appliance
US5339676A (en) * 1993-06-02 1994-08-23 Del Johnson Water leak detection, collection and support device

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1562031A2 (en) * 2004-02-04 2005-08-10 Rolls-Royce Plc Leakage drain
EP1562031A3 (en) * 2004-02-04 2006-07-05 Rolls-Royce Plc Leakage drain
US7146849B2 (en) 2004-02-04 2006-12-12 Rolls-Royce, Plc. Leakage drain
EP1621863A2 (en) 2004-07-26 2006-02-01 Carl Freudenberg KG Device for detecting a leakage
EP2492670A1 (en) * 2011-02-23 2012-08-29 Fujitsu Limited Condensation sensing device, electronic apparatus, and condensation sensing method
CN109519394A (en) * 2017-09-20 2019-03-26 格兰富控股联合股份公司 Pump seal leak detection system
EP3460440A1 (en) 2017-09-20 2019-03-27 Grundfos Holding A/S Pump seal leakage detection system
US10948375B2 (en) 2017-09-20 2021-03-16 Grundfos Holding A/S Pump seal leakage detection system

Also Published As

Publication number Publication date
AU7425098A (en) 1998-12-30
DE19882365T1 (en) 2000-06-15
DK173785B1 (en) 2001-10-08
DK60297A (en) 1998-11-28

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