WO1986004409A1 - A device for detecting the presence or absence of liquid in a vessel - Google Patents

A device for detecting the presence or absence of liquid in a vessel Download PDF

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Publication number
WO1986004409A1
WO1986004409A1 PCT/GB1986/000042 GB8600042W WO8604409A1 WO 1986004409 A1 WO1986004409 A1 WO 1986004409A1 GB 8600042 W GB8600042 W GB 8600042W WO 8604409 A1 WO8604409 A1 WO 8604409A1
Authority
WO
WIPO (PCT)
Prior art keywords
tube
liquid
vessel
sensor
absence
Prior art date
Application number
PCT/GB1986/000042
Other languages
French (fr)
Inventor
Anthony Holden Platt
Original Assignee
The Victoria University Of Manchester
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 The Victoria University Of Manchester filed Critical The Victoria University Of Manchester
Publication of WO1986004409A1 publication Critical patent/WO1986004409A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
    • G01F23/284—Electromagnetic waves
    • G01F23/292—Light, e.g. infrared or ultraviolet
    • G01F23/2921—Light, e.g. infrared or ultraviolet for discrete levels

Definitions

  • THIS INVENTION concerns a device for detecting the presence or absence of liquid in a translucent vessel or tube, and has particular appl ication in the detection of air bubbles in pipelines carrying a stream of liquid.
  • medical appl ications for example, during infusions and transfusions where the presence of a large air bubble in the blood supply can present a danger to l i fe, it i s most important that the continuity of the liquid stream i s monitored to detect the presence of any air bubbles in the stream, if large enough to be dangerous.
  • the invention is based upon the principle that a beam of light passing into a translucent tube containing no liquid, will be sufficiently diffused for at least some of the light to pass through the tube in a generally straight line substantially al igned wi th the incident light beam, whilst a similar beam pas sed through a clear or largely translucent liquid within the tube would be deflected by refraction ? and that the presence of an opaque liquid in the tube would caus e the inc ident l i ght beam to be re flected thus preventing it from pas sing through the liquid.
  • An object of the present invention is to provide a simple device for detecting the present or absence of liquid in a translucent vessel or tube and accordingly the device comprises a light source adapted to transmit a beam of light through said vessel or tube to a photo-electric sensor, the light source and the photo-electric sensor being so disposed relative to one another and to the vessel or tube, that when the latter contains an opaque liquid the incident light path is obstructed thereby; when it contains a translucent liquid the incident light path is deflected by refraction away from said sensor? and when it contains air or other gas so that the incident light path is not obstructed or deflected, a signal is produced by the photo ⁇ electric sensor to provide an indication of the absence of liquid in the vessel or tube.
  • Fig. 1 illustrates in cross-section, a translucent tube through which a fluid substance is to pass, and a light system for detecting the presence or absence of liquid in the tube;
  • Fig. 2 shows the tube containing a translucent liquid
  • Fig. 3 shows the tube containing an opaque liquid.
  • a tube 10 having a translucent material wall contains no liquid and a beam of light transmitted by a light source 11 effectively passes in a straight path through the tube wall to be received by a photo-electric sensor 12.
  • the sensor 12 is adapted under these conditions to produce an electrical signal which can be used to drive a visual or audible indicator or a meter.
  • the distance 'X' between the centre line 'Y' of tube 10 and the path of the incident light beam from light source 11 is equal to about one quarter of the internal diameter of tube 10.
  • the tube 10 now contains a clear or translucent liquid 13 the path of the incident light beam entering the liquid 13 is deflected by refraction and emerges on the opposite side of the centre line of the tube 10 as indicated at 14. In this case the light beam is not received by sensor 12 and no signal is produced.
  • the incident light beam is substantially prevented from passing through the 1 liquid and is thus scattered, and again is not received by sensor 12, so that no signal is produced.
  • the presence or absence of liquid in the tube can be detected since no signal will be produced by the sensor unless the liquid level in the tube falls below that of the incident light beam from source 11.
  • the sensitivity of the device can be adjusted to ensure that the sensor receives no refracted light when the tube is filled or substantially filled with liquid.
  • the device can be produced by placing the light source 11 and sensor 12 on a small platform 16 across which the tube 10 can be placed, and preferably the positions of source 11 and sensor 12 on platform 16 are adjustable to accommodate tubes of different diameter and to vary the distance 'X'.
  • the device can be applied to existing pipelines provided that at least a portion of the pipe where it passes between the source 11 and sensor 12 is transparent or at least translucent.
  • An advantage of the device in accordance with the invention when used in conjunction with toxic, corrosive or contaminatable liquids, is that no parts are caused to come into contact with the liquid within the tube, and it is simple and inexpensive to produce and maintain when compared with systems using, for example, ultrasonics. If the device is exposed to ambient light its sensitivity and reliability can be effected. Therefore, it is preferable in some cases for the light source 11 to emit a beam of infra-red light and for the sensor to detect same, so that ambient light cannot interfere with its operation.
  • the invention has particular application in the medical field for the delivery of blood or other fluids to patients for introduction intravenously where the injection of a large air bubble might be dangerous.
  • the device can be applied to monitoring the flow of liquid in many forms of apparatus, for example, in sight glasses on tanks, in manometers, and it might be used in some instances to replace the conventional ball cock in a liquid storage tank.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Thermal Sciences (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Infusion, Injection, And Reservoir Apparatuses (AREA)

Abstract

A device for detecting the presence or absence of liquid in a translucent vessel or tube which consists of a light source (11) and a light sensor (12) adjustably mounted on a platform (16) on which a tube (10) through which a fluid substance is to pass, is located. If the tube (10) contains no liquid then the sensor (12) receives the light beam and produces a signal for indication. However, if the tube (10) is filled with a translucent or opaque liquid, the light beam is deflected by refraction or scattered to prevent it from activating the sensor (12).

Description

A DEVICE FOR DETECTING THE PRESENCE OR ABSENCE OF LIQUID IN A VESSEL
THIS INVENTION concerns a device for detecting the presence or absence of liquid in a translucent vessel or tube, and has particular appl ication in the detection of air bubbles in pipelines carrying a stream of liquid. In medical appl ications, for example, during infusions and transfusions where the presence of a large air bubble in the blood supply can present a danger to l i fe, it i s most important that the continuity of the liquid stream i s monitored to detect the presence of any air bubbles in the stream, if large enough to be dangerous.
The invention is based upon the principle that a beam of light passing into a translucent tube containing no liquid, will be sufficiently diffused for at least some of the light to pass through the tube in a generally straight line substantially al igned wi th the incident light beam, whilst a similar beam pas sed through a clear or largely translucent liquid within the tube would be deflected by refraction? and that the presence of an opaque liquid in the tube would caus e the inc ident l i ght beam to be re flected thus preventing it from pas sing through the liquid. An object of the present invention is to provide a simple device for detecting the present or absence of liquid in a translucent vessel or tube and accordingly the device comprises a light source adapted to transmit a beam of light through said vessel or tube to a photo-electric sensor, the light source and the photo-electric sensor being so disposed relative to one another and to the vessel or tube, that when the latter contains an opaque liquid the incident light path is obstructed thereby; when it contains a translucent liquid the incident light path is deflected by refraction away from said sensor? and when it contains air or other gas so that the incident light path is not obstructed or deflected, a signal is produced by the photo¬ electric sensor to provide an indication of the absence of liquid in the vessel or tube.
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which:-
Fig. 1 illustrates in cross-section, a translucent tube through which a fluid substance is to pass, and a light system for detecting the presence or absence of liquid in the tube;
Fig. 2 shows the tube containing a translucent liquid; and Fig. 3 shows the tube containing an opaque liquid.
Referring now to the drawings it will be seen in Fig. 1 that a tube 10 having a translucent material wall contains no liquid and a beam of light transmitted by a light source 11 effectively passes in a straight path through the tube wall to be received by a photo-electric sensor 12. The sensor 12 is adapted under these conditions to produce an electrical signal which can be used to drive a visual or audible indicator or a meter. The distance 'X' between the centre line 'Y' of tube 10 and the path of the incident light beam from light source 11 is equal to about one quarter of the internal diameter of tube 10.
Referring to Fig. 2, wherein the tube 10 now contains a clear or translucent liquid 13 the path of the incident light beam entering the liquid 13 is deflected by refraction and emerges on the opposite side of the centre line of the tube 10 as indicated at 14. In this case the light beam is not received by sensor 12 and no signal is produced.
Referring to Fig. 3, wherein the tube 10 now contains an opaque liquid 15, the incident light beam is substantially prevented from passing through the1 liquid and is thus scattered, and again is not received by sensor 12, so that no signal is produced. With the arrangement described therefore, the presence or absence of liquid in the tube can be detected since no signal will be produced by the sensor unless the liquid level in the tube falls below that of the incident light beam from source 11. By varying the distance 'X', the sensitivity of the device can be adjusted to ensure that the sensor receives no refracted light when the tube is filled or substantially filled with liquid.
The device can be produced by placing the light source 11 and sensor 12 on a small platform 16 across which the tube 10 can be placed, and preferably the positions of source 11 and sensor 12 on platform 16 are adjustable to accommodate tubes of different diameter and to vary the distance 'X'. The device can be applied to existing pipelines provided that at least a portion of the pipe where it passes between the source 11 and sensor 12 is transparent or at least translucent.
An advantage of the device in accordance with the invention when used in conjunction with toxic, corrosive or contaminatable liquids, is that no parts are caused to come into contact with the liquid within the tube, and it is simple and inexpensive to produce and maintain when compared with systems using, for example, ultrasonics. If the device is exposed to ambient light its sensitivity and reliability can be effected. Therefore, it is preferable in some cases for the light source 11 to emit a beam of infra-red light and for the sensor to detect same, so that ambient light cannot interfere with its operation.
The invention has particular application in the medical field for the delivery of blood or other fluids to patients for introduction intravenously where the injection of a large air bubble might be dangerous. However, the device can be applied to monitoring the flow of liquid in many forms of apparatus, for example, in sight glasses on tanks, in manometers, and it might be used in some instances to replace the conventional ball cock in a liquid storage tank.

Claims

1. A device for detecting the presence or absence of liquid in a translucent vessel or tube, comprising a light source adapted to be disposed with respect to said vessel or tube to transmit a beam of light through same, a sensor to detect said beam of light, the light source and the sensor being so positioned relative to one another and to the vessel or tube, that when the latter contains an opaque liquid the incident light beam is obstructed thereby; when it contains a translucent liquid the incident light path is deflected by refraction away from said sensor; and when it contains air or other gas or vapour such that the incident light beam is not obstructed or deflected, a signal is produced by the sensor to provide an indication of the absence of liquid in the vessel or tube.
2. A device according to Claim 1, wherein the relative disposition of said light source and said vessel or tube is adjustable.
3. A device according to Claim 1, or Claim 2, wherein the relative disposition of said sensor and said vessel or tube is adjustable.
4. A device according to Claim 1, wherein said light source and said sensor are mounted on a platform and are adjustable thereon to accommodate different sizes of vessel or tube and to adjust the sensitivity of the device.
5. A device according to any preceding claim, in which said light source is adapted to transmit a beam of infra-red light.
6. A device according to any preceding claim, in which said sensor is adapted to drive a visual or audible indicator.
7. A device according to any preceding claim, wherein sai d s ensor i s adapted to dr ive a mete r to g ive an indication of the absence of liquid in the vessel or tube.
8. A device for detecting the presence or absence of liquid in a translucent vessel or tube, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings .
PCT/GB1986/000042 1985-01-18 1986-01-20 A device for detecting the presence or absence of liquid in a vessel WO1986004409A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8501367 1985-01-18
GB858501367A GB8501367D0 (en) 1985-01-18 1985-01-18 Detecting presence/absence of liquid in vessel

Publications (1)

Publication Number Publication Date
WO1986004409A1 true WO1986004409A1 (en) 1986-07-31

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1986/000042 WO1986004409A1 (en) 1985-01-18 1986-01-20 A device for detecting the presence or absence of liquid in a vessel

Country Status (4)

Country Link
EP (1) EP0245272A1 (en)
AU (1) AU5355486A (en)
GB (1) GB8501367D0 (en)
WO (1) WO1986004409A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989001796A1 (en) * 1987-08-28 1989-03-09 Bellhouse Technology Limited Bubble detector
GB2236180A (en) * 1989-08-15 1991-03-27 Bass Plc Detection of bubbles in flowing liquids
GB2272972A (en) * 1992-11-28 1994-06-01 Hargreaves Harold James Safety device for water cooling system
US5672887A (en) * 1995-11-29 1997-09-30 Shaw; Benjamin G. Optical detector for air in fluid line the same
GB2416837A (en) * 2004-08-04 2006-02-08 Univ College London Hospitals A fluid detector having lateral offset along its emitter to receiver radiation paths
WO2018129600A1 (en) * 2017-01-11 2018-07-19 RIBEIRO, Emilio Carlos Precision probe for detecting level variations or the presence of liquids using infrared or visible light
CN110108676A (en) * 2019-04-08 2019-08-09 中南大学湘雅三医院 Cleaning intestinal tract degree detection device and detection method
CN112146725A (en) * 2020-09-14 2020-12-29 武汉深蓝恒业数码科技有限公司 Method and device for detecting liquid level of pipeline

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4920336A (en) * 1988-11-22 1990-04-24 Fisher Scientific Company Method and apparatus for monitoring the level of the contents in a container

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2061821A5 (en) * 1969-05-06 1971-06-25 Commissariat Energie Atomique
FR2124607A1 (en) * 1971-02-10 1972-09-22 Jobling & Co James A
DE2522095B1 (en) * 1975-05-17 1976-05-13 Braun Melsungen Ag Device for checking the level of liquids in transparent tubes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2061821A5 (en) * 1969-05-06 1971-06-25 Commissariat Energie Atomique
FR2124607A1 (en) * 1971-02-10 1972-09-22 Jobling & Co James A
DE2522095B1 (en) * 1975-05-17 1976-05-13 Braun Melsungen Ag Device for checking the level of liquids in transparent tubes

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989001796A1 (en) * 1987-08-28 1989-03-09 Bellhouse Technology Limited Bubble detector
GB2236180A (en) * 1989-08-15 1991-03-27 Bass Plc Detection of bubbles in flowing liquids
GB2272972A (en) * 1992-11-28 1994-06-01 Hargreaves Harold James Safety device for water cooling system
GB2272972B (en) * 1992-11-28 1997-05-14 Hargreaves Harold James Safety device for outboard motor
US5672887A (en) * 1995-11-29 1997-09-30 Shaw; Benjamin G. Optical detector for air in fluid line the same
GB2416837A (en) * 2004-08-04 2006-02-08 Univ College London Hospitals A fluid detector having lateral offset along its emitter to receiver radiation paths
WO2018129600A1 (en) * 2017-01-11 2018-07-19 RIBEIRO, Emilio Carlos Precision probe for detecting level variations or the presence of liquids using infrared or visible light
CN110108676A (en) * 2019-04-08 2019-08-09 中南大学湘雅三医院 Cleaning intestinal tract degree detection device and detection method
CN112146725A (en) * 2020-09-14 2020-12-29 武汉深蓝恒业数码科技有限公司 Method and device for detecting liquid level of pipeline

Also Published As

Publication number Publication date
AU5355486A (en) 1986-08-13
GB8501367D0 (en) 1985-02-20
EP0245272A1 (en) 1987-11-19

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