WO1991013340A1 - A method of measuring slurry - Google Patents

A method of measuring slurry Download PDF

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Publication number
WO1991013340A1
WO1991013340A1 PCT/DK1991/000053 DK9100053W WO9113340A1 WO 1991013340 A1 WO1991013340 A1 WO 1991013340A1 DK 9100053 W DK9100053 W DK 9100053W WO 9113340 A1 WO9113340 A1 WO 9113340A1
Authority
WO
WIPO (PCT)
Prior art keywords
radiation
measuring
fluid
detector
source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/DK1991/000053
Other languages
French (fr)
Inventor
Jan Hansen
Hans Ole Nielsen
Allan Northeved
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lys & Optik
Original Assignee
Lys & Optik
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 Lys & Optik filed Critical Lys & Optik
Priority to EP91904981A priority Critical patent/EP0517759B1/en
Priority to DE69114484T priority patent/DE69114484T2/en
Publication of WO1991013340A1 publication Critical patent/WO1991013340A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/85—Investigating moving fluids or granular solids
    • G01N21/8507—Probe photometers, i.e. with optical measuring part dipped into fluid sample
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G01N21/15—Preventing contamination of the components of the optical system or obstruction of the light path

Definitions

  • the invention relates to a method of continuously determin ⁇ ing the parameters of a fluid, such as the dry-matter percentage in slurry or another industrial product, and whereby said fluid is subjected to a measuring system comprising a radiation source and a radiation detector placed opposite one another, the measuring signals being processed in an evaluation circuit, wherafter the results of the evaluation are displayed on display means.
  • a fluid such as the dry-matter percentage in slurry or another industrial product
  • a system for measuring parameter values of a passing fluid.
  • the system comprises a radiation source and a radiation detector optionally in direct contact with the fluid.
  • Means may furthermore be provided for cleaning the radiation source and the radiation detector.
  • Such means may for instance be in form of a scraper or a jet of wash water.
  • the object of the invention is to provide a method solving the above problems .
  • the method according to the invention is characterised in that the radiation source and the radiation detector are mounted on a forked support immersible in the fluid in question.
  • the measuring signal may be subjected to a simultaneous/following calibration, the source and the detector being subjected to a rinsing.
  • the radiation used may for instance be provided by light, sound or soft isotopic radiation.
  • Fig. 1 illustrates a slurry measuring device comprising a radiation source and a radiation detector placed opposite one another, the radiation source and the radiation detect ⁇ or being cleaned by means of a rotating scraper,
  • Fig. 2 illustrates an alternative embodiment, the so-called T-model, of the slurry measuring device, where the scraper is inserted from the side,
  • Fig. 3 illustrates an alternative embodiment of the slurry measuring device, where the probe is bent
  • Fig. 4 illustrates a slurry measuring device according to the invention, where the surface of the radiation source and the radiation detector are cleaned by means of passing water,
  • Fig. 5 illustrates an example of a measuring signal pro ⁇ quizzed by the slurry measuring device of Fig. 4,
  • Fig. 6 illustrates an example of the electronic measuring circuit .
  • the invention refers to highly polluted fluids, such as sludge.
  • An interest has arisen in measuring the dry-matter percentage relative to the water percentage in slurry.
  • the measuring may for instance be carried out by measuring the damping of a suitably selected radiation light, sound or isotopic radiation over a predetermined measuring length.
  • a problem applies, however, because the radiation source and the radiation detector are polluted on the surface with the result that the measuring signal is degraded.
  • the sludge passes a pipe 1, and the embodiment is provided with two opposing trans ⁇ ducers 2, 3 flushing with the inner side of said pipe 1.
  • the inner side of the transducers 2, 3 are kept clean by means of a rotating, cylindrical scraper 4 comprising V- shaped notches.
  • the rotation of the scraper 4 is caused by means of an outer gear wheel engaging said cylindrical, rotating scraper 4 through a slot in the pipe 1.
  • Such an embodiment is, however, encumbered with sealing problems.
  • the scraper 4 may also be formed such that it is caused to rotate by the passing sludge, and then it is provided with inner fins.
  • the scraper 4 can be made of an electrically conductive material and caused to rotate by means of an electromagnetic, rotating field applied from the outside through electromagnets 5 placed on the outside, whereby sealing problems are avoided.
  • Permanent magnets may furthermore be embedded in the rotating scraper 4, said permanent magnets being caused to follow the rotating field.
  • the rotating scraper is provided with inner fins, the permanent magnets may be used for indicating the flow velocity with the result that it is possible in addition to achieve a measurement of the viscosity which may also be of interest.
  • the so-called T- model shown in Fig. 2 the rotating scraper 22 has been inserted from the side perpendicular to said embodiment.
  • the T-model is advantageous in facilitating the providing of a rotation by means of a motor 6.
  • the rotating scraper 22 need only be mounted in a liquid-proof manner relative to the motor 6.
  • the driving shaft 21 of the rotating scraper 22 extends through a housing via a liquid-proof bearing, said housing sealingly surrounding the pipe.
  • the transducers 7, 7' are preferably ultrasonic transducers.
  • portions of the rotating scraper or a particularly shaped member mounted thereon may be used for calibration.
  • the radiation source 8 and the radiation detector 9 are mounted on a forked support 10 immersible in the fluid to be measured. Before the calibration, the detector 8 and the radiation source 9 are rinsed by means of rinsing water being fed through a channel 11 in the forked support 10.
  • the channel 11 may optinally split up into two branch pipes, one branch pipe facing the radiation source 8 and the other branch pipe facing the radiation detector 9.
  • the feeding hose 14 to the channel 11 is provided with a valve controlling the supply of water.
  • the radiation source 8 is spaced approxi ⁇ mately 10 mm from the radiation detector 9. According to the invention a reference measurement is performed, i.e.
  • the rinsing channel fills the entire space be ⁇ tween the detector 9 and the source 8 with the result that the rinsing fluid functions as a reference fluid because said rinsing fluid fills the entire volume between the radiation source 8 and the radiation detector 9.
  • Fig. 5 illustrates an example of measuring signals.
  • Fig. 6 illustrates an example of the electronic circuic in question, where the transmitter 21 communicates with the transmitter- transducer 2.
  • the signal received by the receiver-transducer 3 is transmitted to an amplifier 26 in turn transmitting said signal to an amplitude and phase detector 23. Subsequently, the signal is processed in a microprocessor circuit 24 connected to a display 25.
  • the radiation in question is not necessarily ultrasound. Alternatively, it may be an electromagnetic radiation, such as light or a soft isotopic radiation when heavy metals are to be measured.
  • the measuring value is compared with the reference value provided at the end of the cleaning process because said comparing turned out to provide sufficiently good measuring results.
  • the measuring method is in particular used for measuring the dry-matter percentage in sludge by means of infrared light.
  • the method can, however, also be used for other easurings of parameter values of a fluid.
  • the light used is infrared and ultraviolet light.
  • the ultraviolet light is attenuated in response to the amount of organic matter (BOD, COD).
  • BOD organic matter
  • COD organic matter
  • the ratio of infrared to ultraviolet damping is related to the amount of organic matter. Accordingly, a measuring of the attenua ⁇ tion of ultraviolet light relative to infrared light results in the percentage of organic matter in for instance sludge .
  • the radiation source for emission of both ultraviolet and infrared light may for instance be a halogen or a xenon lamp.
  • the receiving side is provided with a separate detector for infrared light and separate detector for ultraviolet light.
  • the radiation source may be adapted to pulsed operation.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

A method of continuously determining the parameters of a fluid, such as the dry-matter percentage in slurry or another industrial product, and whereby said fluid is subjected to a measuring system comprising a radiation source (2) and a radiation detector (3) placed opposite one another, the measuring signals being processed in an evaluation circuit, whereafter the results of the evaluation are displayed on display means (25). The radiation source (2) and the radiation detector (3) are mounted on a forked support immersible in the fluid in question, the source (2) and the detector (3) being subjected to a rinsing simultaneously with the measuring signal being calibrated.

Description

Title: A Method of Measuring Slurry.
Technical Field
The invention relates to a method of continuously determin¬ ing the parameters of a fluid, such as the dry-matter percentage in slurry or another industrial product, and whereby said fluid is subjected to a measuring system comprising a radiation source and a radiation detector placed opposite one another, the measuring signals being processed in an evaluation circuit, wherafter the results of the evaluation are displayed on display means.
Background Art
A system is known for measuring parameter values of a passing fluid. The system comprises a radiation source and a radiation detector optionally in direct contact with the fluid. Means may furthermore be provided for cleaning the radiation source and the radiation detector. Such means may for instance be in form of a scraper or a jet of wash water.
The known systems are encumbered with the drawback that it is impossible to maintain clean surfaces and to clean said surfaces to the same extent each time. Accordingly, it is impossible to achieve correct measuring values.
Disclosure of Invention
The object of the invention is to provide a method solving the above problems .
The method according to the invention is characterised in that the radiation source and the radiation detector are mounted on a forked support immersible in the fluid in question. According to the invention the measuring signal may be subjected to a simultaneous/following calibration, the source and the detector being subjected to a rinsing.
The radiation used may for instance be provided by light, sound or soft isotopic radiation.
Brief Description of Drawings
The invention is described in greater detail below with reference to the accompanying drawings, in which
Fig. 1 illustrates a slurry measuring device comprising a radiation source and a radiation detector placed opposite one another, the radiation source and the radiation detect¬ or being cleaned by means of a rotating scraper,
Fig. 2 illustrates an alternative embodiment, the so-called T-model, of the slurry measuring device, where the scraper is inserted from the side,
Fig. 3 illustrates an alternative embodiment of the slurry measuring device, where the probe is bent,
Fig. 4 illustrates a slurry measuring device according to the invention, where the surface of the radiation source and the radiation detector are cleaned by means of passing water,
Fig. 5 illustrates an example of a measuring signal pro¬ duced by the slurry measuring device of Fig. 4, and
Fig. 6 illustrates an example of the electronic measuring circuit .
Best Mode for Carrying Out the Invention
The invention refers to highly polluted fluids, such as sludge. An interest has arisen in measuring the dry-matter percentage relative to the water percentage in slurry. The measuring may for instance be carried out by measuring the damping of a suitably selected radiation light, sound or isotopic radiation over a predetermined measuring length. A problem applies, however, because the radiation source and the radiation detector are polluted on the surface with the result that the measuring signal is degraded.
According to a first embodiment, the sludge passes a pipe 1, and the embodiment is provided with two opposing trans¬ ducers 2, 3 flushing with the inner side of said pipe 1. The inner side of the transducers 2, 3 are kept clean by means of a rotating, cylindrical scraper 4 comprising V- shaped notches. The rotation of the scraper 4 is caused by means of an outer gear wheel engaging said cylindrical, rotating scraper 4 through a slot in the pipe 1. Such an embodiment is, however, encumbered with sealing problems. The scraper 4 may also be formed such that it is caused to rotate by the passing sludge, and then it is provided with inner fins. Alternatively, the scraper 4 can be made of an electrically conductive material and caused to rotate by means of an electromagnetic, rotating field applied from the outside through electromagnets 5 placed on the outside, whereby sealing problems are avoided. Permanent magnets may furthermore be embedded in the rotating scraper 4, said permanent magnets being caused to follow the rotating field. When the rotating scraper is provided with inner fins, the permanent magnets may be used for indicating the flow velocity with the result that it is possible in addition to achieve a measurement of the viscosity which may also be of interest.
According to an alternative embodiment, the so-called T- model shown in Fig. 2, the rotating scraper 22 has been inserted from the side perpendicular to said embodiment. The T-model is advantageous in facilitating the providing of a rotation by means of a motor 6. The rotating scraper 22 need only be mounted in a liquid-proof manner relative to the motor 6. The driving shaft 21 of the rotating scraper 22 extends through a housing via a liquid-proof bearing, said housing sealingly surrounding the pipe. The transducers 7, 7' are preferably ultrasonic transducers. In addition to the cleaning function, portions of the rotating scraper or a particularly shaped member mounted thereon may be used for calibration.
According to the invention, cf. Fig. 4, the radiation source 8 and the radiation detector 9 are mounted on a forked support 10 immersible in the fluid to be measured. Before the calibration, the detector 8 and the radiation source 9 are rinsed by means of rinsing water being fed through a channel 11 in the forked support 10. The channel 11 may optinally split up into two branch pipes, one branch pipe facing the radiation source 8 and the other branch pipe facing the radiation detector 9. The feeding hose 14 to the channel 11 is provided with a valve controlling the supply of water. The radiation source 8 is spaced approxi¬ mately 10 mm from the radiation detector 9. According to the invention a reference measurement is performed, i.e. a calibration, at the end of each rinsing period, and then the actual measuring signal is compared with the reference signal. In this manner an incomplete cleaning has automat¬ ically been taken into account. According to an alternative embodiment, the rinsing channel fills the entire space be¬ tween the detector 9 and the source 8 with the result that the rinsing fluid functions as a reference fluid because said rinsing fluid fills the entire volume between the radiation source 8 and the radiation detector 9.
Fig. 5 illustrates an example of measuring signals.
Fig. 6 illustrates an example of the electronic circuic in question, where the transmitter 21 communicates with the transmitter- transducer 2. The signal received by the receiver-transducer 3 is transmitted to an amplifier 26 in turn transmitting said signal to an amplitude and phase detector 23. Subsequently, the signal is processed in a microprocessor circuit 24 connected to a display 25.
The radiation in question is not necessarily ultrasound. Alternatively, it may be an electromagnetic radiation, such as light or a soft isotopic radiation when heavy metals are to be measured.
It is important that the measuring value is compared with the reference value provided at the end of the cleaning process because said comparing turned out to provide sufficiently good measuring results.
The measuring method is in particular used for measuring the dry-matter percentage in sludge by means of infrared light. The method can, however, also be used for other easurings of parameter values of a fluid.
According to another embodiment, the light used is infrared and ultraviolet light. The ultraviolet light is attenuated in response to the amount of organic matter (BOD, COD). Statistically it turned out in addition, that the ratio of infrared to ultraviolet damping is related to the amount of organic matter. Accordingly, a measuring of the attenua¬ tion of ultraviolet light relative to infrared light results in the percentage of organic matter in for instance sludge .
The radiation source for emission of both ultraviolet and infrared light may for instance be a halogen or a xenon lamp. The receiving side is provided with a separate detector for infrared light and separate detector for ultraviolet light. The radiation source may be adapted to pulsed operation.

Claims

Claims .
1. A method of continuously determining the parameters of a fluid, such as the dry-matter percentage in slurry or another industrial product, and whereby said fluid is subjected to a measuring system comprising a radiation source and a radiation detector placed opposite one ano¬ ther, the measuring signals being processed in an evalua¬ tion circuit, wherafter the results of the evaluation are displayed on display means, c h a r a c t e r i s e d in that the radiation source and the radiation detector are mounted on a forked support immersible in the fluid in question.
2. A method as claimed in claim 1, c h a r a c t e r¬ i s e d in that the measuring signal is subjected to a simultaneous/following calibration, the source and the detector being subjected to a rinsing.
3. A method as claimed in claim 1 or 2, c h a r a c ¬ t e r i s e d by the radiation being light.
4. A method as claimed in claim 3, c h a r a c t e r- i s e d by the radiation being infrared light.
5. A method as claimed in claim 3, c h a r a c t e r¬ i s e d by the radiation being ultraviolet light.
6. A method as claimed in claims 4 and 5, c h a r a c¬ t e r i s e d by measuring the ratio of the transmission of ultraviolet light to infrared light so as to determine the percentage of organic matter.
7. A method as claimed in claims 4 to 6, c h a r a c¬ t e r i s e d in that the light source emitting both ultraviolet and infrared light being a halogen or xenon lamti.
8. A method as claimed in any of the preceding claims, c h a r a c t e r i s e d by using a pulsed radiation.
PCT/DK1991/000053 1990-02-26 1991-02-21 A method of measuring slurry Ceased WO1991013340A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP91904981A EP0517759B1 (en) 1990-02-26 1991-02-21 A method of measuring slurry
DE69114484T DE69114484T2 (en) 1990-02-26 1991-02-21 METHOD FOR MEASURING FOAM.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DK503/90 1990-02-26
DK050390A DK170351B1 (en) 1990-02-26 1990-02-26 Process for continuously determining parameters of a fluid

Publications (1)

Publication Number Publication Date
WO1991013340A1 true WO1991013340A1 (en) 1991-09-05

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DK1991/000053 Ceased WO1991013340A1 (en) 1990-02-26 1991-02-21 A method of measuring slurry

Country Status (6)

Country Link
EP (1) EP0517759B1 (en)
AT (1) ATE130091T1 (en)
AU (1) AU7337791A (en)
DE (1) DE69114484T2 (en)
DK (1) DK170351B1 (en)
WO (1) WO1991013340A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992019954A1 (en) * 1991-04-25 1992-11-12 Fladda Gerdt H A method and an arrangement for making a zero-point calibration
WO2004068127A1 (en) * 2003-01-31 2004-08-12 L'air Liquide - Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and apparatus for monitoring of slurry consistency
WO2008060235A1 (en) * 2006-11-16 2008-05-22 Delaval Holding Ab A device and a method for sampling of milk
CN119715290A (en) * 2023-09-28 2025-03-28 中国石油天然气股份有限公司 A sand-filled pipe mud pollution experimental device and method

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202016106236U1 (en) * 2016-11-08 2018-02-09 Hach Lange Gmbh Optical measuring device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4040743A (en) * 1975-09-22 1977-08-09 Howell Laboratories, Incorporated Method and apparatus for measuring the brightness of pulp slurry
US4201477A (en) * 1978-01-16 1980-05-06 Fmc Corporation Suspended solids meter
EP0039088A1 (en) * 1980-04-30 1981-11-04 Fuji Electric Co. Ltd. Apparatus for determining the concentration of an organic solute in a suspended solid particles containing liquid
US4299495A (en) * 1979-05-17 1981-11-10 Tokyo Shibaura Denki Kabushiki Kaisha Density meter
WO1989003524A1 (en) * 1987-10-15 1989-04-20 Electronic Instrumentation And Technology, Inc. Solution loading analyzer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4040743A (en) * 1975-09-22 1977-08-09 Howell Laboratories, Incorporated Method and apparatus for measuring the brightness of pulp slurry
US4201477A (en) * 1978-01-16 1980-05-06 Fmc Corporation Suspended solids meter
US4299495A (en) * 1979-05-17 1981-11-10 Tokyo Shibaura Denki Kabushiki Kaisha Density meter
EP0039088A1 (en) * 1980-04-30 1981-11-04 Fuji Electric Co. Ltd. Apparatus for determining the concentration of an organic solute in a suspended solid particles containing liquid
WO1989003524A1 (en) * 1987-10-15 1989-04-20 Electronic Instrumentation And Technology, Inc. Solution loading analyzer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992019954A1 (en) * 1991-04-25 1992-11-12 Fladda Gerdt H A method and an arrangement for making a zero-point calibration
WO2004068127A1 (en) * 2003-01-31 2004-08-12 L'air Liquide - Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and apparatus for monitoring of slurry consistency
WO2008060235A1 (en) * 2006-11-16 2008-05-22 Delaval Holding Ab A device and a method for sampling of milk
CN119715290A (en) * 2023-09-28 2025-03-28 中国石油天然气股份有限公司 A sand-filled pipe mud pollution experimental device and method

Also Published As

Publication number Publication date
ATE130091T1 (en) 1995-11-15
DK50390D0 (en) 1990-02-26
DK50390A (en) 1991-08-27
EP0517759B1 (en) 1995-11-08
EP0517759A1 (en) 1992-12-16
DK170351B1 (en) 1995-08-07
DE69114484T2 (en) 1996-07-18
DE69114484D1 (en) 1995-12-14
AU7337791A (en) 1991-09-18

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