WO2016095008A1 - Appareil, systèmes et procédés pour des mesures de teneur en matières solides en temps réel - Google Patents

Appareil, systèmes et procédés pour des mesures de teneur en matières solides en temps réel Download PDF

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Publication number
WO2016095008A1
WO2016095008A1 PCT/CA2014/051220 CA2014051220W WO2016095008A1 WO 2016095008 A1 WO2016095008 A1 WO 2016095008A1 CA 2014051220 W CA2014051220 W CA 2014051220W WO 2016095008 A1 WO2016095008 A1 WO 2016095008A1
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WIPO (PCT)
Prior art keywords
interest
light
solids content
sensors
housing
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PCT/CA2014/051220
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English (en)
Inventor
Ying Yin Tsui
Timothy Ho
Manisha Gupta
David Sego
Abu JUNAID
Andrea SEDGWICK
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Total E&P Canada Ltd.
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Priority to PCT/CA2014/051220 priority Critical patent/WO2016095008A1/fr
Publication of WO2016095008A1 publication Critical patent/WO2016095008A1/fr

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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
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/06—Investigating concentration of particle suspensions
    • 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
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/51—Scattering, i.e. diffuse reflection within a body or fluid inside a container, e.g. in an ampoule
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/30—Control equipment
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/06—Investigating concentration of particle suspensions
    • G01N15/075—Investigating concentration of particle suspensions by optical means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N2015/0042—Investigating dispersion of solids
    • G01N2015/0053—Investigating dispersion of solids in liquids, e.g. trouble
    • 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
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N2021/4704—Angular selective
    • 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
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/4785—Standardising light scatter apparatus; Standards therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
    • G01N9/24—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by observing the transmission of wave or particle radiation through the material

Definitions

  • Embodiments disclosed herein relate to apparatus and methods for analyzing solids content in a material of interest and, more particularly, to analyzing the content in real-time.
  • Gravimetric measurement methods have been widely used, whereby samples are removed from a zone of interest in a process stream, whether dynamic or stagnant, and are subsequently dried. The dried samples are weighed to determine the amount of solid present and the solids concentration, based upon the sample size, is calculated. While relatively inexpensive, such methods are time- consuming, require transport of samples to laboratory facilities and do not provide real time data. Thus, changes to operational parameters based upon such data may be delayed.
  • Gamma ray technology utilizes a strong radioactive gamma-emitting source directed through a sample of the solids-containing material to measure the decrease in gamma ray transmission.
  • Major drawbacks to this technology are the health and safety risks.
  • the footprint of the apparatus is large, making it difficult to incorporate into process streams. Measurement times are relatively long and measurements of medium density are required for correlation to solids content.
  • FBRM Focused Beam Reflectance Measurement
  • FBRM is essentially a laser scanning system used for determining particle sizing. Applicant believes that FBRM cannot be used reliably to determine particle concentration as the laser beam is focused to a spot significantly smaller than the size of the particles in order to scan the size thereof and is limited in broader application by the size of the focal spot of the laser source. FBRM would thus be limited to measuring particles greater than 10 microns. Should one attempt to apply FBRM to solids content measurement, particles having sizes less than 10 microns, such as found in many materials of interest would cause solids content measurements to be grossly over estimated.
  • Optical measurement of solids concentrations are generally based on absorption or on light scattering techniques.
  • Absorption methods are based on the measurement of reduction of light passing through a solids-containing liquid as a result of absorption of the light therein.
  • the solids concentration is relatively high, such as in many process slurry streams, the light cannot penetrate very far into the slurry. Thus, absorption methods are not useful at these concentrations.
  • Embodiments taught herein utilize measurements of single and multiple light scattering to determine solids content in a range from about 0% to about 100% unlike conventional light scattering techniques which are generally used for determining turbidity and which are only able to measure solids content at very low levels.
  • a sensor arrangement for determining a solids content in a material of interest in real-time comprises one or more sensors having at least one light source for emitting an incident beam of light, the light being collimated and adapted to be directed toward the material of interest for producing single and/or multiple scattering from solids therein.
  • the one or more sensors have at least one detector arranged relative to the at least one light source so as to measure intensity of the single and/or multiple scattered light at a detection angle from about ⁇ 5° to about ⁇ 75° from the incident light.
  • a housing supports the one or more sensors therein, protected from the material of interest, at least a portion of the housing being optically-suitable for transmitting the incident light and the scattered light therethrough.
  • the sensor is capable of measuring the scattered light intensity at the solids content from about 0% to about 100%.
  • Embodiments are designed for immersion within materials of interest or are mounted external to process apparatus containing the materials of interest.
  • the portion of the housing which is optically-suitable for transmitting the incident and scattered light may be formed by a transparent window in the wall of process apparatus, such as a pipeline or a flow tube or in process vessels.
  • a method for determining a solids content in a material of interest comprises positioning one or more sensors in optical contact with a material of interest.
  • Each of the one or more sensors has at least one light source for emitting an incident beam of light, the light being collimated and adapted to be directed toward the material of interest for producing single and/or multiple scattering from the solids therein; and at least one photodetector arranged relative to the at least one light source so as to measure intensity of the scattered light at a detection angle from about ⁇ 5° to about ⁇ 75° from the incident light.
  • a housing supports the one or more sensors therein protected from the material of interest, at least a portion of the housing being transparent for optically connecting the one or more sensors to the material of interest by transmitting the incident light and scattered light therethrough.
  • the intensity of the scattered light intensity is measured at the photodetector at the detection angle.
  • the measured light intensity is compared to a calibration curve of the material of interest for determining the solids content.
  • a hybrid opto-electrical/weak gamma solids analyzer incorporates a plurality of weak gamma sources positioned in the materials of interest spaced from the sensors. Suitable scintillation detectors are incorporated within the sensors for determining density of the materials of interest which is directly related to solids content. In the hybrid embodiments, the density measurements are used as an in situ calibration, replacing the calibration curve derived from the materials of interest.
  • band pass filters are incorporated with the detectors to reduce increased background light transmission thereto which results from the high-speed rotation.
  • a fixed light polarizer is operatively connected to the light source to ensure maximum laser power at each of the beam splitters.
  • Figure 1 is a representation of a sensor arrangement according to an embodiment taught herein;
  • Figure 2A is a graph illustrating off-line calibration curves for varying concentrations of kaolin measured in three separate tests
  • Figure 2B is a graph illustrating off-line calibration curves for varying concentrations of gold tailings measured in three separate tests
  • Figure 2C is a graph illustrating off-line calibration curves for varying concentrations of Devon silt measured in three separate tests;
  • Figure 3A is a graph illustrating signal intensities of scattered light measured using a sensor according to Fig. 1 incorporating a blue laser diode emitting at 405nm, a photodetector being positioned to detect the scattered light at detection angles ranging from -60° to + 90°;
  • Figure 3B is a graph according to Fig. 3A, the sensor incorporating a red laser diode emitting at 658nm;
  • Figure 4A is a plan view of a sensor arrangement supported on a rod, wherein detectors are positioned laterally with respect to light sources;
  • Figure 4B is a perspective view according to Fig. 4A, the detectors being aligned axially along on the rod and positioned laterally with respect to corresponding axially aligned light sources;
  • Figure 4C is a side view of an alternate embodiment utilizing beam splitters to split a single light source into a plurality of incident beams directed toward a material of interest and a plurality of axially spaced detectors arranged to detect single and multiple scattered light as a result;
  • Figure 5 is a schematic of electronics for powering an embodiment of a system having a plurality of sensors mounted in spaced arrangement along a length of a rod housed within a transparent member for forming a probe;
  • Figure 6A is a cross-sectional view of the probe of Fig. 5 wherein a transparent member housing the rod is substantially circular in cross-section, a planar window being mounted therein at a location aligned with each of the sensors;
  • Figure 6B is a front view of a portion of the rod according to Fig. 6A illustrating an embodiment of a sensor mounted on the rod, the sensor incorporating a blue laser diode and a red laser diode, axially aligned, with a photodetector mounted therebetween;
  • Figure 7A is a cross-sectional view of a probe according to an embodiment wherein the transparent member is substantially rectangular in cross- section;
  • Figure 7B is a cross-sectional view of a probe according to an embodiment wherein the transparent member is substantially rectangular in cross- section and having rounded corners;
  • Figure 8 is a graph illustrating a comparison between solids content measured at different heights in a cylinder containing thickened tailings using an embodiment according to Fig. 5 and conventional gravimetric and gamma ray measurements;
  • Figure 9A is a cross-sectional view of an in-line, single sensor embodiment mounted to a window in process apparatus for measuring materials of interest flowing therein;
  • Figure 9B is a plan view according to Fig. 9A, illustrating a triangular arrangement of a photodiode detector and first and second laser diode light sources;
  • Figure 10 is a representation of a hybrid opto-electrical/weak gamma solids analyzer utilizing a probe according to Fig. 5 and having scintillation— detectors incorporated therein, in combination with a gamma immersion probe having weak gamma sources attached thereto for in situ calibration for determination of solids content;
  • Figure 1 1A is a photograph of an embodiment of the sensor arrangement according to Fig. 4C constructed in a light-tight box for mounting over a transparent window in an external wall of a cylinder of a centrifuge;
  • Figure 1 1 B is a perspective view according to Fig. 1 1A illustrating the sensor arrangement of Fig. 1 1A mounted to the external wall of the cylinder, the light-tight box having been removed for clarity;
  • Figure 12 is a graph illustrating signal intensities at different depth levels measured over time using an embodiment according to Fig. 5 immersed within a cylinder containing thickened tailings;
  • Figure 13 is a graph illustrating signal intensities at different depth levels measured over time using an embodiment according to Fig. 5 immersed within a cylinder containing thickened tailings treated with 15% flocculant;
  • Figure 14A is a graph illustrating solids content calculated from signal intensities measured at different depth levels at intervals over about a one year period of time using an embodiment according to Fig. 5 immersed within a cylinder containing thickened tailings;
  • Figure 14B is a graph illustrating solids content calculated from signal intensities measured at different depth levels at intervals over about a one week period of time using an embodiment according to Fig. 5 immersed within a cylinder containing thickened tailings;
  • Figure 15 are graphs illustrating two separate experiments whereby a first in-line sensor is placed at an inflow to a process apparatus for dewatering tailings and a second in-line sensor is placed at an outflow to measure signal intensities prior to and after dewatering for calculating changes in solids content in the material of interest; and
  • Figure 16 is a graph illustrating measurement of solids content at different levels within a cylinder containing a slurry of tailings in a high gravitational environment using an embodiment according to Fig. 4C. DETAILED DESCRIPTION
  • embodiments taught herein utilize measurements of the intensity of both single and multiple, elastic, light scattering from solids particles at concentrations ranging from about 0% to about 100% and, more particularly, in ranges from about 0% to about 95%.
  • Such measurements provide real time spatial and temporal solids profiles for a variety of materials of interest, such as in mining industries, including, but not limited to materials from oil sands mining, and further including solids- containing, in situ process streams from a variety of industries.
  • Embodiments are disclosed herein in the context of oil sands mining producing a variety of materials of interest having different solids types therein at varying amounts. As one of skill in the art however will appreciate, embodiments can be applied to heavy oil production or other types of mining and other technologies which produce materials of interest, such as process slurries having variable solids content.
  • Applicant refers herein to "materials of interest" which are intended herein to describe any materials which may comprise solids, such as slurries or materials which are substantially solid. Such materials of interest have solids content therefore that vary from about 0% solids to about 100% solids.
  • inaccuracies in measurement may occur at the highest concentrations, such as from about 90% to about 100%.
  • Applicant believes however, when used for applications discussed herein and particularly for use in monitoring tailings settling, problems related to variations in porosity are reduced as solids content approaching 100% concentration are generally found when the solids are being compressed by a large volume of materials, such as at a bottom of a settling tank or tailings pond.
  • solids content measurement in the context of oil sands processing, is generally within the range of about 0% to about 90% to 95%.
  • the real-time solids content measurement in the oil sands materials of interest permits improved control of bitumen extraction, tailings disposal and reclamation.
  • Solids, especially fines and clays have a direct impact on bitumen liberation and recovery, as well as on tailings settling and dewatering, such as in tailings ponds and deposits therefrom.
  • process parameters can be adjusted accordingly as the solids content within the materials fluctuate within or outside acceptable limits.
  • opto-electronic sensors use light scattering to monitor the solids content without the need for sample preparation.
  • the footprint of the sensors is sufficiently small to permit use in a variety of configurations for measurement of the materials at different operational points within an oil sands operation.
  • a plurality of the sensors are immersed at different depths and positions within a tailings slurry, such as in a tailings pond, process vessels or deposited materials, to obtain real-time data therein regarding characteristics such as settling behavior and the like.
  • sensors can be operatively mounted and used to measure in-line, time-resolved, single or multi-point data, such as in slurry pipelines; can be incorporated at different locations in separation apparatus, such as dynamic separation vessels, centrifuges or the like; or can be employed in tailings deposits.
  • embodiments of the opto-electronic sensor 10 taught herein utilize relatively simple, fixed optics comprising an arrangement of a light source 12 and a photodetector 14 for measuring single and multiple scattered light SL from solids particles over a broad range of solids content, such as from about 0% to about 100%.
  • the sensor 10 is generally separated or isolated from materials of interest S, containing the solids, by an optically-suitable wall or a window 16 capable of passing the incident light toward the material of interest and receiving the scattered light therefrom.
  • the detector 14 is positioned to measure single and multiple scattered light SL at a detection angle ⁇ from about ⁇ 5° to about ⁇ 75° from a collimated beam of incident light I.
  • the collimated beam of light I is directed toward the materials of interest S, to avoid measurement of reflection signals from the light source 12, which may overpower the scattered laser light intensity and prevent correlation to determine the solids content.
  • an optimum detection angle is from about ⁇ 10° to about ⁇ 30° to provide optimum signal intensities with relatively low noise.
  • the collimated incident light I can be directed toward the materials of interest S at any angle provided the detectors 14 are positioned appropriately to collect the scattered light at the detection angle ⁇ as described herein.
  • the incident light I is directed substantially perpendicularly toward the materials of interest S.
  • a variety of visible and infrared light sources 12 can be used, including, but not limited to laser diodes and light-emitting diodes (LED). Embodiments disclosed herein utilize laser diodes as the light source 12. Laser diodes 12 provide a source of coherent light and are commercially available for supplying many different wavelengths.
  • Scattering from solids or particles depends upon the wavelength ( ⁇ ) and the particle size ( ⁇ ).
  • Raleigh scattering is elastic scattering from the particles when the particles are much smaller than the excitation wavelength ( ⁇ / ⁇ >10) and is proportional to the sixth power of the particle diameter and inversely proportional to the fourth power of the wavelength of the light.
  • Mie scattering is scattering from particles of approximately the same scale as the wavelength of light (0.01 ⁇ ⁇ / ⁇ 10). The scattering intensity is more dependent on the particle size and is less dependent on the wavelength of the light.
  • the beam of incident light I used to enable the measurement of both single and multiple light scattering is collimated. While embodiments taught herein are primarily useful in measuring solids content rather than particle size, a far field scattered light image can be used in combination with the laser scatter intensity to determine particle size.
  • wavelengths of light can be used.
  • the material of interest S comprises compounds which may fluoresce and interfere with signal intensity and correlation to calibration curves used to determine solids content
  • wavelengths are selected to minimize such fluorescence.
  • wavelengths in the ultraviolet (UV) portion of the spectrum are therefore generally unsuitable for use in embodiments taught herein when applied to oil sands or heavy oil operations.
  • wavelengths in the visible or Infrared (IR) portion of the spectrum are acceptable for use in such embodiments.
  • spatial coherence of the light source 12 is related to bandwidth of the wavelengths and directionality thereof. Accordingly, too wide a bandwidth may affect signal intensity measurements as the directionality affects focusability, and how small the detection angle ⁇ can be from normal, for collection of scattered light SL.
  • laser light sources 12 have the best coherence properties and thus permit a smaller detection angle ⁇ and achieve higher signal intensities.
  • Light emitting diodes (LED) provide a less coherent light source 12 and low coherence white light sources provide the least coherent light source 12 for use in embodiments taught herein. While spatial coherence can be modified for white light sources, such as a household light bulb, such sources are generally not robust and are not recommended for use in embodiments taught herein.
  • laser diodes emitting light at wavelengths from about 400nm to about 700nm are selected.
  • Silicon photodiodes having maximum sensitivity in the visible portion of the spectrum are used as the detectors.
  • laser diodes 12 used in embodiments taught herein do not require high power, which reduces the overall cost, increases the life span and improves safety during operation.
  • a further advantage of using a lower fluence level is that heat build-up is reduced, which helps avoid operational issues such as algae growth in the material of interest S, or within calibrators, when sensors 10 containing the laser diodes 12 are immersed therein.
  • the fluence level of the laser light source 12 is selected to be at or below about 30mW/mm 2 .
  • a low noise gain amplifier is used to amplify the scatter intensity.
  • the laser diodes 12 are pulsed, which further reduces any heat buildup therein, aiding in avoiding algae growth and extending the life span of the laser diodes 12.
  • the insensitivity of measurement of solids content in the range of from about 90% to about 100% can be mitigated by measuring light scatter intensity as a function of wt/wt concentrations of solids and density to construct a three dimensional function of intensity vs concentration and density.
  • insensitivity of measurement of solids content in the range of from about 90% to about 100% can be mitigated by an on-line calibration using a weak gamma ray source and scintillation-type detectors incorporated with sensors 10 taught herein for forming a hybrid optical-gamma ray solids analyzer, as described in greater detail below.
  • General sensor configuration using a weak gamma ray source and scintillation-type detectors incorporated with sensors 10 taught herein for forming a hybrid optical-gamma ray solids analyzer, as described in greater detail below.
  • embodiments of the sensor 10 taught herein utilize at least one laser diode as a light source 12 and at least one photodetector 14, such as a silicon photodiode detector offset from the light source 12, for detection of the laser light scattered by the solid particles in the material of interest S at a detection angle ⁇ relative to the path of the incident laser light I directed toward the material of interest S.
  • the incident light I is directed substantially perpendicularly toward the material of interest S.
  • optimum signal intensity is a function of angular scattering for different solids concentrations.
  • Signal intensities from samples of a thickened tailings stream having solids content from about 5% to about 57% were measured at detection angles from about -60° to about +90°.
  • the highest signal intensities were observed at about +10° for both a blue (405nm) laser diode and a red (658nm) laser diode.
  • the optimum signal intensities which provide the best differentiation of solids content, over the range of solids content measured, were observed at about +15° for the blue laser diode and about +18° for the red laser diode.
  • the photodiode 14 is positioned to measure single and multiple scattered light intensity at a detection angle ⁇ of from about ⁇ 5° to about ⁇ 75° from the incident light path I to avoid measurement of reflection signals from the laser diode light source 12 which may overpower the scattered laser light intensity and interfere with correlation to determine the solids content.
  • Applicant believes that an optimum detection angle ⁇ of about ⁇ 10° to about ⁇ 30° is particularly useful for measuring solids content over the range of about 0% to about 100%.
  • the at least one photodiode 14 can be supported laterally to either side of the laser diode 12 (Figs. 4A, 4B) or can be supported axially above or below the at least one laser diode 12 (Fig. 6B), for detecting the single and multiple scattered light SL.
  • a plurality of axially spaced beam splitters 18 can be used to reflect the incident beam I from a single laser diode 12, directed downwardly therethrough, substantially perpendicularly toward the material of interest S.
  • Scattered light SL is measured by one or more photodiodes 14 which are axially spaced and operatively positioned to measure the scattered light SL at the detection angle ⁇ .
  • the arrangement of each photodiode 14 relative to the incident beam from the single laser diode 12 directed by each beam splitter 18 measures scattered light intensity at the detection angle ⁇ of from about ⁇ 5° to about ⁇ 75° from the incident light I from the laser diode 12.
  • electronics including at least the low noise gain amplifier 20, as well as laser drivers 22 for powering the laser diodes, DAQ and signal generators 24 for receiving amplified signals from the amplifier 20 and a processor 26 for controlling the analyzer and performing correlations to the calibration curves of known solids content for determining the solids content in the material of interest S at any given point in time, are operatively connected to the sensors 10.
  • pulsing of the laser diodes 12 is generated at the laser driver independent of external software such as used by the processor 26 to process the signal intensity data.
  • Multiplexed sensor control and the use of the amplifiers 20 permits a plurality of sensors 10 to be incorporated with a minimum number of laser drivers 22, reducing the overall footprint.
  • Systems can be networked wirelessly, are fully remote controllable, are flexible with respect to data collection and software modifications and do not require a dedicated processor 26 to operate.
  • the system may have a screen, such as a touch screen, for local control and/or data display.
  • Sensors 10 are periodically calibrated, as is understood by those of skill in the art. Additionally, scattered light signals from the photodiodes 14, monitored in real time, may display behavior which is indicative of a need to recalibrate outside of the normally scheduled calibrations.
  • an immersion sensor 10 system is designed for immersion of one or more of the sensors 10 within a material of interest S. More particularly, a plurality of the sensors 10 are configured to be immersed at different depths within the material of interest S, such as in a tailings pond comprising at least water and mature fine tailings (MFT), or within a process or storage vessel handling the materials of interest S.
  • a support rod 30 supports the plurality of sensors 10, in spaced arrangement, along a length of the rod 30.
  • the rod 30 may be made of any suitable material, such as a metal, plastic and the like, to which the plurality of sensors 10 can be mounted.
  • spacing of the sensors 10 depends upon the depth of the material of interest S and the intervals at which the solids content is to be measured.
  • the sensors 10 are mounted so as to emit the incident beam I substantially perpendicularly relative to the rod 30.
  • the support rod 30 and sensors 10 mounted therein are housed within a sealed, elongate, optically-suitable transparent member or housing 32, such as an acrylic or PLEXIGLAS® cylindrical tube, to protect and isolate the sensors 10 from exposure to the material of interest S.
  • Any transparent material which permits transmission of the incident light I at the wavelengths emitted by the one or more laser diodes 12 and the scattered light SL resulting therefrom, therethrough, is optically-suitable for use in embodiments described herein.
  • ambient light does not affect measurements when the sensors 10 are fully immersed, however optical filters may be operatively connected to the sensors 10 where ambient light may reach the one or more photodetectors 14 and interfere with the detection of signal intensity.
  • the laser diodes 12 and detectors 14 in the sensors 10 are operatively connected to the electronics, which are generally external to probe 34 and the material of interest S.
  • an 8m long PLEXIGLAS® tube 32 having a diameter of 8cm is used to house and isolate the opto-electronic sensors 10 to prevent potential water and chemical damage.
  • Function generators, power supplies and data acquisition equipment for driving the laser diodes 10, for biasing photodetectors 14 and for data collection are located outside of the probe 34 and are operatively connected thereto, such as through cables having Bayonet Neill-Concelman (BNC) connectors (Fig. 5).
  • Light intensity signals indicative of solids settling are generally collected periodically therefrom and processed to determine solids content at each of the locations of the plurality of sensors 10 along the probe 34.
  • the elongate transparent housing 32 is a transparent cylindrical tube being generally circular in cross-section. Applicant has found however that a curved transparent wall 36 of the cylindrical member 32 acts as a lens causing collection of reflected signal from the laser diode 12 which interferes with correlation of the scatter intensity signals to the solids content.
  • a straight-sided or planar transparent window 38 is formed in the wall 36 at least at the location of each of the plurality of sensors 10. Where windows 38 are fit to the cylindrical member 32, the windows 38 are sealed thereabout to prevent leakage of materials into the cylindrical member 32. In embodiments having the transparent windows 38 mounted therein, one of skill will appreciate that the remainder of the housing 32 need not necessarily be transparent.
  • a probe 34 comprising a generally rectangular, elongate transparent member or housing 32 can be used to house the support rod 30 and plurality of sensors 10 mounted thereto.
  • Straight sides 40 of the rectangular member 32 do not act like a lens and therefore there is no need to compromise the sealed structure of the transparent member 32 by fitting planar windows thereto.
  • sharp corners 42 have a tendency to collect bitumen. For this reason, as shown in Fig. 7B, it may be preferable to use rounded corners 42.
  • each of a plurality of sensors 10 comprises two laser diodes 12, a first diode 12a emitting light at 405 nm and a second diode 12b emitting light at 658 nm.
  • the at least one photodiode detector 14 is mounted to the support rod 30, aligned axially between the first and second diodes 12a, 12b, so as to measure scattered light intensity at the detection angle of ⁇ of from about ⁇ 5° to about ⁇ 75°.
  • the photodetector 14 is a silicon photodiode detector having a maximum sensitivity in the visible portion of the spectrum, which is particularly suitable for the laser diodes emitting at 405nm and 658nm. Applicant has found that solids content results measured at each of 405nm and 658nm are relatively consistent.
  • solids content in a column filled with material of interest S in this case a slurry of thickened tailings, was measured using a probe 34, as described herein, over a period of several months.
  • the transparent probe 34 was immersed in the column of thickened tailings S.
  • Intensity signals transmitted from the detectors 14 were correlated to the appropriate calibration curve to determine the solids content at various heights, measured in meters(m), from the bottom of column.
  • an opto- electrical sensor 10 is operatively mounted within a dynamic process, such as in a bore 40 of a pipeline or flow tube 42 through which the material of interest S is flowing, for point-in-time measurements of solids content therein.
  • the senor 10 comprises the at least one photodetector 14 and the at least one light source 12 mounted relative to one another, in a sealed housing 44, for achieving the detection angle ⁇ of about ⁇ 5° to about ⁇ 75°.
  • first and second laser diodes 12a, 12b and the photodetector 14 are mounted in a triangular arrangement (Fig, 9B), the photodetector 14 being located at an apex 46 of the triangle and generally positioned intermediate the first and second laser diodes 12a, 12b for detecting scattered light SL at a detection angle ⁇ within the range of about ⁇ 5° to about ⁇ 75°
  • the first laser diode 12a emits light at a first wavelength, such as 405nm, while the second laser diode 12b emits light at a second wavelength, such as 658nm.
  • the photodetector 14 is a silicon photodetector having a maximum sensitivity in the visible portion of the spectrum.
  • An optically-suitable window 48 is mounted and sealed within a port 50 in a wall 52 of the pipeline or flow tube 42.
  • the housing 44 comprising the opto- electrical sensor 10, is mounted on the outside of the pipeline or flow tube 42 at the window 48 for directing incident light I toward the material of interest S flowing in the bore 40.
  • the collimated incident light I of the first and second laser diodes 12a, 12b is directed to an area of a fixed size, such as about 3mm, within the material of interest S.
  • Light intensity signals of the single and multiple scattering from the solids within the material of interest S are detected at the detection angle ⁇ by the photodiode 14. The light intensity signals are processed as previously described to determine the solids content at the time of measurement.
  • optically-suitable windows 48 capable of withstanding harsh, abrasive environments over extended periods of time are sapphire windows or transparent windows coated with transparent, abrasion resistant coatings.
  • One such coating is a diamond-like carbon coating which is transparent at wavelengths from about 400nm to mid-way through the infrared portion of the spectrum.
  • the window 48 is flush with or protrudes into the bore 40 such that one or more air bubbles are prevented from being trapped between the flowing material of interest S and the window 48 which would adversely affect measurements therethrough.
  • the housing 44 is not transparent so as to shield the photodetector 14, housed therein, from ambient light which may interfere with measurement of scattered light SL.
  • the window protrudes into the bore 40 less than about 1 mm.
  • one or more sensors 10 can be mounted, as described, about a circumference of the pipeline or flow tube 42 and/or along a length of the pipeline or flow tube 42 for measuring solids content at various positions within the flow.
  • single sensor in-line embodiments are particularly useful for measuring changes in solids content in dynamic processes.
  • one or more in-line sensors 10 are positioned circumferentially about the pipeline 42 adjacent an inlet to a process apparatus, such as a thickener or other dewatering apparatus, and one or more in-line sensors 10 are positioned circumferentially about a pipeline 42 fluidly connected to an outlet therefrom.
  • a process apparatus such as a thickener or other dewatering apparatus
  • in-line sensors 10 are positioned circumferentially about a pipeline 42 fluidly connected to an outlet therefrom.
  • solids therein may settle to some degree within the flow.
  • the circumferentially placed sensors 10 permit calculation of an average solids content at the inlet and the outlet providing a better indicator of dewatering performance.
  • the size of the window 48 can be manipulated to permit larger detection angles ⁇ .
  • a convex window 48 can be used to create the larger detection angles ⁇ without acting as a lens which would interfere with signal intensity measurements.
  • Calibrators for the off-line calibration are generally produced by drying and/or diluting the material of interest S to varying solids content. Thus, an entire range of calibrators are produced. However, as one of skill will appreciate there may be inaccuracies introduced as a result.
  • a weak gamma source 60 and suitable detectors 62 are incorporated into embodiments of the optical sensors 10 for calibrating the optical system in situ, avoiding the need for off-line calibration.
  • a weak gamma source is typically a commercially available source having radioactivity from about 1 to 10 Curie, such as Co 60 source having an energy of about 1 .17 and 1 .33 Mev or a Cs 137 source having an energy of 0.66 Mev.
  • a 1 Curie Cs 137 source typically has a radiation power of slightly less than 4 nano-watts.
  • one or more scintillator- detectors 62 capable of detecting gamma radiation are mounted to the support rod 30, such as intermediate the sensors 10.
  • a gamma insertion tube 64 to which one or more weak gamma sources 60 are attached, is operatively positioned parallel to and spaced from the probe 34, external to the transparent housing 32 and in the material of interest S.
  • the gamma sources 60 are generally aligned with the locations of the scintillator-detectors 62 on the support rod 30.
  • the gamma insertion tube 64 has a diameter smaller than that of the multi-sensor probe 34, such as about 1 cm, and is spaced from a few millimeters to several centimeters from the transparent housing 32. In an embodiment, the gamma insertion tube 64 is spaced about 1 cm from the transparent housing 32.
  • the gamma insertion tube 64 is typically mechanically supported, in spaced relationship, to the transparent housing 32.
  • Absorption of the gamma rays from the weak gamma sources 60 by the varying solids content in the material of interest S provides a measure of the density of the materials of interest S.
  • a density calibration curve replaces the off-line calibrators produced from the materials of interest S and provides a more accurate solids content measurement.
  • the gamma measurements add information regarding the size distribution in the materials of interest S. Size distributions can then be deduced using the gamma data, and the optical data, which is sensitive to wavelength-dependent size distribution effects.
  • in situ calibration of a single in-line sensor 10 is also possible through addition of a scintillator-detector 62 to the single sensor 10 embodiment described herein.
  • a weak gamma source 60 is mechanically supported in the material of interest in spaced arrangement from the window 38 of the single sensor 10.
  • a direct comparison between the single density measurement from the gamma absorption technique to the single, signal intensity measurement from the sensor 10 enables determination of the solids content measurement at that point in time.
  • sensors 10 can be mounted external to a variety of process apparatus, provided a transparent window or cylinder can be integrated therein through which the incident beam I is transmitted to the materials of interest and the scattered light SL is transmitted to the detectors 14. Where sensors are mounted outside a containment vessel, such as a cylinder, containing the materials of interest S, convex curved transparent walls or windows mounted therein do not exhibit a lens effect.
  • one such embodiment incorporates a plurality of sensors 10, configured as shown in Figs. 4C, for mounting external to transparent windows 70 formed in a wall 72 of a bucket or cylinder 74 containing materials of interest to be separated in a high gravity-force (g-force) environment, such as in a centrifuge.
  • the laser diodes 12 and detectors 14 are selected and tested to be robust in the high g-force environment, such as up to about 100g.
  • a light-tight enclosure 76 surrounds the sensors 10 to aid in minimizing background light.
  • the light-tight enclosure 76 and sensors 10 are mounted externally to the wall 72 over each of the transparent windows 70 for rotation with the cylinder 74.
  • an optical bandpass filter 77 is operatively connected to each of the photodetectors 14.
  • the optical bandpass filter 77 transmits substantially the laser light and significantly attenuates light at other wavelengths.
  • use of the optical bandpass filters 77 minimizes the background noise and increases the signal-to-noise ratio.
  • a fixed light polarizer 78 implemented therein aids in achieving maximum laser power at each of the beam splitters 18 in the series of axially aligned beam splitters 18.
  • the amount of light reflected from a surface of each beam splitter 18 is dependent on the polarization of the laser light I incident thereon and must be fixed.
  • the fixed polarizer 78 is mounted above the aligned beam splitters 18. As the polarization direction of a laser can be changed by rotating the laser along the direction of propagation, when the laser diode 12 is mounted above the fixed light polarizer 78, the laser is rotated to obtain a maximum reflected light at each of the beam splitters 18. Thereafter, the laser is mechanically fixed at the rotated position.
  • a heater element 80 is operatively mounted adjacent the window 48 to remove condensation or to minimize the formation of condensation on the window 48.
  • the heater element 80 is operatively mounted adjacent the window 48, internal to the housing (Fig. 4C) or external to the housing (Fig. 9A). As one of skill will appreciate, whether mounted inside or outside the housing can vary depending upon the embodiment and the environment into which the sensor arrangement is positioned.
  • signal intensity measurements of scatter light SL measured using a multi-sensor immersion system 10 having a red laser diode (658nm) and a blue laser diode (405nm) as taught herein, were taken at various depths over time within cylinders containing a material of interest S.
  • the material of interest was thickened tailings which were split into two cylinders, a first cylinder containing only the thickened tailings and a second cylinder containing the thickened tailings treated with 15% flocculant. Measurements in the thickened tailings alone were taken over a period of about 20 days whereas the thickened tailings with flocculant were only measured over a period of about 5 days
  • the patterns of settling between the flocculated and untreated thickened tailings are generally the same at each of the depths in the cylinder.
  • the sensors 10, according to embodiments taught herein are relatively insensitive to changes in particle size, the flocculated tailings anticipated to have greater size variability and an overall larger particle size compared to the untreated tailings. Further, it appears that the light scattering, which is measured for the thickened tailings, is likely scattered according to a Mei scattering regime. Settling of thickened tailings over time
  • solids content was calculated from measurements of scattered light intensity using blue laser diodes (405nm) collected over the period of about 1 year.
  • a generally homogenous mixture of thickened tailings was placed in a cylinder and allowed to stand to observe the ability of embodiments taught herein to monitor settling behavior.
  • a multi-sensor probe 34 according to an embodiment taught herein was immersed in the cylinder and measurements of single intensity were obtained at intervals throughout the course of the year.
  • the solids content calculated from correlation to the calibration curve for the thickened tailings at each level at which the measurements were taken was plotted against time.
  • solids content was measured as for Fig, 14A, but over a shorter period of about one week. Initially, the heavier solids tend to settle very quickly and the solids content measured at the top part of the column (Levels B3, B4) decreases rapidly.
  • the solids concentration in the middle part of the column changes relatively less than the top of the column where solids settling is hindered by a constant influx of settling solids from the upper part of the column and an outflux of solids to the bottom part of the column, making the net change in solids content a minimum.
  • the solids concentration in the lower part of the column undergoes slow but steady increase as demonstrated by the sensor at level B1 1 a.
  • a fine sands mixture was flowed into process apparatus for performing a conventional dewatering process.
  • An in-line sensor 10 according to embodiments taught herein, was positioned to measure signal intensity of scattered light over time at the inflow to the dewatering process.
  • a second in-line sensor was positioned to measure signal intensity of scattered light over time at the outflow therefrom.
  • density of the fine sands mixture was monitored at the outflow, using physical sampling, to permit correlation to the signal intensities for determining the solids content.
  • two separate experiments were conducted to illustrate the reproducibility of the system to measure scattered light intensity in such an environment.
  • the signal intensity of scattered light from the red and blue laser diodes respond similarly at both the inflow and the outflow for each experiment. Further, the signal intensities at the outflow are higher than at the inflow indicating an increase in solids content with loss of water from the fine sands mixture.
  • a sensor arrangement as shown in Figs. 4C, 1 1A and 1 1 B was used to monitor separation of solids from a tailings slurry in a centrifuge.
  • the sensor arrangement was capable of discerning the expected behavior of the solids separation therein.
  • solids content drops relatively quickly as a result of the gravitational force.
  • the solids content initially increases as the solids begin to move toward the lower levels and thereafter, gradually decrease as the solids pack toward the bottom of the cylinder.

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Abstract

Selon l'invention, des ensembles de détection utilisent au moins une source lumineuse et au moins un détecteur, disposé pour former un angle de détection compris entre environ ±10° et environ ±75° pour la mesure de la diffusion simple et multiple par des matières solides dans des matériaux d'intérêt. L'intensité lumineuse mesurée est comparée à une courbe d'étalonnage pour les matériaux d'intérêt pour la détermination de la teneur en matières solides dans une plage d'environ 0 % à environ 100 %. Des modes de réalisation hybrides utilisent des sources de rayonnement gamma faible et des détecteurs appropriés pour la détermination de la densité qui est liée à la teneur en matières solides pour l'étalonnage in-situ, ce qui remplace les courbes d'étalonnage pour les matériaux d'intérêt. Des modes de réalisation sont conçus pour être immergés à l'intérieur des matériaux d'intérêt ou pour être montés de façon externe sur des fenêtres transparentes dans un appareil de traitement pour le suivi de changements dynamiques de la teneur en matières solides et peuvent être appliqués à un grand nombre d'environnements, notamment des environnements de force gravitationnelle élevée.
PCT/CA2014/051220 2014-12-17 2014-12-17 Appareil, systèmes et procédés pour des mesures de teneur en matières solides en temps réel WO2016095008A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108152179A (zh) * 2017-12-22 2018-06-12 华东师范大学 一种多功能悬沙浓度标定系统
US11860096B2 (en) 2020-05-20 2024-01-02 Ysi, Inc. Extended solid angle turbidity sensor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4188121A (en) * 1977-02-01 1980-02-12 Hirleman Edwin D Jr Multiple ratio single particle counter
US20100073173A1 (en) * 2005-01-14 2010-03-25 Unitada Europe Limited Particulate detector

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4188121A (en) * 1977-02-01 1980-02-12 Hirleman Edwin D Jr Multiple ratio single particle counter
US20100073173A1 (en) * 2005-01-14 2010-03-25 Unitada Europe Limited Particulate detector

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108152179A (zh) * 2017-12-22 2018-06-12 华东师范大学 一种多功能悬沙浓度标定系统
CN108152179B (zh) * 2017-12-22 2023-07-25 华东师范大学 一种多功能悬沙浓度标定系统
US11860096B2 (en) 2020-05-20 2024-01-02 Ysi, Inc. Extended solid angle turbidity sensor

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