JPS6275331A - Method and device for measuring or monitoring density or viscoelasticity of liquid or slurry, emulsion or dispersion - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for determining the density or viscoelasticity (i.e., viscosity, elasticity, or plasticity) of any region of a liquid, slurry, dispersion, or emulsion by simply using a fixed or mobile probe (p
measurement or monitoring by using a probe or other detection member.
In particular, the present invention relates to a method and apparatus for measuring or monitoring the density or viscoelasticity of a slurry typically formed when finely ground ore is extracted or otherwise processed to recover the required values. , but is not limited to this.

The invention also relates to the measurement of the ratio of two components i in an emulsion when the viscoelastic properties of the two components are sufficiently different that a signal depending on the ratio is obtained.

<Prior Art> In general, when detecting or monitoring physical properties that vary in an arbitrary region selected from homogeneous liquids and non-uniform liquids such as slurries and emulsions, the liquid An ultrasound transducer is appropriately placed in the body, and the driving impedance of the ultrasound transducer or a variable related thereto is detected and monitored.

<Problems to be solved by the invention> However, it is not fully understood how the driving impedance of an ultrasonic oscillator, that is, an ultrasonic transducer, affects the density or viscoelasticity of a liquid. do not have. According to the experimental results conducted to date, the density of the slurry or liquid behaves differently for any slurry or liquid, and the driving impedance of any ultrasonic transducer exhibits different variations. present.

Therefore, any ultrasound transducer used with any liquid requires calibration.

The present invention has been made in order to eliminate the disadvantages of conventional measuring or monitoring methods of measuring or monitoring the density or viscoelasticity of liquids, slurries, emulsions, or dispersions using ultrasonic transducers. A liquid or slurry or slurry that can be appropriately calibrated and used to measure or monitor the driving impedance of an ultrasonic transducer or a variable related thereto properly placed in a non-uniform liquid body such as a limb or a slurry or emulsion. The present invention seeks to provide a method for measuring or monitoring the density or viscoelasticity of emulsions.

The present invention also provides an apparatus that can appropriately carry out the method for measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion, or dispersion as described above.

Means for Solving the Problems The method of measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion or dispersion according to the present invention to achieve the above object is a method for measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion or dispersion. A method for detecting or monitoring the varying physical properties of a liquid selected from non-uniform liquids such as emulsions, i.e., density or viscoelasticity, or for detecting deviations from required values of said physical properties. detecting or monitoring the driving impedance or a variable related thereto of an ultrasonic transducer placed in a liquid, and detecting or monitoring the driving impedance or variable related thereto, and detecting or monitoring the driving impedance or variable related thereto to a required value or the physical property itself or the above. It is characterized by being related to the deviation from the required value.

Furthermore, in the method of the present invention, the ultrasonic transducer used in the probe is a piezoelectric ceramic transducer (PZT).
), the ultrasonic transducer is driven at a predetermined frequency, its impedance is monitored or detected, and the value calibrated to the temperature of the detected value is determined experimentally for a particular liquid or slurry. This is characterized by the fact that the decision is made by comparing it with the data specified in the above.

How the driving impedance of an ultrasonic oscillator (ultrasonic transducer) is affected by the density or viscoelasticity of the liquid, slurry or emulsion is not fully understood, especially in the experiments performed to date. In this case, the density of the slurry or liquid causes each slurry or liquid to behave differently, resulting in different changes in the driving impedance of a particular ultrasound transducer. Therefore, it is necessary to calibrate any particular ultrasound transducer used with a particular type of liquid.

The present invention is intended to be useful for monitoring or detecting slurry generated in mining, and most of the research to date has been conducted in that direction. A preferred type of ultrasonic transducer, a piezoelectric ceramic transducer, was used in the above slurry. The probe was tested for frequencies from 0.21° to 3 degrees and was found to exhibit a rapid decrease in sensitivity as frequency increases. The optimum frequency varies depending on the application, and the above tests on slurries were performed with a particle size of 10I
I followed everything from n to 300 voices. However, this is not to indicate that the principles of the invention will not operate satisfactorily outside the above ranges.

Furthermore, the measurement or monitoring device of the present invention is carried out according to the above measurement or monitoring method and includes an enclosed and suitably mounted ultrasonic transducer type probe connected to this probe and connected to it (ultrasonic transducer type probe). ) and a driving and detecting circuit that detects the driving impedance or a variable related to the driving impedance.

Further, a detection device constituting the main part of the measurement or monitoring device of the present invention is attached to one end of a rectangular probe, and a drive circuit detects the output of the probe (ultrasonic transducer), which is the detection member, and detects liquid or an active circuit relating the density or viscoelasticity of the slurry or emulsion, the detected drive voltage being configured to be input to a computer device having experimentally obtained information to calculate the density; It is characterized by having a configuration in which the measured value or monitoring is temperature compensated through a temperature detection terminal connected to a compensator that compensates for temperature changes in the liquid, slurry, or emulsion. , representative embodiments of the present invention will be described.

1 to 5 show the schematic configuration of an apparatus used to implement the method for measuring or monitoring the density or viscoelasticity of a liquid, slurry, dispersion, or emulsion according to the present invention, and FIG. 1 shows a detector. FIG. 2 is a front view of a sensor assembly; FIG. 3 is a front view of the working end of the sensor assembly of FIG. 1; FIG.
and a block diagram of the circuit to be measured; FIG. 4 is an active bridge circuit diagram in the circuit of FIG. 3; and FIG. 5 is an equivalent circuit diagram of an ultrasonic piezoelectric transducer in the sensor assembly.

The ultrasonic transducer in the sensor assembly as a detector can be represented by a simple equivalent circuit as shown in FIG. In both circuits shown in Figure 5, series arm 4
Part 1 represents the conceptual piezoelectric characteristics of the ceramic transducer, and the parts are the resonant mass of the ceramic,
C represents elastic compliance and part R represents mechanical loss. In addition, C0 is the capacitance between the electrodes on the surface of the ceramic transducer, Ro is the electrical resistance representing the dielectric loss of the ceramic transducer, and R1 is the acoustic load that changes according to changes in the surrounding medium, which is the medium to be measured. is a parameter that corresponds to changes in .

In use, the sensor assembly 1 is housed in a sturdy housing 2 mounted on plated iron pipe 3, as shown in FIGS. 1 and 2, and is communicated with the outside through the wall of the housing by a window 4. The probe itself in this sensor assembly consists of a 20 cm piezoelectric ceramic transducer disk (in this case made of titanium It consists of an acid lead zirconite transducer).

If the thickness of the encapsulating resin is too large, it will adversely affect the sensitivity of the transducer to density changes, so it is necessary that the encapsulating resin is not too thick.

Since it is necessary for encapsulation to maintain its properties in the usage environment, the encapsulation method differs depending on the purpose of use.

The correct encapsulation thickness is obtained by encapsulating to the same thickness on either side of the transducer and then removing layers of material until maximum sensitivity to changes in the medium is obtained.

Furthermore, a temperature-sensitive transducer 8 is sealed within the epoxy resin to perform one-time compensation as described below.

The drive circuit of the detection member is controlled by a stable frequency source 9, the output of which is connected via a drive circuit 10 to a measurement/output circuit shown in block FIG. ■Output. The entire circuit therefore consists of a frequency generator 9 supplying a stabilized output frequency of the desired value, a driver 10 to which its output is supplied, and an active pre-circuit circuit #111 to which the transducer 6 is connected.

The output of the active bridge circuit 11 is connected to the rectifier 12 and the zero i
l! The signal is finally supplied to the converter 15 after passing through the I-shaping circuit 13 and the low-pass filter 12).

If necessary, the output may be temperature compensated by a suitable commercially available temperature converter 16 connected to the temperature-dependent temperature sensitive transducer 8. The outputs of converter 15 as well as temperature converter 16 are fed to computer 18 .

The calibration of the measurements, i.e. the calibration of the instrument, is the same whether for the measurement of slurry density in the mining industry or for the measurement of emulsion ratio, and was carried out using the following procedure.

First, the tube is immersed in a liquid of known density or ratio or emulsion of the same type as the liquid to be measured, the liquid is heated over the temperature range over which the instrument operates, and the probe is The output voltage proportional to the driving impedance and the output voltage V proportional to the temperature are measured, and the formula % of the density or emulsion ratio F (or viscoelastic ratio F) of the slurry being measured is derived. However, ■. is the output voltage proportional to the driving impedance, ■ is the output voltage proportional to the temperature, a,, a2. ...a,, is a constant coefficient.

Tests of the instrument in this case were carried out on slurries having different densities and temperatures and emulsions having different ratios and temperatures, and the characteristic curves shown in FIGS. 6 and 7 were determined.

The output frequency range of the circuit during this test was from 5001& to 5901& in increments of 10.

Furthermore, the operating frequency of the probe 6 (PZT) used in the measurement was two types of slurry having densities at both ends of the measurement target, namely 1.8 g/cc and 1.1 g/cc. First, immerse the probe in the lighter slurry and use an impedance analyzer to measure 0.4! JHz
(A signal generator and RMS voltmeter can also be used.) These impedance values are plotted and shown in Figure 8. For slurries with density < 1.1 g/cc, curve a (1,1 g/cc) was obtained.This procedure was repeated for the heavier (1,8 g/cc) slurry and curve b (1,1 g/cc) was obtained. 8g/cc) was obtained.

Then, the operating frequency was set as close as possible to the point where the impedance change was maximum within this range.

And the actual measurement target is the meter from 1.1 to 1,8
It is important to measure slurry density in the range up to +ng/cc.

The probe was immersed in the slurry at either end of the measurement range and the active bridge (see Figure 4) was set to maximize the change in output voltage.

After performing the above, probe f! immersed in the lowest density slurry). A DC voltage appeared at the output of the rectifier, this voltage was applied to the zeroing circuit and the above recording was adjusted so that the output current of the converter was 4 mA.

The probe was then immersed in the highest density slurry and the converter output current was adjusted to 20 mA.

Using the apparatus described above, the required calibration, and the experimental relationship between the final voltage output, the computer device 18 compares the instantaneous voltage signal with the pre-bucogrammed information regarding voltage and density to determine a density measurement. . Figures 6 and 7 show slurry (Figure 6) and emulsion (Figure 6).
Figure 7) shows the calibration curve of the instrument when measuring. The characteristic values are input into the computer 18 in advance, and the computer 18 is caused to present a value that has been compared and calibrated with respect to the value detected from the liquid to be measured.

To summarize the above explanation, the features of the present invention are as follows: (1) Variable physical property, which is at least one of the density or viscoelasticity, of a liquid selected from a homogeneous liquid and a non-uniform liquid such as a slurry and an emulsion; Monitoring the drive impedance of an ultrasonic transducer placed at a required position in a liquid or a variable related thereto in a method of detecting or monitoring, or detecting deviations of the above-mentioned physical properties from required values. or a method of detecting or monitoring a changing physical property, characterized in that the value of said driving impedance or a variable related thereto is correlated with said physical property itself or with a deviation from said required value. .

2. The method according to item 0, characterized in that the ultrasonic transducer is a piezoelectric ceramic transducer.

(2) The method according to item 0 or 0, characterized in that the ultrasonic transducer is driven at a predetermined frequency and the impedance of the transducer is monitored or detected.

(2) A method according to any one of items 0 to 0, characterized in that the detected value is compensated for temperature changes in the liquid body.

(2) The method according to any of the above items, wherein the detected value is correlated with an experimentally determined value or data regarding the same type of liquid material.

(2) The method according to any of the above, wherein the liquid material is a slurry.

2. Process according to claim 0, characterized in that the solid particles have a size range of 10 to 300 mm.

(2) A method according to any of the above, characterized in that the physical property monitored or detected is the density of the liquid.

■ The operating frequency of the above ultrasonic transducer is 0.2
[The method according to any of the above, characterized in that the time is between 1z and 3 oz.

[Phase] A method of detecting or monitoring the physical properties of a liquid material that is substantially equivalent to the liquid material described with reference to the accompanying drawings.

(2) A device for carrying out any of the methods described above, consisting of a detection member in the form of an ultrasonic transducer encapsulated in a suitable material and mounted on a fixture.

■ Connected to the above transducer to drive it,
Device according to claim 0, characterized in that it has a drive and detection circuit for detecting the drive impedance or a variable related to the drive impedance.

0. Device according to claim 0, characterized in that the drive circuit is an active bridge circuit and the output voltage of the transducer is detectable with respect to the physical properties of the liquid.

2. Device according to paragraph 0 or 0, characterized in that the device comprises a computer device for receiving the output of the detection circuit and comparing it with an experimentally derived value.

(2) The device according to any one of items 0 to 0, characterized in that the detector member is attached to one end of an elongated probe.

(2) The device according to any one of items 0 to 0, wherein a temperature sensing means is provided in the detector member, and the device is compensated for temperature changes in the liquid body.

■ Equipment substantially identical to the equipment described with reference to the accompanying drawings.

It is in.

<Effects of the Invention> As is clear from the above description, the method and apparatus according to the present invention monitor the driving impedance of an ultrasonic transducer that is appropriately disposed in a liquid and immersed in oil, and record the measured values. Determined experimentally for the same type of liquid
The density at specific points within the vessel or paehuea can be measured to monitor mixing efficiency and, for example, to calibrate data compared to carbon-in-pulp gold extraction methods.
in-pulp goldextraction pr
It can be used as a useful control device for simple control of slurry density in microorganisms.

Additionally, the invention can be used to measure other variables that depend on the impedance of an ultrasound transducer.

[Brief explanation of drawings]

Figure 1 shows the sensor assembly (s) with the detection member attached.
FIG. 2 is a plan view of the operating end of the detection member of the sensor assembly in FIG. 1, FIG. 3 is a block diagram of a circuit for driving and measuring the detection member, and FIG. The circuit diagram of the active bridge in the figure,
Fig. 5 is an equivalent circuit diagram of an ultrasonic piezoelectric transducer as a detection member, Fig. 6 is a characteristic curve diagram showing the relationship between the actual density and the detected density after correcting temperature fluctuations, and Fig. 7
The figure is a characteristic curve diagram of the relationship between the measured solvent concentration and the actual solvent concentration, and FIG. 8 is an impedance curve diagram created to determine the operating frequency for a specific p z 'r. In the drawing, sensor assembly, 2, housing 3, iron pipe, 4, window, 6, detection member (probe), 8...
Temperature-sensitive transducer, 9. Frequency generator, 10-drive circuit, 11.. Active bridge circuit, 12.. Rectifier, 1
3...Zero adjustment circuit, 12) ・Reduction filter, 15・
...Converter, 16.Temperature converter, 18.Calculator.

Claims (13)

[Claims] (1) A homogeneous liquid or slurry, emulsion, or dispersion in which a varying physical property, at least one of density or viscoelasticity, is to be detected or monitored, or deviations of that physical property from a desired value are to be detected. An ultrasonic transducer is placed in the liquid, the drive impedance of the ultrasonic transducer or a variable related to it is monitored or detected, and the value of the drive impedance or variable related to it is determined based on the density or viscoelasticity or their necessity. A method for measuring or monitoring the density or viscoelasticity of a liquid or slurry, emulsion or dispersion, characterized in that the density or viscoelasticity of a liquid or slurry, emulsion or dispersion is related to the deviation from a value. (2) The relationship between the density or viscoelasticity of the liquid, slurry, emulsion, or dispersion to be measured, or their deviation from the required value, is determined when the density and/or viscoelasticity or the ratio thereof is known and measured. This is done by comparing the density and/or viscoelasticity of the same type of liquid, slurry, emulsion or dispersion with experimentally determined characteristic curves from the driving impedance of the ultrasonic transducer. A method for measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion, or dispersion according to claim (1). (3) Claim No. 3, characterized in that the ultrasonic transducer is a piezoelectric ceramic transducer (
The method described in section 1). (4) The liquid or slurry according to claim 1 or 2, wherein an ultrasonic transducer is driven at a predetermined frequency and the impedance of the transducer is monitored or detected. , a method for measuring or monitoring the density or viscoelasticity of an emulsion or dispersion. (5) The liquid or liquid according to any one of claims 1 to 4, wherein the detected value is compensated for temperature changes of the liquid, slurry, emulsion, or dispersion. A method of measuring or monitoring the density or viscoelasticity of a slurry, emulsion or dispersion. (6) The slurry has solid particles of 10 μm to 300 μm.
A method for measuring or monitoring the density or viscoelasticity of a liquid or slurry, emulsion or dispersion according to claim 5, characterized in that the liquid has a size in the range of m. (7) The operating frequency of the ultrasonic transducer is 0.
A method for measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion or dispersion according to claims (1) to (6), characterized in that the frequency is between 2 MHz and 3 MHz. (8) A device for measuring or monitoring the density or viscoelasticity of a liquid or slurry, emulsion or dispersion constituted by a sensor assembly having an ultrasonic transducer encapsulated in a suitable material and mounted on a fixture. (9) A driving and detecting circuit connected to the ultrasonic transducer to drive the ultrasonic transducer and detect its driving impedance or a variable related to the driving impedance. Device for measuring or monitoring the density or viscoelasticity of liquids or slurries, emulsions or dispersions. (10) The drive circuit is an active bridge circuit, and the output voltage of the ultrasonic transducer is detectable with respect to the density or viscoelasticity of the liquid or slurry, emulsion or dispersion. A device for measuring or monitoring the density or viscoelasticity of the liquid, slurry, emulsion, or dispersion according to item (9). (11) The device comprises a computer device for receiving the output of the detection circuit and comparing it with an experimentally derived value.
10) A device for measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion or dispersion according to item 10). (12) The liquid or slurry, emulsion or dispersion according to claim 9 or 11, wherein the sensor assembly is attached to one end of an elongated probe. Device for measuring or monitoring the density or viscoelasticity of liquids. (13) Temperature sensing means are provided in the sensor assembly and compensated for temperature changes in the liquid or slurry, emulsion or dispersion. 12) A device for measuring or monitoring the density or viscoelasticity of a liquid, slurry, emulsion or dispersion according to any one of items 12).