JPS61502488A - Rheological property measuring device - 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] Measuring device for rheological properties The present invention is characterized in that a suitably formed rotor is placed in the object to be measured and is driven by a drive device. The rheology of a medium that is rotated only or continuously. This invention relates to a characteristic measuring device. When the rotor rotates, the medium is deformed (sheared), The resulting shear stress is measured. From shear stress, viscosity or elasticity Corresponding rheological values of the medium, such as plasticity or plasticity values, are calculated.

One form of application of the device according to the invention is its use as a rotational viscometer for measuring viscosity. It is.

Rotational viscometers, compared to many other types of viscometers, require a suitable rotor and When using containers (e.g. cone-plate devices), shear within the measured object It has the advantage of uniform speed. Therefore, a rotational viscometer has a viscosity of Evidence of the rheology of so-called non-Newtonian fluids that depends on shear velocity. Extremely suitable for testing. Use of various rotors and measuring vessels and rotor speeds The changeability of the rotational viscosity allows media with very different viscosities to be Can be tested by meter.

Rotational viscometers are often also easily cleaned, e.g. as capillary viscometers. Ru. Therefore, rotational viscometers are often also used to test Newtonian fluids. .

In the case of a conventional rotational viscometer, the rotor is connected to a synchronous motor through a mechanism that can be opened and closed. driven by. The rotation acting on the rotor shaft and measuring vessel due to the viscosity of the medium The rolling moment is most often measured by the twisting of a torsion spring. Rotating motor The viscosity value to be claimed together with the rotational speed of the rotor is obtained from the component.

A typical rotational viscometer is a complex mechanical device with many moving parts. They are prone to failure and are expensive. In particular, direct coupling of the rotor with the measuring part and the drive is often a drawback, as explained below.

The measuring container containing the rotor and the object to be measured should be Since this would cause errors in the measurement results, it cannot be sealed with ordinary equipment.

Therefore, especially when testing corrosive media and at high temperatures, corrosive vapors Corrosion can penetrate equipment, transmission mechanisms, and motors, reducing equipment accuracy. There is danger. The viscosity of many fluids is significantly affected by temperature, so It is necessary to be able to precisely control the temperature. Transmission mechanism and electric motor or measuring equipment In case of measured temperature different from ambient temperature In this case, ambient heat is supplied to the device under test via a rotor, or heat is removed from the device under test. is emitted, which may cause errors in measurement results. In addition, measuring equipment and The fixed mechanical connection of the rotor to the rotor and drive device impedes cleaning. To be measured Definitely within. In the case of a so-called cone-plate device, a rotating cone and a fixed plate are used. The spacing must be maintained very accurately. For many conventional rotational viscometers, This small spacing allows the two long components (rotor shaft and plate retainer) This can have a negative impact on the reproducibility of measurement results. be. Conventional general rotational viscometers cannot seal the container, so the pressure Added measurements are not possible and measurements of substance mixtures with fluid components are inaccurate. However, this is to the extent that it is possible.

Conventional general rotational viscometers can only measure the viscosity and therefore the elastic properties of the medium. Or data on plastic properties are not available. Therefore, e.g. Technically important and often accurate separation with pseudoplastic media is not possible with this instrument. It is.

Traditional devices for testing elastic or plastic properties suffer from some of the same basic drawbacks: (complex mechanism, open measuring vessel, corrosion and heat transfer problems) .

One drawback of conventional rotational viscometers is that the rotor is driven by a magnetic drive gear coupling. Proposals have become known to prevent this by driving (Japanese Patent No. 1648858). This coupling is suitable for It operates through an M wall that separates the fluid space from the rest of the device.

However, this structure requires a magnetic coupling to replace the traditional complex components of a rotational viscometer. Since it is added as a rotating element, it is not completely satisfactory. moreover, The magnetic coupling increases the moment of inertia of the device and the increased axial bearing force may occur.

It is therefore an object of the present invention to overcome this conventional drawback and to Satisfied with mechanically moving parts, at the same time the measuring container is sealed and the temperature can be adjusted. type of rotational viscometer or type of device for measuring elastic and plastic values or viscosity. form of commonly used combined device for measuring elasticity, elasticity, and plasticity To provide a device for measuring highly accurate rheological values that can be constructed by Eq. It is in.

This problem is solved according to the invention by improving the rheological properties of the medium. In this device, a rotor immersed in an object under test has a permanent magnetic moment. rotatable or rotating, having and electromagnetically generated by a fixed magnetic coil driven by an external magnetic field, in which case the torsion of the rotor relative to the external driving magnetic field The angle is measured without contact, and from the size of this torsion angle, the shear stress and This is achieved by determining rheological values corresponding to the measurement process.

Next, the present invention will be explained by way of example using figures. In the drawing, FIG. A partially sectional side view showing one embodiment, FIG. 2 shows the arrangement of FIG. 1 shown in reduced dimensions. floor plan of the FIG. 3 shows an embodiment of the present invention having a cylindrical rotor and a ring-shaped core wrapped with a coil. FIG. 4 is a sectional view showing the second embodiment, and FIG. 4 shows the windings and windings on the core in the embodiment shown in FIG. FIG.

Example 1, shown schematically in a partially sectional side view in FIG. is a combined device for measuring elastic or plastic properties. This is essentially The measurement section unit, non-contact measurement device, electromagnetic drive device l, and power supply/evaluation device Wi unit are included. It consists of The measurement part 1 is protected from twisting and is protected from heat by a thermal insulation part 20. It is held in an insulated measurement unit holding device 19. This measuring part must be cleaned and filled. In order to The following three parts, which can be separated from each other for crushing and crushing: It consists of a lower measuring member, an upper measuring member, and a rotor.

The rotor shaft is designed in the lower part as a conical measuring body 33 and has an adjustable conical bearing 24. ．． 32 on the plate 21 of the lower measuring member. For example, conical bearings The height is adjusted by the sapphire bearing cap 32, set screw 22 and nut 23. It consists of an adjustable tungsten carbide tip 24. Above the rotor shaft 34 At the end is mounted an upper bearing shaft 36 guided by a perforated stone 31. ing. A permanent magnet 35 is fixedly coupled to the rotor shaft 34 and provides a magnetic force to the rotor. causes an event. At the intermediate part between the plate 21 and the rotor plate which is rotatably supported, there is a measuring plate. A fixed object 7 is placed therein. Lower measurement member A, measurement object 7, and rotor The heat flows through the heat exchanger 26 through the supply and discharge conduits 28, 28'. A temperature controlled liquid maintains the desired adjustable temperature.

To facilitate the assembly of the individual parts 4.5.6 of the measuring unit, the cap of the lower bearing 32 and the perforated stone 31 of the upper bearing are connected to the lower bearing point 24 and the upper bearing. It has a relatively large conical shape to allow the shaft 36 to fit automatically.

In this case, the measuring unit Y is equipped with a photoelectric measuring device.

This measuring device uses an infinitive image of the slit 38 illuminated by the lamp 37. It consists of a standard with a mirror 1o that images the image on the tee. For those who have a designated rotor If the beam is in the direction of After passing through lens 40 a second time and being reflected by semi-transparent mirror 39, a bright slit appears. The image is imaged on the photodiode 41.

The electromagnetic drive device 2 includes two pairs of Helmholck coils 13/13', 13"/1 3'' and their axes lie in one horizontal plane and intersect at right angles. A Lumholtz coil pair is a coaxial pair of two similar circular coils with a small ]il cross section. device and the same current flows through it.

The measuring part holding device 19 must be leveled with a bind head bolt and a spirit level. The Helmholtz coil pair is fixed to a base plate that can be It is fixed by a holding member.

When using a universal device as a rotational viscometer, the phase of the power supply/evaluation device is 90°. 'Provides two staggered sinusoidal alternating currents. This current flows through the supply conductor 17 to It is supplied to the Lumholtz coil pair 13/13', 13"/13'. Also, The power supply/evaluation device H sends the 10 signals to the conductor 1 when the non-contact photoelectric transit is detected. 8 and evaluate this signal.

Helmholtz coil pair 13/13', 13"/13"' has a phase difference of 90° By supplying a sinusoidal alternating current that is An extremely uniform rotating magnetic field is generated near the point of difference, and this magnetic field causes the rotor 6 to rotate uniformly. let If the driving magnetic field is in a predetermined direction, for example Helmholtz coil pair 13/1 3', when the alternating current passes through zero from the positive side, it is detected by the electronic detector. A signal is supplied to the power supply and evaluation device 3 and thus the time measurement in the time measuring device. is started. Photoelectric transilluminator 1 to detection 4, 10 four diodes 41 The signal ends this time measurement (tl) and starts a second time measurement.

This time measurement (t2) ends before this cycle is repeated. both measured times t and t2 are memorized and displayed, and the two clocks (counters) of the time measuring device ) is reduced to zero. The sum of the two times is f required for one rotation of the rotor in steady state. Equal to the period, the ratio of one side of the two times to the period is This is the skewer of the phase difference of the rotor. Shear stress τ in the medium, applied shear rate The following equations are approximately used to calculate t and viscosity η.

τ-a”MB-B-sin (2・π・t1/(t1+12)−ψ.)...(1) η−r/”r=(a/ b) -MB-B'-M8: Magnetic moment of rotor B: Magnetic flux during driving time a, b: Instrument constants determined by the geometric dimensions of each rotor Φ. : Another obsolete constant.

If the driving flux is very strong, depending on the circumstances, it may be difficult to obtain the desired measurement degree. In order to take into account the different magnetic properties of the rotor, equations (1) and (3) need to be modified. There is. Instrument constant ψ. is determined by the structure of the meter, and there is no need to know the viscosity. The new fluid is tested at different rotational speeds of the rotor. It can also be discovered experimentally.

This first embodiment constitutes a device characterized by the following data: It was done. Rotor magnetic moment 1-MB = 550 μT; cone radius r = 24 a m: Angle between cone and plate α = 1.2″′: Bearing camp radius + Q, 12am< r'　<0.15m: Radius of tungsten carbide pointed head r'L=0.04mg+ :Error in the sine waveform of the current supplied to the Helmboltz coil: 0.7% or less of I: Phase difference error <0.5': Frequency: Q, 22Hz <f<20Hz. in this way Determined by the formula 1) from time t and t2 depending on the actually configured instrument. The error in the shear stress obtained is less than 1% of the maximum measured value.

FIG. 2 shows the same embodiment as in FIG. 1 in plan view but with reduced dimensions. There is. Screws 8 and 8' are used to connect the upper measuring part to each other and the lower measuring part. It is used.

To some extent, fluid-like media exhibit elastic properties and pJ plasticity properties, and these properties can be measured together with normal viscosity measurements according to the first embodiment of the invention. Wear. For this purpose, the power supply and evaluation device can be switched to other drive types, and this In the drive type, the external magnetic flux generated by the Helmholtz coil is adjustable And instead of rotating at a constant speed, the direction of this magnetic flux is controlled by the power supply/evaluation device. By operating a rotary knob with a scale that can be read on the scale of the rotary knob. The degree can be in the desired direction. Roughly speaking, the rotor has an additional angle scale 11 , and a reading device installed in the fixed part of the measuring part to determine the direction ρ of the rotor. It is equipped with a station 12. To measure the static elastic and malleable properties of a medium, use the example For example, you can do something like this: In other words, the direction χ of the external magnetic field is determined by whether the magnetic field is a closed circuit or Use the aforementioned rotary knob so that the rotor is in the same position in both open and open states. (adjusted. If the direction of the external magnetic field shifts by a small angle Δχ, the medium becomes static. When the elastic properties However, if the medium is not elastic but purely viscous, the rotor will change over the entire angle Δ It is necessary to delay by χ. These two angular differences Δχ and Δρ and the form of the rotor Or from other physical data of the instrument, the elasticity can be calculated. Δχ −△ρ, that is, the value of the rotor's torsion relative to the magnetic field, exceeds the value of the magnetic field. A permanent change in rotor position occurs after the opening of the rotor. In this case, characterizing the plastic properties The size τ. , that is, the liquid limit has been exceeded. to the rheological properties of the medium. Therefore, other methods using the same equipment, such as observing the degree of relaxation after continuous shear deformation, are recommended. can be done.

After the bright slit is reflected by a mirror fixed to the rotor shaft, a fixed scale The rotor direction ρ can also be measured by being projected by a projector onto can. Additionally, the scale can be constructed from a series of photodiodes, By doing so, one can obtain fast electrical measurements of Δρ and thus e.g. relaxation times. The dynamic side T, such as measurements of . as occurs when a viscoelastic liquid is deformed. [3°] For direct stress measurement, a pressure measuring device can be incorporated into the plate 21.

Furthermore, the first embodiment of the present invention superimposes a compensating reverse current on the Helmholtz coil. For example, a device 4-equipped with a device for compensating any interfering direct current magnetic field to the earth's magnetic field. In addition, metals with shielding properties, such as Miko-11 metal, can be used. The influence of external magnetic fields can also be eliminated by using a housing of

Sealable @: Container 215. A second implementation of the present invention, which is equipped with a shaft and has a through L/shaft. The embodiment is used as a rotational viscometer and is shown in cross-section in FIG.

This measuring section includes a cylindrical container 25. Inside this container 25 is a cylindrical rotary plate. The container 25i11i is closed by the container 25i11i. As shown in Figure 1, In the case of , the bearing cap 32 and the stone 31 with 4 holes have the pointed end 24 = 1'3 and a large cone to allow the shaft 36 to fit automatically. M-dan Before loading the container 25, a device 30 for centering the rotation F6' placed in the holding section. This vessel is for pressure regulating conduits or for connecting pressure measuring devices. Equipped with a connecting pipe.

The non-contact measuring device 9.10 is constructed in the same way as in the first embodiment in FIG. In this case, the measurement is carried out through a window 29 built into the container 25 with a pressure-resistant structure. It will be done as follows.

The electromagnetic drive unit @2' consists of 4 magnet coils 14, which are arranged symmetrically in a rectangular manner. 14’, 14”, 14”’ with low residual magnetic flux characteristics wound in the form of a ring core. It consists of a horizontally disposed annular core 15 made of a flexible material. These parts The coils are connected in pairs, and two sinusoidal alternating currents with their transfers shifted by 90° are supplied. It will be done. The winding and wiring type of this annular drive vJ device is schematically shown in FIG. ing.

16 and 16' are two alternating current sources 90' out of phase. This electric An important feature of the magnetic drive is that an iron core with low residual magnetic flux characteristics is rotated around the axis of rotation. It is arranged symmetrically. Therefore, the permanent magnets of the rotor are discontinuous. Since the rotor is not caught by the ferromagnetic poles of the rotor, extremely uniform rotation of the rotor is obtained.

This second embodiment allows measurements at 43°C under pressure and at elevated temperatures. It is suitable for measuring substances with easily volatile components.

This power supply/evaluation device is equipped with a combi coater.

This combination J,-Y processes the measurement results and controls the measurement progress. During this measurement process, we measured the non-neutral measurements versus nutrients at various shear rates. Since the rotational frequency is constant 1", programmed changes in the rotational frequency can be made.

This computer is also used for control purposes such as controlling the temperature of the dye to be measured. can be done.

It is especially suitable for direct coupling with a gauge digital combicoater because it includes counting of periodic processes. Are suitable. Particularly if the walls of the container are thick enough to withstand high pressures, In order to calculate the temperature dependence of the magnetic moment of the rotor and the eddy current effect that cannot be ignored, Therefore, the use of a computer is necessary to take this into account. Also, for electromagnetic drive devices Digitally generates an alternating current that determines the phase difference between the supply reservoirs and sends it to the D-A converter. Therefore, it can also be converted into an analog signal.

The third embodiment of the present invention is almost the same as the first embodiment #i shown in FIGS. It is constructed as follows and is used as a rotational viscometer. Unlike the first embodiment, this The third embodiment does not have a 1-heranshield detector, and the phase difference of the rotor with respect to the driving field is is optically indicated on the scale. In that case, the following structure applies: That is, the sleeve 1 After changing the direction of the image of - by a mirror fixed to a rotor, it emits fluorescence and becomes visible in the visible range. An ultraviolet flash is projected onto a fixed scale with a phosphorescent layer in the A fixed translucent device with a light bulb is provided. Each time it passes through the driving magnetic field in a given direction In each case, unlike the first and second embodiments, the first vi measurement is started. Instead, an ultraviolet flash bulb is turned on. L = Therefore, it emits phosphorescence on the scale. A mark is generated, and this mark has a different scale depending on the phase difference, shear stress or viscosity. You can appear wherever you want.

Since the bearing friction is minimized as much as possible, the actual Ilf! ! Aspect 1゜2 J3 and 3 conical bearings are particularly relatively heavily loaded. Inadvertently installing the measuring unit on a hard base In order to prevent damage to the bearing due to the impact that may occur when Or the bearing V-ship consists of a spring that is reversible (,゛deformation L, This prevents overloading of the bearing. For the purpose of For example (use of other bearings such as double rolling bearings or magnetically deloaded bearings). In some cases, a purpose is specified.

The technical scope of the present invention is not limited to the examples described above. A practically usable embodiment of a one-dimensional D-gee measuring device is the phase shift described above. It can also be constructed by other than the T1-il device, measurement object, etc.

Thus, for example, it is preferable especially for small shear rates, but during one rotation In order to measure the phase difference several times, the 51 instrument uses several mirrors or several optical detectors. A container can be provided. In addition, 1-Lansira 1~detector is used instead of the sleeve 1- An incandescent filament on a raised floor is projected onto the It is also possible to configure the image to be displayed on the photodiode A. infrared, purple The use of external radiation, laser radiation, XvA or gamma rays is advantageous in certain cases.

In addition, the perpendicular magnetic field component generated from the magnet 35 is It can also be realized by being measured by a Hall detector.

Furthermore, the present invention requires that the strength of the driving magnetic field be kept constant during the measurement process. Don't be bullied by not having one. The phase difference between the rotor and the rotating magnetic field varies. Either the shear stress has a constant value or the strength of the rotating magnetic field changes correspondingly. It may be necessary to have at least a minimum value.

The device according to the invention can be used for various rotors, measuring vessels,! 1 or using rotating magnetic field strength. By using this, it can be adapted to a given purpose of use.

Measuring bodies and measuring containers, which are important in special cases characterized by small interstitial volumes, are commonly It is equipped with a circular cone-shaped rotor made of two cones with a base surface of Rotates at a slightly larger cone angle within the container. A second embodiment of the invention shown in FIG. In this case, the sensitivity of the instrument can be adjusted by changing the distance of the magnet 35 from the drive device 2. can be changed. The annular core of this second embodiment has an inner diameter of, for example, 110 A wound wire consisting of 20 turns of M6X transformer iron plate (23m x 0.35aa+) It consists of At 70 meters above the center, the rotating magnetic field strength is around the center value. It's only about 1/3, and I'm not sure about doing it this way! ! The measuring range of Appropriately changed 1゜ Further, the driving rotating magnetic field is generated by, for example, four parallel magnetic cores each including a ferromagnetic core. It can also be caused by files. For such an arrangement of coils, the discontinuous Ferromagnetic poles are present, which generally has a negative effect on the rotational uniformity of the rotor. However, the present invention also allows for a knead-like coil arrangement, if specifically required. .

Other modifications that create rotating magnetic fields include auxiliary permanent magnets with mechanically driven inserts. It is the rotation of However, this modification is mechanically expensive and prone to failure. and therefore cannot be recommended.

A section made of a suitable material with low residual magnetic flux characteristics in place of the permanent magnet EI35 in the rotor. In this case, the rotational force is extremely small, and the shear stress and torsion angle are The quantitative relationship between

The features of the invention shown in the drawings or claims in the foregoing description may be individually , and e.g. using an annular electromagnetic layer 8 device 2' with a conical rotary platen, etc. It is important to apply the present invention to various embodiments by appropriately combining them.

international search report 1m□-+11++　m　T/CH115/　001001111111Ma KT, CH35, Isamu Kari

Claims (10)

[Claims] 1. A measuring section (with a power supply/evaluation device (3) and a rotor (6) immersed in the medium) 1) and an electromagnetic drive device (2). , the rotor (6) has a permanent magnetic moment and is rotatable or in a rotating magnetic field. This magnetic field is applied to the fixed magnetic coil (13) of the electromagnetic drive device (2). , 13', 13'', 13'''). The torsion angle of the rotor relative to the driving magnetic field can be measured without contact. shear stress and viscosity or elasticity of the medium. Other rheological values such as plasticity or plasticity values are The torsion angle of the trochanter, the strength of the magnetic field, the magnetic properties of the rotor, or the morphology of the measuring part of the rheological properties of a medium characterized by being determined from quantitative relationships between dimensions measuring device. 2. If the device is used as a rotational viscometer, then the fixed magnet of the electromagnetic drive (2) Out-of-phase alternating currents are supplied to the air coils (13, 13', 13'', 13'''). The helix angle between the rotor (6) and the rotational drive magnetic field is controlled by the rotation and drive of the rotor. measured by a non-contact measuring device (9, 10) as the phase difference between the rotation of the dynamic magnetic field and An apparatus for measuring rheological properties of a medium according to claim 1, characterized in that: . 3. Devices are used to measure the elastic or plastic properties of the medium, in which case electromagnetic Fixed magnetic coils (13.13', 13'', 13''') of the drive (2) A direct current is supplied to the regulated by selection of the strength of the current flow and rotated by the non-contact measuring device (9, 10). The orientation of the trochanter is measured, which determines the twist angle of the rotor relative to the driving field. This occurs as a difference between the adjusted direction of the magnetic field and the direction measured without contact of the rotor. An apparatus for measuring rheological properties of a medium according to claim 1, characterized in that: 4. The celadon drive (2) comprises at least two pairs of helm holes as fixed magnetic coils. Equipped with a pair of coils (13/13', 13''/13'''), and direct current is applied to this coil. or an alternating current having a phase difference is supplied, as set forth in claim 1. A device for measuring the rheological properties of loaded media. 5. The electromagnetic drive (2') comprises at least two fixed magnetic coils (2') in the form of a ring core. 14, 14', 14'', 14''') It has at least one annular core (15), and the magnetic coil is supplied with a direct current or a phase difference. The medium according to claim 1, characterized in that an alternating current having a Measuring device for ological properties. 6. The bearings (32, 34) used to guide the rotor (6) are placed directly in the medium (7). A device for measuring rheological properties of a medium according to claim 1, characterized in that: . 7. The rotor (6') is in a closable container (25, 5') and The shaft of the rotor does not protrude outward from any part of the rotor. An apparatus for measuring rheological properties of a medium according to claim 1. 8. The device can be connected directly to a computer for evaluating the results, controlling or adjusting the measurement process. of the rheological properties of the medium according to claim 1, characterized in that: measuring device. 9. The non-contact measuring device (9, 10) emits one or more short-wave electron beams, e.g. This short-wave electromagnetic radiation is transmitted by the rotor once or several times during the rotation of the rotor (6). The direction of the rotation can be changed or the strength can be changed, and this movement is accompanied by one or several electronic detectors. A time measuring device is differentially operated through the output device (41), and this time measuring device is controlled by another detector that periodically measures the direction of the magnetic field relative to the driving magnetic field. Claims characterized in that the phase difference of the rotor is determined from measured times. 3. A device for measuring rheological properties of a medium according to item 2. 10. Each time the driving rotating magnetic field moves in a predetermined direction, short-wave pulsed electromagnetic radiation is sent out. This electromagnetic radiation is directed by a rotor (6) to a fixed eye equipped with a fluorescent layer. The direction is changed by the embankment, and by doing so, the rotor relative to the driving magnetic field 2. The medium according to claim 2, wherein the phase difference angle of the medium is read. Measuring device for physical properties.