Visualization Device

Abstract

To provide a visualization device 1 that visualizes a temporal change of phase in a high-temperature furnace 10.SOLUTION: A visualization device 1 comprises: a plurality of electrode rods 20 arranged in a first phase 11 which is a high-temperature liquid phase; a power supply 22 for applying a current or voltage to the plurality of electrode rods 20; a control unit 24 for switching a combination of the plurality of electrode rods 20 to which a current or voltage from the power supply 22 is applied and executing a voltage or a current measurement regarding the selected combination of the plurality of electrode rods 20 to acquire an impedance value; and a calculation unit 25 for calculating, on the basis of the impedance value, an electrical characteristics distribution that indicates one of an electroconductivity distribution, a dielectric constant distribution and a phase distribution before and after the appearance of a second phase 12 in the first phase 11, and outputting an image reconstructed from the electrical characteristics distribution.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a visualization device for visualizing the time-dependent phase change in a high-temperature furnace. [Background technology]

[0002] Various chemical changes occur in the phases inside a high-temperature furnace, resulting in the appearance of foreign matter that can be in a solid, liquid, or gaseous state. As an example of a technology for detecting foreign matter inside such a high-temperature furnace, Patent Document 1 discloses a tomography device that uses an electrical impedance tomography method to reconstruct an electrical impedance distribution image from the measured voltage inside a glass melting furnace. The technology described in Patent Document 1 can identify the location where impurities remain from the electrical impedance distribution image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-195343 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 identifies the locations where impurities (foreign matter) remain, but does not measure the time change in the spatial distribution of the foreign matter. There is a demand for a technology that visualizes the time change in phases in a high-temperature furnace so that the time change in the spatial distribution of such foreign matter can be measured.

[0005] Therefore, the present disclosure provides a visualization device for visualizing the time-dependent change in phase within a high-temperature furnace. [Means for solving the problem]

[0006] A visualization device according to one aspect of the present disclosure includes a plurality of electrode rods disposed in a first phase which is a high-temperature liquid phase; a power source which applies a current or voltage to the plurality of electrode rods; a control unit which switches between combinations of the plurality of electrode rods to which a current or voltage is applied from the power source and performs voltage or current measurements for the selected combination of the plurality of electrode rods to obtain an impedance value; and a calculation unit which calculates an electrical property distribution indicating one of a conductivity distribution, a dielectric constant distribution, or a phase distribution before and after the appearance of a second phase in the first phase based on the impedance value, and outputs an image reconstructed from the electrical property distribution.

[0007] In a visualization device according to one aspect of the present disclosure, a current or voltage is applied to a plurality of electrode rods arranged in a high-temperature first phase while switching between selected combinations, thereby performing voltage measurement or current measurement and acquiring an impedance value. In addition, based on the impedance value, an electrical property distribution (one of the distributions of conductivity, dielectric constant, or phase) before and after the appearance of a second phase in the first phase is calculated, and an image reconstructed from the electrical property distribution is output. According to this configuration, by imaging the electrical property distribution before and after the appearance of a second phase different from the first phase present in the high-temperature furnace, the temporal change in the spatial distribution of the second phase before and after the appearance of the second phase appears in the image. With such an image, the temporal change in the phase in the high-temperature furnace can be visualized. Effect of the Invention

[0008] According to the present disclosure, a visualization device is provided for visualizing the time-dependent phase changes in a high-temperature furnace. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a visualization device. [Diagram 2] FIG. 2 is a diagram showing an example of the structure of an electrode rod. [Diagram 3] FIG. 2 is a diagram showing an example of the structure of an electrode rod. [Figure 4] FIG. 2 is a diagram showing an example of the structure of an electrode rod. [Diagram 5] FIG. 2 is a diagram showing an example of the structure of an electrode rod. [Figure 6] FIG. 2 is a diagram showing an example of a structure of a conductive line. [Figure 7] FIG. 13 is a conceptual diagram showing the directionality of an electrode rod. [Figure 8] FIG. 2 is a diagram illustrating an example of a configuration of a moving mechanism section. [Figure 9] FIG. 2 illustrates an example of a hardware configuration of a control unit and a calculation unit. [Figure 10] 1 is a flowchart showing an example of a method for visualizing the inside of a high-temperature furnace. [Figure 11] FIG. 13 is a conceptual diagram showing an example of a reconstructed image. [Figure 12] FIG. 2 shows the dependence of slag electrical conductivity on composition and temperature. [Figure 13] FIG. 13 is a graph showing capacitance change due to crystallization. [Figure 14] FIG. 1 is a schematic diagram showing a visualization device in a first embodiment. [Figure 15] FIG. 2 is a diagram showing a reconstructed image in the first embodiment. [Figure 16] FIG. 13 is a diagram showing the arrangement pattern of a second phase in Example 2. [Figure 17] FIG. 13 is a diagram showing the arrangement pattern of a second phase in Example 2. [Figure 18] 13 is a graph showing the accuracy of image reconstruction in the second embodiment. [Figure 19] FIG. 11 is a schematic diagram showing a hypothetical high-temperature furnace in Example 3. [Figure 20] FIG. 13 is a diagram showing a reconstructed image in Example 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In the description, the same elements or elements having the same functions are denoted by the same reference numerals, and duplicated description will be omitted.

[0011] [Visualization device for inside high-temperature furnace] FIG. 1 is a schematic diagram showing an example of the visualization device 1. The visualization device 1 is a device that visualizes the time change of phases in a high-temperature furnace by imaging and outputting the electrical property distribution in the high-temperature furnace using an electrical impedance tomography method. Specifically, the visualization device 1 supports the measurement of the time change of the spatial distribution of the second phase by imaging the electrical property distribution before and after the appearance of a second phase different from a first phase existing in the high-temperature furnace. Below, an example in which the visualization device 1 is applied to the iron-making and steel-making processes in the steel industry will be described, but the application is not limited to this.

[0012] A user of the visualization device 1 may be, for example, an operator in an iron-making or steel-making process. In the iron-making or steel-making process, high-temperature furnaces such as blast furnaces, converters, and electric furnaces are used. The temperature inside a high-temperature furnace may range from, for example, 800°C to 2200°C. An example of the first phase is molten metal. An example of the second phase is slag. The phase here refers to a homogeneous state from a macroscopic point of view. Macroscopic refers to a state of about 0.001 mole (6×10 gas molecules). 19 The scale indicates the scale at which there are a sufficiently large number of molecules (each of which exists in a single molecule). In a continuous casting process, which is one of the processes for making pig iron and steel, an operator pours out molten metal in a high-temperature furnace. At this time, the operator needs to control the outflow of the molten metal so that the slag does not flow out together with the molten metal. However, in the past, it was difficult for an operator to measure the state, time, where, and amount of slag present in the molten metal, and it was difficult for the operator to control the outflow of the molten metal. The visualization device 1 visualizes the time change of the phase in the high-temperature furnace, thereby assisting in the measurement of the time change of the spatial distribution of slag. As shown in FIG. 1, the visualization device 1 includes a high-temperature furnace 10, a plurality of electrode rods 20, an electrode support unit 21, a power source 22, a power relay 23, a control unit 24, and a calculation unit 25.

[0013] The high-temperature furnace 10 is a heat-resistant container made of firebricks or the like. Examples of high-temperature furnaces 10 include blast furnaces that use iron ore and coal as raw materials to produce pig iron, converters that refine the iron and steel in a subsequent process, electric furnaces that melt scrap iron using electric Joule heat to produce iron and steel, and continuous casting machines that solidify the molten steel product into semi-finished products. The high-temperature furnace 10 is heated to melt the raw materials fed into it.

[0014] The melted raw materials become a first phase 11, which is a high-temperature liquid phase. The first phase 11 includes, but is not limited to, molten steel, molten slag, molten glass, and the like. In addition, various chemical changes occur in the first phase 11 in the high-temperature furnace 10, and a second phase 12, which is a substance different from the first phase 11, appears. The second phase 12 includes, but is not limited to, slag containing, for example, silicon dioxide, calcium oxide, diphosphorus pentoxide, iron oxide, magnesium oxide, and the like, and reaction products. The second phase 12 can be in a solid, liquid, or gas phase. That is, after the appearance of the second phase 12, the first phase 11, which is a high-temperature liquid phase, and the second phase 12, which can be in a solid, liquid, or gas phase, coexist in the high-temperature furnace 10, and the entire phase is constantly changing.

[0015] The electrode rod 20 is a rod-shaped electrode having heat resistance that can be used in a high-temperature environment (for example, about 1600°C). The electrode rod 20 has a shape such as, for example, a cylinder or a square prism, but is not limited thereto. In the following, the electrode rod 20 will be described as having a cylindrical shape. The electrode rod 20 extends, for example, from one end (base end) side to the other end (tip end) side. The base end refers to the end of the electrode rod 20 that is held by other parts when the electrode rod 20 is in use. The tip refers to the end of the electrode rod 20 that is not held by other parts when the electrode rod 20 is in use. The electrode rod 20 has one or more small electrodes (conductors). The electrode rod 20 has multiple small electrodes, for example, in the extension direction.

[0016] The small electrodes are made of, for example, platinum-rhodium alloys, tungsten-rhenium alloys, transition metal consumable electrodes, or carbide and boride ceramic materials of Group IV elements having electrical conductivity similar to that of iron group elements. An electrode support (not shown) for fixing the electrode rod 20 is attached to the base end side of the electrode rod 20. The electrode support is made of a heat-resistant material (e.g., recrystallized high-purity alumina, etc.) that can be used in high-temperature environments, just like the small electrodes. A guard electrode that removes noise from the outside may be disposed on the electrode rod 20, and electrostatic shielding may be provided.

[0017] Parts (a) to (e) of FIG. 2 are diagrams showing the structure of an electrode bar 20A, which is an example of the electrode bar 20. As shown in part (a) of FIG. 2, the electrode bar 20A has a cylindrical small electrode 201, a cylindrical dielectric 202, and a conductive wire 203. The electrode bar 20A extends in the EX direction (hereinafter simply referred to as the "EX direction") from the base end side to the tip end side. The small electrode 201 includes three small electrodes 201A, 201B, and 201C in order along the EX direction, for example. The dielectric 202 is disposed at both ends of the electrode bar 20A and between each of the three small electrodes 201A, 201B, and 201C. The end faces of the three small electrodes 201A, 201B, and 201C are in contact with the end faces of the adjacent dielectric 202. Conductive wire 203 includes three conductive wires 203 A, 203 B, and 203 C. Three conductive wires 203 A, 203 B, and 203 C each extend inside dielectric 202 in the EX direction.

[0018] Part (c) of Fig. 2 is a cross-sectional view taken along line AA of part (b) of Fig. 2. The small electrode 201A has two through holes 201Ab and 201Ac penetrating from one end face to the other end face. The dielectric 202 has blocking portions 202Ab and 202Ac formed so as to block the two through holes 201Ab and 201Ac of the small electrode 201A, respectively. The conductive wire 203A is electrically connected to the small electrode 201A. The conductive wires 203B and 203C extend in the EX direction inside the blocking portions 202Ab and 202Ac, respectively, and pass through the small electrode 201A.

[0019] Part (d) of Fig. 2 is a cross-sectional view taken along line BB of part (b) of Fig. 2. The small electrode 201B has one through hole 201Bc penetrating from one end face to the other end face. The dielectric 202 has a blocking portion 202Bc formed so as to block the through hole 201Bc of the small electrode 201B. The conductive wire 203B is electrically connected to the small electrode 201B. The conductive wire 203C extends in the EX direction inside the blocking portion 202Bc and passes through the small electrode 201B.

[0020] Part (e) of Fig. 2 is a cross-sectional view taken along line CC of part (b) of Fig. 2. The conductive line 203C is electrically connected to the small electrode 201C.

[0021] Parts (a) to (c) of Fig. 3 are diagrams showing the structure of an electrode bar 20A, which is an example of the electrode bar 20. As shown in part (a) of Fig. 3, the electrode bar 20A may not be provided with a dielectric 202 on the tip side in the EX direction. As shown in part (b) of Fig. 3, the electrode bar 20A may not be provided with a dielectric 202 on the base end side in the EX direction. As shown in part (c) of Fig. 3, the electrode bar 20A may not be provided with a dielectric 202 on the base end side and tip side in the EX direction.

[0022] Parts (a) to (e) of FIG. 4 are diagrams showing the structure of an electrode bar 20B, which is an example of the electrode bar 20. As shown in part (a) of FIG. 4, the electrode bar 20B has a small electrode 201, a cylindrical dielectric 202, and a conductive wire 203. The electrode bar 20B extends in the EX direction. The small electrode 201 includes, for example, three small electrodes 201D, 201E, and 201F in order along the EX direction. The three small electrodes 201D, 201E, and 201F are bonded to the cylindrical dielectric 202 so as to surround the entire periphery of its side surface, and are spaced apart from each other at a predetermined interval. The three small electrodes 201D, 201E, and 201F are each rectangular when viewed from a direction perpendicular to the EX direction. The conductive wire 203 includes three conductive wires 203D, 203E, and 203F. The three conductive lines 203D, 203E, and 203F each extend inside the dielectric 202 in the EX direction.

[0023] Part (c) of Fig. 4 is a cross-sectional view taken along line DD of part (b) of Fig. 4. Conductive wire 203D extends from inside dielectric 202 toward the side of dielectric 202 and is electrically connected to small electrode 201D. Conductive wires 203E and 203F each extend inside dielectric 202 in the EX direction and pass through small electrode 201D.

[0024] Part (d) of Fig. 4 is a cross-sectional view taken along line EE of part (b) of Fig. 4. Conductive wire 203E extends from inside dielectric 202 toward the side of dielectric 202 and is electrically connected to small electrode 201E. Conductive wire 203F extends inside dielectric 202 in the EX direction and passes through small electrode 201E.

[0025] Part (e) of Fig. 4 is a cross-sectional view taken along the line FF of part (b) of Fig. 4. The conductive wire 203F extends from the inside of the dielectric 202 toward the side surface of the dielectric 202, and is electrically connected to the small electrode 201F.

[0026] Parts (a) to (e) of FIG. 5 are diagrams showing the structure of an electrode bar 20C, which is an example of the electrode bar 20. As shown in part (a) of FIG. 5, the electrode bar 20C has a small electrode 201, a cylindrical dielectric 202, and a conductive wire 203. The electrode bar 20C extends in the EX direction. The small electrode 201 includes, for example, three small electrodes 201K, 201L, and 201M in order along the EX direction. The three small electrodes 201K, 201L, and 201M are attached to a half circumference of the side surface of the cylindrical dielectric 202 and are arranged at a predetermined interval. The three small electrodes 201K, 201L, and 201M are each rectangular when viewed from a direction perpendicular to the EX direction. The three small electrodes 201K, 201L, and 201M may have directivity on the side surface on which they are arranged. The conductive wire 203 includes three conductive wires 203K, 203L, and 203M. The three conductive wires 203K, 203L, and 203M each extend inside the dielectric 202 in the EX direction.

[0027] Part (c) of Fig. 5 is a cross-sectional view taken along line KK of part (b) of Fig. 5. The conductive wire 203K extends from inside the dielectric 202 toward the side of the dielectric 202 that is in contact with the small electrode 201K, and is electrically connected to the small electrode 201K. The conductive wires 203L and 203M each extend in the EX direction inside the dielectric 202, and pass through the small electrode 201K.

[0028] Part (d) of Fig. 5 is a cross-sectional view taken along line LL in part (b) of Fig. 5. The conductive wire 203L extends from inside the dielectric 202 toward the side of the dielectric 202 that is in contact with the small electrode 201L, and is electrically connected to the small electrode 201L. The conductive wires 203M each extend in the EX direction inside the dielectric 202, and pass through the small electrode 201L.

[0029] Part (e) of Fig. 5 is a cross-sectional view taken along line MM in part (b) of Fig. 5. The conductive wire 203M extends from inside the dielectric 202 toward the side surface of the dielectric 202 with which the small electrode 201M is in contact, and is electrically connected to the small electrode 201M.

[0030] FIG. 6 is a diagram showing an example of the structure of the conductive wire 203. As shown in part (a) of FIG. 6, the conductive wire 203 has a core wire 2031, a dielectric 2032, an external conductor 2033, and a protective dielectric 2034. The core wire 2031 is electrically connected to the small electrode 201. The dielectric 2032 and the protective dielectric 2034 are made of, for example, heat-resistant ceramics. The external conductor 2033 prevents leakage of signals from the inside and blocks noise from the outside. Part (b) of FIG. 6 is a cross-sectional view taken along the line NN in part (a) of FIG. 6. As shown in part (b) of FIG. 6, the conductive wire 203 has a coaxial structure in which the core wire 2031 is at the center and the dielectric 2032, the external conductor 2033, and the protective dielectric 2034 cover the periphery in this order. The conductive wires 203 are not electrically connected to each other.

[0031] Returning to FIG. 1 , the electrode rod 20 is disposed in the first phase 11, which is a high-temperature liquid phase. The electrode rod 20 is inserted into the high-temperature furnace 10, for example, along the stretching direction, and disposed so as to be immersed in the first phase 11. In one example, the electrode rod 20 is disposed so that all the small electrodes 201 are immersed in the first phase 11. A current or voltage is applied from a power source 22 to the electrode rod 20 while it is immersed in the first phase 11 in the high-temperature furnace 10. When a current is applied to the electrode rod 20, the electrode rod 20 outputs a voltage value at the small electrodes 201 to the control unit 24, and when a voltage is applied, the electrode rod 20 outputs a current value flowing through the small electrodes 201 to the control unit 24.

[0032] The electrode rods 20 are configured to include a plurality of electrode rods 20. The number of electrode rods 20 is an even number, for example, 4, 6, 8, 12, 16, 32, or 64. The plurality of electrode rods 20 may be arranged at equal intervals or at equal circumferential intervals in the high-temperature furnace 10. An example in which the plurality of electrode rods 20 are arranged at equal circumferential intervals will be described below.

[0033] FIG. 7 is a conceptual diagram showing the directivity of the electrode bar 20. The electrode bar 20 may have directivity as a sensor area, or may be non-directional (omnidirectional). When the electrode bar 20 is non-directional, the electrode bar 20 can measure voltage values ​​or current values ​​with the sensor area AR1 being not only the inside but also the outside in the radial direction of the circumference on which they are arranged. When the electrode bar 20 has directivity, the electrode bar 20 can measure voltage values ​​or current values ​​with the sensor area AR2 being a specific position (for example, the inside in the radial direction of the circumference on which they are arranged). The electrode bar 20 having directionality can improve the sensitivity of the sensor to the specific position.

[0034] Returning to FIG. 1 again, the electrode support part 21 is a member that fixes one or more electrode rods 20. The electrode support part 21 is disposed, for example, above the vertical line of the high-temperature furnace 10. The electrode support part 21 holds the base end side of the electrode rod 20 and fixes the electrode rod 20 so that the tip side of the electrode rod 20 faces vertically downward. The electrode support part 21 may be configured by one electrode support part 21 that holds all the electrode rods 20, or may be configured by multiple electrode support parts 21 that hold the electrode rods 20 individually. An example in which the electrode support part 21 holds all the electrode rods 20 will be described below.

[0035] The power source 22 is a power supply circuit capable of supplying a preset voltage or current. The power source 22 is connected to the electrode rods 20 via a power relay 23. The power source 22 applies a current or voltage to the multiple electrode rods 20. The power source 22 applies, for example, an AC current to the electrode rods 20. In one example, when the high-temperature furnace 10 has a furnace capacity of 20 to 120 tons, the power source 22 is configured to be capable of supplying a current of 15,000 to 45,000 A or a voltage of 300 to 700 V.

[0036] The power relay 23 is a circuit that switches the target to which a current or voltage is applied in response to a control signal from the control unit 24. The power relay 23 performs load opening and closing (switching) so that a current or voltage is applied only to a selected combination of electrodes 20, for example, among a plurality of electrodes 20. The power relay 23 switches the selected combination of electrodes 20 continuously at high speed.

[0037] The control unit 24 switches the combination of the electrodes 20 to which the current or voltage from the power source 22 is applied, and performs voltage or current measurement for the selected combination of the electrodes 20 to obtain an impedance value. The control unit 24 outputs a control signal indicating the combination of the electrodes 20 to which the current or voltage is applied to the power relay 23 to switch the load target of the current or voltage. The control unit 24 may control, for example, the frequency, amplitude, and application time of the applied current. The control unit 24 may also be configured to switch the selected combination of the small electrodes 201 of the electrodes 20. The small electrodes 201 can perform more precise voltage or current measurement by combining their respective sensor areas.

[0038] The control unit 24 performs voltage measurement or current measurement to obtain impedance values ​​based on the voltage values ​​or current values ​​output by the multiple electrodes 20. The control unit 24 measures impedance values ​​between the multiple electrodes 20 from, for example, the applied current and the measured voltage, and outputs the measured impedance values ​​to the calculation unit 25.

[0039] The calculation unit 25 calculates an electrical property distribution indicating one of a conductivity distribution, a dielectric constant distribution, and a phase distribution before and after the appearance of the second phase 12 in the first phase 11 based on the impedance value, and outputs an image reconstructed from the electrical property distribution.

[0040] The calculation unit 25 reconstructs an image using electrical impedance tomography based on the impedance value output by the control unit 24. As an image reconstruction algorithm using the electrical impedance tomography method, a method for solving a forward problem and an inverse problem can be used, similar to the conventional image reconstruction under a room temperature environment.

[0041] The forward problem is to calculate the voltage vector V in advance when the applied current I and the conductivity distribution σ are known. The forward problem calculates the governing equation as shown in the following equation (1).

[0042]

number

[0043] where σ is the conductivity, V is the voltage, and σ n is the conductivity of the nth mesh, Φ n is the electric potential of the n-th mesh, and Ω is the sensor area. The boundary condition is as shown in the following equation (2).

[0044]

number

[0045] L is the electrode number, S is the electrode area, n is the outward normal unit vector on the boundary, z l is the contact resistance (impedance) of the lth electrode, e l is the lth electrode, U l is the potential of electrode l. To solve equation (1), the finite element method (FEM) is used in the simulation.

[0046] Fluctuation of conductivity distribution vector in mesh number N, Δσ∈R N (R is a vector) and the associated change ΔV in the measured voltage vector are assumed to be linear approximations, the simultaneous linear equations shown in the following equation (3) are expressed.

[0047]

number

[0048] For convenience of notation, the following equation (3) is simplified to the following equation (4).

[0049]

number

[0050] where J∈R M×N (R is a vector) is the Jacobian matrix shown in the following equation (5).

[0051]

number

[0052] J means the sensitivity of voltage due to the change in conductivity of one mesh. Since J varies depending on the current application pattern, voltage measurement pattern, sensor shape, and number of electrodes, it is calculated by numerical analysis such as the finite element method. J, which is the element of J, mn is calculated using the following equation (6).

[0053]

number

[0054] Here, A n indicates the area of ​​the nth mesh. V m (e, d) indicates the measured voltage V in the measurement pattern m. e indicates the current application electrode pair in the measurement pattern m, and d indicates the voltage measurement electrode pair in the measurement pattern m. Φ(i e ) denotes the potential between the voltage measurement electrode pair d induced by the application of current to the current application electrode pair e. d ) is the potential between the current application electrode pair e induced by applying a current to the voltage measurement electrode pair d.

[0055] The inverse problem is to find the conductivity distribution σ from the measured voltage vector V. Equation (3) is an ill-posed inverse problem with more solutions than equations, and a unique solution cannot be obtained, so an approximate solution σ^ is calculated by iterative calculation using the following equation (7).

[0056]

number

[0057] Here, λ|σ| 2 is a regularization term.

[0058] 8 is a diagram showing an example of the movement mechanism 26. The visualization device 1 may further include a movement mechanism 26 that moves the plurality of electrode rods 20 three-dimensionally. The movement mechanism 26 is configured by, for example, an actuator or the like. The movement mechanism 26 moves the plurality of electrode rods 20 via the electrode support part 21. The movement mechanism 26 may autonomously control the movement of the plurality of electrode rods 20, or may control the movement of the plurality of electrode rods 20 in response to a control signal from the control part 24 or the like.

[0059] The movement mechanism 26 is configured to move the multiple electrodes 20 in the X-direction, the Y-direction, and the Z-direction. The movement mechanism 26 adjusts the positions of the multiple electrodes 20 in the first phase 11 three-dimensionally by moving the multiple electrodes 20 in at least one of the X-direction, the Y-direction, and the Z-direction. By such adjustment, the movement mechanism 26 can change the position of the electrode 20 according to a predetermined measurement condition, such as whether the sensor region of the electrode 20 is a shallow region or a deep region in the first phase 11, or whether the sensor region is a region biased in the X-direction or the Y-direction or a uniform region.

[0060] The movement mechanism 26 may be further configured to change the distance between the electrodes 20. The movement mechanism 26 may adjust the positions of the electrodes 20 in the first phase 11, for example, by moving the electrodes 20 in the radial direction of a circle on which the electrodes 20 are arranged. In this case, the diameter of the circle on which the electrodes 20 are arranged increases or decreases. By such adjustment, the movement mechanism 26 can change the positions of the electrodes 20 in accordance with a predetermined measurement condition, for example, whether the sensor area of ​​the electrodes 20 is a local area or a global area.

[0061] The movement mechanism 26 may be further configured to rotate the plurality of electrodes 20 in a horizontal direction that is a direction parallel to the liquid surface of the first phase 11. The direction parallel to the liquid surface refers to a direction parallel to the X direction and the Y direction. The movement mechanism 26 rotates the plurality of electrodes 20 at a constant angular velocity, for example, with the center of a circle on which the plurality of electrodes 20 are arranged as the rotation axis. The plurality of electrodes 20 are applied with a current or voltage during rotation, and output a voltage value or a current value. By rotating the plurality of electrodes 20, the number of measurement positions of each electrode 20 increases, so that the number of electrodes 20 can be reduced. Even with a configuration in which the number of electrodes 20 is reduced in this way, the visualization device 1 can output a high-resolution image.

[0062] [Hardware configuration] Each function of the visualization device 1 may be realized by a single device that is physically or logically combined, or by two or more devices that are physically or logically separated and connected directly or indirectly to each other.

[0063] 9 is a diagram showing an example of a hardware configuration of the control unit 24 and the calculation unit 25. The control unit 24 and the calculation unit 25 may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0064] Each function in the control unit 24 and the calculation unit 25 is realized by loading a specific software (program) onto hardware such as a processor 1001 and a memory 1002, so that the processor 1001 performs calculations and controls communication via a communication device 1004 and the reading or writing of data in the memory 1002 and the storage 1003.

[0065] The processor 1001, for example, operates an operating device to control the entire computer. The processor 1001 may be configured with a central processing unit (CPU). For example, various processes of the control unit 24 and the calculation unit 25 may be realized by the processor 1001. The processor 1001 also reads out a program (program code), a software module, and data from the storage 1003 or the communication device 1004 to the memory 1002, and executes various processes according to the programs. The functions of executing various processes of the control unit 24 and the calculation unit 25 may be realized by a control program stored in the memory 1002 and operated by the processor 1001, and may be similarly realized for other functional blocks. Note that the various processes in the control unit 24 and the calculation unit 25 may be executed by one processor 1001, or may be executed by two or more processors 1001 simultaneously or sequentially.

[0066] The memory 1002 is a computer-readable recording medium and may be composed of at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), and the like.

[0067] The storage 1003 is a computer-readable recording medium. The storage 1003 may be composed of at least one of a hard disk drive, a flexible disk, a magneto-optical disk, an optical disk such as a CD-ROM (Compact Disc ROM), etc. The above-mentioned storage medium may be, for example, a database including the memory 1002 or the storage 1003, a server, or other appropriate medium.

[0068] The communication device 1004 is a device for performing communication between computers, or between a computer and devices such as the power relay 23 and the moving mechanism unit 26, via a wired or wireless network. For example, some of the various processes of the control unit 24 and the calculation unit 25 may be realized by the communication device 1004.

[0069] The input device 1005 is an input device (such as a keyboard) that accepts input from the outside. The output device 1006 is an output device (such as a display) that outputs to the outside.

[0070] The above devices are connected to a bus 1007 for communicating information. The bus 1007 may be configured as a single bus, or may be configured with different buses between the devices.

[0071] [Visualization method for the inside of a high-temperature furnace] 10 is a flowchart showing an example of a visualization method for the inside of the high-temperature furnace 10. The visualization method includes procedures (steps S1 to S2) before the appearance of the second phase 12 and procedures (steps S3 to S5) after the appearance of the second phase 12. The visualization method is performed by a visualization device 1.

[0072] In step S1, the visualization device 1 calculates a Jacobian matrix. For example, the visualization device 1 calculates the above-mentioned equation (6).

[0073] In step S2, the visualization device 1 calculates a reference voltage vector V0∈R in the conductivity distribution σ0 of the first phase 11 before the appearance of the second phase 12. M (R is a vector, and M is the number of measurement patterns) is measured between the small electrodes 201 of each electrode rod 20.

[0074] In step S3, the visualization device 1 calculates a voltage vector V∈R in the conductivity distribution σ of the first phase 11 after the appearance of the second phase 12. M is measured between the small electrodes 201 of each electrode rod 20.

[0075] In step S4, the visualization device 1 obtains the difference Δσ between the reference conductivity distribution σ0 and the conductivity distribution σ from the voltage vector difference ΔV=V-V0 before and after the appearance of the second phase 12. Here, V is the voltage vector measured in step S3, and V0 is the reference voltage vector measured in step S2. Types of measurement patterns include, for example, the adjacent method and the forward adjacent method, but are not limited to these.

[0076] In step S5, the visualization device 1 sequentially calculates the image reconstruction algorithm using the above-mentioned equation (7) based on the Jacobian matrix calculated in advance in step S1, and outputs an image reconstructed from the electrical property distribution for each mesh.

[0077] The visualization method executed in the visualization device 1 described above is an example, and can be modified as appropriate. For example, some of the steps (processing) described above may be omitted, or each step may be executed in a different order. Any two or more of the steps described above may be combined, or some of the steps may be modified or deleted. Alternatively, other steps may be executed in addition to the steps described above.

[0078] The above-mentioned formulas (1) to (7) are a method for visualizing the conductivity distribution σ, but by performing similar processing using reactance or phase difference (the time difference between current and voltage) instead of voltage, it is also possible to visualize the permittivity distribution or phase distribution.

[0079] FIG. 11 is a conceptual diagram showing an example of a reconstructed image. The reconstructed image in FIG. 11 shows the change over time in the electrical property distribution of the first phase 11 and the second phase 12. FIG. 11 shows that the volume fraction φ of the second phase 12 increases with the passage of time (0 minutes, 30 minutes, and 60 minutes). The visualization device 1 can image the electrical conductivity distribution σ, the dielectric constant distribution ε, or the phase distribution θ for each applied frequency f. Such a reconstructed image can express what state the second phase 12 is in, when (time), where (3D space), and how much (hue, shading, etc.) it appears. In the reconstructed image, the value of the electrical property distribution may be expressed, for example, by hue, shading, etc.

[0080] According to the visualization method described above, the visualization device 1 can visualize the time change of the phases in the high-temperature furnace 10 by imaging and outputting the electrical property distribution in the high-temperature furnace using an electrical impedance tomography method. Specifically, the visualization device 1 can assist in measuring the spatial distribution of the volume fraction φ of the second phase 12 before and after the appearance of the second phase 12, by imaging the electrical property distribution (electrical conductivity distribution σ, dielectric constant distribution ε, or phase distribution θ) before and after the appearance of the second phase 12, which is different from the first phase 11 present in the high-temperature furnace 10.

[0081] The electrical property distribution (electrical conductivity distribution σ, dielectric constant distribution ε, or phase distribution θ) depends not only on the volume fraction φ of the second phase 12 but also on the composition of the second phase 12, the temperature T, and the applied frequency f. That is, the electrical property distribution indicates at least one of the volume fraction, composition, temperature, or frequency of the second phase 12. In the present embodiment, imaging of the volume fraction of the second phase 12 as the electrical property distribution will be described, but the electrical property distribution may indicate at least one of the composition, temperature, or frequency. The visualization device 1 may correct the electrical property distribution in response to these dependencies.

[0082] FIG. 12 is a diagram showing the dependence of the electrical conductivity of slag on the composition and temperature. The table in FIG. 12 shows the relationship between the electrical conductivity σ, composition, and temperature of CaO-SiO2-Al2O3 slag at a constant applied frequency f. When the temperature T is constant, the influence of the composition change of the high-temperature melt on the electrical conductivity σ is at most about four times (for example, at 1550°C, σ = 0.671 to 0.175). On the other hand, it is known that the σ of oxide crystals in slag decreases more rapidly than the σ of the high-temperature melt in the process of their appearance. In one example, the electrical conductivity σ of CaO-SiO2-TiO2 slag decreases several hundred times more than the electrical conductivity σ of the high-temperature melt in the process of their appearance. Therefore, even if the electrical property distribution of the high-temperature melt has a dependency on the composition, the influence is small, and the oxide crystal volume fraction φ can be linearly detected from the electrical conductivity σ. On the other hand, when the composition of the high-temperature melt and the applied frequency f are constant in Fig. 12, the effect of the crystallization of oxide crystals on the electrical conductivity σ is overwhelmingly greater than the effect of the temperature T on the electrical property distribution, so even if the electrical property distribution of the high-temperature melt has a dependency on the temperature T, it is possible to linearly detect the oxide crystal volume fraction φ from the electrical conductivity σ. Furthermore, correction may be performed by utilizing the fact that the Arrhenius equation shown in the following equation (8) holds between the temperature and electrical characteristic of the high-temperature melt. When performing temperature correction, the Arrhenius equation that holds between the temperature and electrical characteristic of the high-temperature melt can be used.

[0083]

number

[0084] Here, Q is the activation energy specific to the object, which is 10 to 50 kcal / g·mol for high-temperature oxide melts such as slag. R is the gas constant, and B is a constant independent of temperature. The exact Q and B in this equation can be determined recursively through experiments. The temperature dependence of the electrical characteristics can be corrected by converting the reference voltage value V0 to a corrected reference voltage V0~ equivalent to the reference voltage value V0 measured at the same temperature as the voltage value V measured in the crystallized state using the Arrhenius equation.

[0085] Fig. 13 is a diagram showing the capacitance change due to crystallization. Specifically, Fig. 13 shows capacitance measurements during the process of cooling a high-temperature melt (50CaO-50SiO2) from T = 1600°C to T = 1250°C. The measurements were performed at a constant current I = 10mA and a frequency f = 10kHz. As shown in Fig. 13, no composition change occurs in the high-temperature melt between T = 1600 and 1360°C, and the capacitance change due to temperature is about several nF. On the other hand, at T = 1350°C, a rapid decrease in capacitance (about 100nF) is observed due to the crystallization of oxide crystals in the high-temperature melt.

[0086] High-temperature oxide melts generated in high-temperature metallurgical processes are composed of polymerized silicate ions, metal ions, and oxygen ions, and are therefore liquids with a high polarizability in which orientation polarization and interface polarization of these ions occur. On the other hand, crystallized oxide crystals generally have low polarizability because the ions are fixed in the crystal lattice. In other words, the effect of temperature change on the dielectric constant ε is considered to be no problem for the detection of oxide crystals in high-temperature melts.

[0087] Examples will be specifically described below, but the present disclosure is not limited to them in any way.

[0088] [Example 1] FIG. 14 is a schematic diagram showing a visualization device 1 in Example 1. In Example 1, an example of outputting a two-dimensional reconstructed image using a small visualization device 1 applicable to a laboratory is shown. As shown in part (a) of FIG. 14, a high-temperature melt (60ZnO-40B2O3 (mol%), temperature T=1200°C) as the first phase 11 is present in a cylindrical high-temperature furnace 10 with a bottom. The electrode rod 20 is made of platinum (Pt-20mass%Rh) and is protected by a ceramic coating to remove noise from the outside. The electrode rod 20 has a small electrode 201 at the tip. Eight electrode rods 20 are arranged at equal circumferential intervals so that the small electrodes 201 are immersed in the first phase 11. Cylindrical Al2O3 is arranged as the second phase 12 in the high-temperature furnace 10. The second phase 12 is also arranged so as to be exposed from the liquid surface of the first phase 11. This second phase 12 is a simulation of a crystallized oxide crystal. Part (b) of FIG. 14 is a cross-sectional view taken along the line NN of part (a) of FIG.

[0089] The control unit 24 is configured by a combination of, for example, a microcontroller unit, an analog multiplexer, etc. The control unit 24 performs voltage measurement while switching the combination of the electrodes 20 to which a current (f=10.485 kHz) is applied. The control unit 24 is also connected by wireless communication to the calculation unit 25 so as to be able to send and receive data. The calculation unit 25 is configured by a PC (personal computer).

[0090] FIG. 15 is a diagram showing a reconstructed image in Example 1. FIG. 15 is a reconstructed image showing the electrical conductivity distribution by hatching for a two-dimensional cross section in the X direction and Y direction in the high-temperature furnace 10. Since the electrical conductivity of the second phase 12 (Al2O3) is lower than that of the first phase 11 (60ZnO-40B2O3 (mol%), temperature T=1200°C), the difference appears in the reconstructed image. In FIG. 15, the hatched area corresponding to a conductivity value of about -0.2 indicates the electrical conductivity distribution of the second phase 12. The position and size of the hatched area in the reconstructed image correspond to the position and size of the second phase 12 in the high-temperature furnace 10. In this way, the visualization device 1 can visualize the location of the second phase 12 in the high-temperature furnace 10 and the size of the second phase 12 (spatial distribution of the volume fraction φ).

[0091] [Example 2] In Example 2, an example of evaluating the accuracy of the number and size of the second phase 12 is shown. An Al2O3 crucible is placed inside the high-temperature furnace 10, and a cylindrical test furnace with a bottom is further placed inside the crucible. A high-temperature melt (60ZnO-40B2O3 (mol%), temperature T = 1200 °C) which is the first phase 11 is present inside the high-temperature furnace 10. The electrode rod 20 is made of platinum (Pt-20mass%Rh) and has a cylindrical shape with a diameter of 2 mm. The electrode rod 20 has a small electrode 201 at the tip. Eight electrode rods 20 are arranged at equal circumferential intervals with an inner diameter of 24 mm so that the small electrode 201 is immersed in the first phase 11. Cylindrical Al2O3 is arranged as the second phase 12 inside the high-temperature furnace 10. The second phase 12 is arranged so as to be exposed from the liquid surface of the first phase 11. This second phase 12 simulates a precipitated oxide crystal.

[0092] The control unit 24 is configured by a combination of, for example, a microcontroller unit, an analog multiplexer, an impedance analyzer, etc. The control unit 24 performs voltage measurement while switching the combination of the electrodes 20 to which the current is applied. The control unit 24 is also connected to the calculation unit 25 so as to be able to transmit and receive data thereto. The calculation unit 25 is configured by a PC.

[0093] Parts (a) to (d) of Fig. 16 are diagrams showing the arrangement patterns of the second phases 12 in Example 2. In Example 2, the second phases 12 were arranged in the high-temperature furnace 10 using four arrangement patterns with different sizes and numbers. Specifically, the cylindrical second phases 12 were arranged using four patterns, namely, one piece with a diameter of 3 mm shown in part (a) of Fig. 16, two pieces with a diameter of 3 mm shown in part (b) of Fig. 16, one piece with a diameter of 8 mm shown in part (c) of Fig. 16, and one piece with a diameter of 3 mm and one piece with a diameter of 8 mm shown in part (d) of Fig. 16. In Example 2, the voltage in the high-temperature furnace 10 was measured for each of the four patterns, and image reconstruction was performed.

[0094] Parts (a) to (d) of FIG. 17 are diagrams showing reconstructed images in Example 2. FIG. 17 is a binarized two-dimensional reconstructed image of the electrical conductivity distribution in Example 2. Parts (a) to (d) of FIG. 17 correspond to the four arrangement patterns of parts (a) to (d) of FIG. 16, respectively. As shown in parts (a) to (d) of FIG. 17, the position and size of the second phase 12 can be visualized in any arrangement pattern. However, when one piece with a diameter of 3 mm and one piece with a diameter of 8 mm are arranged as in part (d) of FIG. 17, the sensitivity in the interval between the second phases 12 is low. In order to evaluate the accuracy of image reconstruction, the area relative error E is defined as the following formula (9).

[0095]

number

[0096] Here, A true is the true value of the area, A cal is the area calculated based on the number of pixels with a pixel value of 0 (black) in the reconstructed image.

[0097] 18 is a graph showing the accuracy of image reconstruction in Example 2. In FIG. 18, the horizontal axis shows four arrangement patterns of Al2O3, which is the second phase 12, and the bar graph shows A true , and A calThe area of ​​each pattern is shown in the figure, and the line graph shows the area relative error E. For the four patterns, namely, 1 piece with a diameter of 3 mm shown in part (a) of Fig. 16, 2 pieces with a diameter of 3 mm shown in part (b) of Fig. 16, 1 piece with a diameter of 8 mm shown in part (c) of Fig. 16, and 1 piece with a diameter of 3 mm and 1 piece with a diameter of 8 mm shown in part (d) of Fig. 16, the results were E = 9.48, E = 27.44, E = 7.02, E = 3.09 [%], and the average (E) = 11.76 [%]. The area relative error E for each arrangement pattern is within the allowable range.

[0098] [Example 3] In Example 3, an example is shown in which the structure of the electrode rod 20 is assumed and the three-dimensional conductivity distribution in the high-temperature furnace 10 is reconstructed by electromagnetic simulation. Fig. 19 is a schematic diagram showing a virtual high-temperature furnace 10 in Example 3. Part (a) of Fig. 19 is a structural diagram of the virtual high-temperature furnace 10, and part (b) of Fig. 19 is a mesh division diagram thereof.

[0099] In Example 3, six electrode rods 20 (radius 1 cm, height 18 cm) are arranged at equal circumferential intervals so as to be perpendicular to the end face of the cylinder in the high-temperature furnace 10, which is a cylindrical container (radius 10 cm, height 20 cm) filled with a highly conductive material. Three small electrodes 201 (radius 1 cm, height 2 cm) are arranged in the extension direction on each electrode rod 20, and a dielectric 202 (radius 1 cm, height 4 cm) is arranged between each small electrode 201. In addition, a low-conductivity sphere (radius 1 cm) that assumes an oxide crystal as the second phase 12 is arranged in the center of the high-temperature furnace 10. In Example 3, measurements are performed at multiple points using each small electrode 201 while switching between a current application pattern and a voltage measurement pattern. The electrode rods 20 are switched using the adjacent method.

[0100] Fig. 20 is a diagram showing a reconstructed image in Example 3. As shown in Fig. 20, a part with low conductivity appears in the center of the cylinder in the three-dimensional image. In this way, even when a three-dimensional image is reconstructed from the conductivity distribution, the three-dimensional existence position and its volume amount appear in the reconstructed image.

[0101] [Effects] Next, the effects of the visualization device 1 according to this embodiment will be described.

[0102] The visualization device 1 of this embodiment includes a plurality of electrode rods 20 arranged in a first phase 11, which is a high-temperature liquid phase; a power source 22 that applies a current or voltage to the plurality of electrode rods 20; a control unit 24 that switches between combinations of the plurality of electrode rods 20 to which a current or voltage is applied from the power source 22, performs voltage measurement or current measurement for the selected combination of the plurality of electrode rods 20, and acquires an impedance value; and a calculation unit 25 that calculates an electrical property distribution indicating one of a conductivity distribution, a dielectric constant distribution, or a phase distribution before and after the appearance of a second phase 12 in the first phase 11 based on the impedance value, and outputs an image reconstructed from the electrical property distribution.

[0103] In the visualization device 1 according to the present embodiment, a current or voltage is applied to a plurality of electrode rods 20 arranged in a high-temperature first phase 11 while switching the selected combination, thereby performing voltage measurement or current measurement and acquiring an impedance value. In addition, based on the impedance value, an electrical property distribution (one of the distributions of conductivity, dielectric constant, or phase) before and after the appearance of a second phase 12 in the first phase 11 is calculated, and an image reconstructed from the electrical property distribution is output. According to this configuration, by imaging the electrical property distribution before and after the appearance of a second phase 12 different from the first phase 11 present in the high-temperature furnace 10, the temporal change in the spatial distribution of the second phase 12 before and after the appearance of the second phase 12 appears in the image. With such an image, the temporal change in the phase in the high-temperature furnace 10 can be visualized.

[0104] In the visualization device 1 according to this embodiment, the second phase may be a solid phase, a liquid phase, or a gas phase. In general, it is very difficult to measure the time change in the spatial distribution of the second phase in a liquid or gas state. On the other hand, in the visualization device 1 according to this embodiment, the time change in the spatial distribution of the second phase before and after the appearance of the second phase appears in an image, so that the time change in the phase in the high-temperature furnace can be visualized regardless of the state of the second phase.

[0105] In the visualization device 1 according to this embodiment, the multiple electrode rods 20 may have multiple small electrodes 201 in the extension direction. With this configuration, more precise measurements can be performed three-dimensionally by combining the sensor areas of the multiple small electrodes 201.

[0106] The visualization device 1 according to this embodiment may further include a movement mechanism 26 that moves the multiple electrode rods 20 three-dimensionally. With this configuration, the positions of the electrode rods 20 can be changed according to predetermined measurement conditions, such as whether the sensor region of the electrode rods 20 is a shallow region or a deep region in the first phase 11, or whether the sensor region is a region biased in the X direction or Y direction or a uniform region. This can improve the measurement accuracy of the phases in the high-temperature furnace 10.

[0107] In the visualization device 1 according to this embodiment, the movement mechanism 26 may be further configured to change the distance between the multiple electrode rods 20. With such a configuration, the positions of the electrode rods 20 can be changed according to a predetermined measurement condition, such as whether the sensor area is a local area or a global area. This can improve the measurement accuracy of the phases in the high-temperature furnace 10.

[0108] In the visualization device 1 according to this embodiment, the movement mechanism 26 may be further configured to rotate the plurality of electrodes 20 in a horizontal direction that is a direction parallel to the liquid surface of the first phase 11. With such a configuration, the number of electrodes 20 can be reduced because the number of measurement positions of each electrode 20 is increased. Even with such a configuration with a small number of electrodes 20, the visualization device 1 can output a high-resolution image.

[0109] In the visualization device 1 according to the present embodiment, the electrical property distribution may indicate at least one of the volume fraction, composition, temperature, and frequency of the second phase. Even with such a configuration, the electrical property distribution of the second phase before and after the appearance of the second phase appears in an image reconstructed from the electrical property distribution.

[0110] [Variations] The present disclosure is not limited to the above-described embodiment. The present disclosure can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0111] In the embodiment, an example has been described in which a current is applied to a plurality of electrodes 20 to perform voltage measurement, but a voltage may be applied to a plurality of electrodes 20 to perform current measurement. Even in this case, the visualization device 1 can obtain an impedance value and perform subsequent processing.

[0112] In the embodiment, an example in which a conductivity distribution is calculated for an electrical property distribution has been described, but a permittivity distribution or a phase distribution may be calculated. Even in this case, the visualization device 1 can output an image reconstructed from the permittivity distribution or the phase distribution.

[0113] In the embodiment, the multiple electrode rods 20 are described as being arranged so as to be immersed in the first phase 11 in the high-temperature furnace 10, but they may be arranged so as to abut against the side surface (outer circumferential surface) of the high-temperature furnace 10. The multiple electrode rods 20 may be arranged, for example, perpendicular to the side surface of the high-temperature furnace 10 and at equal intervals from one another.

[0114] Each functional module of the visualization device 1 is realized by loading a visualization program for the inside of a high-temperature furnace onto the processor 1001 or memory 1002 and having the processor 1001 execute the program. The visualization program includes code for realizing each functional module of the visualization device 1. The processor 1001 operates the input / output port 38 in accordance with the visualization program, and executes reading and writing of data in the memory 1002 or storage 1003. Each functional module of the visualization device 1 is realized by such processing.

[0115] The visualization program may be provided in a state where it is fixedly recorded on a non-transitory recording medium such as a CD-ROM, a DVD-ROM, a semiconductor memory, etc. Alternatively, the visualization program may be provided via a communication network as a data signal superimposed on a carrier wave. [Explanation of symbols]

[0116] 1...visualization device, 10...high-temperature furnace, 11...first phase, 12...second phase, 20...electrode rod, 21...electrode support part, 22...power source, 23...power relay, 24...control part, 25...calculation part, 26...movement mechanism part, 201...small electrode, 202...dielectric, 203...conductive wire.

Claims

1. A plurality of electrodes disposed in a first phase which is a high-temperature liquid phase; A power source that applies a current or a voltage to the plurality of electrode rods; a control unit that switches a combination of the plurality of electrodes to which a current or voltage from the power source is applied, and performs voltage measurement or current measurement for the selected combination of the plurality of electrodes to obtain an impedance value; a calculation unit that calculates an electrical property distribution indicating one of a conductivity distribution, a dielectric constant distribution, and a phase distribution before and after the appearance of a second phase in the first phase based on the impedance value, and outputs an image reconstructed from the electrical property distribution; A visualization device comprising:

2. The visualization device of claim 1 , wherein the second phase is a solid phase, a liquid phase, or a gas phase.

3. The visualization device according to claim 1 or 2, wherein the plurality of electrode bars have a plurality of small electrodes in an extending direction.

4. The visualization device according to any one of claims 1 to 3, further comprising a movement mechanism that moves the plurality of electrode rods three-dimensionally.

5. The visualization device according to claim 4 , wherein the movement mechanism is further configured to change the spacing between the plurality of electrode rods.

6. The visualization device according to claim 4 , wherein the movement mechanism is further configured to rotate the plurality of electrode rods in a horizontal direction that is a direction parallel to a liquid surface of the first phase.

7. The visualization device according to any one of claims 1 to 5, wherein the electrical property distribution indicates at least one of a volume fraction, a composition, a temperature, or a frequency of the second phase.

Images