JP3395886B2 - Refractory residual thickness measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the remaining thickness of refractory materials such as refractory bricks and metallic water-cooled cooling panels installed in a furnace for protecting the furnace shell of a blast furnace or the like, The present invention relates to a device for continuously measuring the remaining thickness of a CS panel for reducing a heat load, which is arranged on a refractory brick of a shaft portion of a blast furnace or an inner surface of a steel skin at an upper portion of a tuyere at a lower portion of the blast furnace.

[0002]

2. Description of the Related Art In a blast furnace, refractory bricks are installed on the inner surface of a steel shell serving as an outer wall to protect the furnace from high temperatures. In addition, at the part where the heat load is particularly high just above the tuyere of the lower part of the blast furnace, a cooling panel made of cast iron called CS (Cooling Stable) panel is installed between the iron shell and the refractory bricks to reduce the heat load. There is. Since long-term continuous operation is performed in the blast furnace, the refractory bricks on the inner surface are gradually worn due to heat load and mechanical load such as friction with the raw material in the furnace. In addition, the wear of the refractory bricks on the inner surface progresses at the CS panel mounting portion. When the refractory bricks disappear, a load is directly applied to the CS panel, and the wear of the CS panel itself occurs. Damage occurs and it becomes difficult to function as a cooling panel. The wear of these refractory materials such as refractory bricks and CS panels adversely affects the heat load on the iron shell of the blast furnace and the operation itself. Therefore, it is very important to understand the wear condition of refractory materials in the blast furnace.

As a method for monitoring the wear state of a refractory, the temperature of each part of the refractory in the blast furnace is measured and monitored by a thermocouple installed in the refractory or on the surface of the refractory, and the refractory is detected by the temperature and its change. There is a method to estimate the wear situation. As a method for measuring the residual thickness of refractory materials, boring of refractory materials is performed from the outer surface of the iron shell when the blast furnace is in a blast state, a through hole is opened to the inside of the blast furnace, and the residual thickness of the panel is directly measured. All of these are known methods.

Regarding the method of measuring the damage to the refractory of the CS panel, the inventors have made an ultrasonic probe contact the outer surface of the panel on the iron skin side to inject an ultrasonic wave, and reflect the signal reflected from the inner surface. The inventors invented a method for detecting the residual thickness of the panel from the signal propagation time and applied for a patent as Japanese Patent Application No. 9-198112 (hereinafter referred to as "prior invention").

The outline of the prior invention will be described with reference to FIG. C
A plurality of bolts 34, one end of which is fixed to this panel, are embedded in the S panel 31. A through hole 35 is provided at a corresponding portion of the blast furnace iron shell 32, and the bolt 34 projects to the outside of the iron shell through the through hole 35. By attaching a washer and nut to the protruding bolt 34, CS
The panel 31 is fixed to the iron skin 32 via the stamp material 33.

In the invention of the prior application, this CS panel 31
The thickness of the CS panel 31 is measured by using the steel skin through hole 35 of the bolt 34 used for mounting.
That is, the ultrasonic probe 36 is inserted into the gap between the bolt 34 and the steel through-hole 35, and the ultrasonic probe 36 is brought into direct contact with the exposed surface 38 of the CS panel 31. Ultrasonic probe 36
Is connected to the flaw detector 37 by a connection cable 39, generates an ultrasonic wave by an electric signal from the flaw detector 37, and sends the ultrasonic signal into the CS panel 31.

The ultrasonic signal propagates in the CS panel 31 and is reflected on the furnace inner surface side of the CS panel 31. The reflected signal is detected by the ultrasonic probe 36, converted into an electric signal, and sent to the flaw detector 37. The flaw detector 37 measures the time elapsed from the transmission of ultrasonic waves to the detection of reflected ultrasonic waves,
From this, the thickness of the CS panel 31 is measured.

[0008]

However, these conventional techniques have the following problems. In estimating the wear state of a refractory by monitoring the temperature with a thermocouple inserted in the refractory, the temperature of the refractory is not limited to the wear state of the refractory,
There is a problem that it is difficult to know the exact remaining thickness of the refractory because it fluctuates depending on the fluctuation of the heat load accompanying the operating state of the blast furnace.

Since the method of boring from the outer surface of the iron skin is a destructive test and can be carried out only when the blast furnace is in a blast, there is a problem that continuous measurement cannot be carried out. Further, there is a problem that the refractory material cooling effect is reduced due to the destructive inspection, and the durability thereof is also significantly reduced.

Further, in the method of measuring by contacting the ultrasonic probe with the CS panel, if the contact state between the outer surface of the CS panel and the ultrasonic probe is not kept good, the ultrasonic signal is incident on the inside of the CS panel. However, there is a problem in that the mechanism for continuously maintaining the contact state at all times during operation becomes complicated. In addition, depending on the material of the CS panel, the ultrasonic signal in the panel may be greatly attenuated and it may be difficult to detect the signal. In addition, the temperature of the outer surface of the CS panel rises during operation, and blow-through of high-temperature furnace gas may occur between the steel skin and the CS panel, which increases the thermal load on the ultrasonic probe. However, there is also a problem that the probe may be destroyed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an apparatus for continuously and stably measuring and monitoring the remaining thickness of a refractory material in a blast furnace or the like.

[0012]

[Means for Solving the Problems] A first means for solving the above problems is (1) embedded in a through hole provided in a thickness direction of a refractory,
A metal tube having one end reaching the refractory inner surface and the other end reaching the refractory outer surface, a conductive rod or cable inserted into the metal tube, and the metal tube and the conductive rod or cable electrically insulated A probe composed of a non-conductive refractory material for (2) inputting a high-frequency signal between the conductive rod or cable and the metal tube from one end on the iron skin side of the probe. Means, and (3) means for separating and detecting a high-frequency signal that propagates along the rod that constitutes the probe and is reflected at the end of the refractory inner surface and returned to the input end, (4) the input high-frequency wave A residual thickness measuring device for a refractory having a means for measuring a time difference between a signal and a separately detected high-frequency signal and calculating a propagation distance of the signal.
Is a sheath thermocouple, and the sheath protection tube is
Using a tube or thermocouple cable as the cable
The remaining thickness measuring device (claim 1).

In the present means, the metal pipe inserted and buried in the through hole provided in the thickness direction of the refractory and the conductive rod or cable inserted in the metal pipe are inserted into the metal pipe. Since they are electrically insulated by the non-conductive refractory material, the probe constituted by them electrically forms a pseudo coaxial cable. Therefore, when a high frequency electric signal is input from one end of the outer surface of the probe on the metal tube to the ground (ground electrode), the conductive rod and the cable as signal lines, the electric signal propagates in the probe and reaches the inner end of the refractory. To reach. The signal reaching the inner surface end is reflected at the end and propagates to the input side (iron skin outer surface side).

When the reflected signal is separated and detected on the outer surface of the iron skin, the time delay from the input of the signal to the detection of the reflected signal is determined by the length of the probe and the propagation speed of the signal in the probe. The probe length can be measured by measuring this time delay.

Since the probe is inserted into the through hole of the refractory, when the inner surface of the refractory wears due to the operation, the inner surface of the probe also wears and the probe length becomes shorter. Therefore, by continuously measuring the probe length, it becomes possible to continuously observe and measure the remaining thickness of the refractory.

[0016]

In this means, a sheath thermocouple is used as a probe embedded in the refractory through hole, and a high frequency signal is input between the sheath protection tube and the thermocouple cable inside. The sheath protection tube and the thermocouple cable form a pseudo coaxial cable. Therefore, the high-frequency signal propagates along the sheath thermocouple, is reflected at the tip, and returns to the input end.Therefore, the length of the sheath thermocouple can be determined by measuring the time delay from the input of the signal to the detection of the reflected signal. It becomes possible to measure. As the inner surface side of the refractory material is abraded, the sheath thermocouple is also worn out sequentially, so that the remaining thickness of the refractory material can be measured by measuring the length of the buried sheath thermocouple.

Since the sheath thermocouple can be easily obtained, this means eliminates the need to manufacture a special probe, and can be an inexpensive device.

The second means for solving the above-mentioned problems is (1) embedded in a through hole provided in the thickness direction of the refractory material so as to be isolated from each other by a non-conductive refractory material, and one end of the refractory material is buried. A probe composed of a pair of electrically conductive rods, the other end of which reaches the outer surface of the refractory on the inner surface, and (2) a high frequency signal is input between the rods forming the probe from one end on the iron skin side of the probe. Means, (3) means for separating and detecting a high-frequency signal propagating in the probe, reflected at the end of the refractory inner surface and returning to the input end, (4) separated and detected from the input high-frequency signal. And a means for calculating the propagation distance of the signal by measuring the time difference from the high frequency signal, and measuring the residual thickness of the refractory.
(Claim 2)

According to the present means, the probe is constituted by a pair of conductive rods which are separated from each other by a nonconductive refractory material. When a high frequency signal is input with one of the conductive rods as the signal line and the other as the ground electrode, the signal propagates along the probe (signal line) and is reflected at the probe tip (panel inner surface edge) and returns to the input terminal. The length of the probe can be measured by measuring the time delay from the input of the signal to the detection of the reflected signal. Therefore, the residual thickness of the refractory can be measured in the same manner as the above-mentioned means.

A third means for solving the above problems is
In the second means , the refractory is a CS panel,
One of the pair of rods is replaced by the CS panel itself ( Claim 3 ).

When the refractory is a CS panel, a metal C
When the S panel itself is used as the ground electrode and the conductive rod inserted in the through hole is used as the signal line, the probe forms a pseudo coaxial cable. Therefore, when a high frequency signal is input, the signal propagates along the probe (signal line). To do. Therefore, the thickness of the CS panel can also be measured by this method.

A fourth means for solving the above-mentioned problems is (1) embedded in a through hole provided in the thickness direction of the refractory,
A probe that is a cable that reaches the refractory inner surface at one end and the refractory outer surface at the other end, and is composed of a cable in which a plurality of conductors are insulated by a heat-resistant insulator, and Means for inputting a high-frequency signal from one end of the cable between a pair of conductors of the cable, and (3) separating the high-frequency signal propagating in the probe and reflected at the inner end of the refractory and returning to the input end. Detecting means, (4) measuring the time difference between the input high-frequency signal and the separately detected high-frequency signal, and measuring the propagation distance of the signal, the residual thickness measurement of the refractory It is a device ( Claim 4 ).

According to the present means, the cable in which the plurality of conductors are insulated by the heat-resistant insulator constitutes the probe. As such a cable, an MI cable can be used, for example. When a high frequency signal is input with one of the cable conductors as the signal line and the other as the ground electrode, the signal propagates along the probe (signal line) and is reflected at the probe tip (panel inner surface end) and returns to the input end. It is possible to measure the length of the probe by measuring the time delay from the input of the signal to the detection of the reflected signal. Therefore, the residual thickness of the refractory can be measured in the same manner as the above-mentioned means.

The fifth means for solving the above-mentioned problems is as follows.
In any one of the first to fourth means, a pseudo random signal is used as the high frequency signal ( claim 5 ).

A pseudo random signal has periodicity,
A signal that can be regarded as an irregular signal in one cycle. If a pseudo-random signal is used as the input signal and only the signal whose pattern matches the input signal is extracted as the detection signal, only the detection signal that has a correlation with the input signal can be selected and extracted, greatly reducing the influence of noise. can do. As a method, for example, a method of taking a cross-correlation between the input signal and the detection signal and calculating the delay time from the position of the peak appearing in the cross-correlation can be considered. When cross-correlating pseudo random signals having the same pattern, a peak appears when the phases match and the cross-correlation value becomes 0 when the phases differ. In advance, the position where the peak of the cross-correlation value between the input signal and the detection signal appears indicates the phase difference between them, and the delay time of the detection signal can be calculated from this.

A sixth means for solving the above-mentioned problems is as follows.
The fifth means is a means for inputting a pseudo-random signal to a probe embedded in a refractory, separating and detecting a reflected signal, and calculating a propagation distance of the signal from the first pseudo-random signal. First pseudo-random signal generating means for generating a signal, and second pseudo-random signal generating means for generating a second pseudo-random signal having the same signal pattern as the first pseudo-random signal but a slightly different frequency. First multiplication means for multiplying the first and second pseudo-random signals, means for inputting the first pseudo-random signal to the probe, propagation through the probe, reflection at the probe tip, and return to the input end. Means for separating and detecting the signal, second multiplying means for multiplying the separated and detected signal by the second pseudo random signal, and first and second integrating means for integrating the results of the first and second multiplying means. A minute unit, a one output each of the first and second integration means and having a means for measuring the time difference between the time at which an extreme value (claim 6).

When the cross-correlation of the same pseudo-random signal is taken, a peak signal appears only for one pulse in which the phases are coincident with each other in one cycle, and the cross-correlation becomes 0 when the phase is shifted by one pulse or more. .

When the cross-correlation of the second pseudo-random signal whose frequency is F + ΔF (F >> ΔF) and whose pattern is the same as that of the first pseudo-random signal whose frequency is F is taken, the point where the phases of both are coincident As a result, a peak signal appears over a pulse width of 2 / ΔF, and the cross-correlation becomes 0 when the phase shifts more than that. The time from when the phases of the two coincide with each other to the coincidence again is T
Then, it becomes TF / ΔF. That is, by using the cross-correlation of the first pseudo random signal and the second pseudo random signal as the detection signal, the time axis is F
It is possible to obtain the same effect as when observing by extending to / ΔF.

Therefore, when a time delay of Δd occurs in the first pseudo random signal, the time at which the peak of the cross correlation with the second pseudo random signal appears is ΔdF / ΔF. Therefore, by observing a cross-correlation of the first pseudo random signal and the second pseudo random signal and measuring the peak occurrence position, the delay time Δd can be measured with a resolution of F / ΔF times. Therefore, the extremely short time Δd can be measured. (For details, refer to JP-A-2-145985 and JP-A-2-98685).

This means is an application of this measuring method, in which the first pseudo-random signal is input to the probe,
The reflected wave is separated and detected. This reflected wave is detected with a time delay corresponding to the length of the probe. The detection signal is multiplied by a second pseudo-random signal having the same signal pattern as the first pseudo-random signal but a slightly different frequency, and integrated to calculate the cross-correlation between the two. Then, as the reference signal, the first pseudo-random signal and the second pseudo-random signal are multiplied and integrated to calculate the cross-correlation between them. And these 2
The delay time of the input signal is calculated by measuring the time difference at which two cross-correlation peaks appear.

As described above, since this delay time is expanded by F / ΔF times, it is possible to measure even an extremely short time difference.

The seventh means for solving the above-mentioned problems is as follows.
The fifth means or the sixth means, wherein the pseudo random signal is an M-sequence signal (claim 7). Since the M-sequence signal can be easily formed by a shift register having a specific feedback loop and a simple logic circuit, it is optimal as a pseudo-random signal used for measurement.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of a method for measuring the residual thickness of a blast furnace refractory according to the first embodiment of the present invention. In FIG. 1, 1 is a refractory brick or CS panel (refractory), 2 is an iron skin, 3 is a stamp material, 4 is a through hole, 5 is a flange, 6 is a metal tube, 7 is a conductive rod, a cable,
8 is a non-conductive refractory material, 9 is a coaxial cable, and 10 is a connector.

In this embodiment, a through hole 4 having a diameter of 10 mm is provided in the thickness direction of the refractory 1 and a probe composed of a metal tube 6, a conductive rod 7 and a non-conductive refractory 8 is provided in the through hole 4. Inserting. An SUS pipe having an inner and outer diameter of φ6 / 8 mm is used for the metal pipe 6 which constitutes the probe, and a rod 7 made of SUS having an outer diameter of 1 mm is inserted in the center position of the metal pipe to form a gap between the metal pipe 6 and the rod 7. Non-conductive refractory 8 (MgO)
Is inserted to electrically insulate the metal tube 6 from the rod 7 and mechanically hold the rod 7.

Each dimension shows one example, and various combinations are possible. However, since the line impedance when the probe is viewed as a coaxial cable changes depending on the combination, signal attenuation and reflection increase. , It may be difficult to measure. The line impedance also changes depending on the electrical characteristics of the non-conductive refractory material inserted between the metal tube and the rod.

In the present embodiment, the line impedance is about 40 to 50Ω, and the signal attenuation can be suppressed to a low level.

A probe having a predetermined length (1.5-2.0 m) which is integrally shaped in advance is manufactured and then inserted into the through hole 4 of the refractory 1. An opening having a diameter of about 100 mm is provided in the blast furnace iron shell 2 at a position corresponding to the through hole 4 of the refractory, and the stamp material 3 is removed to expose the through hole portion 4 of the refractory, and a flange 5 is provided at the opening of the iron shell 2. With the rear end of the probe that is attached and inserted into the through hole 4 being pulled out to the outer surface of the iron skin, sealing is performed at the probe pulling out portion of the flange 5. A coaxial type connector 10 (M type, N type, BNC, etc.) is attached to the rear end of the probe and is connected to the coaxial cable 9 for connection to a measuring instrument. In this embodiment, the tip of the probe is inserted according to the position of the inner surface of the refractory 1 and the rear end of the probe is attached with a connector at a position of 1 to 1.5 m from the surface of the iron shell 2.

As for the coaxial cable 9 for connecting the probe and the measuring instrument, if the line impedance of the probe and the coaxial cable 9 are significantly different, the attenuation and reflection at the connecting connector portion will increase. In addition, 5D with a line impedance of 50Ω
I am using a 2V cable.

In addition, this embodiment is to be installed in a blast furnace which is in actual operation, and after opening the shell and stamping material in the blast furnace in a resting state, the refractory boring on the inner surface of the furnace is performed. After performing the through hole construction, the probe is inserted and fixed.

FIG. 2 shows an example of a reflected signal waveform detected when a high frequency pulse signal is input to the probe. Figure 2
(a) shows an example of a reflection signal in an open state in which the outer metal tube and the inner conductive rod are electrically insulated at the probe tip. The position of the reflected signal pulse on the time axis is detected, and the change in the probe length is measured from the change in the time delay due to the round trip of the signal.

FIG. 2 (b) shows an example of a reflected signal in a short state in which the inside and the outside of the probe are in electrical contact with each other,
A signal whose phase is inverted with respect to the open state is observed. Since the electrical contact state of the tip changes depending on the inside of the furnace and the presence or absence of deposits on the tip, inversion of the phase of the reflected signal may occur, but the signal time delay itself does not change. If the phase is determined and the time delay of the signal is accurately measured, the influence on the measurement of the probe length is small.

FIG. 3 is a diagram showing a second embodiment of the present invention. In the following figures, the same reference numerals are given to the configurations shown in the above-mentioned figures showing the embodiment of the present invention, and the description thereof will be omitted. In FIG. 3, 11 is a sheath thermocouple sheath tube, and 12 is a sheath thermocouple thermocouple wire.

In the present embodiment, a SUS tube having an inner and outer diameter of φ6 / 8 mm is used as a sheath tube 11 (protection tube) as a probe, and the thermocouple wire 12 is inserted into the sheath tube 11 to connect the sheath tube 11 and the thermoelectric tube. A sheath thermocouple filled with a non-conductive refractory (MgO) is used in the gap between the pair of wires 12, and is inserted and embedded in the through hole 4 so that the tip is located on the inner surface of the refractory 1 and the probe rear end. It is taken out to the outer surface of the iron skin 2. The sheath portion 11 of the sheath thermocouple is regarded as a pseudo coaxial cable using the ground (ground electrode) and the thermocouple element wires 12 (one or two) as signal lines, and the coaxial cable connector 10 is attached to the coaxial cable 9 Is connected with. When a sheath thermocouple is regarded as a pseudo coaxial cable and used as a probe, its line impedance differs from that of a normal coaxial cable, and since variations occur at various parts of the cable, signal attenuation and distortion usually occur. However, it is possible to reduce the influence of signal attenuation by shortening the portion of the sheath thermocouple which is the probe.

Further, the inserted and buried sheath thermocouple can be used for temperature measurement by utilizing the original function of the thermocouple until the tip portion is worn. In the present embodiment, the tip of the sheath thermocouple is inserted as the inner surface position of the refractory and grounded.However, when the tip is inserted and buried so that the tip position is the middle position of the refractory, wear of the refractory is small. It is also possible to monitor the temperature and to measure the residual thickness by measuring the probe length when the refractory has worn out more than a certain amount (probe tip position).

The third embodiment of the present invention is shown in FIG.
In FIG. 4, 13 indicates a carbon rod. In the present embodiment, two carbon rods 13 are inserted in parallel into the through holes 4 provided in the refractory 1 and non-conductive refractory 8 is filled between the through holes and the carbon rods. The carbon rod 13 is fixed with the tip of the carbon rod 13 protruding from the outer surface.

In the present embodiment, one carbon rod 13 is used as a ground electrode, the other is used as a signal line, and the rear end of the carbon rod 13 is connected to the coaxial cable 9 inserted from the outside of the iron shell 2. The connecting portion between the carbon rod 13 and the coaxial cable 9 is covered with a refractory material for heat protection. Two carbon rods 13 installed almost in parallel
When one of the (conductors) is used as a ground electrode and the other is used as a signal line to input a high frequency signal, an electromagnetic field is maintained between the two carbon rods 13 and the signal propagates.

In the present embodiment, only the carbon rod 13 and the refractory 8 are inserted into the through hole 4, and no metal tube or the like is inserted. Therefore, the difference in mechanical strength between the probe and the refractory 1 becomes small. There is. Therefore, it is possible to more accurately measure the residual thickness of the refractory while avoiding a situation in which only the strong probe portion remains in the furnace.

Further, in this embodiment, two carbon rods are inserted, but a plurality of carbon rods are inserted, and
It is also possible to improve the signal propagation state by using the book as a signal line and the rest as a ground electrode and using these as a pair. Moreover, even if the carbon rod to be inserted is one and the ground electrode is made of blast furnace iron shell, signal attenuation,
Although the distortion becomes severe, it is possible to propagate the signal along the probe (carbon rod) and detect the reflected signal, and it is possible to realize the measurement with a simple configuration.

Further, when the object to be measured is a metal CS panel, even if one conductive material is inserted into the through hole, the CS panel itself should be the ground electrode and the conductive material should be the signal line. Thus, it is possible to configure a pseudo coaxial cable, and more stable signal propagation and reflected signal detection can be performed.

FIG. 5 shows an example of the configuration of a measuring instrument used in each of the above-mentioned embodiments for detecting the input reflection signal of the high frequency signal and calculating the probe length. In FIG. 5, 14, 1
5 is a clock signal generator, 16 and 17 are pseudo random signal generators, 18 and 19 are multipliers (frequency mixers), 2
Reference numerals 0 and 21 denote integrators (band limiting filters), 22 denotes a directional coupler, 23 denotes a signal processing device, and clock signal generators 14 and 15 respectively have F (1500.000).
MHz) and F + ΔF (1500.010 MHz) clock signals are generated and input to the pseudo random signal generators 16 and 17. In this embodiment, an M-sequence signal generator configured by a shift register having a feedback loop is used as a pseudo-random signal generator, and an M-sequence signal (pseudo-random signal) having a code length 127 is generated by a clock signal. ing.

The outputs of the pseudo random signal generators 16 and 17 are input to and multiplied by a multiplier 18, and the output of the multiplication result is integrated (band-limited) by an integrator 20 to calculate the cross-correlation of the two pseudo random signals. It As described above, this cross-correlation signal is T
For each F / ΔF, the signal has a peak only during 2 / ΔF. In the case of this embodiment, T = 127 / (1.5 × 10 ⁹ ),
Since F = 1.5 × 10 ⁹ and ΔF = 1.0 × 10 ⁴ , 1.27 × 10 ^-2
A cross-correlation signal with a peak over 2.0 × 10 ⁻⁴ is obtained every sec. This signal is used as a time reference signal with no time delay in signal transmission.

On the other hand, the output of the pseudo random signal generator 16 is output to the outside via the directional coupler 22 and input to the coaxial cable 9. The signal propagating through the coaxial cable 9 is input to the probe connected to the tip of the cable, and the signal reflected at the probe tip is propagated in the opposite direction of the coaxial cable 9 and returned to the measuring instrument to be input to the directional coupler 22.

The reflected signal inputted to the directional coupler 22 from the opposite direction is separated by the directional coupler 22, and the separated signal is multiplied by the pseudo random signal generator 17 by the multiplier 19.
Is multiplied by the output of. The output of the multiplication result is integrated (band-limited) by the integrator 21, and the cross-correlation signal of both is obtained.
This cross-correlation signal has the same period and pattern as the reference cross-correlation signal obtained by the integrator 20, but is delayed by the time required for the round trip to the probe tip. As described above, since this delay time is expanded to F / ΔF = 1.5 × 10 ⁵ times, precise measurement becomes possible.

The output signals of the integrators 20 and 21 are input to the signal processing device, and the signal processing device measures the time delay between the signals to convert the time delay due to the round trip propagation of the signal in the probe portion into a distance. Thus, the length of the probe portion is calculated. In signal processing equipment, it becomes possible to measure changes in probe length from changes in the time delay of the detection signal with respect to the time reference signal.

[0056]

As described above, according to the present invention,
By embedding the probe in the thickness direction in the refractory,
It becomes possible to continuously measure and monitor the remaining thickness of the refractory by a simple method. Further, the processing of the refractory material may be minimal, and the measurement can be performed without impairing the heat resistance, cooling effect, mechanical strength, and durability of the refractory material. In addition, stable continuous measurement can be realized with little influence on the measurement of the refractory material. Furthermore, since the embedded probe is composed of metal and non-conductive refractory, it is not easily affected by the temperature of the refractory, blow-through of high-temperature furnace gas between the iron shell and the refractory, and has excellent durability and stability. It is possible to realize the measurement.

Further, since the pseudo-random signal is used for the measurement, the S / N ratio can be increased, and in addition, the measuring method utilizing the total correlation processing of the two pseudo-random signals whose frequencies are slightly deviated Since it is adopted,
Precise measurement is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a residual thickness measuring method for a blast furnace refractory according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a reflected signal waveform detected when a high frequency pulse signal is input to the probe.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a third embodiment of the present invention.

FIG. 5 is a diagram showing an example of a configuration of a measuring instrument used in the embodiment of the present invention.

FIG. 6 is a diagram showing an example of a conventional refractory residual thickness measuring device.

[Explanation of symbols]

1 Refractory brick or CS panel (refractory) 2 iron skin 3 stamp materials 4 through holes 5 flange 6 metal tubes 7 Conductive rod, cable 8 Non-conductive refractory 9 coaxial cable 10 connectors 11 Sheath thermocouple sheath tube 12 Thermocouple element of sheath thermocouple 13 carbon rod 14, 15 Clock signal generator 16, 17 Pseudo random signal generator 18, 19 Multiplier (frequency mixer) 20, 21 Integrator (band limiting filter) 22 Directional coupler 23 Signal processing device

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01B ⁷ /00-7/34 C21B 7/00-9/16 F27B 1/00-3/28 F27D 1 / 00-1/18 F27D 17/00-23/04

Claims (7)

(57) [Claims] (1) A metal pipe embedded in a through hole provided in a thickness direction of a refractory and having one end reaching an inner surface of the refractory and the other end reaching an outer surface of the refractory, and a conductive member inserted in the metal pipe. A rod or cable of, and a probe constituted by a non-conductive refractory for electrically insulating the metal tube and the conductive rod or cable, (2) iron probe side of the probe From one end, means for inputting a high-frequency signal between the conductive rod or cable and the metal tube, and (3) propagated along the rod constituting the probe and reflected at the end of the inner surface of the refractory. refractory having means for separating and detecting the high frequency signal returned to the input end, and means for calculating (4) the measured time difference between the input high-frequency signal and separates the detected high frequency signal, the signal propagation distance of Te A device for measuring the remaining thickness of an object,
Is a sheath thermocouple, and the sheath protection tube is
Using a tube or thermocouple cable as the cable
A residual thickness measuring device characterized by: 2. (1) Conductivity that is embedded in a through-hole provided in the thickness direction of a refractory material so as to be isolated from each other by a non-conductive refractory material, with one end reaching the inner surface of the refractory material and the other end reaching the outer surface of the refractory material. A probe formed of a pair of flexible rods, (2) means for inputting a high-frequency signal between the rods forming the probe from one end on the iron skin side of the probe, and (3) propagation inside the probe. Then, means for separating and detecting the high frequency signal reflected at the end of the refractory inner surface and returning to the input end, (4) measuring the time difference between the input high frequency signal and the separately detected high frequency signal, And a means for calculating the propagation distance of the refractory. 3. The refractory residual thickness measuring device according to claim 2 , wherein the refractory is a CS panel, and one of the pair of rods is replaced by the CS panel itself. Refractory residual thickness measuring device. 4. (1) A cable which is embedded in a through hole provided in the thickness direction of a refractory material and has one end reaching the inner surface of the refractory material and the other end reaching the outer surface of the refractory material, the plurality of conductors having heat resistance. A probe constituted by a cable insulated with an insulator, (2) means for inputting a high-frequency signal between a pair of conductors of the cable from one end on the iron skin side of the probe, (3) inside the probe Means for separating and detecting the high-frequency signal that propagates through, is reflected at the end of the refractory inner surface and returns to the input end, and (4) measures the time difference between the input high-frequency signal and the separated and detected high-frequency signal. And a means for calculating a propagation distance of a signal, the residual thickness measuring apparatus for a refractory. 5. The refractory residual thickness measuring device according to claim 1, wherein a pseudo-random signal is used as the high frequency signal. 6. A first pseudo-random signal is generated as a means for inputting a pseudo-random signal to a probe embedded in a refractory, separating and detecting a reflected signal, and calculating the propagation distance of the signal from this. A first pseudo-random signal generating means, a second pseudo-random signal generating means for generating a second pseudo-random signal having the same signal pattern as the first pseudo-random signal and a slightly different frequency; First multiplication means for multiplying two pseudo-random signals, means for inputting the first pseudo-random signal to the probe, and a signal that propagates in the probe, is reflected at the probe tip, and returns to the input end is separated and detected. Means, second multiplying means for multiplying the separately detected signal and the second pseudo random signal, and first and second integrating means for integrating the results of the first and second multiplying means, Remaining thickness measurement apparatus of the refractory according to claim 5, wherein the output of each of the first and second integration means and having a means for measuring the time difference between the time at which the extreme value. 7. The refractory residual thickness measuring device according to claim 5, wherein the pseudo-random signal is an M-sequence signal.