JP5809512B2 - Brick residual thickness measuring device - Google Patents

Description

  The present invention relates to an apparatus for measuring a remaining brick thickness of a blast furnace brick using an ultrasonic sensor.

  The furnace bottom (lower side wall) structure of the blast furnace has carbon bricks (carbon blocks) on the working surface side (inner surface side) inside the furnace, and is staircase (water cooling by cooling pipes) arranged on the inner surface side of the outer skin, which is an external container. It has a structure that allows heat to escape. In addition, there is a structure without a stave, but in this case, cooling is performed by spraying cooling water directly onto the iron skin. In any structure, carbon bricks have the opportunity to come into direct contact with hot metal on the working surface side (inner surface side) and wear out over long periods of time, so this thickness must be measured and managed. is there.

  Conventionally, in order to inspect the thickness of the furnace bottom brick, a means for estimating using a thermocouple has been used, but the variation is large and stable measurement is difficult. The estimation means using a thermocouple can be estimated with relatively high accuracy when the furnace inside the blast furnace is in a stable state, but the accuracy decreases when the heat load is changing rapidly due to the flow state in the furnace. Tended to be.

  Therefore, for example, the means of Patent Document 1 has already been proposed. An ultrasonic sensor related to the present invention is disclosed in Patent Document 2.

  As shown in FIG. 1, the means of Patent Document 1 forms an opening 4 by shifting the joints of the refractories 3 in the iron skin 1 or the iron skin 1 and the stave 2. The element 5 is inserted and brought into contact with the stave 2 or the refractory 3 facing the opening, and an ultrasonic wave of 20 to 200 kHz is propagated from the ultrasonic probe 5 to the refractory 3, and the propagated ultrasonic wave is refractory. The thickness of the refractory 3 is measured by measuring the time required to reciprocate the object 3.

  As shown in FIG. 2, the ultrasonic sensor disclosed in Patent Document 2 has a conductive pedestal 52 having a detection outer surface 52a that is brought into contact with the inspection target surface B and a detection inner surface 52b that is a plane having an arbitrary angle with respect to the detection outer surface 52a. A first electrode 54a made of a heat-resistant soft metal that is in close contact with the detection inner surface 52b, a plate-like piezoelectric element 56 that is in close contact with the first electrode 54a in a form sandwiched between the first electrode 54a and the pedestal 52, and a piezoelectric element The second electrode 54b made of a heat-resistant soft metal that is in close contact with the piezoelectric element 56 in a form sandwiched between the first electrode 54a and the piezoelectric element 56 elastically toward the detection inner surface 52b via the second electrode 54b. A heat-resistant urging member 60 that urges, a pressing member 70 that presses the heat-resistant urging member 60 toward the detection inner surface 52b, and one end connected to the pedestal 52, and the first electrode 54a, the piezoelectric element 56, the first 2-electrode 54b, resistance A main body 50 that houses the urging member 60 and the pressing member 70; and a support means 69 that is screwed into the main body 50 and receives a reaction force from the pressing member 70 on the other end side of the main body with respect to the pressing member 70. The means 69 has a first through hole 65 for applying a pressing force to the pressing member 70 from the outside toward the detection inner surface 52b, and the pressing member 70 has a receiving portion 72 for receiving the pressing force. .

JP 09-264735 A, “Method and apparatus for measuring thickness of refractory” JP 2008-256423 A, “High-temperature ultrasonic probe and manufacturing method thereof”

The conventional means described above has the following problems.
Due to changes in the operating conditions of the blast furnace, the surface of the refractory 3 moves three-dimensionally relative to the iron shell 1. This three-dimensional movement amount is, for example, about ± 2 to 5 mm in two directions and about ± 2 to 5 mm in the radial direction within the measurement surface of the ultrasonic probe 5.

In order to accurately measure the thickness of the refractory 3 using the ultrasonic probe 5, the contact surface of the ultrasonic probe 5 is copied while closely contacting the measurement surface of the refractory 3, and the entire contact surface is desired. It is necessary to be pressed against the surface of the refractory 3 with a surface pressure of.
However, in the conventional means, when the surface of the refractory 3 moves relative to the iron shell 1 in a three-dimensional manner, the contact surface of the ultrasonic probe 5 is inclined with respect to the measurement surface of the refractory 3. There is a problem that a gap is formed in a part of the contact surface, or the surface pressure therebetween is not uniform.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to follow the contact surface of the ultrasonic probe in close contact with the measurement surface of the refractory, even if the measurement surface of the refractory moves relatively three-dimensionally with respect to the iron skin. Brick residual thickness measuring device that can press the entire contact surface against the refractory measurement surface with a desired surface pressure and can accurately measure the thickness of the refractory using an ultrasonic probe Is to provide.

According to the present invention, a brick residual thickness measuring device that is attached to a blast furnace having a carbon brick inside a metal iron skin and measures the thickness of the carbon brick,
The blast furnace has a measurement hole that penetrates through the iron skin and reaches the carbon brick, and a mounting flange that is airtightly provided in the through hole of the iron skin that communicates with the measurement hole.
An ultrasonic sensor inserted into the measurement hole and pressed against the measurement surface of the carbon brick via the contact medium;
An urging device attached to the mounting flange, extending inward along the axis, and elastically pressing an intermediate member located at the inner end thereof toward the carbon brick;
A sensor pressing rod extending along an axis between the intermediate member and the ultrasonic sensor;
A pair of spherical bearings that pivotably connect both ends of the sensor pressing rod to the intermediate member and the ultrasonic sensor;
There is provided a brick residual thickness measuring device comprising a spherical bearing, a sensor pressing rod, and a signal line drawn from the ultrasonic sensor to the outside of the iron shell through an urging device.

According to the above configuration of the present invention, since the pair of spherical bearings that pivotably connect the both ends of the sensor pressing rod to the intermediate member and the ultrasonic sensor are provided, the measurement surface of the carbon brick is against the iron skin. Even if the ultrasonic sensor moves in two directions within the measurement surface of the ultrasonic sensor, the axes of the ultrasonic sensor and the biasing device can always be maintained in parallel.
The length of the sensor pressing bar is set to a distance from the surface of the carbon brick to the surface of the iron shell or more (for example, 300 to 500 mm), so that the swing angle of the sensor pressing bar in each spherical bearing is very large. It becomes smaller (for example, 0.95 to 1.43 ° in the case of a fluctuation of 5 mm).
Therefore, the pressing force by the urging device acts on the ultrasonic sensor in the same direction via the sensor pressing rod, so that the contact surface of the ultrasonic sensor can follow the carbon brick measurement surface while closely contacting it. The entire surface can be pressed against the measurement surface of the carbon brick with a desired surface pressure, whereby the thickness of the carbon brick can be accurately measured by the ultrasonic sensor.

1 is a configuration diagram of an apparatus according to Patent Document 1. FIG. 10 is a configuration diagram of an ultrasonic sensor according to Patent Document 2. FIG. It is a whole block diagram of a blast furnace provided with a brick residual thickness measuring device by the present invention. It is 1st Embodiment figure of the brick remaining thickness measuring apparatus by this invention. It is an enlarged view of the A section of FIG. It is an enlarged view of the B section of FIG. It is 2nd Embodiment figure of the brick remaining thickness measuring apparatus by this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

FIG. 3 is an overall configuration diagram of a blast furnace provided with a brick residual thickness measuring apparatus according to the present invention, and schematically shows a horizontal sectional view.
In this figure, 10 is a blast furnace, and in this example, a stave 2 and a carbon brick 3 are laminated in this order on the inside of a metallic iron skin 1. The thickness of the carbon brick 3 is 2 m or more, for example, and the temperature of the outer surface of the carbon brick 3 is maintained at 100 to 200 ° C., for example.
In many cases, there is a castable between the iron skin 1 and the stave 2 or there is a stamp material between the stave 2 and the carbon brick 3. However, regardless of the presence or absence of these materials, the apparatus of the present invention can be used. The remaining thickness of the carbon brick can be measured.

  The blast furnace 10 includes a measurement hole 12 that penetrates through the iron skin 1 and reaches the carbon brick 3, and a mounting flange 14 that is airtightly provided in the through hole of the iron skin 1 that communicates with the measurement hole 12.

  The remaining brick thickness measuring device 20 of the present invention is a device that is attached to the mounting flange 14 of the blast furnace 10 and measures the thickness of the carbon brick 3.

  FIG. 4 is a diagram showing a first embodiment of a remaining brick thickness measuring apparatus according to the present invention.

  In FIG. 4, the remaining brick thickness measuring device 20 of the present invention includes an ultrasonic sensor 16, an urging device 30, a sensor pressing rod 22, a pair of spherical bearings 24 a and 24 b, and a signal line 26.

  The ultrasonic sensor 16 is inserted into the measurement hole 12 and pressed against the measurement surface 3a of the carbon brick 3 via the contact medium.

The ultrasonic sensor 16 is a high-temperature ultrasonic sensor in which a lithium niobate vibrator is sandwiched between two electrodes. This high-temperature ultrasonic sensor has a heat resistance of, for example, a maximum of 600 ° C. and is configured to withstand the temperature near the measurement surface 3 a of the carbon brick 3.
The structure of the ultrasonic sensor 16 is disclosed in Patent Document 2, for example, as shown in FIG.

The contact medium is a contact medium that can withstand the temperature (for example, 100 to 200 ° C.) of the measurement surface 3 a of the carbon brick 3.
The contact medium is necessary to reduce the influence of the uneven surface with the carbon brick 3 and the sensor surface of the ultrasonic sensor 16 which are obstructive factors during ultrasonic transmission, and perform ultrasonic transmission with the loss reduced as much as possible. In addition, the ultrasonic transmission performance must be stably provided in the use environment temperature region. For this reason, the contact medium has a deformability, and can be freely deformed under stress as a material such as clay, and the uneven portions are leveled to bring the carbon brick 3 and the ultrasonic sensor 16 into close contact via the contact medium. Any material that can transmit ultrasonic waves from the sensor surface to the carbon brick 3 may be used. In order to satisfy such a function, the contact medium is preferably composed of an aggregate constituting the clay and a binder for bonding them.

In this case, the aggregate can be a metal or metal oxide powder that can transmit ultrasonic waves stably even at relatively high temperatures (for example, 0.1 mm or less). While having a role as a binder, it has high deformability and is stable at a thermal decomposition starting temperature higher than the operating environment temperature range, and does not create a large gap even if the volatile components in the binder volatilize. A material that does not obstruct the transmission of ultrasonic waves as much as possible is more preferable.
Specific examples of the aggregate include alumina powder, mullite powder, aluminum powder, frit powder and the like, and these can be used alone or in combination.
Specific examples of the binder include resin, tar and pitch, and these can be used alone or in combination. Among these, since the phenol resin satisfies the above functions at a high level, it is preferably contained in the binder.
Moreover, in order to further improve the deformability of the contact medium, for example, monoethylene glycol or the like may be included.
In the commercial product, “Kurojoc” (registered trademark) manufactured by Kurosaki Harima sold as a refractory material product can be used as a contact medium.

The biasing device 30 is attached to the attachment flange 14, extends inward along the axis, and elastically presses the intermediate member 31 positioned at the inner end thereof toward the carbon brick 3. Further, the urging device 30 has a hollow hole along the axis.
The intermediate member 31 is located in the vicinity of the surface of the iron skin 1 or on the outside thereof. The shape of the intermediate member 31 is preferably a hollow cylindrical plate, preferably a flat plate, and is preferably made of metal that can withstand the temperature in the vicinity of the iron skin (for example, 30 to 100 ° C.).

(Necessity of intermediate member 31)
When the space outside the iron skin is narrow and the sensor pressing bar 22 and the biasing bar 36 are integrated, it is difficult to insert the ultrasonic sensor 16 from the mounting flange 14, and the sensor pressing bar 22 is divided into iron The sensor can be inserted even in a place where the space outside the skin is narrow.
Further, the shape of the intermediate member 31 is preferably a hollow cylindrical shape because the signal line 26 is passed through the center of the sensor pressing rod 22 and the biasing rod 36.

  The sensor pressing rod 22 has a hollow cylindrical shape, has a hollow hole 22 a along the axis, and extends along the axis between the intermediate member 31 and the ultrasonic sensor 16. In this example, the sensor pressing rod 22 is a hollow cylindrical tube, and is preferably made of metal that can withstand the temperature (for example, 100 to 200 ° C.) of the measurement surface 3 a of the carbon brick 3.

The length of the sensor pressing bar 22 is such that the swing angle of the pair of spherical bearings 24a and 24b is within a predetermined range (for example, ± 5 mm) even if the sensor pressing rod 22 moves about ± 5 mm in two directions within the measurement surface 3a of the ultrasonic sensor 16. 2 °).
This length is preferably set to a distance from the surface of the carbon brick 3 to the surface of the iron skin 1 or longer.
For example, when the length is 300 to 500 mm, the swinging angle of the spherical bearings 24 a and 24 b with respect to a variation of 5 mm is 0.95 to 1.43 °.

The pair of spherical bearings 24 a and 24 b have a hollow hole along the axis, and both ends of the sensor pressing rod 22 are swingably connected to the intermediate member 31 and the ultrasonic sensor 16.
The spherical bearings 24a, 24b can swing in any direction of 360 degrees with respect to the axis, and the swing range is set to a predetermined range (for example, ± 2 °).
The pair of spherical bearings 24a and 24b can be separated from the sensor pressing rod 22 by a fixing screw (not shown).

As described above, the spherical bearings 24a and 24b, the sensor pressing rod 22, and the urging device 30 each have a hollow hole along the axis. This hollow hole is for passing the signal line 26 and the two-core connector 18.
The signal line 26 is drawn from the ultrasonic sensor 16 to the outside of the iron skin 1 through the spherical bearings 24 a and 24 b, the sensor pressing rod 22, and the hollow hole of the urging device 30.

The signal line 26 from the ultrasonic sensor 16 is a two-core cable having one end connected to two electrodes and the other end connected to a two-core connector 18 (see FIG. 6) having a cylindrical portion. One of the two electrodes may be grounded.
The signal line 26 has a length extending from the ultrasonic sensor 16 to the outside of the iron skin 1 through the spherical bearings 24 a and 24 b, the sensor pressing rod 22, and the hollow hole of the biasing device 30. The cylindrical portion of the two-core connector 18 is formed of a sealed cylindrical metal pipe having a diameter of about 8 mm, and a connector contact is provided on the outer end thereof.

FIG. 5 is an enlarged view of a portion A in FIG.
In this figure, the measurement hole 12 has an inner diameter that suppresses the inclination of the ultrasonic sensor 16. The inner diameter of the measurement hole 12 is preferably close to the diameter of the ultrasonic sensor 16 as long as the insertion of the ultrasonic sensor 16 is not hindered. Specifically, it is preferable to have a clearance of 2 to 8 mm with respect to the diameter of the ultrasonic sensor 16.
For example, when the ultrasonic sensor 16 has a cylindrical shape with a diameter of about 40 mm, the ultrasonic sensor inside the measurement hole 12 is set by setting the inner diameter of the measurement hole 12 to 42 to 48 mm (diameter gap of 2 to 8 mm). 16 can be prevented, and the axis of the ultrasonic sensor 16 can be maintained substantially perpendicular to the measurement surface 3a.
Moreover, the measurement surface 3 a is located inside the outer surface of the carbon brick 3. The depth from the outer surface of the measurement surface 3a is maintained so that the ultrasonic sensor 16 is substantially perpendicular to the measurement surface 3a even if the measurement surface 3a moves relative to the iron skin 1 in a three-dimensional manner. And it sets so that it may not leave | separate from the measurement surface 3a. When the ultrasonic sensor 16 has a cylindrical shape, this depth is preferably about 50 to 100 mm when the ultrasonic sensor 16 is about half to one time, for example, 100 mm.

FIG. 6 is an enlarged view of a portion B in FIG.
In this figure, the urging device 30 includes a jig flange 32, a screw pipe 34, an urging rod 36, and an urging member 38.

The jig flange 32 is attached to the attachment flange 14 and has a female screw portion 33 centering on the axis of the measurement hole 12.
The screw pipe 34 has a hollow cylindrical shape, has a male screw portion 35 that is screwed with the female screw portion 33, and extends from the outer side to the inner side of the iron skin 1 along the axis.
The biasing bar 36 extends from the outside to the inside of the screw pipe 34 through the hollow hole of the screw pipe 34, and the intermediate member 31 is provided at the inner end.
In this example, the urging member 38 is a coil spring, and is positioned between the inner end surface of the screw pipe 34 and the intermediate member 31, and elastically presses the intermediate member 31 toward the carbon brick 3.

With the configuration of the urging device 30 described above, the compression length of the urging member 38 is adjusted by moving the screw pipe 34 in the axial direction by screwing the female screw portion 33 and the male screw portion 35, and the intermediate member 31. It is possible to adjust the pressing force (for example, 50 to 100 kg) that elastically presses against the carbon brick 3.
In addition, although the sensitivity characteristic of the ultrasonic sensor 16 has a favorable sensitivity at 50 kg or more, it has been confirmed that the sensitivity decreases when the sensitivity exceeds 100 kg.

According to the configuration of the present invention described above, since the pair of spherical bearings 24a and 24b that connect the both ends of the sensor pressing rod 22 to the intermediate member 31 and the ultrasonic sensor 16 so as to be swingable are provided, the carbon brick 3 Even if the measurement surface 3a moves in two directions within the measurement surface 3a of the ultrasonic sensor 16 with respect to the iron skin 1, the axes of the ultrasonic sensor 16 and the biasing device 30 can always be maintained in parallel.
The length of the sensor pressing bar 22 is set to a distance from the surface of the carbon brick 3 to the surface of the iron shell 1 or longer (for example, 300 to 500 mm), so that the sensor pressing bar 22 in each of the spherical bearings 24a and 24b. Is very small (for example, 0.95 to 1.43 ° for a variation of 5 mm).
Accordingly, the pressing force by the urging device 30 acts in the same direction on the ultrasonic sensor 16 via the sensor pressing rod 22, so that the contact surface of the ultrasonic sensor 16 follows while closely contacting the measurement surface 3 a of the carbon brick 3. The entire contact surface can be pressed against the measurement surface 3a of the carbon brick 3 with a desired surface pressure, whereby the thickness of the carbon brick 3 can be accurately measured by the ultrasonic sensor 16.

In FIG. 6, the remaining brick thickness measuring apparatus 20 of the present invention further includes a main case 42 and a sub case 44.
The main case 42 and the sub case 44 hermetically surround the urging device 30 and take out the signal of the signal line 26 to the outside while maintaining the hermeticity.

  The main case 42 includes an L-shaped pipe 42a composed of a main pipe and a branch pipe, a main flange 42b attached to the opening flange of the main pipe and airtightly attached to the mounting flange 14, and an intermediate mechula flange 42c attached to the opening of the branch pipe. Become.

  The sub case 44 includes a straight pipe 44a, an intermediate flange 44b attached to one end of the straight pipe 44a and hermetically coupled to the intermediate mechula flange 42c, an external flange 44c attached to the other end of the straight pipe 44a, and an external flange 44c. It consists of an outer mecha flange 44d that is hermetically coupled.

  The ultrasonic sensor 16, the urging device 30, the sensor pressing rod 22, and the spherical bearings 24a and 24b described above are airtightly attached to the mounting flange 14, and the signal line 26 is taken out while keeping the airtightness. It has a structure.

With the above-described configuration, the main case 42 has an L shape, so that the axial lengths of the ultrasonic sensors 16 of the main case 42 and the sub case 44 can be shortened.
Further, since the spherical bearing 24a can be separated from the sensor pressing rod 22 by a fixing screw (not shown), the urging device 30 can be separated from the sensor pressing rod 22 together with the main case 42.
Therefore, even if the distance from the surface of the iron skin 1 to the back of the emergency fence (not shown) is within 900 mm, the brick remaining thickness measuring device 20 according to the present invention can be assembled or disassembled.

FIG. 7 is a diagram showing a second embodiment of the remaining brick thickness measuring apparatus according to the present invention.
In this example, a flexible coupling 17 is disposed between the ultrasonic sensor 16 and the spherical bearing 24a. Other configurations are the same as those of the first embodiment.

  With this configuration, in addition to good followability of brick displacement fluctuation in the vertical direction of 5 mm (for example, fluctuation due to thermal expansion) that the spherical bearing 24a is good at, the brick displacement fluctuation in the lateral direction (furnace body circumferential direction) (for example, (Fluctuation due to furnace expansion at the initial stage of blast furnace start-up) can be obtained with better followability, and the remaining thickness can be measured stably for a long time.

The brick remaining thickness measuring apparatus shown in FIG. 4 was installed at the bottom of the blast furnace in which members were arranged in the order of iron skin, castable, stave, stamp material, and carbon brick. At that time, the apparatus was installed with an ultrasonic sensor diameter of 40 mm with a hole diameter of 50 mm passing through from the iron skin to the carbon brick wall (back surface).
As a result, a brick displacement fluctuation of 5 mm in the vertical direction due to thermal expansion occurred during the measurement, but the reflected wave signal could be stably obtained by the apparatus of the present invention.
In addition, it was able to withstand pressure fluctuations during a temporary shutdown of the blast furnace equipment, followed up sufficiently, and performed continuous and stable measurements.
In addition, when the in-furnace state of the blast furnace is in a stable state, when compared with the measured value of the prior art by the thermometer provided at the same time, almost the same measured value of the remaining thickness is obtained in the range of 0 to 10 mm. The measured value was confirmed to be reliable.

The residual thickness of the carbon brick in the blast furnace was measured in the same manner as in Example 1 by using an apparatus in which a flexible coupling was disposed between the ultrasonic sensor and the spherical bearing of the apparatus used in Example 1. In Example 2, the remaining thickness was measured from the start of the blast furnace.
As a result, not only following the vertical displacement of 5mm brick due to thermal expansion, but also sufficiently following the movement of 3-5mm in the lateral direction (furnace body circumferential direction) due to the furnace body expansion at the initial stage of blast furnace startup, A stable signal could be obtained continuously from the initial rise.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

1 Iron skin, 2 stave, 3 carbon brick (refractory),
3a Measuring surface, 4 holes, 5 ultrasonic probe,
10 blast furnace, 12 measuring holes, 14 mounting flanges,
16 Ultrasonic sensor, 17 Flexible coupling,
18 2-core connector,
20 Brick residual thickness measuring device,
22 sensor pressing rod, 22a hollow hole,
24a, 24b spherical bearing, 26 signal line,
30 biasing device, 31 intermediate member,
32 jig flange, 33 female thread,
34 thread pipe, 35 male thread,
36 biasing bar, 38 biasing member,
42 Main case, 42a L-shaped tube,
42b main flange, 42c intermediate mekura flange,
44 Subcase, 44a Straight pipe, 44b Intermediate flange,
44c External flange, 44d External mecha flange

Claims (7)

A brick residual thickness measuring device that is attached to a blast furnace having a carbon brick inside a metal iron skin and measures the thickness of the carbon brick,
The blast furnace has a measurement hole that penetrates through the iron skin and reaches the carbon brick, and a mounting flange that is airtightly provided in the through hole of the iron skin that communicates with the measurement hole.
An ultrasonic sensor inserted into the measurement hole and pressed against the measurement surface of the carbon brick via the contact medium;
An urging device attached to the mounting flange, extending inward along the axis, and elastically pressing an intermediate member located at the inner end thereof toward the carbon brick;
A sensor pressing rod extending along an axis between the intermediate member and the ultrasonic sensor;
A pair of spherical bearings that pivotably connect both ends of the sensor pressing rod to the intermediate member and the ultrasonic sensor;
A brick residual thickness measuring device comprising: a spherical bearing, a sensor pressing rod, and a signal line drawn from the ultrasonic sensor to the outside of the iron skin through an urging device. The ultrasonic sensor has a cylindrical shape extending along an axis;
The measurement hole has an inner diameter close to the diameter of the ultrasonic sensor ,
2. The brick residual thickness measuring apparatus according to claim 1, wherein the measurement surface is located on an inner side than an outer surface of the carbon brick. The intermediate member is located in the vicinity of the iron skin surface or outside thereof,
The length of the said sensor pressing bar is set to the distance from the surface of a carbon brick to the iron skin surface or more, The brick residual thickness measuring apparatus of Claim 1 or 2 characterized by the above-mentioned. The spherical bearing, wherein the sensor pressing rod, and the biasing device comprises a hollow hole, respectively along the axis, brick residual thickness measuring apparatus according to claim 1, characterized in that. Wherein the biasing device includes a jig flange having an internal thread portion is attached to the mounting flange about the axis of said measuring hole,
A hollow cylindrical threaded pipe having a male threaded portion that engages with the female threaded portion and extending from the outside to the inside of the iron skin along the axial center;
A biasing rod extends to the inside, which is the intermediate member at an inner end provided from the outside of the Nejipaipu through the hollow hole of the Nejipaipu,
Having a biasing member to press elastically toward the intermediate member to the carbon brick located between the intermediate member and the inner end surface of the Nejipaipu, any one of the preceding claims, characterized in that 1 The brick residual thickness measuring apparatus as described in the item. The brick residual thickness measuring apparatus according to any one of claims 1 to 5, wherein a flexible coupling is disposed between the ultrasonic sensor and the spherical bearing. The ultrasonic sensor, wherein the biasing device, wherein the sensor pressing rod, the spherical bearings is attached to the inside of said mounting flange,
A hollow case having a main flange airtightly attached to the outside of the mounting flange, and a mekura flange,
The signal line is a two-core cable connected to a two-core connector having an outer end having a cylindrical portion;
The cylindrical portion of the two-core connector is formed of a sealed cylindrical metal pipe, and a connector contact is provided on the outer end thereof.
7. The signal line according to claim 1, wherein the signal line passes through the inside of the hollow case, and the cylindrical portion is airtightly attached through the mechula flange . Brick residual thickness measuring device.