JP4886576B2 - Refractory thickness measurement terminal and refractory thickness measurement method - Google Patents

Description

  The present invention relates to a terminal for measuring the thickness of a refractory used when measuring the thickness of the refractory, and a method for measuring the thickness of a refractory.

  For example, the furnace wall of a blast furnace is usually made of iron shell, amorphous refractory, cooling stave, stamp material, and refractory brick from the outside, but the refractory brick at the bottom of the blast furnace furnace is always exposed to hot metal, It gradually wears away with the operation of the blast furnace. Therefore, to accurately measure and manage the change in the remaining thickness (residual thickness) of refractory bricks during the operation of the blast furnace is to prevent erosion of the iron shell due to hot metal, outflow of hot metal, etc. Is extremely important.

  For this reason, various methods for measuring the remaining thickness of the refractory brick have been proposed in the past. For example, in Patent Document 1, an elastic wave is transmitted from the outermost wall surface to the inner refractory brick, and the refractory A method of measuring the thickness of a refractory brick by receiving a reflected signal from the innermost surface on the surface of the outermost wall surface is disclosed. Patent Document 2 discloses that a thickness of the object to be measured is measured by bringing a terminal incorporating an ultrasonic transducer into contact with the surface of the object to be measured and measuring an ultrasonic reflection time.

JP 2001-294918 A JP-A-2005-354281

  However, in the method of transmitting elastic waves from the outermost wall surface toward the inner refractory brick, the measurement accuracy may be affected by the elastic waves being absorbed and scattered by the presence of the stamp material described above. Further improvements are desired. In addition, the method of bringing the terminal with the built-in ultrasonic transducer into contact with the object to be measured is because the pedestal is interposed between the transducer and the object to be measured, so that the ultrasonic waves from the transducer can be reliably measured. In order to transmit to the device under test with the required level of output, the entire terminal must be strongly pressed against the device under test with the conductive base in contact with the device under test. The machine was required separately. In addition, since it is necessary to install such a mechanical device in the vicinity of the measurement location, depending on the measurement location, there is a restriction on the measurement location due to the presence of a cooling structure such as a stave, or there is no space in the blast furnace bottom. In some cases, measurement was not possible. Therefore, further improvement is desired in this respect.

  The present invention has been made in view of such a point, and in measuring the thickness of the refractory, it eliminates the need for a mechanical device for pressing the terminal as described above, and accurately uses a refractory such as a refractory brick. The purpose is to measure the thickness.

In order to achieve the above object, the present invention comprises a contact body that is disposed in the main body and is disposed in close contact with the surface of the piezoelectric element on the refractory side, and is made of the same material as the refractory. ing. And the contact body is locked or fixed to the main body, the measurement end face is exposed from the main body, and the piezoelectric element is urged to the contact body side by the urging member , in particular, A terminal for measuring the thickness of a refractory characterized by any of the following three.
(1) It is a terminal for measuring the thickness of a refractory by ultrasonic waves, both ends are opened, and a locking step portion protruding inwardly is formed on the periphery of the opening portion of one end portion. A single cylindrical main body having a thread groove formed in the inner periphery of the opening, a biasing member disposed in the main body, and a screw thread formed in the outer periphery, the other opening of the main body A pressing member that is screwed into a thread groove on the inner periphery of the portion to hold the biasing member, a piezoelectric element that is disposed in the main body, and the refractory in the piezoelectric element that is disposed in the main body. A contact body made of the same material as that of the refractory and disposed in close contact with the surface on the side, and the contact body is locked to the locking step portion so that the end face for measurement is exposed from the main body. The piezoelectric element is urged toward the contact body by the urging member via a support plate portion. To, thickness measuring terminal of the refractory.
(2) A terminal for measuring the thickness of the carbon block by ultrasonic waves, a cylindrical main body, a biasing member disposed in the main body, a piezoelectric element disposed in the main body, A contact body that is disposed in the main body and is in close contact with the surface of the piezoelectric element on the carbon block side, and is made of the same material as the carbon block, and the contact body is locked to the main body. The measurement end face is exposed from the main body, the piezoelectric element is urged toward the contact body by the urging member, and the carbon block surface and the measurement end face of the contact body are the same material as the carbon block and the contact body. A terminal for measuring the thickness of a refractory, characterized by being bonded with an adhesive having a phenol resin as a main component.
(3) A terminal for measuring the thickness of the carbon block by ultrasonic waves, both ends are opened, and an engaging step portion protruding inwardly is formed on the periphery of the opening at one end portion. A single cylindrical main body having a thread groove formed in the inner periphery of the opening, a biasing member disposed in the main body, and a screw thread formed in the outer periphery, the other opening of the main body A pressing member that is screwed into a thread groove on the inner periphery of the portion to hold the biasing member, a piezoelectric element that is disposed in the main body, and the carbon block in the piezoelectric element that is disposed in the main body. A contact body made of the same material as the carbon block, which is disposed in close contact with the surface on the side, and the contact body is locked to the locking step portion so that the end face for measurement is exposed from the main body. The piezoelectric element is contacted by the urging member via the support plate portion. The carbon block surface and the end face for measurement of the contact body are biased toward the body side, and are bonded with an adhesive having a phenol resin as a binder, the main component being the same material as the carbon block and the contact body. A terminal for measuring the thickness of a refractory.

According to the present invention, since the main body has a contact body made of the same material as the refractory in close contact with the surface of the piezoelectric element on the refractory side, when measuring, the measurement end face of the contact body Is used by adhering to the surface of the refractory to be measured. Since the piezoelectric element itself is in close contact with and energized with a contact body of the same quality as the refractory in the body, for example, when used as a terminal for ultrasonic transmission, the ultrasonic wave from the piezoelectric element is In this way, it does not pass through other substances on the way, and is directly transmitted to the refractory from the contact body of the same quality as the refractory to be measured. Therefore, it is not necessary to press the entire terminal strongly against the refractory. Further, since the end face for measurement of the contact body of the terminal may be set by adhering to the refractory as described above, the measurement terminal of the present invention can be installed in an arbitrary measurement desired place in advance.
In the present invention, the “homogeneous material” means a material having substantially the same elastic modulus, and the composition is not necessarily the same. However, if the materials have the same composition and the same elastic modulus, attenuation of ultrasonic waves and mixing of noise can be most suppressed. The elastic modulus being substantially the same means a range that can be regarded as a variation in measurement, that is, a range of, for example, ± 1% with respect to the elastic modulus of the refractory.

  As the material of the piezoelectric element used in the present invention, it is preferable to use a material having a large piezoelectric effect that sufficiently exhibits a piezoelectric effect for transmitting ultrasonic waves at an operating environment temperature. For example, lithium niobate is used. Is preferred. Moreover, as a refractory to which this invention can be applied, a carbon block (elastic modulus is about 10 GPa) can be mentioned, for example. Of course, the present invention is not limited to this, and the refractory whose thickness is to be measured by the present invention can be applied to one having an elastic modulus of about 500 MPa (for example, clay brick) to about 30 GPa (for example, SiC brick).

According to another aspect, the present invention provides a method of measuring the thickness of the refractory using a thickness measuring terminal of the refractory described above, the measuring end face of the contact body as before Symbol refractory surface The thickness of the refractory is measured by applying a voltage to the piezoelectric element in the bonded state. In such a case, the adhesion is preferably realized by an adhesive, and the adhesive used at that time preferably has an elastic modulus after curing of 1/10 to 1/1 of the refractory. According to the inventor's knowledge, by using an adhesive having such physical properties, the influence on the ultrasonic propagation by the adhesive layer that will be interposed between the refractory material to be measured and the contact body, for example, Accurate measurements can be performed with minimal attenuation and noise. The force for urging the piezoelectric element to the contact body may be appropriately selected according to the strength of the contact body. For example, 1/2 to 1/3 of the compressive strength of the contact body is sufficient. Yes, a force smaller than the force pressing the entire terminal as in the conventional case is sufficient.

  According to the present invention, in measuring the thickness of the refractory, it is not necessary to press the entire terminal against the refractory side as in the prior art, and no mechanical device for that purpose is required. Therefore, measurement at an arbitrary location is possible and the measurement accuracy is high.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 shows a cross section of a measuring terminal 1 according to the present embodiment, which is configured as a terminal for measuring the thickness of a refractory brick of a blast furnace composed of a carbon block. The measuring terminal 1 has a cylindrical main body 2 made of stainless steel, and both ends of the main body 2 are open. On the periphery of the opening at the lower end, there is formed a locking step 3 that protrudes annularly inward.

  In the main body 2, the contact body 11 is first inserted and arranged on the lowermost side. This contact body 11 consists of the same material as the refractory brick which is a measuring object. This type of carbon block used as a refractory brick for a blast furnace is, for example, an anthracite, graphite or the like mixed with a resin binder and then press-molded. The contact body 11 also has the same composition as the carbon block. Is used.

  The contact body 11 has a substantially cylindrical shape as a whole, and a locking portion 11 a that is locked to the locking step 3 at the lower end of the main body 2 is formed on the lower outer periphery. When the locking portion 11 a is locked to the locking step portion 3, the contact body 11 does not fall off from the lower end of the main body 2, and the lower end surface of the contact body 11, that is, the measurement end surface 11 b is It is exposed from the lower end opening. Further, the end face 11b for measurement of the contact body 11 slightly protrudes from the lower end face of the main body 2 as shown in FIG. The protrusion length D is preferably 1 mm or less. The measurement end surface 11b of the contact body 11 is protruded in this way in order to ensure that the entire measurement end surface 11b is adhered to the surface of the measurement object when it is adhered to the measurement object as described later. .

  A substantially cylindrical piezoelectric element 12 is disposed on the upper surface of the contact body 11. At this time, in order to improve adhesion between the lower end surface 12 a of the piezoelectric element 12 and the upper end surface 11 c of the contact body 11, the bonding material 13 made of soft metal is used as the lower end surface 12 a of the piezoelectric element 12 and the upper end surface 11 c of the contact body 11. You may interpose between. The thickness of the bonding material 13 is preferably as thin as possible, and may be sufficient to fill at least the concave portion of the surface of the upper end surface 11c of the contact body 11 as shown in FIG. Examples of the soft metal used for the bonding material 13 include copper and indium. As a material for the piezoelectric element 12, lithium niobate having excellent heat resistance is used.

  A disk-shaped electrode 14 is disposed on the upper end surface of the piezoelectric element 12. Also in this case, a bonding material 15 made of the same material as the bonding material 13 may be interposed between the lower end surface of the electrode 14 and the upper end surface of the piezoelectric element 12.

  An insulating washer 16 having a hole 16a formed in the center is disposed on the upper end surface of the electrode. A spring support member 17 is disposed on the upper surface of the insulating washer 16. The spring support member 17 includes a flange-shaped support plate portion 17a having a hole formed in the center thereof, and a tube portion 17b that stands upward from the center of the support plate portion 17a. A spring 18 is provided as an urging member on the outer periphery of the tube portion 17b.

  The upper end opening of the main body 2 is provided with a pressing member 19 having a hole 19a formed in the center. A screw thread is formed on the outer periphery of the pressing member 19 and is screwed into a screw groove on the upper inner periphery of the main body 2. Accordingly, when the presser member 19 is turned and screwed to the main body 2, the contact body 11 disposed at the lower end in the main body 2 is locked to the main body 2. And the support plate 17a of the spring support member 17 are contracted, whereby the insulating washer 16, the electrode 14, and the piezoelectric element 12 can be urged toward the contact body 11 side. The pressure at that time can be adjusted by the tightening degree of the pressing member 19, but it is important to make it at least smaller than the breaking strength of the material of the contact body 11. When the same material as that of the blast furnace carbon block is used as the material of the contact body 11, the biasing pressure by the spring 18 is suitably set to 7.35 MPa or less, for example.

  The measurement terminal 1 according to the present embodiment has the above-described configuration. For example, when the measurement terminal 1 is used as an ultrasonic wave transmission terminal, as shown in FIG. What is necessary is just to apply the pulse voltage for ultrasonic transmission by the pulse power supply 21, for example between 14 and the spring support member 17. FIG.

  Next, the measuring method which measures the thickness of the refractory brick of a blast furnace using the measuring terminal 1 concerning this Embodiment is demonstrated. FIG. 4 schematically shows the cross section of the furnace wall of the blast furnace. In this example, the furnace 31 is composed of an iron shell 31, a back castable 32, a stave 33, a stamp material 34, and a carbon block 35 as a refractory brick in order from the outside. A wall is constructed.

  When measuring the thickness of the carbon block 35 of the furnace wall having such a structure, the measurement holes 36 and 37 that reach the outermost peripheral surface of the carbon block 35 are formed, the bottoms of the measurement holes 36 and 37, That is, as shown in FIG. 5, the measurement end surface 11 b of the contact body 11 exposed from the end surface of the measurement terminal 1 is bonded to the outermost peripheral surface of the carbon block 35. In the example shown in FIG. 4, measurement holes 36 and 37 are formed at two locations on the furnace wall, and the measurement terminals 1 are set therein, respectively. This is because the set measurement terminal 1 is used for transmitting ultrasonic waves, and the measurement terminal 1 set in the measurement hole 37 is used for receiving reflected waves. The measurement terminals set in the measurement holes 36 and 37 have the same configuration.

  As shown in FIG. 6, when the end surface 11 b for measurement of the contact body 11 is bonded to the outermost peripheral surface 35 a of the carbon block 35, bonding is performed using an adhesive 41. In such a case, it is preferable that the adhesive itself has a homogeneity with the carbon block 35 and the contact body 11 even after the adhesive is cured. Therefore, the material of the adhesive 41 used in the present embodiment includes: A material in which the same material as that of the carbon block 35 and the contact body 11 is used as a main component and a phenolic resin is mixed as a binder is suitable. However, it is of course possible to measure using an adhesive made of any other material. However, considering the attenuation of ultrasonic waves, the mixing of noise, etc., the elastic modulus after curing is the elasticity of the object to be measured (carbon block 35 in the present embodiment) regardless of the adhesive made of any material. It is preferable to use an adhesive that is 1/10 to 1/1 of the rate. The thickness E of the adhesive 41 is preferably 1 mm or less.

  As shown in FIG. 5, a protective tube 43 is provided on the outer periphery of the signal cable 42 drawn from the electrode 14 or the like.

  After the measurement end surface 11b of the contact body 11 is bonded to the outermost peripheral surface 35a of the carbon block 35 and the measurement terminal 1 is set in the measurement holes 36 and 37 as described above, for example, the measurement terminal 1 By applying a measurement voltage, for example, a pulse voltage, to the piezoelectric element 12, an ultrasonic wave is transmitted from the piezoelectric element 12 and propagates directly from the contact body 11 into the carbon block 35. Then, the reflected wave reflected by the furnace side inner peripheral surface of the carbon block 35 is received by the receiving measurement terminal 1 set in the measurement hole 37, so that the carbon block 35 can be obtained from the reflection time and the ultrasonic wave propagation speed. Can be measured.

  As described above, according to the embodiment of the present invention, when measuring the thickness of the carbon block 35, it is not necessary to press the measurement terminal 1 against the outermost peripheral surface of the carbon block 35. It is only necessary to bond the measurement end face 11 b to the outermost peripheral face 35 a of the carbon block 35. Therefore, a mechanical device or the like for strongly pressing the terminal against the outermost peripheral surface of the carbon block 35, which is necessary for this type of conventional measuring terminal, is unnecessary.

  The measurement holes 36 and 37 may be formed after the furnace wall is formed. However, when the furnace wall itself is formed, the measurement holes 36 and 37 are formed at the same time, and the measurement terminals are previously connected to the measurement holes 36 and 37. May be set. In this way, after the furnace wall is completed, the thickness of the carbon block 35 can be measured even in a place where a measurement hole cannot be formed. Therefore, if the measurement terminal 1 according to the present embodiment is used, measurement at an arbitrary place becomes possible.

  In addition, since the piezoelectric element 12 and the contact body 11 are urged and brought into close contact with each other in the main body 2 in advance, a sufficient transmission level and reception level of ultrasonic waves can be ensured only by setting the measurement terminal 1 by the above-described adhesion. In addition, since the contact body 11 uses the same material as the carbon block 35, accurate measurement is possible.

  The present invention is useful, for example, when measuring the thickness of a refractory in the bottom of a blast furnace, a hot stove, a converter, or a vacuum degassing facility.

It is side surface sectional drawing of the terminal for a measurement concerning embodiment. It is an enlarged view of the lower end part of the measurement terminal of FIG. It is explanatory drawing which shows the contact | adherence state of the contact body of the measurement terminal of FIG. 1, and a piezoelectric element. It is explanatory drawing of the cross section which shows a mode that the thickness of the carbon block of a blast furnace is measured. It is explanatory drawing of the cross section which shows a mode that the terminal for a measurement was adhere | attached on the outermost peripheral surface of the carbon block. It is explanatory drawing of the cross section which shows the adhesion state of the terminal for a measurement, and a carbon block.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measurement terminal 2 Main body 3 Locking step part 11 Contact body 11a Locking part 11b Measurement end surface 11c Upper end surface 12 Piezoelectric element 13, 15 Bonding material 14 Electrode 16 Insulating washer 16a Hole 17 Spring support member 17a Support plate part 17b Tube Part 18 Spring 19 Pressing member 31 Iron skin 32 Back castable 33 Stave 34 Stamp material 35 Carbon block 35a Outermost peripheral surface 36 Measurement hole 41 Adhesive

Claims (6)

A terminal for measuring the thickness of a refractory by ultrasonic waves,
A single cylindrical shape with both ends open, a locking step protruding inwardly on the periphery of the opening at one end, and a thread groove formed on the inner periphery of the other opening The body of
An urging member disposed in the body;
A screw member formed on the outer periphery, screwed into an inner peripheral screw groove of the other opening of the main body, and holding the biasing member;
A piezoelectric element disposed in the body;
A contact body that is disposed in the main body and disposed in close contact with the surface of the piezoelectric element on the refractory side, and made of the same material as the refractory,
The contact body is exposed from the measuring end face locked to the locking stepped portion main body,
The piezoelectric element is urged toward the contact body by the urging member via a support plate portion ,
A terminal for measuring a thickness of a refractory , wherein the surface of the refractory and the measurement end face of the contact body are bonded with an adhesive . A terminal for measuring the thickness of the carbon block by ultrasonic waves,
A tubular body,
An urging member disposed in the body;
A piezoelectric element disposed in the body;
A contact body that is disposed in the main body and disposed in close contact with the surface of the piezoelectric element on the carbon block side, and is made of the same material as the carbon block ;
The contact body is locked to the main body and the measurement end face is exposed from the main body.
The piezoelectric element is biased toward the contact body by the biasing member ,
The refractory material is characterized in that the carbon block surface and the measurement end face of the contact body are bonded with an adhesive having a phenol resin as a binder, the main component being the same material as the carbon block and the contact body . Thickness measurement terminal. A terminal for measuring the thickness of the carbon block by ultrasonic waves,
A single cylindrical shape with both ends open, a locking step protruding inwardly on the periphery of the opening at one end, and a thread groove formed on the inner periphery of the other opening The body of
An urging member disposed in the body;
A screw member formed on the outer periphery, screwed into an inner peripheral screw groove of the other opening of the main body, and holding the biasing member;
A piezoelectric element disposed in the body;
A contact body that is disposed in the main body and disposed in close contact with the surface of the piezoelectric element on the carbon block side, and is made of the same material as the carbon block ;
The contact body is exposed from the measuring end face locked to the locking stepped portion main body,
The piezoelectric element is urged toward the contact body by the urging member via a support plate portion ,
The carbon block surface and the end face for measurement of the contact body are bonded with an adhesive containing a phenol resin as a binder, the main component being the same material as the carbon block and the contact body ,
Refractory thickness measurement terminal. The terminal for measuring a thickness of a refractory according to any one of claims 1 to 3, wherein lithium niobate is used as a material of the piezoelectric element. A method for measuring the thickness of a refractory using the refractory thickness measuring terminal according to any one of claims 1 to 4 ,
Before Symbol state wherein the measuring end surface of the refractory surface the contact body is bonded, and measuring the thickness of the refractory than applying a voltage to the piezoelectric element, the thickness measurement of the refractory Method. A method for measuring the thickness of a refractory using the refractory thickness measuring terminal according to claim 2 ,
Before Kise' Chakuzai has an elastic modulus after curing, the thickness measuring method of resistance fire was you, wherein a 1 / 10-1 / 1 of the refractory.

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