JP4568233B2 - Method for measuring remaining thickness of wearable members - Google Patents

Description

The present invention relates to a residual thickness measuring how the wear member for measuring the residual thickness of the wear member.

Conventionally, in containers and piping members in which it is difficult to see the inside directly, the material that flows through the inside of the container and the members constituting the piping member wears out. There is a request to measure.
For example, in a blast furnace, a bottom refractory such as a refractory brick is used for a bottom portion that receives hot metal. This furnace bottom refractory is worn by hot metal flow and is considered to be one of the major factors governing the life of the blast furnace, and the remaining thickness of the bottom refractory is sequentially measured during blast furnace operation to estimate the life of the blast furnace. Is required.

As a method for measuring the wear state of the bottom refractory from the outside, there is conventionally known a method of measuring the temperature of the outer surface of the bottom refractory and estimating and calculating the remaining thickness of the bottom refractory based on the measured temperature. It has been.
On the other hand, as a method for measuring the thickness of a measurement object made of a non-destructive insulator, a method using capacitance is also known. In this thickness measurement method, electrodes are arranged so as to sandwich the measurement object in the thickness direction. Then, by forming a capacitor and measuring the capacitance of the capacitor, the thickness of the measurement object can be estimated (see, for example, Patent Document 1 and Patent Document 2).

When this method using capacitance is used to measure the remaining thickness of the hearth refractory of the blast furnace, as shown in FIG. 11, the outer peripheral surface of the bottom wall brick 13 serving as the hearth refractory is placed on a metal plate. An electrode is formed by covering with 101, ensuring electrical continuity with the hot metal S inside the blast furnace, and detecting the capacitance between the hot metal S and the metal plate 101 separated via the furnace bottom side wall brick 13. Thus, it is conceivable to calculate the remaining thickness due to wear of the furnace bottom side wall brick 13.
In this case, assuming that the dielectric constant of the furnace refractory is ε (F / m), the remaining thickness is d (m), the capacitance is C (F), and the electrode area is S (m ² ), C = ε · Based on the expression S / d, the remaining thickness can be calculated.

JP-A-6-109409 (see FIGS. 1 and 5) JP-A-6-194114 (see FIG. 3)

However, such a conventionally proposed method for measuring the remaining thickness has the following problems. That is, in the method of estimating the remaining thickness by measuring the temperature of the outer surface of the furnace bottom refractory, there is a problem that it is difficult to estimate the remaining thickness with high accuracy because the measurement temperature varies greatly.
Also, in the method of measuring the remaining thickness by capacitance, a conductive material is indispensable on the inner surface of the furnace bottom refractory, that is, the worn surface, and it can be used except in special cases where hot metal is present inside. There is a problem that it is difficult. In addition, even when a conductive material such as a blast furnace is present, when the initial wear is not progressing, the inter-electrode distance d is detected too long as can be seen from the above equation. As a result, there is a problem that it is difficult to measure with high accuracy.
In addition to the above blast furnace bottom refractories, such a problem, in the structure such as a machine or a container having a sliding surface inside, the wear surface can not be directly observed, from the outside, The same problem can be recognized when it is desired to measure the remaining thickness due to sliding.

An object of the present invention is to provide a remaining thickness measurement how wear member capable of measuring the residual thickness of the wear member with high accuracy.

(1) The method for measuring the remaining thickness of a wearable member according to the present invention is a method for measuring the remaining thickness of a wearable member for measuring the remaining thickness of a wearable member used in combination .
A step of forming electrodes extending along the thickness decreasing direction of the wear member on the mutually opposing surfaces of the boundary portion between the wear members, and forming a capacitor by filling an insulating material between the formed electrodes; ,
And a procedure for detecting a change in capacitance of the capacitor and calculating a remaining thickness of the wearable member based on the detected change in capacitance.

According to this invention, by detecting the change in the capacitance of the capacitor formed as described above, the end portion on the wear surface side in the extending direction of the electrode is worn as the thickness of the wear member is reduced due to wear. Therefore, it is possible to detect a change in capacitance in the form of a decrease in electrode length, and the remaining thickness can be measured with high accuracy without any change in detection accuracy regardless of the degree of wear. .
Furthermore, according to the present invention, since it is not necessary to use a special member or the like separately, an electrode is formed on each end face of the wear member facing the boundary portion and the insulator material is simply filled. You can enjoy the actions and effects.

Here, as a method of calculating the remaining thickness from the detected change in capacitance, for example, a capacitance corresponding to the length of the electrode that decreases due to wear is detected in advance, and a calibration curve is based on this. Can be obtained by creating
The detected capacitance is C (F), the dielectric constant of the insulator between the pair of electrodes is ε (F / m), the remaining thickness of the wear member is L (m), and the width of the electrode is W (m). ), Where the distance between the opposing electrodes is d ₀ (m), it can also be obtained based on the following equation (A).
L = C · d ₀ / ε / W (A)

(2) In the present invention, the method for forming the electrode is to oppose the metals of Mo, Cu, W, Ta, Ti, Fe, Cr, Au, Ag, or Pt to each other at the boundary portion between the wear members. It can be formed by spraying or vapor-depositing on the surface to be adhered, or by attaching a synthetic resin film having the metal thin film formed on one surface to the opposing surfaces of the boundary portion between the wear members .

Here, as a method of forming the electrode on the end face of the wear member, a metal material such as copper, platinum, tungsten, molybdenum, iron, vanadium, titanium, etc. is formed as a thin film on the end face of the wear member by thermal spraying, vapor deposition or the like. These metal materials can be formed into a thin film on a film, and a method of sticking this to the end face of the wearable member can be employed.
Moreover, as the insulator material to be filled, since a plurality of wear members are combined, it is preferable to employ a material that joins the wear members such as mortar.

(3) In the present invention, the wear member used in combination may be a bottom wall brick of a blast furnace, and a boundary portion between the wear members may be a joint of the bottom wall brick. it can.

  According to the present invention as described above, there is an effect that the remaining thickness can be measured with high accuracy regardless of the degree of the remaining thickness due to the wear of the wear member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Blast furnace structure]
FIG. 1 shows a blast furnace 10 according to an embodiment of the present invention. The blast furnace 10 includes an iron skin 11, a furnace bottom brick 12 and a furnace bottom side wall brick 13 lined inside the iron skin 11, a bottom plate 14 for holding the furnace bottom brick 12, and tuyere 15 and 16. ing.
The furnace bottom brick 12 is stacked in a plurality of stages on the bottom board 14, and the furnace bottom side wall brick 13 is stacked in a plurality of stages in contact with the inner wall of the iron shell 11 outside and above the furnace bottom brick 12. The brick 12 and the bottom wall brick 13 are integrated.

Specifically, as shown in FIG. 2, the bottom wall brick 13 is arranged in a substantially circular shape in plan view so as to surround the bottom brick 12 and is stacked in the vertical direction to form the bottom wall. ing. The furnace bottom brick 12 and the furnace bottom side wall brick 13 are made of a material having excellent resistance to melting, such as anthracite, soil black smoke, and artificial black smoke. For example, one or more types of tar, pitch, and resin are kneaded and pressed. It can be filled between plates and molded with a pressure press.
Although not shown, the bottom plate 14 is provided with a cooling pipe so that the amount of cooling water supplied to the cooling pipe can be adjusted by an adjustment valve.
As shown in FIG. 1, the tuyere 15 can blow oxygen, pulverized coal, or the like into the blast furnace 10, can increase or decrease the blowing amount ratio, and can increase or decrease the combustion temperature at the front 16 of the tuyere. it can.

When the blast furnace 10 having such a structure is normal, the furnace bottom side wall brick 13 is free from abnormal wear and can maintain a stable operation.
However, a solidified layer (also referred to as a viscous layer) having metal and slag may be abnormally formed on the surface of the bottom brick 12 due to improper cooling of the bottom plate 14 or abnormal conditions in the furnace. Depending on the amount of the solidified layer formed, an annular flow along the bottom wall brick 13 of the hot metal is generated at the bottom of the blast furnace 10 and the bottom wall brick 13 is worn out.

Moreover, since the abnormally formed solidified layer suppresses the heat at the bottom of the blast furnace 10 from being transmitted to the furnace bottom brick 12, in this case, the temperature of the furnace bottom brick 12 decreases. Thereby, since the furnace bottom brick 12 contracts, the furnace bottom side wall brick 13 integrated with the furnace bottom brick 12 moves to the center of the blast furnace 10, and between the iron skin 11 and the furnace bottom side wall brick 13, For example, a gap of about 0.2 to 1 mm is formed. For this reason, even if it cools from the outer side of the iron skin 11, the furnace bottom side wall brick 13 cannot be cooled, but the furnace bottom side wall brick 13 is worn out.
Due to the above phenomenon, the furnace bottom side wall brick 13 is worn out from the inner surface side of the blast furnace 10, and therefore, the degree of wear, that is, the measurement of the remaining thickness of the furnace bottom side wall brick 13 from the outside with high accuracy is performed. This is very important in considering the lifetime of 10.

[First Reference Form]
In order to measure the remaining thickness due to wear of the bottom wall brick 13 of the blast furnace 10, the measurement method according to the first reference embodiment penetrates the inside and outside of the bottom wall brick 13 as shown in FIG. 3. That is, by drilling a hole 131 extending along the direction in which the thickness of the bottom wall brick 13 decreases, inserting the probe 20 into the hole 131, and detecting a change in the capacitance of the probe 20, The remaining thickness of the bottom wall brick 13 is measured.
The mounting position of the probe 20 can be set at an arbitrary position of the furnace bottom side wall brick 13. For example, in a wall body configured by combining a plurality of furnace bottom side wall bricks 13, a plurality of locations in the vertical direction and further a plane It is possible to set a plurality of locations that equally divide the circular wall body.
Further, since the probe 20 has a band shape and the hole 131 is usually drilled in a circular cross section, a gap portion of the hole 131 is filled with a sealing mortar 132.

The probe 20 includes a strip-shaped insulator 21 and an electrode 22 made of a conductor formed on the front and back surfaces of the insulator 21, and on the outer peripheral surface of the furnace bottom side wall brick 13 on the right side in the figure, The terminal 23 drawn out from the electrode 22 is exposed.
As the insulator 21, a ceramic such as alumina or a synthetic resin material such as polyimide tape can be used.
As shown in FIG. 4, the electrode 22 made of a conductor has a width dimension W slightly smaller than the width dimension W _{0 of} the insulator 21, and a plurality of electrode cells 221 arranged along the extending direction of the insulator 21. And a connecting portion 222 for ensuring electrical continuity between the electrode cells 221. As a conductor constituting the electrode 22, a metal film such as Mo, Cu, W, Ta, Cr, Au, Ag, or Pt can be used.

When such a probe 20 is used at a high temperature such as the side wall of the blast furnace 10, among the materials of the insulator 21 and the electrode 22 described above, an alumina foil is used as the insulator 21 and a Mo film is used as the electrode 22 made of a conductor. It is preferable to have good heat resistance.
On the other hand, when used at a low temperature as compared with the side wall of the blast furnace 10, it is preferable to adopt a polyimide tape as the insulator 21 of the probe 20 and a Cu film as the electrode 22 made of a conductor because of low cost and cost.
In addition, as a thickness dimension of the insulator 21, a thing of 400 micrometers is employ | adopted, for example, and the thickness dimension of the electrode 22 can be 10 micrometers, for example.
The probe 20 can be formed by adhering a conductive metal to the insulator 21 by a technique such as adhesion, vapor deposition, or thermal spraying. The most preferable is thermal spraying.

The electrodes 22 formed on the front and back surfaces of the insulator 21 are arranged so that the electrode cells 221 face each other, and a slight gap is formed between the adjacent electrode cells 221, The connection is made by the connecting portion 222 at the center in the width direction.
Although not shown in FIGS. 3 and 4, an LCR meter or the like for measuring the capacitance of the probe 20 is connected to the terminal 23 provided at the end of the electrode 22.
The capacitance of the probe 20 changes as the length L decreases from the end on the side where the terminal 23 is not provided due to wear or the like, and this change is detected by an LCR meter connected to the terminal 23. be able to.

Next, a procedure for measuring the residual thickness of the furnace bottom side wall brick 13 according to this preferred embodiment in detail.
First, in FIG. 4, the electrode cell 221 is cut out in the length direction from the end opposite to the terminal 23 side, and the capacitance C at each length is measured in advance. At this time, it is preferable to sequentially cut the gap between the electrode cells 221 with scissors or the like.
Specifically, for example, when a chemical impedance meter (manufactured by Hioki Electric Co., Ltd.), which is a type of LCR meter based on JIS R 1661, is used to measure the capacitance according to the number of defects of the electrode cell 221, the figure As shown in FIG. 5, a calibration curve G <b> 1 that gives the relationship between the number of missing cells by cutting and the capacitance C according to the number of electrode cells 221 is obtained. The number of missing cells is grasped as a decrease amount in the length L direction of the probe 20.

Next, a hole 131 is formed from the outer periphery to the inside of the furnace bottom side wall brick 13, and the probe 20 having the same specifications as the calibration curve G 1 is inserted into the hole 131, and the mortar 132 is inserted into the gap portion of the hole 131. Is filled and cured to block communication between the inside and outside of the blast furnace 10.
When the probes 20 are mounted in a plurality of locations on the bottom wall brick 13 and the blast furnace 10 is operated in this manner, the contact surface of the bottom wall brick 13 with the hot metal is caused by the phenomenon described above, as shown in FIG. Gradually wear out. At this time, the inner end of the probe 20 is in contact with the hot metal for a moment, and the pair of electrodes 22 are short-circuited via the hot metal. However, since the probe 20 is contracted by the heat of the hot metal thereafter, the end portion is recessed inward from the contact surface of the furnace bottom side wall brick 13, and electrical conduction between the pair of electrodes 22 is interrupted. Acts as a suitable capacitor.

In such a state that the bottom wall brick 13 of the furnace bottom is worn, the above-described chemical impedance meter is connected to the terminal 23, the capacitance of the capacitor formed by the probe 20 is measured, and the calibration curve G1 shown in FIG. Based on the number of missing electrode cells 221, the remaining thickness L of the furnace bottom side wall brick 13 (see FIG. 6) can be calculated using the above-described equation (A).
In the present reference embodiment, the bored holes 131 in the furnace bottom side wall bricks 13, had inserted a probe 20 into the hole 131 is not limited thereto, for example, pressure pressing of the furnace bottom side wall bricks 13 At the time of molding, pressure press molding may be performed with the probe 20 embedded in the furnace bottom side wall brick 13, and the furnace bottom side wall brick 13 embedded with the probe 20 may be incorporated at a predetermined position when the blast furnace 10 is constructed. Moreover, at the time of construction of the blast furnace 10, the probe 20 may be arrange | positioned in the boundary part between furnace bottom side wall bricks 13, ie, the joint part, and the probe 20 may be embed | buried in joint mortar.

First Embodiment
Next, a first embodiment of the present invention will be described. In the following description, members already described in the first reference embodiment are assigned the same reference numerals and description thereof is omitted.
In the first reference embodiment described above, the pre-formed probe 20 is inserted into the hole 131 formed in the furnace bottom side wall brick 13 and the capacitance of the capacitor formed by the probe 20 is measured. The residual thickness of the bottom side wall brick 13 was measured.
On the other hand, in the measurement method according to the first embodiment, as shown in FIG. 7, during construction of the blast furnace, the electrodes 31 are formed on the mutually opposing surfaces of the adjacent furnace bottom side wall bricks 13. The capacitor 30 is formed by filling the gap between the electrodes 31 with the joint mortar 32.

In the present embodiment, the electrode 31 is formed on the bottom wall brick 13 at an appropriate position during blast furnace construction. Specifically, the capacitor 30 is formed by the following procedure.
As shown in FIG. 8, the electrode 31 is formed on an end face corresponding to the joint portion of the bottom wall brick 13, and as a method of forming the electrode 31, for example, Mo, Cu, W, Ta, Cr, Au A metal such as Ag, Pt or the like is sprayed on the end face of the furnace bottom side wall brick 13, vapor deposited, or a synthetic resin film having a metal thin film formed on one side is attached to the end face of the furnace bottom side wall brick 13. The method to do can be adopted. The electrodes 31 do not have to be formed on the entire end surface of the furnace bottom side wall brick 13 and may be formed in a strip shape at some positions where the respective electrodes 31 are arranged to face each other.

When the formation of the electrode 31 is completed, a terminal wire 33 is provided at the outer peripheral side end of the furnace bottom side wall brick 13, and the terminal wire 33 is drawn outside the blast furnace in a state in which electrical continuity with the electrode 31 is ensured.
When the formation of the electrode 31 and the attachment of the terminal wire 33 are completed, as shown in FIG. 9, the joint mortar 32 is applied so as to cover the electrode 31 of one furnace bottom side wall brick 13, and both the electrodes 31 face each other. Thus, the other furnace bottom side wall brick 13 is joined.
When measuring the remaining thickness due to wear of the bottom wall brick 13, an LCR meter is connected to the terminal 33 to detect the capacitance C (F), and the joint width d ₀ (m ), The electrode width W (m), and the dielectric constant ε (F / m) of the joint mortar 32, the remaining thickness L = C · d ₀ / ε / W is calculated.

[ Second Embodiment]
Next, a second embodiment of the present invention will be described.
The probe 20 according to the first reference embodiment described above is configured such that the electrode cell 221 having the wide electrode 22 and the connecting portion 222 having the narrow width are continuous.
On the other hand, the probe 40 according to the second embodiment is different in that the electrodes 22 are formed in a band shape on the front and back surfaces of the insulator 21 as shown in FIG.
In the probe in this embodiment, the width direction dimension W1 of one electrode 22 is smaller than the width direction dimension W2 of the other electrode 22. This is to prevent conduction during manufacture.
In addition, since the material of the probe 40 in this embodiment, a formation method, and a usage method are the same as that of a 1st reference form, description is abbreviate | omitted.

As a further specific construction, shape and the like of the practice of the present invention, objects may be other structures such as in the range of the present invention can be achieved.

  The present invention can be suitably used to accurately measure the remaining thickness of partition walls and the like for which it is difficult to measure the internal wear state, and in particular, the remaining thickness of the blast furnace bottom brick and the bottom wall brick. It is suitable for measuring.

The schematic cross section showing the structure of the blast furnace concerning the embodiment of the present invention. The partial perspective view showing the structure of the furnace bottom in this embodiment. Sectional drawing showing the state which attached the probe to the furnace bottom side wall brick in this reference form. The top view showing the structure of the probe in this reference form. The graph showing the relationship between the defect | deletion number of the electrode cell of a probe in this reference form, and an electrostatic capacitance. Sectional drawing showing the state of the probe at the time of wear of the furnace bottom side wall brick in this reference form. Sectional drawing showing the structure of the capacitor | condenser which concerns on 1st Embodiment of this invention. The schematic diagram for demonstrating the procedure of the capacitor | condenser formation in this embodiment. The schematic diagram for demonstrating the procedure of the capacitor | condenser formation in this embodiment. The top view showing the structure of the probe which concerns on 2nd Embodiment of this invention. The schematic diagram for demonstrating the measuring method of the remaining thickness of the wearable member in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Blast furnace, 11 ... Iron skin, 12 ... Furnace bottom brick, 13 ... Furnace bottom side wall brick (abrasion member), 14 ... Bottom board, 15 ... Tuyere, 16 ... Before tuyere, 20 ... Probe (probe for residual thickness measurement) , 21 ... insulator, 22 ... electrode, 23 ... terminal, 30 ... capacitor, 31 ... electrode, 32 ... joint mortar (insulator material), 33 ... terminal wire, 40 ... probe, 101 ... metal plate, 131 ... hole 132 ... Mortar, 221 ... Electrode cell, 222 ... Connection part

Claims (3)

A method for measuring the remaining thickness of a worn member for measuring the remaining thickness of a worn member used in combination ,
A step of forming electrodes extending along the thickness decreasing direction of the wear member on the mutually opposing surfaces of the boundary portion between the wear members, and forming a capacitor by filling an insulating material between the formed electrodes; ,
Measuring the remaining thickness of the wearable member, comprising detecting a change in the capacitance of the capacitor and calculating the remaining thickness of the wearable member based on the detected change in the capacitance. Method. The electrode is formed by spraying or vapor-depositing Mo, Cu, W, Ta, Ti, Fe, Cr, Au, Ag, or Pt metal on the opposing surfaces of the boundary portion between the wear members. forming Te, or, according to claim 1, characterized in that pasting the synthetic resin film on which a thin film is formed of metal on one side surface to oppose to each other at the boundary between the wear member Method for measuring the remaining thickness of a worn member. The wear member used in combination of the plurality is a blast furnace bottom side wall brick,
The method for measuring the remaining thickness of a wear member according to claim 1 or 2 , wherein a boundary portion between the wear members is a joint of the bottom wall brick .

Images