JP2636735B2 - Repair method of metallurgical furnace wall stamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a stamp of a metallurgical furnace wall, and more particularly, to a method of repairing a furnace wall brick of a metallurgical furnace represented by a blast furnace by restoring a decrease in cooling capacity of the wall brick. TECHNICAL FIELD The present invention relates to a method for repairing a stamping portion of a metallurgical furnace wall performed to suppress wear of a metal.

[0002]

2. Description of the Related Art FIG. 1 shows an air gap 6 formed in a stamp portion 2 provided between a lining brick 3 and a steel shell 1 of a metallurgical furnace (hereinafter, represented by a blast furnace) such as a blast furnace. Pressure inlet 5
2 shows a state in which a press-fitting material having good fluidity is press-fitted. When the position of the pressure inlet 5 matches the position of the air gap, the press-fitting is easily performed.

[0003] The press-fitting of a press-fitting material into such a furnace wall stamp portion (between a steel shell and a lining brick, the same applies hereinafter) has been widely practiced in the past. It is also described in the "Prior Art" section of "Press-fitting material for filling the furnace wall gap". However, the problem is how to accurately detect the presence of the air gap 6 in the stamp section 2 of FIG.

Conventionally, for example, as described in the above-mentioned publication, the necessity of press-fitting is determined by a thermometer embedded in a lining brick or pressed against the back surface (surface on the steel shell side) of the lining brick. The judgment was based on the detected temperature rise. Alternatively, in some cases, press-fitting was performed without determining whether or not there was an air gap.

[0005] For example, Japanese Patent Publication No. 4-25322 entitled "Press-fitting method for blast furnace press-fitting material" includes "opening a blast furnace furnace wall repair part,
A method of press-fitting through the opening, in which a hardening agent is added to a pre-kneaded refractory material immediately before press-fitting and supplied to a press-fit pump, and the press-fit material is press-fitted while being kneaded by the press-fit pump. '' However, there is no indication as to where to press fit.

[0006]

Therefore, the prior art has the following problems. When performing press-fitting without prior judgment The air gap generated in the stamp part is often local, and it is necessary to perform press-fitting using a large number of press-fitting holes, but press-fitting into a part where no air gap occurs Even if you try to press-fit, work costs (preparation,
There was a disadvantage that some of the prepared press-fitting materials were wasted.

[0007] In the case of judging from the temperature rise of a thermometer pressed against the back of the lining brick or embedded in the brick, and press-fitting into a portion where the temperature rises, the temperature rise of the brick is caused by the heat load in the furnace. Increase, brick wear,
This reflects the apparent decrease in the thermal conductivity of the stamp part (generation of air gap), the decrease in external cooling, and the like. Even if the temperature increases, the air gap does not necessarily occur in the stamp part. Rather, it is more often the case.

[0008] Therefore, there is a disadvantage in that, when press-fitting is attempted to a portion where an air gap is not generated and the press-fitting cannot be performed, the working cost is wasted as in the case described above. In addition, when the brick wear is small and the heat load in the furnace is small, the temperature rise of the brick is small even if an air gap is generated in the stamp part,
In some cases, it is determined that press-fitting is not necessary even though press-fitting is necessary, and press-fitting may not be performed.

In this case, when the heat load in the furnace rises in a state where an air gap is generated in the stamp portion, there is a large drawback that the bricks wear out at a stretch because cooling from outside the bricks is insufficient. In particular, since the wear of bricks shortens the life of the furnace, it is necessary to surely detect the occurrence of the air gap and to accurately know its position.

Thus, an object of the present invention is to detect the occurrence of an air gap in a stamp portion as reliably as possible, detect the position as accurately as possible, and press-fit only in the detected air gap. In the development of technology.

[0011]

Means for Solving the Problems Here, the present inventors have
As a result of various studies to achieve the above-mentioned purpose, the apparent thermal conductivity of the stamp part at the air gap generating part of the stamp part
(Thermal conductivity including the air gap of the stamp part) decreases, so by accurately detecting the part where the apparent thermal conductivity has decreased, the press-fitting material can be pressed into the air gap generating part without leaking. With this idea, the present invention has been completed.

Namely, it is an aspect of the present invention, determine the thermal conductivity of the apparent stamp portion constituting the blast furnace wall, air gap when it becomes smaller than a certain value the thermal conductivity of the calculated et the apparent The metallurgical furnace wall stamping repair method is characterized in that it is determined that there is a stamping material, and a press-fitting material is pressed into the air gap generation site detected in the stamping portion in this way.

According to a specific operation example according to the present invention, the apparent thermal conductivity of the stamp portion of each part is obtained by temperature measuring means attached at a pitch on a metallurgical furnace wall such as a blast furnace. It is judged that an air gap has occurred when the air gap has become smaller than the value obtained in advance, and by detecting the presence or absence of an air gap at the stamp portion, the press-fitting with good fluidity is performed without fail at the stamp portion where the air gap is occurring. The material is pressed in to restore the apparent thermal conductivity of the stamp.

[0014]

Next, the operation of the present invention will be described more specifically with reference to the accompanying drawings. Note that the same members are denoted by the same reference numerals throughout this specification. FIG. 2 is a schematic explanatory view of an air gap detecting operation according to the present invention when the present invention is applied to a furnace bottom side wall of a blast furnace, and a plurality of measuring means such as thermometers provided at predetermined intervals on the outer wall of the metallurgical furnace Is used to determine the apparent thermal conductivity of the stamp material in that area. In the illustrated example, a measurement hole that penetrates the steel shell 1 and reaches the stamp portion 2 and the lining brick 3 is provided to measure the temperature of the stamp portion 2 and the lining brick 3.
A point thermometer 4 is provided. This lining brick is in contact with the hot metal in the furnace. The pressure inlets 5 are provided at a similar pitch so as to surround these measurement holes, and are usually closed by a lid.

FIG. 3 shows the distribution of measurement holes and pressure inlets as viewed from the steel shell side. In the illustrated example, the measurement holes are provided at a constant vertical and horizontal pitch. When the thermal conductivity is reduced at −1 and the presence of the air gap is detected, the press-fitting of the stamp material is started from four pressure inlets 5-1 so as to surround the gap.

Here, a method for detecting the presence of an air gap will be described as follows. As shown in FIG. 4, the back surface temperature T ₃ of the lining brick 3 and the inside temperature T ₃ ′ of the brick are measured, and assuming that the cooling water temperature to the outer surface of the steel shell is T ₀ , the air gap is as follows. Its existence is determined.

First, the outer surface of the steel shell is spray-cooled,
The brick 3 is cooled by cooling the brick 3 through the steel skin 1 and the stamp portion 2.
Wear is suppressed. A two-point thermometer 4 (usually using a thermocouple, for example, a temperature measuring means using an optical fiber can also be used) is used to measure the back surface temperature T ₃ of the lining brick ₃ and the inside temperature of the brick (for example, a depth of 100 mm from the back surface). Temperature) T ₃ ′ is measured, and using this value, the heat flux q of the furnace wall is obtained from (Equation 3) described later.
Ask for. In addition, apart from measuring the furnace wall steel shell watering temperature T ₀ from this.

A plurality of two-point thermometers are previously mounted on the outer surface of the furnace wall in a vertical direction and a circumferential direction at a pitch of about 0.5 m to 2.0 m. Obtaining a thermal conductivity lambda ₂ of apparent stamp of that site using later from the heat flux q and the lining bricks back temperature T ₃ of the respective sites (Equation 2).

It is determined that an air gap is generated in the stamp portion for a portion where the obtained value of λ ₂ is lower than a certain reference value. Thus, by monitoring this value λ ₂ , it is possible to detect the occurrence of an air gap in the stamp portion.

FIG. As the detection reference of the air gap thickness and calculated by the air gap occurs whether shows the relationship between the thermal conductivity of the apparent determined stamp portion in the embodiment described later to 5, for example of the stamp portion lambda ₂ (heat Conductivity) should be half or 1/3 of the catalog value or the value at the time of construction.

As a means for measuring the heat flow rate q, the two-point temperature of the brick
(T ₃ , T ₃ ')
(T ₂ , T ₁ ) may be used. It is also possible to use a steel shell temperature (T ₁ or T ₂₎ in place of the water spray temperature.

A portion where an air gap has occurred in the stamp portion
(4-1 in Fig. 2), press-fit holes around it (5- in Fig. 2).
1) Low particle size, low viscosity, good filling property to air gap
Then, if possible, the air gap is filled with the press-fitting material by press-fitting a press-fitting material having high thermal conductivity, thereby making it possible to recover from a decrease in cooling to the lining brick.

As described above, the press-fitting material having good fluidity is press-fitted from the surrounding press-fitting holes (5-1) and the air gap is filled with the press-fitting material to recover the lowered heat conductivity of the stamp portion. The press-fitting material having good fluidity and the press-fitting operation at that time may be performed according to, for example, the above-mentioned Japanese Patent Publication No. 4-25322, and are not particularly limited in the present invention.
Further, the press-in holes (5-1) may be additionally provided as necessary.

In the present invention, the equations for calculating the thermal conductivity from the temperature measurement by calculation are summarized as follows. See FIG. The thermal conductivity λ ₂ of the stamp part is calculated from (Equation 2) derived from the steady one-dimensional heat conduction equation (Equation 1). The heat flow rate q was determined by (Equation 3).

[0025]

(Equation 1)

Where λ _{1 is} the thermal conductivity of the steel shell (kcal / mh
° C) λ ₂ : Thermal conductivity of stamp part (kcal / mh ° C) r ₁ : Outer radius of steel shell (m) r ₂ : Inner radius of steel shell (m) r ₃ : Outer radius of lining brick (m) r ₃ ' distance from the furnace center of the brick internal thermometer (m) alpha _0: nozzle unit heat transfer coefficient (kcal / m ² h ℃) However, lambda ₁ is 41.0 a known. Thus, according to the present invention, since the position of the air gap generated in the stamp portion can be specified, the following disadvantages can be eliminated as compared with the conventional method.

Waste of work and material costs due to the fact that it is not possible to press-fit into a part that does not require press-fitting. Insufficient cooling of the furnace wall bricks and the progress of brick wear because they were not pressed into the area where the air gap was generated (brick wear shortens furnace life). Next, the effects of the present invention will be described more specifically based on examples.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, the present invention was implemented in an arrangement as shown in FIGS. The temperature measuring means used in this example was a thermocouple-type two-point thermometer embedded in a brick so that the inside and the back of the lining brick could be measured.

A plurality of these two-point thermometers were previously mounted on the outer surface of the furnace wall at a pitch of about 0.5 m to 2.0 m in the vertical and circumferential directions. Brick two-point temperature of each part
From T ₃ , T ₃ ′, and the cooling water temperature T ₀ , the apparent thermal conductivity λ ₂ of the stamp portion at that site was determined using (Equation 2, Equation 3).

By monitoring this value, it was detected that an air gap had occurred in the stamp portion. In this example, since the catalog value of λ ₂ was 12.0 kcal / mh ° C., 1/3 thereof was used as the detection reference value. Table 1 shows an example of the result of applying the present invention to the bottom wall of a large blast furnace.

At the part (a), the lining brick temperature (T ₃ ) rises,
This is an example in which an air gap has occurred in the stamp section, and the apparent thermal conductivity of the stamp section has increased (recovered) after press-fitting. This is the conventional method (judgment by lining brick temperature)
This is an example in which press-fitting is determined to be necessary regardless of the method of the present invention.

In the part (b), the temperature of the lining brick is increased, but no air gap is generated in the stamp part.
I tried a press fit but could not press it. This is an example in which the conventional method incorrectly determines that press-fitting is necessary, while the method of the present invention correctly determines that press-fitting is unnecessary.

In the portion (c), the rise in the temperature of the lining brick was small, but an air gap was generated in the stamp portion, and the apparent thermal conductivity of the stamp portion increased after the press-fitting was performed.

If the heat load in the furnace increases (eg, the temperature of the hot metal or the flow velocity of the hot metal near the brick surface increases) if the air gap of the stamp portion is left, the bricks for cooling outside the furnace (water cooling to the steel shell) Since the cooling effect on the bricks is reduced, the bricks are worn out more quickly.

This is an example in which the conventional method makes an erroneous determination that press-fitting is unnecessary, while the present invention makes an accurate determination that press-fitting is necessary. FIG. 5 is a graph showing the results of the apparent thermal conductivity obtained by the calculation of this example.

[0036]

[Table 1]

[0037]

According to the conventional press-fitting method, the press-fitting is performed without knowing whether or not the air gap is generated in the stamp portion.
The following disadvantages were observed. Even if an attempt is made to press-fit into a place where there is no air gap, the press-fit cannot be performed, so that working costs and material costs are wasted. In large blast furnaces, there are about 100 injection holes,
It is difficult to press-fit all parts at once. Hasten. When the brick is worn out, the life of the furnace is shortened, leading to a large loss.

On the other hand, according to the present invention, since the position of the air gap generated in the furnace wall stamp portion can be accurately specified, there is no leakage to the air gap generating portion, and press-fit only to necessary portions. Since it can be implemented, the above-mentioned disadvantages of the conventional method can be solved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a state in which a stamp material is pressed into an air gap seen in a stamp portion.

FIG. 2 is a schematic explanatory view of temperature measuring means provided at predetermined intervals according to the present invention.

FIG. 3 is a distribution diagram of measurement holes.

FIG. 4 is an explanatory diagram showing each temperature and dimensions in (Equation 1).

FIG. 5 is a diagram (calculated value) of a relationship between an air gap thickness of a stamp portion and an apparent heat transfer coefficient.

[Explanation of symbols]

1: Iron skin 2: Stamp part 3: Lining brick 4: Measuring means 4-1: Stamp part thermal conductivity reduction part 5: Press-in hole 5-1: Press-in execution part 6: Air gap

Claims (1)

(57) [Claims] 1. A search of the thermal conductivity of the apparent stamp portion constituting the blast furnace wall, it is determined that the air gap when it becomes smaller than a certain value the thermal conductivity of the calculated et the apparent presence, thus A method for repairing a stamping part of a metallurgical furnace wall, wherein a press-fitting material is press-fitted into an air gap generation site detected in the stamping part.