JP3607779B2 - Blast furnace bottom cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling apparatus for a blast furnace bottom that can determine a cooling region in the bottom of a blast furnace and can easily change and set the cooling region.
[0002]
[Prior art]
Conventionally, in order to protect the bottom brick lined on the bottom of the blast furnace, the bottom of the furnace is water-cooled by cooling pipes disposed on the side walls and the bottom of the bottom plate.
However, when there is a part where the heat removal by the cooling pipe is excessive, a high melting point component of the hot metal is deposited, forming deposits on the working surface of the furnace bottom brick, and the flow of hot metal in the furnace bottom changes, In some cases, the melting of the bottom brick becomes uneven, which may cause abnormal melting of the bottom brick.
Therefore, it is necessary to control the formation and fluctuation of such deposits and to perform cooling under appropriate cooling conditions in accordance with local heat load fluctuations at the blast furnace bottom.
For example, in Japanese Patent Laid-Open No. 2-104603, in the cooling method of the bottom of a blast furnace, the circular cooling range of the bottom of the furnace is divided into a central portion and a peripheral portion, and an indication of a temperature sensor embedded in the bottom brick Describes a method for cooling the bottom of a blast furnace in which the flow rate of cooling water is independently adjusted.
Japanese Laid-Open Patent Publication No. 63-105913 discloses a bottom of a blast furnace in which a cooling pipe is embedded, a heat transfer resistor is provided in a part of the cooling pipe, and the cooling capacity in the longitudinal direction of the cooling pipe is changed. A method of cooling the blast furnace bottom that forms regions with different cooling capacities is shown.
Furthermore, Japanese Patent Application Laid-Open No. 63-105399 describes a method of adjusting the amount of heat transfer by inserting a tube having heat transfer resistance into a heat transfer tube, which is a cooling tube, so that it can be expanded or contracted.
[0003]
[Problems to be solved by the invention]
However, in the method disclosed in Japanese Patent Laid-Open No. 2-104603, in order to set a predetermined cooling range, the cooling pipe is bent and embedded in the bottom of the blast furnace furnace. It is not easy to change, and there is a problem that it is difficult to repair when the cooling pipe breaks during use and the cooling water leaks.
[0004]
In the method disclosed in Japanese Patent Laid-Open No. 63-105913, the thickness of the deposit is calculated or estimated based on the indicated value of the thermometer embedded in the furnace bottom brick, and the parts of the slow cooling part and the normal cooling part are calculated. The decision is made.
However, since the layer thickness distribution of the deposits changes with time, it is not easy to strictly determine the boundary between the slow cooling part and the normal cooling part using the indication value of the thermometer at the setting time as an index. However, there is a problem that it is difficult to set optimum cooling conditions that change according to furnace conditions such as operation history and raw material components.
When the boundary cannot be set strictly in this way, when the boundary line is too close to the center, the amount of heat removed near the center of the blast furnace furnace increases, and the deposit in the center does not disappear. Maintained.
On the other hand, if the boundary line is too close to the outer periphery, the cooling effect due to normal cooling is insufficient and the amount of heat removed in the direction of the bottom plate decreases, so the heat load on the side wall increases and the side wall melts more intensely. This causes harmful effects such as
Further, in order to control the bottom plate cooling capacity, the cooling pipe is extracted from the bottom board, and the heat insulating material or the like is rearranged at a predetermined position of the cooling pipe and adjusted so as to have a predetermined cooling efficiency, or the cooling pipe It is necessary to insert a nozzle in the necessary place inside the inside and spray the heat insulating material, and attach a heat transfer resistor by forming a film, etc.In such a change of arrangement, or installation of the heat transfer resistor There was a problem of requiring a lot of labor and time.
[0005]
Also, in the method of inserting a tube having heat transfer resistance into a heat transfer tube (cooling tube) as described in JP-A-63-105399, the tube is expanded or contracted or moved accurately to a predetermined position. It is difficult to fix to the tube, and a tube expansion / contraction wire is required for pulling and holding the tube. The structure is complicated and the heat transfer resistance depends on the material of the tube itself. The resistance cannot be increased so much, and there is a drawback that a sufficient heat insulating effect cannot be exhibited.
Furthermore, when a part of the cooling pipe is abnormally heated, there is a problem that there is a risk of causing a steam explosion because there is no pressure escape path.
The present invention has been made in view of such circumstances, and appropriate cooling conditions can be accurately set according to the situation of the blast furnace bottom, and the cooling conditions can be easily changed. An object of the present invention is to provide a blast furnace bottom cooling device capable of maintaining operation.
[0006]
[Means for Solving the Problems]
The blast furnace bottom cooling device according to claim 1, wherein the cooling medium is supplied to a base end of a cooling pipe embedded in the bottom of the blast furnace, from the base end to the seal of the cooling medium. A cooling region in which the cooling medium reciprocates is provided in the cooling pipe, and a non-cooling region is provided in the cooling pipe ahead of the seal portion to cool the blast furnace bottom. The seal portion is provided with an expansion / contraction diameter mechanism that expands and contracts the inside of the cooling pipe in the pipe diameter direction and contacts and separates from the inner pipe wall .
[0007]
The blast furnace bottom cooling device according to claim 2 is the blast furnace bottom cooling device according to claim 1, wherein the seal portion and the cooling region have a pressure that flows from the non-cooling region to the outside air at the base end portion. A punch tube is provided.
The blast furnace bottom cooling device according to claim 3 is the blast furnace bottom cooling device according to claim 1 or 2 , wherein the expansion / contraction diameter mechanism of the seal portion is disposed on the inner wall of the cooling pipe; Deformation means for elastically deforming the rubber member in the tube diameter direction is provided.
[0008]
The seal portion refers to a portion that seals the cooling medium supplied from the base end side of the cooling pipe, and divides the cooling pipe into a cooling area that is cooled by the cooling medium and a non-cooling area where the cooling medium does not flow. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
First, a blast furnace bottom structure to which a blast furnace bottom cooling device according to an embodiment of the present invention is applied, based on a side sectional view and a plan sectional view of a blast furnace bottom 10 shown in FIGS. 1 and 2, respectively. I will explain.
As shown in FIG. 1 and FIG. 2, the blast furnace bottom 10 supports an iron shell 11a that constitutes the outer shell of the blast furnace, a furnace bottom brick 11 lined inside the iron shell 11a, and a furnace bottom brick 11 supported. And a cooling pipe 14 disposed between the bottom board 12 and the base 13 and a beam (not shown) that supports the bottom board 12 and forms an insertion gap of the cooling pipe 14.
The cooling pipe 14 is composed of a substantially straight pipe and is partitioned into a cooling area 20 that is cooled by cooling water, which is an example of a cooling medium, and a non-cooling area 21 in which the inflow of cooling water is restricted.
Here, the cooling region refers to a portion of the bottom brick where the cooling efficiency is set high. The cooling efficiency refers to the amount of change in the amount of heat removal in the cooled region per hour, and is adjusted by the flow rate of cooling water flowing through the cooling pipe, the heat transfer resistance of the cooling pipe, the heat transfer area, and the like. The cooling efficiency can be defined even in a state where the flow rate of the cooling water in the cooling pipe is reduced and this flow rate becomes zero.
And the position adjustment of such a cooling area | region 20 and the non-cooling area | region 21 moves the seal part 19 of the cooling device 18 inserted in the cooling pipe 14, and fixes this seal part 19 in a predetermined position. Thus, the setting of each cooling region 20 and the non-cooling region 21 can be performed.
[0010]
FIG. 3 is a side sectional view of the cooling device 18 inserted and arranged in the cooling pipe 14.
As shown in the figure, the cooling device 18 includes a seal portion 19 having an expansion / contraction diameter mechanism 46, a pressure release pipe 23 that supports the seal portion 19, and an outside of the pressure release tube 23, and the seal portion 19. And a sliding tube 22 provided so as to be slidable in the axial direction. The sliding tube 22 is slidably supported via a gland packing 33 and, if necessary, the gland packing 33 is fastened and fixed. A cooling pipe base end flange 30 provided at the base end of the cooling pipe 14, and a T-type connector 29 having a cooling water supply hole 27 attached to the base end of the sliding pipe 22. And a cooling device base end flange 31 which is attached to the T-type connector 29 and supports the pressure release pipe 23.
The cooling water supplied from the supply hole 27 flows between the pressure release pipe 23 and the sliding pipe 22 and flows into the sealing portion 19, and is provided on the sliding pipe 22 near the sealing portion 19. The bottom plate 12 is cooled while passing through the gap between the sliding pipe 22 and the cooling pipe 14, and the cooling water disposed at the base end of the cooling pipe 14 is cooled. The heated cooling water is discharged from the discharge hole 28 for discharging.
[0011]
As shown in FIGS. 3 to 5, the expansion / contraction diameter mechanism 46 includes a fixed flange 25 fixedly disposed outside the vicinity of the distal end portion of the pressure release pipe 23, and the pressure release pipe 23 at a position rearward of the fixed flange 25. A sliding flange 24 is slidably disposed on the outside and connected to the sliding tube 22, and a rubber member 32 provided between the fixed flange 25 and the sliding flange 24.
Therefore, by loosening the proximal packing bolt 36 of the cooling device proximal flange 31 to release the pressing pressure applied to the proximal packing 34 and adjusting the relative position between the sliding tube 22 and the pressure releasing tube 23, The distance between the fixed flange 25 and the sliding flange 24 can be increased or decreased.
FIG. 4 shows a state in which the distance between the fixed flange 25 and the sliding flange 24 is increased, and the rubber member 32 is reduced in diameter by being pulled in the length direction of the cooling pipe 14 to be cooled. It shows that a gap is created between the tube 14 and the position to be the seal portion 19 can be changed as necessary.
On the other hand, FIG. 5 shows that the distance between the fixed flange 25 and the sliding flange 24 is reduced, so that the rubber member 32 is compressed and expanded in the pipe radial direction, and the rubber member 32 is pressed against the inner wall of the cooling pipe 14. This shows a state where the seal portion 19 is formed.
[0012]
The cooling water flow rate in the cooling region 20 in the cooling pipe 14 can be adjusted via a supply valve 27 a and a discharge valve 28 a arranged at the base end of the cooling pipe 14, and the cooling pipe 14 is connected to the bottom plate 12. By arranging a plurality of cooling waters between the base plates 13 and supplying a predetermined flow rate of cooling water into the respective cooling pipes 14, a cooling zone in a predetermined range can be formed to cool the bottom plate 12.
In addition, thermocouples are arranged at a plurality of locations in the bottom brick 11, and the temperature of the bottom brick 11 that changes every moment can be measured, and the measured temperature data is taken into a computer (not shown) to perform necessary statistical calculation processing. It can be done.
[0013]
Then, the cooling method using the cooling device 18 of the blast furnace bottom which concerns on one embodiment of this invention arrange | positioned at the blast furnace bottom 10 demonstrated above is demonstrated.
First, the temperature of each part is measured by a thermocouple in which many furnace bottom bricks 11 in the blast furnace bottom 10 are arranged, and the temperature distribution of the blast furnace bottom 10 is obtained based on the measurement data and the like.
If the number of measurement point data obtained by a thermocouple or the like is small, set the heat conditions such as the cooling efficiency of the cooling pipe 14 and the thermal conductivity of the material involved, and based on the operation data such as the furnace bottom profile. It is also possible to obtain more accurate temperature distribution data by performing heat transfer calculation using a necessary finite element method or the like.
For example, such heat transfer calculation can be performed by the following procedure.
1) A furnace bottom profile including 11 furnace bottom brick thicknesses and a viscous layer (attachment layer) thickness is determined from the latest operation data.
2) As shown in FIG. 6, the furnace bottom brick 11 of the furnace bottom profile is divided into meshes as elements of heat transfer calculation, and physical properties such as thermal conductivity and specific heat of the material corresponding to each mesh position are obtained. decide.
3) Using the current furnace bottom brick 11 temperature (bottom temperature, sidewall temperature, etc.), cooling water temperature, hot metal temperature, measured base temperature, furnace profile data, and physical property data, each mesh Heat transfer calculation is performed in the middle or in a macro condition, and a heat constant that is a basis such as an overall heat transfer coefficient to the base 13 is determined.
4) Using the thermal constant including the obtained overall heat transfer coefficient and the known temperature data, the unknown temperature in each part of the furnace bottom brick 11 is calculated by back calculation, thereby obtaining a more detailed furnace bottom brick 11. Obtain the temperature distribution of.
In the heat transfer calculation, a Fourier heat conduction equation in which the heat flow between two parallel planes is proportional to the temperature difference, area, and time between the parallel planes and inversely proportional to the distance is applied. Can calculate the temperature of any point between two known points.
[0014]
And the adhesion distribution of the deposit 15 deposited on the working surface of the furnace bottom brick 11 can be estimated from the data of the temperature distribution changing every moment as follows.
That is, based on the heat constant data of the deposit layer and the profile data of the furnace bottom brick 11, an estimated temperature distribution that varies depending on the thickness of the deposit 15 layer is obtained by simulation calculation.
Then, by comparing the estimated temperature distribution with the temperature distribution, it is possible to set the distribution of the layer thickness of the deposit 15 corresponding to the estimated temperature distribution having the highest fitness, that is, the adhesion distribution.
Next, the adhesion distribution is compared with the optimum distribution of the deposit 15 obtained in advance, and the cooling area 20 of the furnace bottom brick 11 to be cooled preferentially is determined.
The adhesion distribution of the deposit 15 refers to the amount of deposit or the profile of the deposited layer of the high-melting point component on the working surface of the bottom bottom brick when the temperature of the bottom bottom brick 11 is measured.
The optimum distribution of deposits means that there is an abnormality in the deposit layer at the time of temperature measurement, which is calculated and estimated based on the operation period in the blast furnace, production volume, history of raw material components, and wear status of the bottom brick. Not a standard profile.
FIG. 7 shows an adhesion distribution in which the furnace bottom brick, which is an example of the adhesion distribution thus obtained, accumulates on the working surface of the furnace 11, and FIG. 8 shows a distribution showing an average optimum distribution of the deposit 15 at this point. FIG.
By comparing and comparing such an adhesion distribution with the optimum distribution, it can be seen that the thickness of the deposit 15 is particularly insufficient in the hatched portion in the upper left of FIG. 7, and the hatched portion needs to be cooled. It is judged.
Note that the setting of such a cooling region 20 may be the difference between the deposition distribution and optimum distribution is calculated using the computer a threshold value which are predetermined as regions as obtain super.
[0015]
The cooling device 18 inserted into each cooling pipe 14 is set to the corresponding position of the cooling region 20 as follows, with this necessary portion of cooling as the cooling region 20.
First, as shown in FIGS. 3 and 4, the base end packing tightening bolt 36 provided on the base end flange 31 of the cooling device is loosened to release the pressing force applied to the base end packing 34 and press the slide tube 22. The rubber member 32 is reduced in diameter by moving toward the base end side with respect to the extraction tube 23.
Then, in a state where the gland packing tightening bolt 35 provided on the cooling pipe base end flange 30 is loosened, the cooling device 18 is inserted and moved into the cooling pipe 14, and each cooling is performed as shown in FIG. The seal portion 19 of the device 18 is arranged at the boundary position of the cooling region 20.
Next, after the gland packing tightening bolt 35 of the cooling pipe base end flange 30 is tightened to fix the sliding pipe 22, the deforming means for extending the pressure release pipe 23 in the direction of the seal portion 19, FIG. As shown in FIG. 6, the rubber member 32 can be deformed and crimped to the inner wall of the cooling pipe 14 by reducing the distance between the sliding flange 24 and the fixed flange 25.
Then, in this state, the base end packing tightening bolt 36 of the cooling device base end flange 31 is tightened to fix the entire cooling device 18.
[0016]
Such an operation is performed for every necessary cooling pipe 14 so that the cooling region 20 determined by the position of the seal portion 19 of the cooling device 18 becomes the necessary predetermined cooling region 20.
The amount of the cooling medium supplied from the supply hole 27 of the T-type connector 29 is 0 to 20 T / Hr depending on the temperature condition of the furnace bottom. When cooling is required, it is about 15 ° C., which is an example of the cooling medium. Cooling water is supplied at a supply flow rate of 1 to 20 T / Hr.
This cooling water flows through the flow path between the pressure release pipe 23 and the sliding pipe 22 toward the front seal portion 19.
Next, the cooling water passes through a water passage hole 26 provided in the sliding tube 22 near the seal portion 19, and the flow direction of the cooling water is reversed toward the base end portion. While passing through the flow path between the pipes 14, heat is exchanged with the bottom plate 12 and heated, and the heated cooling water is discharged from the discharge holes 28 arranged at the base end of the cooling pipe 14.
[0017]
During this time, the cooling water is maintained without being supplied to the non-cooling region 21 in front of the seal portion 19, but the non-cooling region 21 communicates with the outside air through the pressure release pipe 23. Even if the sealing effect of the sealing portion 19 becomes incomplete and the cooling water leaks to the non-cooling region 21, the pressure is released, so there is no danger of a steam explosion and the furnace bottom can be cooled safely. it can.
In addition, if necessary, a cooling medium having a cooling capacity different from that of the cooling water, such as air, water vapor, or a mixed gas thereof, is circulated through the non-cooling region 21 via the pressure release pipe 23, and the respective cooling media are used. By adjusting the cooling capacity for each region, it is also possible to manage the adhesion distribution more precisely.
Further, two cooling devices 18 may be inserted into the same cooling pipe 14 so as to face each other, and both end portions of the cooling pipe 14 may be set as the cooling region 20 and the intermediate portion may be set as the non-cooling region 21.
And the said cooling water was sent in into the said cooling area | region 20 over a predetermined period, for example, 1 month, and the blast furnace bottom 10 was cooled.
As a result, the temperature distribution of the furnace bottom brick 11 changes, and the adhesion distribution of the deposit 15 estimated and calculated based on this temperature distribution is substantially uniform so as to match the initial target of FIG. It was possible to change to 15 distribution states.
[0018]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment, The change of the conditions etc. which do not deviate from a summary are all the application scopes of this invention.
For example, in the present embodiment, a mechanism made of a rubber member is used as the expansion / contraction diameter mechanism applied to the seal portion, but a metal umbrella having an expansion / contraction diameter mechanism can also be used.
Further, the rubber member can be pressed into the inner wall of the cooling pipe so as to form a plurality of pleats, and can be pressed against the inner wall by the elastic force when the rubber member expands to form the seal portion.
[0019]
【The invention's effect】
The blast furnace bottom cooling device according to any one of claims 1 to 3 , wherein the cooling device has a seal portion for a cooling medium fed into a cooling pipe from a base end portion of the cooling pipe, and the seal from the base end portion. A cooling region in which the cooling medium reciprocates is provided in the cooling pipe up to a portion, and a non-cooling region is provided in the cooling pipe ahead of the seal portion. The cooling region can be intensively cooled by dividing into the region.
For this reason, it becomes possible to efficiently cool the parts that require cooling of the blast furnace bottom brick, and the cooling region can be set or changed easily and easily without requiring significant modification of the existing cooling pipe. .
Further, since the seal portion is provided with an expansion / contraction diameter mechanism that expands and contracts the inside of the cooling pipe in the pipe diameter direction and contacts and separates from the inner pipe wall, the seal section is fixed at a predetermined position in the cooling pipe, Or the operation to move can be performed easily.
[0020]
In particular, in the blast furnace bottom cooling device according to claim 2, the seal portion and the cooling region are provided with a pressure release pipe that escapes from the non-cooling region to the outside air at the base end portion, so that the seal portion is not used. Even if the cooling water leaks from the cooling region to the non-cooling region, the non-cooling region is not sealed, the internal pressure does not increase, and the blast furnace can be operated safely.
In the blast furnace bottom cooling device according to claim 3 , the expansion / contraction diameter mechanism of the seal portion includes a rubber member disposed on the inner wall of the cooling pipe, and a deformation means for elastically deforming the rubber member in the pipe radial direction. Therefore, the seal portion can be easily and reliably formed in the cooling pipe.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a structure of a blast furnace bottom.
FIG. 2 is a plan sectional view showing a structure of a blast furnace bottom.
FIG. 3 is a side sectional view of a blast furnace bottom cooling device according to an embodiment of the present invention.
FIG. 4 is a detailed sectional view of an expansion / contraction diameter mechanism in the cooling device.
FIG. 5 is a detailed cross-sectional view showing a sealed state of the expansion / contraction diameter mechanism in the cooling device.
FIG. 6 is a mesh division diagram in a furnace bottom profile.
FIG. 7 is a diagram showing an adhesion distribution of deposits on an operating surface of a furnace bottom brick.
FIG. 8 is a diagram showing an optimum distribution of deposits on the operating surface of the furnace bottom brick.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Blast furnace bottom 11 Furnace brick 11a Iron skin 12 Base 13 Base 14 Cooling pipe 15 Deposit 18 Cooling device 19 Sealing part 20 Cooling area 21 Non-cooling area 22 Sliding pipe 23 Depressurizing pipe 24 Sliding flange 25 Fixed flange 26 Water passage hole 27 Supply hole 27a Supply valve 28 Discharge hole 28a Discharge valve 29 T-type connector 30 Cooling pipe base end flange 31 Cooling device base end flange 32 Rubber member 33 Gland packing 34 Base end packing 35 Gland packing tightening bolt 36 Base End packing tightening bolt 46 Expansion / contraction mechanism

Claims (3)

A cooling medium is supplied to the base end portion of the cooling pipe embedded in the bottom of the blast furnace furnace, and a cooling region in which the cooling medium reciprocates is provided in the cooling pipe from the base end portion to the cooling medium seal portion. In addition, in the cooling device for the blast furnace bottom where the non-cooling region is provided in the cooling pipe ahead of the seal portion to cool the blast furnace bottom,
The blast furnace bottom cooling device according to claim 1, wherein the seal portion is provided with an expansion / contraction diameter mechanism that expands and contracts the inside of the cooling pipe in the pipe diameter direction and contacts and separates from the inner pipe wall . The blast furnace bottom cooling device according to claim 1, wherein a pressure release pipe is provided in the seal portion and the cooling region to escape from the non-cooling region to the outside air at the base end. The seal portion of the expansion diameter mechanism, wherein a rubber member disposed on the inner wall of the cooling tube, according to claim 1 or 2, characterized in that the rubber member has a deformation means to elastically deform in the pipe diameter direction The blast furnace bottom cooling device described.

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