JP4294206B2 - Blast furnace wall structure and blast furnace operation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a side wall of a blast furnace body, particularly to a furnace wall structure of a high heat load portion and a method of operating the blast furnace.
[0002]
[Prior art]
In the blast furnace wall, a furnace wall is formed by stretching a stave cooler provided with an internal cooling mechanism inside the iron skin. Cast coolers are used as stave coolers. Generally, stave coolers are made of cast iron with a cooling pipe that circulates the cooling medium inside, and fixed bricks are spaced on the furnace cooler surface of the stave cooler. Are embedded in multiple stages.
[0003]
Further, as disclosed in Japanese Patent Laid-Open No. 11-293312, a stave cooler using copper or a copper alloy instead of cast iron is also employed in order to improve the cooling capacity of the stave cooler. Conventionally, in these stave coolers, cast iron stave coolers have been adopted for the low heat load portions 11 such as the middle upper portion and tuyere portion of the blast furnace main body shaft portion, which are relatively low in load. A copper or copper alloy stave cooler is employed for the load section 10 and is used in accordance with the cooling capacity of the stave cooler.
[0004]
Japanese Patent Laid-Open No. 10-60510 is disclosed as a method for monitoring the furnace condition in the blast furnace furnace. This method is a method in which a plurality of pressure sensors are arranged on the shaft portion, the pressure detected by the pressure sensors is analyzed in time frequency, the vicinity of a specific frequency is monitored, and the abnormal furnace condition is predicted in advance.
[0005]
[Problems to be solved by the invention]
Since the cast iron stave cooler employed in the low heat load portion has a lower cooling capacity than the copper and copper alloy stave cooler, the portion facing the furnace maintains a relatively high temperature. For this reason, there is little adhesion of the deposit | attachment to the surface of a stave cooler, and it is in the state which is easy to detect the change of a furnace condition.
[0006]
The surface of the copper and copper alloy stave cooler used in the high heat load section adheres to the adhesion of the molten material in the furnace and the iron ore powder, which grows and heats the main body of the stave cooler. Self-flying phenomenon that protects from impact and wear occurs. This cell flying results in a prolonged life of the stave cooler.
[0007]
In addition, a copper and copper alloy stave cooler employed in a high heat load section has a high cooling capacity, and thus has a characteristic that the temperature of the stave cooler is usually about 70 ° C. and the temperature fluctuation is small. Therefore, even if an attempt is made to determine the in-furnace condition of the furnace body using this copper and copper alloy stave cooler, the temperature fluctuation is very small, so the heat load condition in the furnace should be estimated based on this temperature fluctuation. I could not. For this reason, it has been delayed to detect changes in the state of the furnace, and the furnace state has been sluggish. To avoid it, there has been a tendency to operate at a high fuel ratio.
[0008]
An object of the present invention is to provide a blast furnace wall structure and a method of operating a blast furnace that can quickly estimate fluctuations in the furnace even in a place where a copper and copper alloy stave cooler is used.
[0009]
[Means for Solving the Problems]
That is, the gist of the present invention is as follows.
(1) In a furnace wall structure of a blast furnace in which a stave cooler is stretched on the side wall of the blast furnace furnace body to form a furnace body, a plurality of cast iron ribs 1 at predetermined intervals on the circumference of the inner peripheral surface of the furnace wall The rib 1 has a longitudinal direction in the furnace height direction, and a pressure gauge 6 for detecting the pressure in the furnace and a thermometer 5 for detecting the temperature of the cast iron rib are embedded in the rib 1, A blast furnace wall structure characterized in that the stave cooler stretched between the cast iron ribs disposed on the wall is a stave cooler 2 made of copper or copper alloy .
(2) In a furnace wall structure of a blast furnace in which a stave cooler is stretched on the side wall of a blast furnace furnace body to form a furnace body, a plurality of cast iron ribs 1 are arranged at predetermined intervals on the inner peripheral surface of the furnace wall, The longitudinal direction of the cast iron rib 1 is directed in the furnace height direction, and a pressure gauge 6 for detecting the pressure in the furnace and a thermometer 5 for detecting the temperature of the cast iron rib are embedded in the rib 1 and arranged on the furnace wall. A blast furnace wall structure characterized in that a stave cooler stretched between ribs made of cast iron is a stave cooler 2 made of copper or copper alloy .
(3) The blast furnace wall structure according to (1) or (2), wherein a cooling pipe 7 for cooling the rib is embedded in the cast iron rib.
(4) The blast furnace furnace wall structure according to any one of the above (1) to (3), wherein the wear-resistant material 8 is cast on the furnace inner surface of the cast iron rib.
(5) The blast furnace furnace wall structure according to any one of the above (1) to (4), wherein the cast iron rib projects further from the furnace inner surface of the stave cooler and is exposed to the furnace inner side. .
(6) The blast furnace wall structure according to (5) above, wherein a plurality of thermometers having different lengths are embedded in one cast iron rib.
( 7 ) A method for operating a blast furnace having the blast furnace wall structure according to any one of (1) to ( 6 ) above, wherein the pressure gauge is embedded in a rib 1 made of cast iron disposed on the inner peripheral surface. A method for operating a blast furnace, wherein the in-furnace situation is estimated from detection results of the thermometer 6 and the thermometer 5.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 is a longitudinal sectional view showing a blast furnace furnace wall structure according to the present invention, as viewed from the direction of arrows EE in FIG. 2, FIG. 2 is an end view taken along line AA in FIG. 1, FIG. 3 is a partially enlarged view of FIG. 3 is a sectional view taken along the line BB in FIG. 3, FIG. 5 is a sectional view taken along the line CC in FIG. 3, FIG. 6 is a sectional view taken along the line DD in FIG. 8 is a longitudinal sectional view of a blast furnace furnace wall structure, FIG. 8 is a graph of the temperature of a copper or copper alloy stave cooler and a temperature in a cast iron rib, and FIG. 9 is a longitudinal end view of a conventional blast furnace furnace wall structure.
[0011]
In the blast furnace wall structure shown in FIG. 1, a copper or copper alloy stave cooler is stretched on a high heat load portion 10 of the blast furnace furnace body, and the cast iron rib 1 of the present invention is placed on the copper or copper alloy stave cooler stretched portion. Is adopted. FIG. 2 shows a cross-sectional view of a blast furnace cast iron rib 1 arrangement portion. In the above (1) of the present invention, a plurality of the cast iron ribs 1 are disposed at predetermined intervals in the circumferential direction of the inner peripheral surface of the blast furnace body. In the above (2) of the present invention, A plurality of stages are arranged at predetermined intervals in the inner peripheral furnace height direction. The embodiment shown in FIGS. 1 and 2 is a combination of the above (1) and (2) of the present invention, in which eight cast iron ribs 1 are arranged at equal intervals on the circumference and at the same time in the vertical direction. Are continuously arranged in four stages. In the embodiment shown in FIG. 1, a cast iron stave cooler 2a is disposed in the low heat load portion 11 of the blast furnace furnace body.
[0012]
The cast iron rib 1 has its longitudinal direction oriented in the furnace height direction. That is, the cast iron rib 1 is a vertical rib. This is because the cast iron ribs 1 are in direct contact with the contents of the blast furnace, and the contents of the blast furnace descend in the blast furnace, so that the contents of the blast furnace are deposited on the cast iron ribs 1 unless the ribs are vertical.
[0013]
FIG. 3 shows an enlarged structure of the cast iron rib 1. In FIG. 3, the cast iron rib 1 is divided into a plurality of parts in the furnace height direction. Each of the cast iron ribs 1 divided into a plurality of pieces and arranged in the vertical direction is provided with a pressure gauge 6 for detecting the pressure in the furnace, and the pressure difference detected by each of the pressure gauges 6 (furnace By observing the internal differential pressure, the fluctuation state in the furnace is estimated. In the operation of the blast furnace, the operation is controlled so that the pressure difference in the furnace falls within a certain range. Therefore, if the in-furnace differential pressure fluctuates and exceeds the certain range, it means that the fluctuating furnace condition has occurred. That is, the fluctuation of the furnace condition is predicted in advance by observing the in-furnace differential pressure. can do.
[0014]
Since a copper or copper alloy stave cooler has a very high cooling capacity, the temperature of the surface inside the furnace of the stave cooler is low, and deposits 4 adhere to the surface as shown in FIG. On the other hand, the cast iron rib of the present invention has a lower cooling capacity than a copper or copper alloy stave cooler, so the furnace inner surface of the cast iron rib 1 is in a high temperature state reflecting the furnace temperature. It is difficult for deposits to adhere. For this reason, if the temperature near the furnace inner surface of the rib 1 made of cast iron is measured, the temperature in the furnace can be detected.
[0015]
A plurality of thermometers 5 having different lengths are arranged on each of the cast iron ribs 1 divided into a plurality in the furnace height direction. The longest thermometer 5a reaches the furnace inner surface of the cast iron rib 1 and embeds it. The thermometer 5a detects the temperature state in the furnace. With this thermometer 5a, the temperature distribution in the furnace is investigated, and the abnormality of the furnace condition is estimated from the temperature condition in the furnace.
[0016]
Each cast iron rib 1 is sequentially provided with thermometers 5b, 5c, 5d having different lengths. The thermometers 5b, 5c, and 5d are for estimating the thickness of the deposit 4 that adheres to the furnace inner surface of the copper and copper alloy stave cooler 2.
[0017]
Copper or copper alloy stave coolers are stretched on both sides of the cast iron rib 1. The cast iron rib 1 projects further from the furnace inner surface of the stave cooler and is exposed to the furnace inner side. When the thickness of the deposit adhered to the surface of the stave cooler is thin, the heat of the high-temperature furnace contents is also supplied from the side surface of the cast iron rib 1, so the temperature of the shortest thermometer 5c is also high. To be kept. When the thickness of the adhering matter adhering to the stave cooler increases, it becomes difficult for heat to be transmitted from the portion of the side surface of the cast iron rib 1 covered with the adhering matter 4. Therefore, as the deposit thickness increases, the temperature tends to decrease in the order of the short thermometers 5d to 5c and 5b. That is, based on the measurement results of the thermometers 5b, 5c, and 5d, it is possible to estimate the thickness of the deposits attached to the surface of the copper or copper alloy stave cooler 2.
[0018]
FIG. 4 is a view showing the pressure gauge 6 shown in FIG. 3, which is attached to the cast iron rib 1, and the pressure gauge 6 itself uses a generally used pressure gauge. FIG. 5 is a view in which the thermometer 5 a is attached to the cast iron rib 1. Further, as shown in FIG. 6, a cooling pipe 7 for cooling the cast iron rib 1 is embedded in the cast iron rib 1 on the iron skin side.
[0019]
As shown in FIGS. 4 to 6, the wear-resistant material 8 is cast on the side of the cast iron rib 1 facing the furnace, whereby the durability of the cast iron rib 1 can be increased. . As the wear-resistant material 8, heat-resistant cast steel (SCH22 or the like) can be used.
[0020]
FIG. 7 shows another embodiment of the present invention, in which cast iron ribs 1 are arranged at predetermined intervals in the circumferential direction on the inner peripheral surface of the furnace body, and the cast iron ribs 1 arranged on the upper stage thereof are: It is arranged so as to be shifted in the circumferential direction from the cast iron rib 1 located in the lower stage.
[0021]
FIG. 8 shows a time change state of the temperatures of the copper alloy stave cooler 2 and the cast iron rib 1. As shown in this figure, since the copper alloy stave cooler 2 has a high cooling capacity, the temperature distribution of the stave cooler 2 itself does not fluctuate very much. However, the cast iron rib 1 has a temperature fluctuation compared to the copper alloy stave cooler 2. Is big. This finding was found, and it was found that a pressure gauge and a thermometer were embedded in the cast iron rib 1 to estimate the state in the furnace.
[0022]
【The invention's effect】
As described above, the vicinity of the surface of the cast iron rib is maintained at a high temperature, and it is not covered with thick deposits grown on the surface of the copper or copper alloy stave cooler, making it sensitive to temperature and pressure changes in the furnace. Since it can be detected, fluctuations in the furnace can be estimated quickly. In addition, since it is possible to detect changes in the furnace conditions without delay and respond quickly, it is possible to maintain stable operation of the blast furnace and to reduce the manufacturing cost of hot metal by pursuing a low fuel ratio. Further, since the water-cooled tube and the wear-resistant material are cast on the cast iron rib, the durability of the cast iron rib is also improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a blast furnace furnace wall structure according to the present invention, and is a view taken in the direction of arrows EE in FIG.
FIG. 2 is an AA end view of FIG. 1, showing the arrangement of cast iron ribs.
FIG. 3 is a partially enlarged view of FIG. 1, showing a cast iron rib.
4 is a cross-sectional view taken along the line BB of FIG. 3 and shows a pressure gauge embedded in a cast iron rib.
5 is a cross-sectional view taken along the line CC of FIG. 3 and shows a thermometer embedded in a cast iron rib.
6 is a cross-sectional view taken along the line DD of FIG. 3, showing a cooling pipe embedded in a cast iron rib.
FIG. 7 is a longitudinal sectional view of a blast furnace wall structure showing another embodiment relating to the arrangement of cast iron ribs according to the present invention.
FIG. 8 is a graph showing changes over time in the temperature of a copper or copper alloy stave cooler and the temperature in a cast iron rib.
FIG. 9 is a vertical end view showing a conventional blast furnace wall structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cast iron rib 2 Copper or copper alloy stave cooler 2a Cast iron stave cooler 3 Iron skin 4 Deposit 5 Thermometer 6 Pressure gauge 7 Cooling pipe 8 Abrasion resistant material 9 Heat insulating material 10 High heat load part 11 Low heat load part

Claims (7)

In a furnace wall structure of a blast furnace in which a stave cooler is stretched on the side wall of the blast furnace furnace body to form a furnace body, a plurality of cast iron ribs are arranged at predetermined intervals on the inner peripheral surface of the furnace wall. The rib is made of cast iron and the pressure gauge for detecting the pressure inside the furnace and the thermometer for detecting the temperature of the cast iron rib are embedded in the rib, and the rib is disposed on the furnace wall. A blast furnace wall structure characterized in that the stave cooler stretched between the ribs is a stave cooler made of copper or copper alloy . In a furnace wall structure of a blast furnace in which a stave cooler is stretched on the side wall of the blast furnace furnace body to form a furnace body, a plurality of cast iron ribs are arranged at predetermined intervals on the inner peripheral surface of the furnace wall, and the cast iron Between the cast-iron ribs, the pressure gauge for detecting the pressure in the furnace and the thermometer for detecting the temperature of the cast iron rib are embedded in the rib, with the longitudinal direction of the rib directed in the furnace height direction, and disposed on the furnace wall A blast furnace furnace wall structure characterized in that the stave cooler stretched on is a stave cooler made of copper or copper alloy .   The blast furnace wall structure according to claim 1 or 2, wherein a cooling pipe for cooling the rib is embedded in the cast iron rib.   The blast furnace wall structure according to any one of claims 1 to 3, wherein a wear-resistant material is cast on a furnace inner surface of the cast iron rib. The blast furnace furnace wall structure according to any one of claims 1 to 4, wherein the cast iron rib projects further from the furnace inner surface of the stave cooler and is exposed to the furnace inner side. 6. The blast furnace wall structure according to claim 5, wherein a plurality of thermometers having different lengths are embedded in one cast iron rib. A method for operating a blast furnace having a blast furnace wall structure according to any one of claims 1 to 6 , wherein a detection result of a pressure gauge and a thermometer embedded in a rib made of cast iron disposed on the inner peripheral surface. A method of operating a blast furnace, characterized by estimating an in-furnace situation.

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