JPH11229014A - Means for detecting temperature of furnace hearth part of blast furnace and operation of blast furnace using this temperature detecting means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the concentration of heat load into a specific position in a furnace hearth part, to restrain the erosion of a refractory and to attain the long service life by arranging a temp. detecting part for detecting the refractory temp. in the refractory of the furnace hearth part, lining up at least three pieces of temp. sensors with a prescribed interval and embedding on the same diameter line toward the outside from the axial center of a blast furnace. SOLUTION: In order to detect the temp. of the side wall refractory 2 with the temp. detecting part 3, the temp. sensors 4a, 4b, 4c are embedded on the same diameter line toward the side wall outside from the axial center of the blast furnace 1 with the prescribed interval. In the measuring instrument 5, the temp. distribution in the blast furnace 1 is analyzed in three-dimensions based on the detection signal transmitted from the temp. detecting part 3. When molten iron flow concentrates to a specific position in the inner wall of the blast furnace 1, the side wall refractory 2 thereat is worn. The temp. is raised in the order of 4a, 4b, 4c, and when the temp. diffence between 4a and 4b and the temp. difference between 4b and 4c, are made larger in this order, it is judged that the molten iron flow in the blast furnace 1 is strengthened, and cake ratio is changed and the float-up level of the furnace core is changed to prevent the concentration of the heat load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blast furnace hearth temperature detecting means and a blast furnace operating method using the temperature detecting means, and more particularly, to eliminating the concentration of hot metal flow on the inner wall of a blast furnace. .

[0002]

2. Description of the Related Art A blast furnace is operated by charging iron ore and coke from the furnace top and blowing oxygen and pulverized coal together with hot air from a tuyere. At that time, for the purpose of stable operation of the blast furnace, an operation is performed in which the pulverized coal ratio and the coke ratio are maintained at almost constant levels and are not varied. That is, the operation is often performed for a long period of time while keeping the amounts of iron ore and coke charged from the furnace top constant and the amount of pulverized coal blown from the tuyeres constant.

[0003] Further, in the operation of raising or lowering the pulverized coal ratio according to a production plan or a raw fuel plan, an operation of gradually changing the pulverized coal ratio or the coke ratio is performed. . In such a blast furnace operation, the ups and downs of the furnace core are determined by the balance between the load from the charge and the buoyancy of the hot metal and slag. Therefore, if the weight ratio between iron ore and coke is constant, the load is substantially constant, and the floating level of the furnace core is also substantially constant. The position of the lower end of the core of the blast furnace and its profile greatly affect the flow of molten iron in the hearth.

By the way, in the conventional blast furnace operating method, the molten iron flow at each tap hole repeats substantially the same pattern because the furnace core is fixed at a substantially constant position. Therefore, the heat load due to the flow of the hot metal concentrates at a specific position of the hearth, the erosion of the refractory located at that portion is accelerated, and the life of the blast furnace is shortened. For this reason, conventionally, in order to predict the temperature distribution of the hearth and the erosion line due to the flow of hot metal, a temperature detecting means including a temperature sensor such as a thermocouple has been provided in the side wall refractory of the blast furnace hearth. This temperature detecting means is configured by embedding one or two thermocouples at a predetermined interval on the same diameter from the axis center of the blast furnace to the outside of the side wall.

[0005]

However, in the above-mentioned conventional temperature detecting means, one or two points in the side wall refractory are required.
Since it was only possible to detect a temperature change at several places, there was a problem that the detection accuracy was low and the unsteady change could not be accurately analyzed. That is, when a temperature change is detected by one thermocouple, a temperature change in the blast furnace is analyzed based on the thermal conductivity of the refractory, and a temperature change is detected by two thermocouples. The temperature change in the blast furnace is analyzed based on the temperature difference between the two points where the thermocouples are installed. However, in any case, the three-dimensional analysis considering the passage of time cannot be performed. The concentration of hot metal flow in the blast furnace could not be grasped.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and accurately grasps the temperature distribution of the refractory on the side wall of the hearth so that the heat load on a specific position of the hearth can be improved. To prevent refractory erosion in the hearth,
It is an object of the present invention to provide a blast furnace hearth temperature detecting means capable of achieving a longer life of a blast furnace and a blast furnace operating method using the temperature detecting means.

[0007]

(Features) The present invention has the following features in order to achieve the above object. The invention according to claim 1 is temperature detection means for detecting the temperature of a refractory in a blast furnace hearth, wherein the temperature detection means detects the temperature of the refractory in the refractory in the blast furnace hearth. The temperature detector is characterized in that at least three temperature sensors are arranged at predetermined intervals and buried on the same diameter going outward from the center of the shaft of the blast furnace.

[0008] The second aspect of the present invention provides the first aspect.
In addition to the configuration of the invention described in the above, the temperature detecting section is provided at least two at the same height and the same circumferential position on the side wall of the blast furnace.
It is characterized by being provided in three places.

According to a third aspect of the present invention, a temperature detector for detecting the temperature of the refractory is provided in the refractory of the blast furnace hearth, and each of the temperature detectors extends outward from the axis of the blast furnace. A method for operating a blast furnace using temperature detecting means in which at least three temperature sensors are arranged side by side at predetermined intervals and embedded on the same diameter toward the blast furnace. In the temperature detecting section, the temperature rises sequentially from the center side of the blast furnace. When the temperature difference detected by a pair of adjacent temperature sensors increases in order from the center side of the blast furnace, the hot metal in the blast furnace facing the refractory where the temperature detection unit is installed is detected. It is characterized in that it is determined that the flow has become stronger, and an operation for relaxing the hot metal flow is performed.

(Operation) Since the present invention has the above-mentioned features, it has the following operation. According to the first aspect of the present invention, the temperature change of the refractory at each buried position is detected by each temperature sensor of the temperature detecting section. Since the temperature change is measured at three or more measurement positions, it is possible to perform a three-dimensional analysis in consideration of the passage of time, and to grasp the concentration of the molten iron flow in the blast furnace.

According to the second aspect of the present invention, the temperature change of the refractory at each installation position is detected by a plurality of temperature detection units provided at the same height and the same circumferential position of the side wall refractory. For this reason, the measurement accuracy can be further improved.

According to the third aspect of the present invention, the temperature detecting section detects that the temperature has risen in order from the center of the blast furnace, and detects a difference in temperature detected by a pair of adjacent temperature sensors from the center of the shaft of the blast furnace. When it is detected that the temperature increases in order, it is determined that the flow of the hot metal in the blast furnace facing the side wall refractory on which the temperature detection unit is installed is strengthened. By performing an operation for relaxing the hot metal flow based on this determination, concentration of the heat load on a specific position of the hearth is avoided.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a schematic configuration of a blast furnace using a temperature detecting means according to the present invention. FIG. 1 is a cross-sectional view, FIG.
FIG. 3 is an explanatory view showing a situation inside a blast furnace. As shown in FIGS. 1 and 2, a blast furnace 1 has a side wall refractory 2 inside a side wall refractory 2.
Is provided with a temperature detecting section 3 for detecting the temperature of the radiator. The temperature detector 3 is configured by burying three temperature sensors 4a, 4b, and 3c at predetermined intervals on the same diameter from the axis center of the blast furnace 1 to the outside of the side wall. Note that the number of temperature sensors 4 is not limited to three as described above, and may be four or more. Further, the temperature detector 3 may be provided at the bottom of the blast furnace 1.

The temperature sensor 4 is composed of, for example, a thermocouple, and is connected to a measuring device 5 installed at an appropriate position outside the blast furnace 1. The measuring device 5 includes a temperature sensor 4a,
This is a device for monitoring the detection output from b and c, and comprises, for example, a computer and its peripheral devices.
In addition, the above-mentioned temperature detecting unit 3 is configured such that the side wall refractory 2 is at the same height and the same circumferential position as the side wall refractory 2.
It is preferable to provide at two or more locations. The position at which the temperature detecting section 3 is provided is not limited to the two places described above, but may be one place or three or more places.

As shown in FIG. 3, iron ore 6 and coke 7 are charged into the blast furnace 1 from the furnace top, and oxygen and pulverized coal are blown together with hot air from a tuyere 8 provided at the lower part of the side wall. To make iron. The furnace core 9 located in the lower part of the furnace is a layer filled with coke 7, and receives buoyancy from the hot metal 10 and the slag 11, and the lower surface floats in the hot metal or sinks to the furnace bottom depending on the magnitude of buoyancy and load. This is because the specific gravity of the hot metal 10 is about seven times that of the coke 7.

When the operation is performed in such a blast furnace 1, the blast furnace 1
The internal heat is transmitted to the side wall refractory 2. The temperature detecting section 3 detects a temperature change in the side wall refractory 2 by each of the temperature sensors 4a, 4b and 4c and transmits a detection signal to the measuring device 5. In the measuring device 5, the temperature distribution and the like in the blast furnace 1 are three-dimensionally analyzed based on the detection signal transmitted from the temperature detecting unit 3. For example, when the hot metal flow is concentrated on a specific location on the inner wall of the blast furnace 1, the side wall refractory 2 at that location is heated, and the temperature rises toward the outside of the side wall refractory 2. As described above, when the hot metal flow is concentrated at a specific location on the inner wall of the blast furnace 1, the side wall refractory 2 at the location is worn.

Therefore, the temperature detecting section 3 detects that the temperature has risen in order from the axial center side of the blast furnace 1, and detects a pair of adjacent temperature sensors 4a, 4b and 4b, 4b.
c, it is detected that the temperature difference has increased in order from the center side of the blast furnace 1, that is, 4a, 4b, 4
The temperature rises in the order of c, and the temperature difference between 4a and 4b, 4b and 4
When the temperature difference of c increases in this order, it is determined that the flow of hot metal in the blast furnace 1 facing the side wall refractory 2 on which the temperature detecting unit 3 is installed is strengthened, and an operation for relaxing the flow of hot metal is performed. I do.

The procedure for detecting a change in the flow of molten iron in the temperature detecting section 3 will be specifically described with reference to FIGS. FIG. 6 is an explanatory diagram of the flow of molten iron in the blast furnace 1, FIG. 7 is an explanatory diagram of a temperature change of the side wall refractory 2, and FIG.
FIG. 9 is an explanatory diagram of a change in the detected temperature at a, 4b, and 4c
FIG. 4 is an explanatory diagram of a change in a detected temperature difference between the temperature sensors 4a, 4b, and 4c. As shown in FIG.
When the flow of hot metal flowing along the inner wall refractory 2 of the blast furnace 1 facing the a, 4b, 4c increases, the temperature boundary layer along the furnace wall of the blast furnace 1 becomes thinner as shown in FIG. The temperature of the furnace inner surface of No. 2 rises.

At this time, if the cooling of the inner wall refractory 2 on the outside of the furnace is kept constant, as shown in FIG. The temperature rises outward. That is, the temperatures T1, T2, T3 detected by the temperature sensors 4a, 4b, 4c
Rises in the order of 4a, 4b, and 4c as shown in FIG. Also, the temperature difference between the two adjacent points T1-T2, T2-
As shown in FIG. 9, T3 firstly rises T1-T2,
Subsequently, first, T2-T3 rises.

Therefore, the temperature sensors 4a, 4b, 4c
8 shows the behavior shown in FIGS. 8 and 9, it is determined that the flow of hot metal in the blast furnace 1 facing the side wall refractory 2 on which the temperature detection unit 3 is installed is strengthened. Can be. When it is determined that the hot metal flow at a specific position in the blast furnace 1 has increased, an alarm may be issued by an alarm device. The warning by the warning device is performed by, for example, generating a warning sound from a speaker, turning on a warning lamp, or displaying a warning display on a display device connected to a computer.

An example of a blast furnace operating method for relaxing the above hot metal flow will be described. First, the coke ratio, which is the amount of coke consumed per ton of pig iron, is periodically changed. The load of the iron ore 6 and coke 7 charged from the furnace top is applied to the furnace core 9 of the blast furnace 1, but if the coke ratio is changed, the load applied to the furnace core 9 will fluctuate. That is,
By periodically changing the coke ratio, the load applied to the mandrel 9 is varied to periodically change the floating level of the mandrel 9. When the floating level of the core 9 changes, the molten iron flow for each tap hole also changes, and
Concentration of heat load on a specific position of the hearth for a long time is avoided. Therefore, by periodically changing the coke ratio, refractory erosion in the hearth can be suppressed, and the life of the blast furnace 1 can be extended.

However, when the coke ratio is changed, the fuel ratio changes, and the production of pig iron is not stable. Therefore, in the blast furnace operating method of the present embodiment, when changing the coke ratio, the blowing amount of pulverized coal is periodically changed at a predetermined replacement rate in accordance with the periodic change of the charged coke.
In the present embodiment, the replacement rate is set to 0.8 to 1.0 kg of coke per 1 kg of pulverized coal. This takes into account the physical properties of coke and pulverized coal, the amount lost due to carburization, and the like. As described above, the amount of pulverized coal injected is periodically changed at a predetermined replacement rate in accordance with the periodic change in the amount of coke charged, so that the fuel consumption per unit of the hot metal 10 is maintained substantially constant. Will be done.

For example, the coke charging amount is 360 kg / t,
In the case of blast furnace operation based on the pulverized coal injection amount of 130 kg / t, the coke charging amount is increased from 385 kg / t to 335 kg / t.
t → 385 kg / t →, and pulverized coal is changed from 100 kg / t → 160 kg / t → 10
It changes periodically like 0 kg / t →. The change cycle in this case is, for example, two months. Such periodic changes in the coke ratio and the pulverized coal ratio can be expressed by the following equations. Coke 360-25 sin (π (t-t0)
/ 30) Pulverized coal 130 + 30 sin (π (t-t0)
/ 30) In the above equation, t: day, t0: reference date.

That is, the periodic changes in the coke ratio and the pulverized coal ratio show a sine curve as shown in FIG. 4, and the conditions in the furnace at that time are shown in FIGS. 5 (a), 5 (b) and 5 (c).
The floating level of the core changes periodically in the order shown in FIG. Therefore, the molten iron flow for each tap hole can be changed by the periodic change of the floating level of the core.

In this way, by changing the basic unit per ton of hot metal periodically so that the sum of the charged amount of coke and the injected amount of pulverized coal becomes substantially constant, the fuel consumption per unit of hot metal is reduced. While keeping the volume almost constant,
By changing the load applied to the furnace core, the floating level of the furnace core is changed periodically to change the molten iron flow for each tap hole. Thus, it is possible to prevent the heat load from being concentrated on a specific position of the hearth for a long time, suppress refractory erosion of the hearth, and achieve a longer life of the blast furnace. Also, in the operation of high pulverized coal, powder easily accumulates in the furnace core.
The cleaning effect of the furnace core can be provided, and the furnace core can be prevented from being deactivated. Further, depending on the condition of the furnace core, the sin curve fluctuation cycle can be advanced or delayed to deal with various conditions in the furnace.

[0026]

According to the present invention having the above-described structure,
The following effects can be obtained. Claim 1
According to the invention described above, the temperature detection unit is configured by embedding at least three temperature sensors at predetermined intervals on the same diameter extending outward from the axis center of the blast furnace. Therefore, based on the detection output from each temperature sensor, the temperature distribution of the refractory can be accurately grasped, and a three-dimensional temperature change analysis in consideration of the passage of time can be performed.

According to the second aspect of the present invention, at least two temperature detectors are provided at the same height and the same circumferential position on the side wall of the blast furnace. Therefore, since the temperature change of the side wall refractory at a plurality of positions can be detected, the temperature distribution of the side wall refractory can be grasped more accurately, and the temperature change can be analyzed in more detail.

According to the third aspect of the present invention, the temperature detecting section detects that the temperature has risen in order from the center of the blast furnace, and detects a difference in temperature detected by a pair of adjacent temperature sensors in the center of the blast furnace. When the temperature increases sequentially, it is determined that the hot metal flow in the blast furnace facing the refractory provided with the temperature detecting unit is increased, and an operation for relaxing the hot metal flow is performed. Therefore, by avoiding concentration of a heat load on a specific position of the hearth, refractory erosion of the hearth can be suppressed, and the life of the blast furnace can be extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a blast furnace using a temperature detecting means according to the present invention.

FIG. 2 is a partial vertical sectional view of the blast furnace shown in FIG.

FIG. 3 is a schematic diagram showing a situation inside a blast furnace.

FIG. 4 is an explanatory diagram showing changes in a coke charging amount and a pulverized coal blowing amount in the embodiment.

FIG. 5 is a schematic diagram showing a change state of a floating level of a furnace core in the present embodiment.

FIG. 6 is an explanatory diagram of the flow of hot metal in a blast furnace.

FIG. 7 is an explanatory diagram of a temperature change of a refractory wall.

FIG. 8 is an explanatory diagram of a change in detected temperature in a temperature sensor.

FIG. 9 is an explanatory diagram of a change in a detected temperature difference in a temperature sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blast furnace 2 Side wall refractory 3 Temperature detection part 4 Temperature sensor 5 Measuring device 6 Iron ore 7 Coke 8 Tuyere 9 Furnace core 10 Hot metal 11 Slag

Claims (3)

[Claims] A temperature detector for detecting the temperature of the refractory is provided in the refractory of the blast furnace hearth, wherein the temperature detector is at least on the same diameter extending outward from the axis of the blast furnace. A temperature detecting means for a blast furnace hearth, wherein three temperature sensors are buried side by side at predetermined intervals. 2. The temperature of the blast furnace hearth section according to claim 1, wherein at least two pre-temperature detecting sections are provided at the same height and the same circumferential position on the side wall of the blast furnace. Detection means. 3. A temperature detector for detecting the temperature of the refractory is provided in the refractory of the blast furnace hearth, wherein the temperature detector has at least the same diameter extending outward from the axis of the blast furnace. A blast furnace operating method using temperature detecting means in which three temperature sensors are arranged side by side at predetermined intervals and embedded therein, wherein the temperature detecting section detects that the temperature has increased in order from the center of the blast furnace, and When it is detected that the temperature difference detected by a pair of matching temperature sensors increases in order from the center side of the blast furnace, it is determined that the flow of hot metal in the blast furnace facing the refractory in which the temperature detection unit is installed is strengthened. A method for operating a blast furnace, wherein the operation for relaxing the hot metal flow is performed.