JP3938658B2 - A method for predicting blow-through phenomena associated with blast furnace wind pressure fluctuations. - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for predicting an operation abnormality associated with fluctuations in wind pressure in a blast furnace, and particularly to predicting a blow-through phenomenon to prevent an operation abnormality.
[0002]
[Prior art]
In recent blast furnace operation, in order to reduce the amount of coke to be used and to reduce the cost, operation to increase the pulverized coal ratio to about 135 to 140 kg / t is performed.
However, when high production is performed, the lower part of the cohesive zone is lowered to near the limit, and the furnace wall is beaten to adjust the heat level of the pulverized coal, resulting in fluctuations in wind pressure. When such wind pressure fluctuations occur, a so-called blow-through phenomenon occurs, resulting in abnormal operation, and stable blast furnace operation cannot be performed.
[0003]
The following can be considered as causes of such a blow-through phenomenon.
First, troubles in charging the raw materials, troubles in coming out of the raw materials, or the disturbance of the balance in the circumferential direction during the charging of the raw materials cause the blow-through phenomenon.
Secondly, by reducing the coke ratio (coke / slag amount) and increasing the ore-by-coke (ratio of ore and coke amount), poor coke bed formation occurs, which is the cause of the blow-through phenomenon. Become.
Third, accumulation of powder due to coke pulverization or reduced sinter ore pulverization causes a blow-through phenomenon.
Fourth, high production, that is, high Bosch gas amount, causes poor ventilation in the lower part of the furnace, which causes a blow-through phenomenon.
[0004]
In order to perform stable operation of the blast furnace, it is necessary to identify the causes of these blow-through phenomena and remove them in advance. Further, in order to specify the cause of the blow-through phenomenon, the blow-through portion must be specified.
Conventionally, as a method for predicting this type of operation abnormality, for example, Japanese Patent Publication No. 60-41123 and Japanese Patent Publication No. 3-126806 have disclosed the technology. In such a conventional method of predicting operational abnormalities, sensors for detecting temperature, pressure, gas composition, etc. are installed in the furnace, and based on the measured values of these sensors, set reference values and theoretical values are detected. A comparison was made to predict operational abnormalities.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional operation abnormality prediction method, even though an operation abnormality is about to occur, the measured value of the sensor may not indicate an abnormality, so the occurrence of the operation abnormality can be accurately predicted. There wasn't.
Further, even when the measured value of the sensor indicates an abnormality, the analysis requires specialized knowledge, and no one can read out the occurrence of an operation abnormality.
For this reason, even if a sensor is installed, in order to predict the occurrence of abnormal operation, it is ultimately necessary to rely on the intuition of skilled workers, making it difficult to maintain stable blast furnace operation. .
The method for predicting abnormal operation associated with wind pressure fluctuations in a blast furnace according to the present invention has been proposed in view of the above-described circumstances, and stable and reliable operation of blast furnaces can be achieved by easily and accurately predicting operational abnormalities associated with wind pressure fluctuations in a blast furnace. The purpose is to do.
[0006]
[Means for Solving the Problems]
A method for predicting a blow-through phenomenon associated with a wind pressure fluctuation of a blast furnace according to the present invention is for achieving the above-described object, and a pressure measuring device and a stave temperature for measuring the pressure in the blast furnace in the height direction of the blast furnace side wall. A plurality of temperature measuring devices for measuring the temperature are provided as a measuring device group, and the measuring device group is installed in a plurality of locations in the circumferential direction of the blast furnace, and the differential pressure of each stage is provided for each measuring device group provided in the plurality of steps. In the measurement of the differential pressure of each stage, the difference in absolute pressure of each stage is divided by the distance between each stage to obtain the differential pressure of each stage. of the change with time of the differential pressure and stave temperature displayed by distinguishing each differential pressure and stave temperature, by monitoring the change in the differential pressure and stave temperature of each stage that the display, to predict the blow phenomena It is characterized by. By adopting such a blow-through phenomenon prediction method, it is only necessary to monitor the change of the three-dimensionally displayed differential pressure and stave temperature with the passage of time. Stable blast furnace operation can be performed without reliance.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, based on the drawings, an embodiment of a method for predicting abnormal operation associated with wind pressure fluctuations in a blast furnace according to the present invention will be described.
FIG. 1 is an explanatory view showing the arrangement of measuring devices and the like used in the abnormal operation prediction method according to the present invention, FIG. 1 (a) is an explanatory view showing a longitudinal section of a blast furnace, and FIG. It is explanatory drawing which shows the cross section of a blast furnace.
[0010]
On the side wall of the blast furnace 1, as shown in FIG. 1A, a pressure measuring device 2 for measuring the pressure in the blast furnace 1 and a temperature measuring device 3 for measuring the stave temperature are arranged in the height direction. A measuring device group 4 is configured by providing a plurality of stages. Moreover, this measuring device group 4 is installed in multiple places in the circumferential direction of the blast furnace 1 as shown in FIG.1 (b).
In the example shown in FIG. 1, ten measuring device groups 4 are provided in the height direction of the blast furnace 1, and four measuring device groups 4 are installed at equal intervals in the circumferential direction of the blast furnace 1. Each measuring device group 4 is connected to a processing device 5 for collecting and processing the measured pressure information and temperature information.
[0011]
The processing device 5 is composed of a computer including input means such as a keyboard and a mouse, output means such as a CRT display and printer, and storage means such as a hard disk storage device.
The pressure information and temperature information measured by each measuring device group 4 are transmitted to the processing device 5 and processed, and output as a three-dimensionally displayed graph.
In the arithmetic processing in the processing device 5, the differential pressure is obtained by standardizing by dividing the difference in absolute pressure of each stage by the distance between each stage.
[0012]
In addition, the arrangement | positioning number and arrangement position of the pressure measuring device 2 and the temperature measuring device 3 in each measuring device group 4 can be changed suitably, and can be implemented. Further, in each measuring device group 4, there may be a place where only the pressure measuring device 2 or only the temperature measuring device 3 is installed.
Furthermore, the number of arrangements and the arrangement positions of the measuring device groups 4 installed in the circumferential direction of the blast furnace 1 can be changed as appropriate.
The processing device 5 is not necessarily configured by a single device, but is configured by a plurality of devices such as a device that collects information and a device that processes the collected information and outputs a three-dimensional graph. You can also
[0013]
The three-dimensional graph output by the processing device 5 will be described with reference to FIG.
FIG. 2 is a graph that three-dimensionally displays changes in measured information over time, FIG. 2A is a three-dimensional graph of differential pressure, and FIG. 2B is a three-dimensional graph of stave temperature.
The example shown in FIG. 2A represents the measurement result of the differential pressure in the measuring device group 4 installed in the 270 degree direction. The horizontal axis represents time, the vertical axis represents differential pressure, and the time passes. It shows the change in differential pressure.
[0014]
(I) to (iii) shown on the horizontal axis represent the date, and numbers such as 1200 and 1400 represent time.
BP to B3, S1 to S5, and TP shown on the vertical axis represent the installation position of the pressure measuring device 2 in the measuring device group 4, and BP, B2, B3, S1, S3, S5, TP from the bottom to the top. It is installed in the order. Therefore, for example, S5-TP is a differential pressure between TP and S5, and S3-S5 is a differential pressure between S5 and S3.
Further, differential pressure, as shown in FIG. 2 (a), are presented separately for each 0.05 kg / cm ³ in the range of 0.00~0.25kg / cm ^3.
[0015]
Similarly, the example shown in FIG. 2B represents the measurement result of the stave temperature in the measuring device group 4 installed in the 270 degree direction. The horizontal axis represents time and the vertical axis represents the stave temperature. The change of the differential pressure with progress is shown.
(I) to (iii) shown on the horizontal axis represent the date, and numbers such as 1200 and 1400 represent time.
B1L to B3U and S1 to S5 shown on the vertical axis represent the installation positions of the temperature measuring device 3 in the measuring device group 4, and B1L, B1U, B2L, B2U, B3L, B3U, S1, S2 from the bottom to the top. , S3, S4, S5.
Further, the stave temperature is displayed separately for each 100 ° C. in the range of 0 to 500 ° C. as shown in FIG.
In FIGS. 2A and 2B, a blow-through phenomenon occurs at the position of the vertical broken line.
[0016]
According to the three-dimensional graphs of FIGS. 2 (a) and 2 (b), a blow-through phenomenon has occurred around 17:30 on day (ii), and the differential pressure between B2 and B3 has increased extremely. .
In addition, before this blow-through phenomenon occurs, the differential pressure between B2 and B3 has increased from about 10:30 on the day (ii), and in particular, (13) about 13:30 on the day and 14 At about 30 minutes, the differential pressure between B2 and B3 increases extremely. Correspondingly, (2) the B2U stave temperature has risen from about 11 o'clock on the day (ii), and in particular, the B2U stave temperature has risen extremely at around 13:00 on the (ii) day.
A similar phenomenon occurs at about 6 o'clock on day (i).
[0017]
As described above, when the analysis results based on the three-dimensional graphs of FIGS. 2A and 2B are comprehensively judged, at the B2 level, for example, the temperature is high immediately above the tuyere, but the air permeability is poor due to the softening of the ore. The layer, that is, the cohesive zone, is caused to stagnate due to some reason and becomes a stagnation layer.This stagnation layer partially collapses over time or partially creates cavities. It is speculated that the blow-through phenomenon was induced by passing.
However, although not shown, since no change is seen except in the direction of 270 degrees, it can be considered as a local descent stagnation.
[0018]
It is thought that the cause of such a stagnant layer suggests the limit of one blast furnace operation. In the above example, it can be inferred that the heat level and gas distribution in the vicinity of the tuyere and the consistency of ore reduction and melting ability cannot be achieved, and the thermal reduction balance of the entire blast furnace is balanced. However, it can be considered as an example of failure when partial inconsistencies occur.
Further, in the example shown in FIG. 2A, the differential pressure periodically fluctuates for each stage in the 270 degree direction. Such a cyclic differential pressure fluctuation of 10 hours or more can be estimated as the influence of the charging of raw materials or operation change.
[0019]
The changes in the three-dimensional graph as described above can be easily read even by those who have no specialized knowledge or many years of experience. Therefore, it is possible to perform stable blast furnace operation by predicting abnormal operation based on such a change in the three-dimensional graph and removing the cause of the blow-through phenomenon.
Note that the blow-through phenomenon occurs in the example shown in FIG. 2 described above, but this is for explaining the abnormal operation prediction method according to the present invention. In the abnormal operation prediction method according to the present invention, the blow-through phenomenon is actually performed. By removing the cause before the phenomenon occurs, it is possible to prevent the occurrence of the blow-through phenomenon.
[0020]
【The invention's effect】
Since the method for predicting the blow-through phenomenon associated with the wind pressure fluctuation of the blast furnace according to the present invention has the above-described configuration, the following effects can be achieved. That is, in the method for predicting a blow-through phenomenon associated with wind pressure fluctuation of a blast furnace according to the present invention, a pressure measuring device provided in a plurality of stages in the height direction of the blast furnace and a temperature measuring device for measuring a stave temperature are used for each stage in the blast furnace. In the measurement of the differential pressure and the stave temperature , and the measurement of the differential pressure of each stage, the difference in absolute pressure of each stage is divided by the distance between each stage to obtain the differential pressure of each stage, the change with time of the differential pressure and stave temperature of each stage is presented separately for each differential pressure and stave temperature monitors the changes in differential pressure and stave temperature of each stage that the display. Therefore, by the display changes in differential pressure and stave temperature of each stage, it is possible to recognize the change in the differential pressure and stave temperature of each stage at a glance, without the need for specialized knowledge and skilled Stable blast furnace operation can be performed without relying on the intuition of engineers.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view showing the arrangement of measuring devices used in an abnormal operation prediction method according to the present invention, (a) is an explanatory view showing a longitudinal section of a blast furnace, and (b) is a transverse section of the blast furnace. It is explanatory drawing which shows.
FIGS. 2A and 2B are graphs in which changes with time of measured information are three-dimensionally displayed. FIG. 2A is a three-dimensional graph of differential pressure, and FIG. 2B is a three-dimensional graph of stave temperature.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Blast furnace 2 Pressure measuring device 3 Temperature measuring device 4 Measuring device group 5 Processing device

Claims (1)

In the height direction of the blast furnace side wall, a pressure measuring device for measuring the pressure in the blast furnace and a temperature measuring device for measuring the stave temperature are provided in a plurality of stages to form a measuring device group. Installed at multiple locations in the circumferential direction, measure the differential pressure and stave temperature of each stage for each measurement device group provided in the plurality of stages , and measure the differential pressure of each stage, and normalized by dividing the distance between the stages seeking differential pressure of each stage, the change with time of the differential pressure and stave temperature of the respective stage and presented separately for each differential pressure and stave temperature, the display A method for predicting a blow-through phenomenon associated with fluctuations in the wind pressure of a blast furnace, wherein the blow-through phenomenon is predicted by monitoring the differential pressure and stave temperature change of each stage .

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