KR940007489B1 - Method of repair time decision - Google Patents

Abstract

The method deicides the proper time to repair the sprue, which is not influenced by the descent of the temperature of the external environment in using the data from the thermocouple which is located in the furnace sprue. In determining the proper time to repair the blast furnace sprue, a thermocouple (9) in the fireproof material of the sprue (2) of the drop point (4) of the molten metal is set at the same height as the ash discharger hole (6). The slope of the change in temperature is acquired and after the remaining thickness of the fireproof material is checked, the relationship of these data will be calculated. So the proper time for repairment can be estimated by this relationship.

Description

Determination Method of Repair Time for Goro-Tangdo Using Thermocouple

1 is a schematic diagram of a blast furnace and large tap water for carrying out the method according to the present invention, b is a longitudinal cross-sectional schematic diagram of a large tap water in FIG.

2 is a view showing a state in which a temperature sensor is installed in a large bath to implement a method using a conventional temperature sensor, b is a relationship between the number of days of use and the temperature in the conventional method of using a temperature sensor Some graphs to be omitted.

3 is a view showing the slope of the temperature change according to the number of days of use of the water used in the method of the present invention.

* Explanation of symbols for main parts of the drawings

1: exit 2: large bath

3: melt 6: discharging outlet

7: SKIMMER 8: outlet

9: thermocouple

The present invention relates to a method for determining the repair timing of a blast furnace, and more specifically, to install a thermocouple in the Daetangdo which is a passage for separating and transporting molten iron and slag in the blast furnace steelmaking process of the steel mill. It relates to a method of determining the repair time of the Goro-tangdo using the temperature information obtained through this.

The blast furnace usually has four tapholes and large taps, and the melt of 1500 ℃, which flows out at intervals of 2-3 hours, is transported through a large tap and separated into molten iron and slag. Will be used. On the other hand, the point where the melt falls to the large tap through the exit of the blast furnace is a sharp wear due to falling and high impact compared to other locations of the tap. Daetangdo is composed of various refractory materials. If the refractory wears out a lot, there is a problem of maintaining the continuity and safety of operation such as a short circuit. Therefore, each blast furnace plant decides the maintenance time of the large bathway by visual observation, direct observation, etc. in order to manage the waterway in order to maintain the refractory of safe thickness to prevent leakage. In other words, the maintenance time of the large bath is determined by the degree of erosion of the melt dropping part during the large bath, and the degree of wear is directly measured by visual observation or by discharging the melt remaining in the large bath after finishing the departure. do. However, in the conventional blast furnace factory, since the cover is installed on the upper side of the main bath in consideration of safety and environmental aspects, it takes a lot of manpower and time to determine the wear state of the main road by the conventional method as described above. . In addition, the visual observation method can not accurately determine the erosion state due to the high temperature during the flow of molten iron, the direct measurement method has a disadvantage that must discharge the residual melt in the large bath.

In addition, there is a method of using a temperature sensor obtained from the temperature sensor by installing a temperature sensor in the conventional large waterway, which is shown in FIG. In this method, when the temperature measured at the sensor measurement point reaches a predetermined threshold temperature, the timing is determined as the time for repairing the water. That is, as shown in FIG. 2A, when the melt passes through the large bath and local erosion and abrasion 14 occurs, there is a temperature change as shown in FIG. 2B and the temperature sensor 13 senses the temperature change. The wear state will be judged. However, the temperature rise in the large bathway is due to external factors such as non-uniformity of the usage time of the large bath, which is caused by the intermittent operation of the large bath in addition to local erosion or abrasion, that is, the change in the departure time during one operation. In this case, it is difficult to accurately determine the wear state of the large hot water because the temperature value in Equation changes.

Therefore, an object of the present invention is to not discharge the melt in the use of temperature information collected by installing a thermocouple in a large waterway to solve the above-mentioned disadvantages and problems as described above, and also affects the temperature rise due to external factors. It is to provide a method of determining the time for repairing large baths that do not receive a fee.

According to the present invention, there is provided a method for determining a water bath maintenance time for installing a thermocouple in a refractory of a melt-falling portion of a water bath at a height of an exhaust outlet and diagnosing abrasion from a slope of a temperature change obtained therefrom.

That is, according to the present invention, in the method for determining the maintenance time of the blast furnace, the temperature change obtained from the thermocouple is installed at the height of the exhaust outlet in the large-water refractories of the melt-dropping portion of the molten water, and the slope of the temperature change obtained therefrom is obtained. The remaining refractory thickness was measured at a time point corresponding to the slope of, and then the correlation between the slope of the temperature change and the amount of remaining refractory thickness was obtained, and the temperature gradient at the time point of repairing the large turbidity was set based on the correlation. And since the slope of the measured temperature change reaches the set slope of the temperature change relates to a method for determining the maintenance period of the Goro-tang water.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 shows a thermocouple installation in accordance with the implementation of the method according to the invention, in which the molten slag and molten iron 3 from the outlet 1 of the blast furnace fall into the large bath 2 and the melt falling portion ( 4) is more abrasion than other parts of the large bath (2). Then, the melt that has fallen is separated into slag and molten iron while passing through the large hot water, and the slag is discharged below the skimmer (SKIMMER) 7 into the exhaust hole 6. At this time, when the melt is ejected from the blast furnace and the molten iron outlet 8 is closed below the skimmer, the melt is always remaining as high as the height of the outlet in the large bath. In addition, a plurality of thermocouples 9 are installed between the insulating brick 10 and the clay brick 11 having the same height as the outlet of the melt dropping point for collecting temperature information, and are connected to the data collection system 12.

Here, reference numeral 5 denotes a lid.

As a result of collecting and analyzing the temperature information at the blast furnace water bath under actual operation for a long time using a thermocouple installed in the same structure as the first degree, a graph indicating the slope of the temperature change as in the third degree can be obtained.

FIG. 3 shows the temperature change of the initial use of the large bath 16 and the change of the temperature 17 when the melt flows and does not flow in the large bath and the slope 17 when the temperature rises. When the melt begins to pass through the large bath (18 parts in Figure 3) a temperature rise occurs and when the melt flow stops (19 parts in Figure 3) a temperature drop occurs. Since the rising temperature maintains a constant slope according to the wear state of the large bath, the wear state can be predicted from this slope. This slope is calculated by connecting the lowest and highest points in the waveform of temperature information.

The slope obtained by installing the thermocouple as shown in FIG. 1 is the amount of heat flow through the refractory per unit time, and the heat passed is dependent on the thickness of the refractory, so the state of the refractory can be determined from the calculated slope. will be. In order to determine the state of the refractory from the slope of the temperature change, by measuring the thickness of the refractory remaining at the time corresponding to the slope of each temperature change, the correlation between the slope of each temperature change and the amount of remaining refractory thickness at that time You need to get That is, as the residual thickness of the refractory decreases, the slope of the temperature change increases, so there is an inverse relationship between them. Is the standard that can determine the repair time of large baths. Therefore, the present invention is very simple and accurate to measure the slope of the current temperature change and determine the time point as the maintenance period of the large spring when the slope of the measured temperature change reaches the slope of the temperature change set through the correlation It is a way.

Hereinafter, the present invention will be described in detail through examples.

EXAMPLE

Table 1 shows the change in temperature rise slope (° C./min) three times in the large bath as shown in FIG.

TABLE 1

As can be seen in Table 1 above, the slope of the first part of the renovation and the total renovation after the cooling of the large fountain is completely cooled for the first time after the use of the large fountain. 0.3-0.46 and 1.52-1.75, respectively.

That is, the slope of the temperature rise by the method according to the present invention was found to be the main factor (factor) that can determine the repair time of the large bath.

On the other hand, in order to obtain more accurate data, the amount of molten iron that passed the large turbidity, the thickness of the residual refractory material, and the temperature rise slope at that time were measured at the slag side and the molten iron side, and the results are as shown in Table 2 below.

TABLE 2

As can be seen from Table 2 above, the fact that the refractory erosion of the molten iron side is less than that of the slag side, although the molten iron on the molten side (70,000 tons) is higher than the molten iron on the slag side (50,000 tons). While the amount of molten iron passes and the degree of refractory erosion are not necessarily proportional, the temperature rise slope according to the present invention shows that the degree of refractory erosion is accurately predicted.

That is, it can be seen that it is a very reliable method that can determine the repair time of the large hot water from the temperature rise slope according to the present invention.

As described above, according to the present invention, by determining the time of repair of the large bath using the slope of temperature information collected by the thermocouple installed at the height of the outlet in the large bath, the repair time of the large bath is determined more simply and accurately than the conventional method. The effect is to provide a way to do it.

Claims (1)

In the method for determining the maintenance time of the blast furnace, a thermocouple is installed at the height of the outlet in the large-water refractories of the melt-falling portion of the large-water bath to obtain the slope of the temperature change obtained therefrom, and corresponds to the slope of each temperature change. After measuring the refractory thickness remaining at the time point, the correlation between the slope of the temperature change and the residual thickness of the refractory is obtained, and based on the correlation, the temperature gradient at the time point to repair the large hot water is set and then the measured temperature How to determine the maintenance period of the Goro-tang road, characterized in that when the slope of the change reaches the set slope of the temperature change.