JPS5993809A - Blast furnace operation method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for operating a blast furnace, and more specifically, a thermocouple on the furnace wall is inserted and installed up to the inside of the furnace to accurately grasp the gas flow inside the furnace, thereby achieving stable operation of the blast furnace. Concerning blast furnace operating methods that aim to achieve these goals.

Understanding the gas flow inside the blast furnace is essential for stable operation.

Therefore, the conventional methods are (1) using a furnace wall thermometer with a thermocouple installed in the refractory of the furnace wall, (2) measuring the space above the charge using a furnace top gas sonde, ( 3) The method used was to insert the probe of the furnace body gas sonde into the furnace.

However, since method (1) measures temperature by embedding a thermocouple in the furnace wall refractories, the sensitivity is extremely low when it comes to understanding changes in gas flow as temperature changes. Therefore, it is not possible to immediately follow changes in gas flow, and it is difficult to take quick action.

Method (2) measures the temperature in the upper space of the charge, but cannot measure the gas flow in the charge, and the measurement is also intermittent. The method (3) requires a large amount of equipment and can only detect the gas flow intermittently, and in many cases only one direction can be detected.

The present invention replaces the conventional method with such problems by directly and sensitively detecting the gas flow inside the blast furnace and achieves stable operation of the blast furnace. The invention installs thermocouples that are inserted into the furnace at multiple positions in the height direction of the blast furnace and at multiple positions in the circumferential direction at the positions, and the temperature measured by the thermocouples is measured by the temperature of the gas flow in the furnace. This temperature measurement result is used as an index to control the distribution of the charge so that the target gas flow is achieved.

That is, the present invention directly detects the temperature inside the furnace by installing a thermocouple protruding from the furnace wall to the inside of the furnace, instead of the conventional furnace wall temperature sensor, and measures the detected temperature and its temperature. This is based on the knowledge that this change is a direct indicator of gas flow changes based on the gas flow conditions in the charge and the formation and disappearance of deposits and inert zones. Based on this knowledge, if we try to control the distribution of the charge by manipulating the movable armour, for example, at the top of the furnace to achieve the target gas flow, we can quickly respond to the gas flow. It became clear that it was possible.

The present invention will be explained below with reference to the drawings.

In the present invention, at a plurality of positions spaced apart in the height direction of the blast furnace 1 and at a plurality of azimuth positions in the circumferential direction at each position,
A plurality of thermocouples 2, 2, . . . are inserted into the furnace wall 3 so as to protrude into the furnace interior.

Details of how the thermocouple 2 is installed are shown in FIG. That is, a plurality of thermocouples, e.g., 2A to 2C, are inserted into temperature measurement holes 3b formed in advance in the refractory brick 3a, with their protrusion lengths being changed sequentially, and the temperature measurement holes 3b are filled with refractory material 4. I'll keep it.

Further, it is necessary that at least one of the thermocouples 2A to 2C at each position protrudes into the refractory brick 3aJ: and into the furnace. Furthermore, one of the thermocouples at each position may be buried in the furnace wall 3 without protruding into the furnace, similar to conventional furnace wall thermometers. By the way, a conventional furnace wall thermometer is used when the inner surface of the refractory brick 3a is 890 m from the outer surface of the iron shell.
300 from the outer surface at a distance of m.

On the other hand, the thickness D of the inert zone 50 shown in Fig. 2 varies depending on the temperature measurement position in the blast furnace and changes over time.
Generally, it is about 50 (1-1000 mm). Therefore, even if the protrusion length of the thermocouple from the inner surface of the refractory brick is longer than the thickness of the inert @50, the degree of damage caused by the charge 51 will only increase. Furthermore, since this goes against the objective of the present invention, which is to grasp the gas flow near the reactor wall, it is usually desirable to set the protrusion length l of the longest thermocouple to 500 < 1. < 1000.

The heightwise installation position of the thermocouple can be determined as appropriate, but it can be installed across the belly shaft. Regarding the circumferential direction, it is preferable to provide at least four locations in the north, south, east, and west.

On the other hand, in order to control the distribution of the charge at the top of the furnace, a movable armor 6 for the charge falling from the large bell 5 is provided as a concrete example.

In this way, the results of temperature measurement via the thermocouples 2, 2, . Current temperature information 8 of the pattern and/or temperature change is obtained. Assuming that this current temperature information 8 gives the gas flow state of the furnace, it is compared with the target temperature 9 as an index of the target gas flow in the comparator 10, and if the comparison result is different, the movable Agomaro is Now, as shown in Figure 3, for example, for a 1850 m blast furnace, there is a tuyere 11 with an upper berth of 7.6 m in height, a 10.2 m high / When the temperature pattern becomes TPI or TP2 for the lower shaft shaft, and further for the middle and upper shaft stages, it is assumed that the target temperature pattern for increasing the target gas flow is TPO. T.P.
In case I, the gas flow is too strong and the temperature is high, so the movable armor 6 is operated to increase the ore/coke (0/C) ratio near the furnace wall to suppress the gas flow. Figure 9: Bring the temperature closer to the target temperature pattern TPO. In the case of TP2, on the other hand, the Q/C ratio is lowered to improve gas flow,
The disappearance of deposits and inert zones is controlled so that the target gas flow is achieved both in the height direction and the circumferential direction of the blast furnace. 0 preset by 0 Next, the effects of the present invention will be explained based on examples.

The transition of the furnace temperature shown in Figure 4 (4) is as shown in Figure 5 (a) 2.
It is powered by the three thermocouples in the upper berry section and the three thermocouples in the lower south section of the shaft shown in (b). -! , in Fig. 4) is a conventional furnace wall depth meter,
In the same figure (Q is the top of the furnace).

According to the results, the conventional furnace wall thermometer shows almost no temperature change (Fig. A3), while the Ushida furnace top sonde is also insensitive to temperature changes (Fig. (C)). ), (5) l? in the case of the thermocouple according to the present invention as shown in the figure. It can be seen that the + degree change shows a sensitive change. Also, in the CA) figure, the thermocouples marked ■ and ■ were disconnected during the measurement period, but if you think about this, the temperature gradually rose by 2'2 before the disconnection occurred, and the temperature was high. It is believed that the reason for the disconnection was due to the flow of gas at a temperature higher than the melting point of the thermocouple. Therefore, on the contrary, inserting and installing thermocouples in the furnace 1 according to the present invention shows that the gas flow in the furnace can be sensitively detected. This has the advantage that it can be used even if it is completely eroded.

As described above, the present invention is to insert a thermocouple into the furnace and use the temperature measurement result as an index of the gas flow in the furnace, so it is possible to directly measure the gas flow in the charge. Since the gas flow in the entire furnace can be economically and accurately detected, it is possible to detect the gas flow in the entire furnace accurately and sensitively, and it is also possible to detect at multiple locations, and also to perform continuous detection. Therefore, if the distribution of the charge is controlled using a movable armor or the like based on the temperature measurement results, stable operation can be achieved reliably.

[Brief explanation of the drawing]

Fig. 1 is a detailed explanatory diagram of the present invention, Fig. 2 is a detailed sectional view of the installed state of the thermocouple, Fig. 3 is an explanatory diagram showing the method of controlling the current temperature pattern to the target temperature pattern, and Fig. 4 is the temperature (5) is from each thermocouple according to the present invention, (J3) is from a conventional furnace wall thermometer, (
C) is a conventional furnace top sonde, Figure 5 (a,)
(b) is a schematic diagram showing the installation positions of thermocouples. 1. Blast furnace 2. Thermocouple 3. Furnace wall 6°°m bubble armor Fig. 1 10 Fig. 2 7; l” 1-D-← Fig. 3

Claims (1)

[Claims] (1) Thermocouples inserted into the furnace are installed at multiple locations in the height direction of the blast furnace and at multiple locations in the circumferential direction of the blast furnace, and the temperature measured by the thermocouples is measured based on the temperature of the gas flow in the furnace. A blast furnace operating method characterized by controlling the distribution of the charge so that the gas flow reaches the target based on the temperature measurement results.