JPS6041682B2 - Method and device for measuring heat level in a reduction melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for measuring heat level in a reduction melting furnace.

In general, reduction melting furnaces such as blast furnaces and shaft furnaces are charged with coke and oxides such as raw ore, pellets, and sintered ore (hereinafter referred to as ore) from the top of the furnace, while hot air is blown through tuyeres at the bottom of the furnace. This equipment burns coke and reduces ore using the generated high-temperature reducing furnace gas (hereinafter referred to as furnace gas) and melts it into pig iron.

Therefore, as the ore charged into the furnace descends, it comes into contact with the high-temperature furnace gas rising from the lower part of the furnace, and as the temperature rises, it is reduced. It follows the process of melting and dripping when it comes into contact with gas.

The transformation process of the ore in such a furnace is closely related to the ore temperature and gas temperature in that part, forming approximately Ξ zones as follows. In other words, as shown in Figure 1, depending on the rate of consumption of coke, which is charged from the top of the furnace and is consumed by burning at the tip of the tuyere at the bottom of the furnace, and of ore, which is reduced and melted and dripped, As it descends through the furnace, it comes in contact with the high-temperature furnace gas rising from the bottom, and the temperature rises relatively slowly, reaching about 10% at about 8 to 9 wL below the charge surface.
The first zone reaches 00°C, the second zone has very little temperature change below the first zone and continues from the charge surface to around 18 to 19 TrL in an almost constant temperature state, and the second zone This is the third zone where the temperature rapidly rises from the zone to the melting temperature of the reduced ore of 514,000 C or higher.

Generally, the first zone is referred to as a preheating zone, the second zone as a constant temperature zone, and the third zone as a melting zone. ]
- In the preheating zone, water contained in ore, coke, etc. evaporates, and the following reduction reaction mainly occurs.

In addition, the following reduction reactions mainly occur in the constant temperature zone.

In addition, in the melting zone, the following reduction reaction occurs simultaneously with the softening, shrinkage, melting, and dripping phenomena of the ore.

Generally, the rate at which ore is reduced in the furnace is 1 in the preheating zone.
It is known that it is 0 to 20%, 50 to 60% in the constant temperature zone, and 25 to 35% in the melting zone. Therefore, knowing at what level the constant temperature zone where ore is most reduced is an important point in understanding the efficiency of reduction melting furnaces such as blast furnaces and shaft furnaces. Conventionally, the constant temperature zone has been measured by inserting a vertical probe with a built-in thermometer into the furnace from the top of the furnace.

However, in the conventional method, the temperature distribution in the direction of the furnace height could only be grasped intermittently.

In other words, as shown in Figure 2, when measuring the temperature inside the furnace using the conventional method, the temperature distribution differs each time it is measured. There was a problem that I had to do it. Moreover, as is clear from Fig. 2, the boundary point where the preheating zone changes to the constant temperature zone (point R shown in Figs. 1 and 2, hereinafter referred to as R point)
No place! The location and temperature fluctuate greatly due to changes in operating conditions from time to time, and simply fixing a vertical sonde at a fixed point in the furnace and measuring temperature continuously will not be enough to measure the temperature at point R or the constant temperature zone. It was difficult to grasp the changes.
cThe present invention solves the problems of the conventional method, accurately measures the position of the R point, and
The present invention provides a method and device for continuously measuring the displacement of a point and the temperature of a constant temperature zone. The probe is inserted into the inner container, and the temperature inside the furnace is measured with the plurality of temperature detection terminals, and the probe is raised and lowered based on the temperature difference between the temperature detection terminals, and the tip of the probe is placed between the preheating zone and the constant temperature zone in the furnace. Heat level measurement in a reduction melting furnace characterized by measuring the position of the boundary point between the preheating zone and the constant temperature zone in the furnace by detecting the position of the tip of the sonde from the amount of elevation and descent of the sonde. Method and (2) A sonde that has a temperature detection end at its tip and can be raised and lowered to measure the temperature inside the furnace by being inserted into the charge in the furnace from above the reduction melting furnace. 1-3.0
A plurality of temperature detection terminals are arranged at predetermined intervals within a range of m, and the difference between the measured values obtained from these temperature detection terminals is compared with a predetermined set value to issue a command to raise or lower the sonde. The gist is a heat level measuring device in a reduction melting furnace, which comprises a control device, a detection device that detects the position of the tip of the sonde from the amount of elevation and descent of the sonde, and a display device that displays the temperature measurement value and the position of the tip of the sonde. It is something.

The present invention will be explained below based on the drawings.

FIG. 3 is a sectional view of a blast furnace showing an embodiment of the present invention.

As shown in FIG. 3, the present invention is a method that is inserted vertically from the top of a blast furnace 1 into the charge 2 in the furnace and measures the temperature of the charge 2 in the furnace with a built-in thermometer. For example, Sonde 4 disclosed in Japanese Patent Publication No. 47-43721
This was done by focusing on the fact that the constant temperature zone in the furnace exists continuously for a long time with little change in temperature in the height direction inside the furnace. The detection ends are arranged in stages like X, Y, and Z at a predetermined interval 1, and the temperature values detected at the respective temperature detection ends X, Y, and Z are input to the control device 16, which will be described later. The logic compares the difference between each temperature value and the set value, and based on the results, the motor 12 is controlled by a command from the control device 16.
is driven to rotate the wire drum 13 in the normal or reverse direction, and the sonde 4 suspended by the wire lobe 11 is raised and lowered, and the tip of the sonde 4 is positioned at the boundary point R between the preheating zone and the constant temperature zone in the furnace. The purpose is to accurately measure the position of this boundary point R and continuously measure not only the temperature of the constant temperature zone but also the displacement of the boundary point R over time.

The temperature detection terminals X, Y, and Z according to the present invention may be thermocouples, and the temperature values detected by the thermocouples are sent from the top of the sonde 4 to the outside of the furnace by conductive wires 17A, 17B, and 17C through the inside of the sonde 4. A temperature measurement signal is sent to the control device 16 via the thermoelectric temperature converter 15.

In the figure, 7 is a gas seal device, 6 is a sonde cutting detector, 5 is a valve, 3 is a bell, 9 is a sonde hanging fitting, and 10 is a wire sheep. Next, the functions of the control device 16 according to the present invention will be explained with reference to FIG.

Set temperatures b and Tm are provided in advance in the control device 16.

The set temperature ω is a value set within the range of 10 to 50 °C as the upper limit of temperature variation within the constant temperature zone, Tm
is the starting point of the melting zone, 1100-12000C
It is desirable to set it within the range of . When the tip of the sonde 4 is above point R and the sonde 4 is lowered into the furnace, the motor 12 is rotated in the opposite direction and the wire lobe 11 is rotated in the opposite direction.
loosen.

In this state, the sonde 4 is inserted vertically into the furnace as the charge in the furnace descends, so the rotation speed and rotation angle of the wire drum 13 are detected by the detection device 14, and the sonde is detected from the surface of the charge at the top of the furnace. The distance between the four tips is determined, and the value is sent via the control device 16 to the display device 18, where it is continuously recorded. On the other hand, the measurement detection end X stepped at the tip of the sonde 4
, Y, Z, the temperature difference Tx-Ty (5ty-Tz) is compared with the set value b as follows in the control device 16, and the temperature value Tx, ty, tz obtained from When both are satisfied, this indicates that the tip of the sonde 4 is in the preheating zone with large temperature changes, so the sonde 4 continues to descend.

The temperature measurement value Tx and the temperature difference -Ty, ty-Tz are controlled by the controller 16.
The data is then sent to the display device 18 and continuously recorded. When the following occurs due to the descent of the sonde 4, it indicates that the temperature detection end X has entered the constant temperature zone and the temperature detection end Z is in the preheating zone. It is determined that the rotation of the motor 12 is stopped, the position of the sonde is maintained in this state, and the temperature measurement by the temperature detection terminals X, Y, and Z is continued, and the monitoring of the R point is continued.

Then, when the R point moves downward due to the situation inside the reactor, the condition satisfies the above equations (1) and (2), so the sonde 4 is lowered again and the above (3) and (2) are satisfied. When the equations are simultaneously satisfied, the vertical sonde is fixed at that position. At this time, the position of point R and the temperature state of the constant temperature zone are continuously recorded on the display device 18. Also, when the R point moves upward, 2yreBireν

This indicates that both temperature detection terminals X and Y have entered the constant temperature zone, so in this case, raise sonde 4 and repeat step (3) above.
, (4) may be fixed at a position that satisfies both equations.

In the present invention, if the tip of the sonde were to reach the melting zone, there is a risk that the sonde 4 would be damaged.

Therefore, the measured temperature value ■ is constantly compared with the set value Tm, and the temperature value
It is necessary to lift and lower the sonde while confirming that the following conditions are satisfied, and when Tx≧Tm,
The sonde must be raised immediately. The sonde will also be raised in other abnormal situations. Temperature detection end X according to the present invention
It is effective that the distance 1 between Y, Y (5Z) is within the range of 0.1 to 3.07 TL, preferably 0.3 to 1.07 TI.

Within this range, the smaller l is, the more accurately the R point can be measured, but if it is less than 0.1 m, the number of times the Zosode will go up and down will be large, making it impractical, and 3.07 TL. If the value exceeds 100%, the measurement accuracy will drop significantly. 1 to 0.3 to 1.
It is particularly preferable to set the distance within the range of 0 m because the workability is good and the R point can be measured with high accuracy.

Furthermore, it has been explained that the set temperature b according to the present invention is preferably in the range of 10 to 50°C, but the smaller this temperature is, the better the measurement accuracy of the R point is, but if it is less than 10°C, the temperature will vary within the constant temperature zone. If the temperature exceeds 50°C, the accuracy of measuring the R point will decrease, which is not desirable.

Although the display device 18 according to the present invention has been described as recording the position of point R, the temperature difference, and the temperature of point R, it can also be displayed on an oscilloscope, or if the above conditional expression is not satisfied, a message to that effect can be displayed. Alternatively, it is also possible to issue an alarm.

Although the case where three temperature detection terminals are provided in stages has been described above, it is also possible to have two temperature detection terminals. That is, in the case of two temperature detection terminals X and Y, the sonde is lowered when , and raised when , and the sonde is raised and lowered so that point R is between temperature detection terminals X and Y. It is possible to measure the R point.

In this case, the sonde must be raised or lowered at all times, but a narrow set temperature range t1 is provided within the set temperature ramp, and this set temperature range t1 is set between the center point of the sonde.
If the sonde is not raised or lowered when there is an R point in the area, highly accurate measurements can be made and the problem of having to constantly move the sonde can be solved. Even if four or more temperature detection terminals are arranged in stages, the corresponding effect cannot be obtained and it is not economical.

As illustrated in FIG. 2, there is little change in the vertical position of the boundary point between the constant temperature zone and the melting zone.

Therefore, if the boundary point between the constant temperature zone and the melting zone is considered as a fixed point, the extent of the constant temperature zone can be determined from the position of point R measured by the method of the present invention. Further, after measuring the R point according to the method of the present invention, the sonde 4 can be further lowered to measure the position of the boundary point between the constant temperature zone and the melting zone. In this case, when the tip of the sonde reaches the set temperature Tm, this position may be used as the boundary point, or by setting Tm to a low value, a means is provided to prevent melting of the tip of the sonde. The temperature may be determined by the method of the present invention based on the temperature differences Tl and T2. Example One temperature detection end was provided at the leading edge of the sonde, and two temperature detection ends were further provided at intervals of 0.47 TL from this detection end, and the sonde was inserted into the furnace from the top of the blast furnace. Then, the position of point R was measured.

The set value b at this time was 30°C, and Tm was 1100°C.
The measurement results are shown in FIG.
3 As shown in Figure 5, from the start of the chart to point A, the temperature value Tx measured by the temperature detection end
The difference T1 between the measured temperature value Ty and the temperature value Ty due to Y, and the difference between Ty and the detection end Z
The difference T2 from the measured temperature value Tz is both less than 30°C,
The R point is 9.0 Tr1. from the top charge surface. However, since T1 was higher than the TO level at point A and Tx was lower than Tm, it was determined that the R point had decreased.
The sonde was lowered in time with the descent of the charge. And B
At point T1 became below level b again and reached point R, so the sonde stopped descending and moved from the top of the furnace to about 11.
It was held at the 0TL position. Similarly, at points C, D, E, and F, the change in point R is detected depending on the temperature change at T1 and T2, respectively, and the sonde is repeatedly lowered and raised according to this change, and the R point is continuously measured. , the temperature change between point R and the constant temperature zone. We were able to measure temporal changes with high accuracy. As described above, according to the present invention, the position and displacement of the R point can be measured extremely accurately and continuously, and changes in the situation inside the furnace can be accurately grasped from changes in the R point. Since temperature and changes over time can also be measured, the heat level inside the furnace can be accurately measured, which is extremely effective in managing the operation of reduction melting furnaces such as blast furnaces.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the temperature distribution in the blast furnace, Fig. 2 is a diagram showing an example of measuring the temperature distribution in the blast furnace using the conventional method, Fig. 3 is a block diagram showing the embodiment of the present invention, and Fig. 4 is the method of the present invention. FIG. 5 is a measurement chart showing an embodiment of the present invention. 1... Blast furnace, 2... Charge, 4...
...Sonde, 6...Sonde cutting detector, 7...
... Gas seal device, 9 ... Hanging fittings, 10.
...Wire sheave, 11...Wire robe, 12
...Motor, 13...Wire drum,
14...Sonde position detection device, 15...
... Thermoelectric temperature converter, 16 ... Control device, 18
...Display device, X, Y, Z...Temperature detection end.

Claims (1)

[Claims] 1. A sonde with a plurality of temperature detection ends arranged in stages at its tip is inserted into the contents of the furnace from above the reduction melting furnace, and the temperature inside the furnace is measured with the plurality of temperature detection ends. At the same time, based on the temperature difference between the temperature detection ends, the sonde is raised and lowered to position the sonde tip at the boundary point between the preheating zone and the constant temperature zone in the furnace, and the position of the sonde tip is detected from the amount of elevation of the sonde. A method for measuring heat level in a reduction melting furnace, characterized by measuring the position of a boundary point between a preheating zone and a constant temperature zone in the furnace. 2. In a sonde which has a temperature detection end at the tip and which can be raised and lowered and which is inserted into the charging material in the furnace from above the reduction melting furnace to measure the temperature inside the furnace, the temperature at the tip of the sonde is 0.1 to 3. A plurality of temperature detection terminals are arranged at predetermined intervals within a range of 0 m, and the difference between the measured values obtained from these temperature detection terminals is compared with a predetermined set value to issue a command to raise or lower the sonde. A heat level measuring device in a reduction melting furnace, comprising a control device, a detection device that detects the position of the tip of the sonde from the amount of elevation of the sonde, and a display device that displays the measured temperature value and the position of the tip of the sonde.