JPS5850291B2 - Level and shape measurement method of blast furnace melting zone - Google Patents

Description

[Detailed Description of the Invention] This invention provides a method for accurately measuring the level and shape of the melting zone in a blast furnace, which is important for operational management of a blast furnace.
This invention relates to a shape measuring method and device.

Maintaining the region where heated and reduced iron ore begins to soften and melt in the blast furnace (usually called the dissolution zone) at a certain level and shape is important for stabilizing the blast furnace heat and increasing the efficiency of the reactions in the furnace. Very important.

For example, the time it takes for iron ore to reach the hearth after melting varies depending on the level of the melting zone, and the various metallurgical reactions that occur during that time vary. Trends will also be affected.

In addition, gas ventilation resistance is extremely high in the dissolution zone, so
When the shape of the dissolution zone changes, the efficiency of gas reduction, etc. changes.

Control of the shape and level of the dissolution zone is thus a very important factor in blast furnace operation, and it is necessary to measure the shape and level as accurately as possible.

For example, a conventional method is to install a sheathed thermocouple inside the blast furnace when it is fired, and measure changes in the temperature distribution inside the furnace after firing to trace the formation process of the melting zone inside the furnace. .

However, although this method allows the location of the measurement point to be clearly determined, once the thermocouple is disconnected, subsequent measurements become difficult, making it impossible to measure the dissolution zone over a long period of time.

An alternative method is to attach a weight to the tip of the thermocouple, place this weight on the stock line of the charge, and as the load lowers, the thermocouple is fed into the furnace to continuously control the temperature distribution in the height direction inside the furnace. There is a way to measure it.

However, this method has problems such as the position of the weight in the furnace is unknown and temperature information alone is insufficient to know the melting zone level.

Recently, a method has been proposed in which a gas introduction capsule is attached to the tip of a metal tube into which a thermocouple is inserted, and the level of the dissolution zone is measured by simultaneously measuring not only the temperature but also the gas composition and gas pressure.

However, even with this method, the position of the capsule in the furnace is not clear, and since the measured temperature is the gas temperature, it is difficult to accurately measure the level of the melting zone by varying the temperature difference between the gas temperature and the melting zone temperature. was difficult.

In other words, as is well known, the shape of the blast furnace body is so-called wide at the base up to the bottom level, and is constricted at the bottom and bosch sections, so the charged raw material is not necessarily unloaded vertically, but rather extends down the shaft. In the lower part of the furnace, the melt descends while moving mainly in the radial direction, and in the dripping zone area at the bottom of the furnace, only the iron ore drips, and a large amount of coke is consumed at the tuyere, so the flow of solids is more rapid. It gets complicated.

Furthermore, the flow of this solid changes even more complexly as the shape and level of dissolution changes.

For this reason, when the measurement capsule reaches the position in the furnace where the important dissolution zone is formed, it is completely unclear where in the furnace the measurement capsule is actually located.

Furthermore, it is well known that the solid temperature and gas temperature are generally not close to each other in a furnace, and that the solid temperature decreases by about 20 to 300° C., although it varies in the height direction.

Particularly in the region where the ore softens and melts, the solid temperature is about several hundred degrees lower than the gas temperature.

This difference between the solid temperature and the gas temperature is not always constant even at the same location in the furnace, and changes greatly when the level, shape, etc. of the melting zone changes and the gas flow changes.

Therefore, if there is a temperature measurement point inside the metal tube, the temperature will be the gas temperature, making it impossible to accurately measure the solid temperature.

For the above reasons, it is difficult to accurately measure the level of the dissolution zone using the conventional method described above.

The present invention has been made to solve the above-mentioned conventional problems, and proposes a method and apparatus that can accurately measure the level and shape of a dissolution zone.

This invention method has a weight made of a high melting point metal at the tip of a flexible high melting point metal tube into which a thermocouple is inserted, the temperature measuring part of the thermocouple is embedded in a pattern, and the temperature measuring part of the thermocouple is embedded in the tip of the metal tube. Using a sonde with multiple through holes, a plurality of sondes are charged from the top of the furnace in the radial direction of the furnace, and the weight at the tip of each sonde is brought into contact with the surface of the stock line of the charging material in the furnace. As the load is lowered, each sonde is sequentially fed into the furnace while applying the necessary tension to make it vertical, and the length of each sonde is measured. By introducing a tracer gas into the furnace and measuring the radial distribution of the tracer gas at the top of the furnace, the height and radial positions of each weight within the furnace can be determined, and the solid temperature at that position can be measured using a thermocouple. The method is characterized in that the shape of the dissolution zone is measured by suitably suctioning the furnace gas through the through hole at the tip of each of the metal tubes and measuring the gas composition and gas pressure. .

Further, the device of the present invention includes a flexible high-melting point metal tube into which a thermocouple is inserted, a plurality of through holes provided at the tip of the metal tube, and a temperature measuring portion of the thermocouple embedded in the tip. A sonde having a weight made of a high melting point metal and penetrating through the opening at the top of the furnace, a reel that rotates with the proximal end of the sonde firmly connected, and a correction that corrects the bending of the sonde by sandwiching the sonde. A sonde feeding device consisting of a roller, a payout length measuring device that measures the length of the sonde payout from the reel, a temperature recorder that displays the temperature value from the thermocouple, and a hollow rotating shaft of the reel. A gas pressure measuring device that measures the gas pressure inside the suction furnace from the sonde, and
and a gas composition analyzer for analyzing the gas composition in the suction furnace;
A sonde for measuring the shape of a dissolution zone having a structure in which a tracer gas supply pipe and a purge gas supply pipe to be supplied to the through hole at the tip of the metal tube of the sonde are connected to the pipe, and a device below the sonde for measuring the shape of the dissolution zone. The furnace top gas sampler is inserted into the feed layer and measures the concentration of tracer gas from the tracer gas supply pipe.

In a moving bed where gas and solids move, such as in a blast furnace, (1) calculates the center temperature of a solid that is close to the average diameter of the solids in the bed and has a thermal conductivity several times better than that of the solids in the bed. By measuring the temperature of the surrounding solid body, it is possible to determine the temperature of the surrounding solid body.

Based on this knowledge, this invention employs a method of attaching a weight to the tip of a metal tube into which a thermocouple is inserted, and embedding the temperature measuring part of the thermocouple in this weight to measure the temperature of the weight inside the furnace. It is.

Furthermore, a through hole is provided at the tip of the metal tube, and the gas in the furnace is sampled through the through hole into the metal tube to measure the gas pressure and gas composition. was introduced into the furnace through a hole at the tip of the metal tube, and the radial distribution of this He gas at the top of the furnace was measured using a top gas sampler installed separately at the top of the furnace.

That is, this invention measures the temperature of a weight in the furnace using a thermocouple embedded in the weight to measure the solid temperature in the furnace, and also samples the gas in the furnace using a metal tube to measure the gas in the furnace. The pressure and composition are measured, and the radial position of the weight is determined from the radial distribution of He and other gases introduced into the furnace from the metal tube, and the height position of the weight within the furnace is determined from the length of the metal tube. This is a method and an apparatus for measuring the level and shape of the dissolution zone from the solid temperature, gas pressure and composition, and the position of the weight in the radial direction and height direction.

According to this invention, it is possible to accurately grasp the position of a weight in a furnace where the flow of solids changes in a complicated manner, and it is also possible to accurately measure the solid temperature, gas pressure, and gas composition at the tip of the weight. Therefore, the level and shape of the dissolution zone can be measured with high accuracy.

Next, an example of the inventive apparatus for carrying out the inventive method will be explained with reference to FIGS. 1, 2, and 3.

In Fig. 1, 1 is a blast furnace, 2 is a charge stock line, 3 is a tuyere, 4 is a sonde for measuring the shape of a melting zone, 5 is the sonde feeding device, 6 is a furnace top gas sampler, and 7 is a melting zone. It is an obi.

The sonde 4 for measuring the shape of the dissolution zone consists of a flexible high-melting point metal tube 4-2 made of stainless steel, titanium, etc. into which a doku-sheathed thermocouple 4-1 shown in FIGS. 2 and 3 is inserted, and the tip of the metal tube. The tip of the sheathed thermocouple 4-1 is embedded in the center of the weight 4-3, and the tip of the sheathed thermocouple 4-1 is embedded in the center of the weight 4-3. A plurality of through holes 4-4 are bored at the tip.

This sonde is fed into the blast furnace by a feeding device 5 installed at the top of the blast furnace.As shown in FIG.
-2, it is composed of a feeding length measuring device 5-3, and a reel 5-4 with a braking device, and the sonde 4 fed out from the reel 5-4 passes through the feeding length measuring device 5-3,
After the bend is corrected by the straightening roller 5-2, it is lowered to a fixed position in the radial direction on the stock line 2 in the furnace through the protection pipe 5-1, and as the charge is unloaded, the Apply a certain amount of tension to reel 5 to make the sonde vertical.
-4 is applied by a built-in braking device and is sequentially drawn out into the furnace.

Further, the tension on the sonde is applied by the load of the weight and the load of the charge placed on the weight, and a plurality of weights may be attached to increase this tension.

Note that 8 is an emergency shutoff valve. Further, in FIG. 2, numeral 9 indicates a temperature recorder, 10 indicates a gas pressure measuring device, and 11 indicates a gas composition analyzer. A gas pressure measuring device 10 and a gas composition analyzer 11 are installed in a pipe 12 connected to a hollow reel rotating shaft 5-5.

In the figure, 13 is a tracer gas supply pipe such as He, 14
is a supply pipe for purge gas (inert gas such as N2 gas) to prevent the metal pipe 4-2 of the sonde from clogging;
■１゜■２． ■3. ■4 is a solenoid valve for switching the flow path.

When measuring the level and shape of the melted zone in the blast furnace using the above device, the sonde 4 wound on the reel 5-4 is unwound and the weight 4-3 at the tip is lowered onto the stock line 2 of the charge. As the charge is unloaded, the sondes are sequentially fed into the furnace.

At this time, the sonde is reeled out while applying a constant tension necessary to make it vertical by a braking device built into the reel 5-4.

During this time, the sonde prevents dust from entering the furnace through the through hole 4-4 at the tip of the purge pupil tube using a small amount of N2 gas or the like.

The purge gas is supplied using the solenoid valve ■1 with the solenoid valve ■2 of the tracer gas supply piping and the solenoid valve ■4 for switching the flow path to the gas analyzer 11 closed. ■3 Open and supply.

When sampling the furnace gas, the purge is interrupted, the solenoid valve v4 is opened, the furnace gas is sucked through the through hole 4-4 at the tip of the metal tube, and the gas is sampled by the gas pressure measuring device 10 and gas composition analyzer 11. Measure and analyze gas pressure and gas composition, respectively.

Note that the furnace gas is sampled every 20 minutes, for example, 10 times.
This will take about a minute.

When not sampling the furnace gas, use the solenoid valve■2. ■4 is closed and solenoid valve V1 s V3 is open to prevent dust from entering the furnace from entering the sonde and clogging the pipes.
As mentioned above, purging is performed using two gases or the like.

Next, to measure the position of the weight 4-3 at the tip of the sonde,
A solenoid valve ■1. Close solenoid valve v4 and close solenoid valve v2. ■３
Open it and feed it into the furnace.

Thereafter, the top gas sampler 6 is moved in the radial direction to measure the radial distribution of the tracer gas, and the radial position of the weight at the tip of the sonde is determined from the peak position of the distribution. The height direction position of the weight 4-3 is determined from the measured sonde delivery length and the amount of deviation of the weight from the stock line landing point.

The level of the dissolution zone can be measured from the solid temperature, gas pressure, and gas composition at the weight tip position determined in this manner.

Moreover, as shown in FIG. 1, by arranging a plurality of these probes in the radial direction, the shape of the dissolution zone can be measured.

FIG. 4 is a representative example of sonde measurement information obtained when various measurements were carried out by applying the method of this invention to an actual blast furnace.

In the figure, R is the absolute ventilation resistance.

From this chart, it is determined that the place where the furnace pressure P and the solid temperature Ts change greatly at the same time is the melting zone level where the iron ore softens and melts.

In particular, if the absolute ventilation resistance R, which represents the rate of change in the pressure drop in the furnace, is used, it becomes clear that the iron ore is softened and melted, and the ventilation resistance increases significantly.

Further, the content ratio of the in-furnace gas composition CO2CO2 also varies in the dissolution zone, and the position where this C02C02 fluctuates can be said to be the dissolution zone.

As explained above, according to the method of this invention, it is possible to accurately measure the level and shape of the dissolution zone, which is important for blast furnace operational management, and it is extremely effective in contributing to stable blast furnace operation and low fuel cost operation. be.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an apparatus for carrying out the method of this invention, FIG. The figure is a chart showing an example of sonde measurement information when this invention method is applied to an actual blast furnace. 1... Blast furnace, 2... Charge stock line, 3... Tuyere, 4... Sonde, 4
-1...Sheath thermocouple, 4-2...Metal tube, 4-3...Weight, 4-4...
Through hole, 5...Sonde feeding device, 5-1...
・Protection pipe, 5-2...Correction roller, 5-
3...Feeding length measuring device, 5-4...
・Reel, 6...Gas sampler, 7...
...Dissolution zone, 8...Shutoff valve, 9...Temperature recorder, 10...Gas pressure measuring device, 11...
... Gas composition analyzer, 12 ... Piping, 13
...Tracer gas supply pipe, 14...
Purge gas supply pipe, ■1. ■2. ■3. ■４・・・・・・
··solenoid valve.

Claims (1)

[Claims] 1. A flexible high melting point metal tube with a thermocouple inserted therein;
A sonde having a weight made of a high melting point metal with a plurality of through holes provided at the tip of the metal tube and a temperature measuring part of the thermocouple embedded in the tip thereof is used, and the sonde is inserted into the furnace from the top of the furnace. Charging is carried out in the radial direction, and the weight at the tip of each sonde is brought into contact with the stock line surface of the charge in the furnace, and as the charge is unloaded, each sonde is sequentially loaded while applying the necessary tension to make it vertical. The length of each sonde is measured. At the same time, a tracer gas such as He is introduced into the furnace through the hole at the tip of the metal tube, and the radial distribution of the tracer gas at the top of the furnace is measured. By measuring the height and radial position of each weight in the furnace, the solid temperature at that position is measured via a thermocouple, and the gas in the furnace is A method for measuring the level and shape of a blast furnace melting zone, characterized in that the shape of the melting zone is measured by suitably aspirating gas composition and gas pressure. 2. A flexible high melting point metal tube with a thermocouple inserted,
A sonde is formed by providing a plurality of through holes at the tip of the metal tube, and having a weight made of a high melting point metal in which the temperature measurement part of the thermocouple is embedded in the tip, and penetrating the furnace top opening. , a reel that rotates with the proximal end of the sonde fixedly connected, a correction roller that pinches the sonde and corrects the bending of the sonde, and a length measuring device that measures the length of the sonde that is fed out from the reel. A sonde feeding device, a gas pressure measuring device with piping connected to the hollow rotating shaft of the reel to measure the gas pressure in the suction furnace from the sonde, and a gas composition analyzer to analyze the gas composition in the suction furnace. and a sonde for measuring the shape of a dissolution zone having a structure in which a tracer gas supply pipe and a purge gas supply pipe to be supplied to the through hole at the tip of the metal tube of the sonde are connected to the pipe, and a lower part of the sonde for measuring the shape of the dissolved body. A top gas sampler inserted into the charge layer of the furnace to measure the concentration of tracer gas from a tracer gas supply pipe.