JPS5933164B2 - Blast furnace molten zone level measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for simply and safely measuring the level of a blast furnace molten zone.

As is well known, a blast furnace is an equipment in which iron ore, limestone, coke, etc. are charged from the top of the furnace, and hot air is blown from the bottom of the furnace body to reduce and melt the iron ore to obtain pig iron. There is a region where the reduced iron ore fuses together, forming branch-like structures where the melt falls off all at once.

This area is an extremely narrow area within the entire blast furnace;
Depending on the level of the bottom, the time it takes for the dropped pig iron to reach the hearth varies, and during that time it undergoes various metallurgical reactions, which have an important effect on the quality of the final pig iron product.

In addition, the permeability of gas inside the blast furnace is rate-determined by this molten zone, and the resistance to gas flow changes depending on the shape and level of the molten zone, so the level of the molten zone depends on the blast furnace operation. This is also a major factor in stabilizing the situation.

The melting level varies depending on the nature of the charge, the distribution of the charge at the top of the furnace, and the gas temperature and flow rate at the tip of the tuyere that blows hot air, and generally depends on each of these factors. The blast furnace molten zone is maintained at a desirable level by appropriately changing the blast furnace.

Thus, the blast furnace molten zone level is an extremely important factor in blast furnace operation, and the level must be measured as accurately as possible.

For this reason, various methods have been tried in the past for measuring the level of the blast furnace molten zone.

For example, iron ore with a large amount of special components (such as Mn) can be charged into a certain charge, and the level of the molten zone in the furnace can be calculated backward from the fluctuations in the tapped components.
There is a method of estimating the melting level by doubling the charge (ore, coke, etc.) and examining the change in ventilation resistance when the layer of the charge melts.

However, this method has the disadvantage that there are many estimation factors such as the residence time of the melt in the furnace, and the measurement data also varies and lacks accuracy.

Another method is to emit a pressure wave from one side of the shaft and perform numerical analysis on the response to estimate the melting level, but this method requires too many other disturbances to detect minute fluctuations, making it difficult to distinguish between them. Therefore, there is a drawback that the data lacks reliability.

Although the level control of the molten zone is an important condition in blast furnace operation, the conventional methods have difficult measurement conditions, making it difficult to obtain accurate data and making it difficult to stabilize blast furnace operation. This was a major hindrance in terms of

The present invention has been proposed as a result of various studies in view of the current situation, and is a new blast furnace molten zone that can accurately measure the level of the blast furnace molten zone and that can easily and safely carry out the measurement work. This is the invention of a measuring device.

Next, one embodiment of the present invention will be explained with reference to the attached drawings. First, in FIG. The refractory pipe 3 is inserted downward into the furnace.

That is, this gas seal part is connected to the blast furnace 1 as shown in detail in Fig. 2.
A valve 5 is attached to an opening 4 on the side of the furnace top, and a hollow support 6 is provided above the valve 5, and a flange 7 is attached to a bolt 8 above the support 6.
etc. is fixed.

The pipe insertion portion 7a of the flange 7 is fitted with a gland packing, etc., and is configured to be gas-tight when the pipe 3 is inserted therein.

On the other hand, a wire drawing machine 9 composed of a plurality of rollers is installed above the flange 7, and the pipe 3 is guided downward by the wire drawing machine 9, and is guided by the wire drawing machine 9 to the insertion part 7a of the flange 7 and the valve 5. It is inserted perpendicularly into the furnace through the

A protection pipe 10 is installed below the valve 5 in the direction of the inside of the furnace, which prevents the pipe 3 from being damaged or misaligned when raw material is charged from the top of the blast furnace. is prevented.

A thermocouple 11 is installed inside the poorly soluble pipe 3 (see Fig. 3), and a temperature measuring device 12, a pressure gauge 13, a gas detector 14, etc. are connected to the rear end of the pipe 3. The tip of the pipe 3 is sealed with a metal material that is more easily soluble than the pipe 3 and has a melting point close to the temperature of the melting zone (for example, focused malleable cast iron, melting point: 1320° C.).

FIG. 3 shows an example of the structure of the tip of the pipe 3, and the tip of the pipe 3 has a hollow capsule 15 made of a material that is hardly soluble (for example, has a melting point of 1500° C. or higher). Fixed by screw-in and welding.

A gas introduction hole 16 is formed in the side of the hollow capsule 15, and a filter material 17 such as a ceramic filter is installed inside the gas introduction hole 16 to remove dust that enters from the introduction hole 16 at the same time as the furnace gas. A plug 19 made of the above-mentioned focused malleable cast iron or other relatively easily soluble material is enclosed in the through hole 18 which is filled and is formed at the tip end.

The configuration described above is merely an example of the present invention, and it goes without saying that the detailed configuration can be easily changed as necessary in accordance with the spirit of the invention.

For example, a CA thermocouple is used as the thermocouple 11, and as shown in FIG.
The passage of the melting zone level may be detected by monitoring a specific phenomenon of thermoelectromotive force at 0° C.).

Next, in order to measure the blast furnace molten zone level according to the present invention, first close the valve 5 to shut off the furnace atmosphere, loosen the bolts 8 and remove the flange 7, and install a pipe of a length that can reach the lower part of the furnace. 3 along the wire drawing machine 9 and pass it through the insertion part 7a of the flange 7, and lower it to the position where the capsule is attached.

Next, after attaching the capsule 15 to the tip of the pipe 3, the flange 7 is fixed with the pole l-8, and then the valve 5 is opened and the handle (not shown) of the wire drawing machine 9 is operated to remove the capsule. 15 is lowered to the charge stock line 2 of the blast furnace.

As a result, the pipe 3 and capsule 15 descend as the blast furnace raw material charge descends, determined by the rate of descent of the charge.

However, in the present invention, as the pipe 3 descends inside the furnace, the temperature inside the furnace is measured by the thermocouple 11 built into the pipe 3, and the pipe 3 is melted. As the band level approaches 20, a rapid temperature rise is observed.

Moreover, if the tip of the pipe 3 is constructed as shown in Fig. 3,
It is possible to take gas samples on the way to reaching the melt zone level 20.

That is, from the gas introduction hole 16 provided on the side of the capsule 15, the furnace gas is introduced from time to time during the process of the capsule 15 descending, and while the gas is released to the atmosphere through the pipe 3, the pressure gauge 13 The amount of gas is measured every moment by a gas detector 14.

On the other hand, when the tip of the pipe 3 reaches the melting zone level 20,
The easily soluble plug 19 at the tip of the pipe 3 melts, and a large amount of gas is led into the pipe 3. By measuring changes in the amount of gas with the pressure gauge 13 and gas detector 14, Can read belt level 20.

After completing the measurement in this way, the pipe 3 is cut at an appropriate position, such as directly above the wire drawing machine 9, and after this cut pipe passes through the valve 5, the valve 5 is closed to complete the series of operations. It is something to do.

Note that the cut pipe is melted in the blast furnace and becomes the contents of the blast furnace.

Figure 4 shows an example of actual measurement of the blast furnace molten zone level using the present invention, and as is clear from this figure, the present invention allows extremely stable molten zone level measurement. becomes.

As described above, according to the present invention, it is possible to easily and safely measure the level of the blast furnace molten zone, and moreover, as in the conventional method,
It has various advantages such as being able to obtain extremely accurate data because it is not influenced by external factors.
This is an invention with excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing the implementation status of the present invention, Fig. 2 is a detailed view of part A of Fig. 1, Fig. 3 is a detailed view of part B of Fig. 1, and Fig. 4 is a detailed view of part B of Fig. 1. Actual measurement diagram of blast furnace melting level,
FIG. 5 is a graph showing the temperature characteristics of the CA sheath thermocouple. In the figure, 1 is a blast furnace, 2 is a stock line, 3 is a refractory pipe, 4 is an opening, 5 is a valve, 6 is a hollow support, 7 is a flange, 7a is a pipe insertion part, 8 is a bolt, and 9 is a Wire drawing machine, 10 is a protection tube, 11 is a thermocouple, 12 is a temperature measuring device, 1
3 indicates a pressure ratio, 14 indicates a gas detector, 15 indicates a poorly soluble capsule, 16 indicates a gas introduction hole, 17 indicates a filter material, 18 indicates a hole, 19 indicates an easily soluble plug, and 20 indicates a melting zone level.

Claims (1)

[Claims] 1. Consists of a device for inserting a refractory pipe containing a thermocouple in a downward direction into the blast furnace, and a refractory capsule fixed to the tip of the refractory pipe, and inserting the tip of the refractory capsule into the blast furnace. A blast furnace melting zone level characterized by being sealed with a metal plug having a melting point similar to the melting zone temperature, and having gas introduction holes provided at appropriate locations in this poorly soluble capsule, and a filter material being loaded into the capsule. measuring device.