JPH0625372B2 - Blast furnace tapping method and tapping device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tapping method and apparatus for a refining furnace such as a blast furnace.

<Prior art> In the tapping work for extracting molten metal from a refining furnace such as a blast furnace for producing hot metal, a kind of drill called a hole puncher is used to open the taphole, and when it is closed, a device called mud gun is used for plasticity. Push the refractory (mud) in to the taphole to finish tapping. In order to carry out stable tapping work, it is necessary to secure a taphole depth of an appropriate length. In order to secure the tap hole depth, conventionally, it is necessary to secure the amount of plastic refractory material called botter to be filled in the hole, or to adjust it by means such as devising a method of opening a hole with a hole opening machine, I was trying to secure a smooth tapping.

Usually, the number of tapping is about 10 times / day, which requires 6 to 10 people / shift personnel in three shifts.

Conventionally, attempts have been made to reduce the number of tapping, reduce the number of personnel in front of the furnace, and reduce the basic unit of mud, gold rod, etc. used for tapping. Normally, the number of tapping times is reduced by improving the method of opening holes and optimizing the quality of mud, but this method limits the number of times to 6 times a day.

Furthermore, an attempt was made to fundamentally reduce the number of tapping,
Japanese Patent Publication No. 58-49609 discloses a method of tapping work in a blast furnace, which enables tapping for a long time without increasing the burden of tapping and opening. That is, after opening the blast furnace tap hole, a removable refractory cylindrical nozzle having a through hole in the center is pressure-welded to the tap hole, and the tap slag is carried out through this nozzle. Closing for stopping is a blast furnace tapping work method which is carried out by removing the pressure-contacted nozzle from the tapping hole and filling the mud into the tapping hole.

Here, the reduction of the number of workers in front of the furnace by reducing the number of tapping,
Although it is reported that labor saving is possible, the minimum number of tapping is 2 times / day as shown in the examples, and the number of tapping is up to 1 time / day which is the target of the present invention. Has not reached.

On the other hand, Japanese Laid-Open Patent Publication No. 52-133036 discloses a molten metal supply device using an electromagnetic pump as a means for controlling the outflow amount of molten metal.

That is, one opening of the electromagnetic pump that causes the molten metal to act as a secondary conductor is connected to the molten metal discharge port of the container and is attached to the reaction container side of the electromagnetic pump through the electromagnetic pump. An orifice that limits the amount of metal is provided so that the required amount of tapping water per unit time is equal to the amount of tapping metal when power is not supplied to the electromagnetic pump. It is expected that the control will be constant regardless of the level of the molten metal.

<Problems to be Solved by the Invention> The conventional method disclosed in JP-B-58-49609 merely aims to reduce the number of tapping, and does not aim to set the number of tapping once per day. In addition, after opening the tap hole of the blast furnace, a removable refractory cylindrical nozzle with a through hole in the center is pressed against the tap hole, and tap slag is carried out through the hole of this nozzle. In the conventional method, since the molten pig iron flows at a high speed in the nozzle, erosion of the refractory is unavoidable. Therefore, the tapping speed increases with the progress of tapping. In the conventional method that does not have means for controlling the tapping speed, operating fluctuations such as increase and decrease in the amount of slag remaining in the furnace during tapping, fluctuations in blast pressure, abnormal drops in charging, etc. The minimum amount of tapping that can be reduced by the conventional method is 2 times / day because the amount of tapping is decreased and the hot metal component is changed. As a result, as shown in the examples.

In view of the above-mentioned current situation, the present invention constantly controls the tapping iron flow rate of the blast furnace once by controlling the tapping tapping flow rate of the blast furnace in accordance with the molten pig iron production amount regardless of the erosion of the refractory material in the taphole. With the aim of reducing the number of workers by the day, a large reduction in personnel can be achieved by achieving the objective, and in particular, most of the tapping work can be performed in the daytime. It was made to provide a tapping method and tapping device for a blast furnace.

<Means for Solving the Problems> The present invention has a cylindrical refractory nozzle capable of controlling the flow rate of tapping slag, which has a hole for tapping slag in the center after opening a taphole for blast furnace. The tapping method of the blast furnace, characterized in that the taphole is pressed into contact with the taphole so that the taphole communicates with the taphole, and the taphole control device of the nozzle adjusts the taphole flow rate. The output of the electromagnetic pump was changed so that the actual tapping speed measured using a tope, a slag pan, etc. and the molten pig iron production rate in the furnace calculated from the blast furnace operating specifications were equalized. With the tapping method of the blast furnace described in the preceding paragraph for adjusting the amount of slag, and having a through hole for tapping slag in the center, and controlling the flow rate of tapping slag with an electromagnetic pump in a part of the refractory cylindrical member. Tapping device for a blast furnace, comprising a nozzle capable of tilting and a swivel having a tilting lever for tilting the nozzle and a suspending arm for suspending the nozzle. Is.

<Operation> In the present invention, after opening the taphole of the blast furnace, a refractory having a through hole in the center, a detachable nozzle in the form of a cylinder is attached to the taphole, and fired in advance with high corrosion resistance. By using the object cylinder as the nozzle, the erosion of the taphole by the molten pig iron can be minimized.

In order to continue the tapping for 24 hours even with the minimum erosion of the taphole, the fluctuation of the tapping rate due to the erosion during that period becomes a problem. Further, in order to continue the stable pig iron slag corresponding to the change in the operating speed within one day, a pig iron slag speed control device is required. Therefore, in the present invention, an electromagnetic pump type pig iron slag speed control device is provided. Was installed at the rear end of the refractory cylindrical nozzle to control the tapping speed.

In addition, even if the output of the electromagnetic pump is the same, the efficiency of the pump changes depending on the ratio of the amount of hot metal and the amount of slag, and the outflow rate changes, so the rate of hot metal production in the furnace can be adjusted from the blast furnace operating specifications. The output of the electromagnetic pump was controlled according to the difference between the calculated speed and the tapping speed from the furnace so that the tapping rate was constant.

The configuration of the present invention will be described in detail below.

FIG. 1, FIG. 2 and FIG. 3 show the nozzle swirling method and equipment configuration used in the present invention.

Reference numeral 1 is a main body of a refractory cylindrical nozzle having a through hole 2 in the center thereof, which is rotatably supported by a tilting lever 8 and a suspension arm 6 arranged on a swivel base 5 to start tapping. After that, when the tapping speed becomes higher than the average speed, the tip 1a of the nozzle is pressed against the end face of the tapping hole 3. An electromagnetic pump 10 having a passage formed of a ceramic tube having a rectangular cross section is provided at the rear end portion 1b of the nozzle, and the output of the electromagnetic pump is adjusted to adjust the tapping speed.

The nozzle 1 that is attached to and detached from the tap hole 3 is shown in FIGS.
As shown in the figure, it is supported by a suspension arm 6 fixed on the swivel base 5, and rotates in synchronization with the rotation of the swivel base 5. Further, the function of closely contacting the nozzle tip portion 1a with the tap hole 3 is performed by the continuous hammering operation of the cylinder 7 installed between the swivel 5 and the suspension arm 6 and the tilting lever 8 of the link mechanism.

The operation of the present invention will be described according to the progress of tapping. Some time after the start of tapping, the taphole normally expands, and when the tapping speed becomes faster than the molten pig iron production rate in the furnace, the nozzle 1 is swung from the retracted position and its tip end portion is rotated. 1a is brought into pressure contact with the taphole, and the passage of the taphole drilled by a drill is communicated with the through hole 2 of the nozzle so that the taphole is the rear end portion 1 of the nozzle.
Perform from b. While the tapping is continued, the inner diameter of the tapping hole 3 gradually increases, and the pig iron slag flows at a high speed through the tapping hole 2 in the ceramic tube of the nozzle 1. Erosion will inevitably occur.

As a result, at the same output of the electromagnetic pump, the tapping speed gradually increases due to the reduction of the flow resistance. Further, the efficiency of the electromagnetic pump is inversely proportional to the electric resistance of the flowing molten fluid, but if the discharge rate of the molten slag having a large electric resistance increases, the efficiency decreases and the tapping speed increases.

On the other hand, during tapping for a long time, the amount of molten pig iron generated in the furnace changes due to disturbances other than tapping.

In order to continue tapping for a long time, it is necessary to adjust the tapping speed of the tapping and keep the amount of molten pig iron retained in the furnace constant. If the tapping speed is too high, the liquid level of the molten pig iron in the furnace is lowered, and the gas in the furnace is blown out from the taphole, making it difficult to continue tapping. Further, if the tapping speed is too low, the liquid level of the molten pig iron in the furnace rises, causing blast furnace operation troubles such as slip and unloading instability.

It is calculated from the actual slag speed and the blast furnace operating parameters measured by adjusting the amount of slag with an electromagnetic pump, which is a slag control device, according to the changes in the flow resistance, etc., or measured with the weight of topede. The present invention is characterized in that the output of the electromagnetic pump is changed so as to balance the molten pig iron production rate in the furnace with the molten pig iron production rate to adjust the tapping rate.

The flow chart of the method for controlling the tapping speed of the present invention
As shown in the figure.

The method for obtaining the amount of molten pig iron (speed) will be described below.

The amount of oxygen atoms contained in the top gas can be calculated from the analysis values (CO, CO ₂ , H ₂ , N ₂ ) of the top gas composition. Also, the top gas amount can be calculated back from the balance of N ₂ of N ₂ flow rate in the furnace to be discharged from the N ₂ flow rate and furnace top in blast entering the tuyere.

The amount of oxygen discharged per unit time is calculated from the product of the amount of this furnace top gas and the amount of oxygen atoms in the furnace top gas.

Oxygen brought into the furnace comes from blast and ore,
The oxygen amount derived from the ore is obtained by subtracting the oxygen amount derived from the blast from the discharged oxygen amount.

On the other hand, the amount of oxygen contained in the unit amount of ore is known by chemical analysis, and the amount of hot metal produced can be calculated backward from the amount of oxygen derived from the ore.

The cross-sectional shape of the ceramic tube of the nozzle tip 1a is circular in order to make it the same as the shape of the tap hole, and the shape of the ceramic tube 9 of the electromagnetic pump section is rectangular in order to increase the efficiency of the electromagnetic pump. Is equipped with a tapered ceramic tube. As the material of the ceramic tube, a pre-fired refractory having a strong corrosion resistance of molten pig iron is used.

By using the present invention, it is possible to keep the amount of molten pig iron retained in the furnace constant, and to avoid blast furnace operation problems such as instability of slippage and unloading due to an increase or decrease in the amount of retained molten iron in the furnace.

By the above, stable one-time / sunrise pig is possible.

<Example> An example to which the present invention is applied will be described below. The applied blast furnace is a large blast furnace with a tapping capacity of 10000 T / D, and in the past it was a three-shift work of 6 people / shift, and the actual work was done by 18 people / day.

The related uses of the tapping apparatus of the blast furnace shown in FIGS. 1, 2 and 3 are as follows.

The pressure difference between the inside and outside of the furnace is about 3.5 kg / cm ² , of which 3.0 kg / cm ² is the nozzle at the end of tapping, and the inner diameter of the initial nozzle is 80 mm so that it occurs at the tapping hole. The length was 2.5 m. In order to adjust the change in the amount of tap metal due to the erosion of the refractory material in the nozzle during tapping, the capacity of the electromagnetic pump is 1.0
A force equivalent to the pressure loss of kg / cm ² is applied to the hot metal.
A 200 kw electromagnetic pump was used.

The change in the amount of tap slag and the like in the embodiment to which the present invention is applied
Although shown in the figure, the description will be made in comparison with FIG. 6 in the case of the conventional example.

In all cases, tapping started at 10 o'clock, and after a while after tapping started, the taphole expanded and the nozzle 1 was evacuated when the tapping speed became higher than the molten pig iron production rate in the furnace. The tip 1a is swung from the position and pressed into contact with the taphole, and the passage of the taphole drilled by a drill and the through hole 2 of the nozzle are made to communicate with each other, and tapping slag is carried out from the nozzle rear end 1b.

As shown in FIG. 6, in the conventional example, the inner diameter of the taphole gradually increased while the tapping was continued, and the nozzle 1
Corrosion of the refractory material in the nozzle inevitably occurs because the molten pig iron flows at a high speed through the holes for tapping slag inside. as a result,
The tapping speed was gradually increased, and when the amount of molten pig iron retained in the furnace became less than a certain value, gas was blown out from the taphole, so tapping was stopped and the next tapping was started. In addition, the blast pressure fluctuates according to the change in the amount of molten pig iron retained in the furnace, causing operational fluctuations.

On the other hand, in the embodiment of the present invention shown in FIG. 5, the tapping speed of the tapping metal is controlled by an electromagnetic pump during tapping. For a while after the nozzle is pressed, the amount of molten pig iron retained in the furnace is large, so braking is not performed by the electromagnetic pump.However, when the amount of molten pig iron retained in the furnace is reduced to the original level, molten pig iron is generated in the furnace. The amount of slag produced is controlled by adjusting the output of the electromagnetic pump. In the latter half of tapping, melting of ceramic pipe becomes remarkable, and the output of electromagnetic pump becomes almost maximum. During this tapping period, tapping holes and tapping stop work do not occur in front of the furnace, so it is sufficient to have two personnel who perform monitoring work.

Stop tapping at 10 o'clock on the next day, and open other tap holes.
During this period, since the amount of molten pig iron retained in the furnace can be kept constant, it is possible to avoid an increase in blast pressure due to an increase in the amount of molten pig iron retained in the furnace and troubles in blast furnace operation.

According to the present invention, the required front personnel is six during the day,
At night, there are 2 people x 2 shifts for a total of 10 people. Number of tapping times is 1
It is possible to cope with the shortage of shift workers by setting the number of people to work at night / night as a minimum of two people, and the economic effect is remarkable.

Comparing the effect of the present invention with a conventional method of a simple nozzle system,
The results are summarized in Table 1.

The number of tapping has decreased from the conventional 2.3 times / day to 1.0 times / day, and at the same time, the fluctuations in the number of wind reductions and the blowing pressure have significantly decreased. In addition, the required number of personnel in front of the furnace for actual work was reduced from a total of 18 to 10, and the number of night shift personnel was reduced to 2.

<Effects of the Invention> According to the present invention, the number of tapping times can be reduced to 1.0 times / day, and at the same time, the fluctuations in the number of wind reductions and the blowing pressure can be greatly reduced. As a result, the number of personnel in front of the furnace and the number of night shift personnel could be significantly reduced.

[Brief description of drawings]

FIG. 1 is a front view showing the tapping device according to the present invention, FIG. 2 is a side view showing the tapping device according to the present invention, and FIG. 3 is a plan view showing the tapping device according to the present invention. FIG. 4 is a flow chart of a control method according to the present invention, FIG. 5 is a characteristic diagram showing changes with time in the flow rate of pig iron and the amount of residence in the furnace in the embodiment of the present invention, and FIG. It is a characteristic view which shows a time-dependent change, such as a pig iron slag flow rate and an amount of residence in a furnace in an example. 1 ... Nozzle, 1a ... Nozzle tip, 1b ... Nozzle rear end, 2 ... Hole for tapping slag, 3 ... Tap tapping hole, 4 ... Tap tap, 5 ... Swivel base, 6 ... Suspension arm, 7 ... Cylinder, 8 ... Tilt lever, 9 ... Ceramic tube, 10 ... Electromagnetic pump, 11 ... Heat resistant cover.

Claims (3)

[Claims] 1. A refractory cylindrical nozzle, which has a hole for tapping slag in the center after opening the taphole for blast furnace and is capable of controlling the flow rate of tapping slag, is formed by tapping the taphole. A tapping method for a blast furnace, characterized in that tapping is carried out so as to communicate with a hole, tapping is performed, and a tapping control device for a nozzle adjusts a tapping flow rate. 2. The output of the electromagnetic pump is adjusted so that the actual slag production rate measured using a tope, slag pan, etc. and the molten pig iron production rate in the furnace calculated from the blast furnace operation specifications become equal. The tapping method for a blast furnace according to claim 1, wherein the tapping amount is adjusted by changing the amount. 3. A nozzle having a through hole for tapping slag at the center thereof, which is equipped with an electromagnetic pump in a part of a refractory cylindrical member, and a tilting lever for tilting the nozzle. A tapping device for a blast furnace, which comprises a revolving base equipped with a suspension arm.