JPH0650535Y2 - Charging device for powdered raw material in molten metal furnace - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention relates to the use of a powder metal material, particularly a high temperature powder material in a metal bath in a molten metal furnace such as a converter or a smelting reduction furnace. Molten metal).

[Prior Art] Various metal powder raw materials are charged into a metal bath held by a converter, a smelting reduction furnace, or the like. For example, converters are charged with lime and ferroalloys as auxiliary materials, and in smelting reduction furnaces,
Ore as a main raw material and lime as a reducing agent are charged together with lime. Note that the smelting reduction furnace is a reactor for reducing ore containing a metal oxide such as iron ore in a molten state, and is a reaction furnace that has recently begun to attract attention as a reduction furnace that replaces a blast furnace and the like.

The above-mentioned powdery material is generally charged from above the furnace body, that is, from above the metal bath. In rare cases, the gas may be blown from the bottom or side of the furnace body under the bath surface,
In this case, if the amount of the blown gas is not properly controlled, there is a risk of gas blow-through or backflow of the metal bath to the blow pipe, and the gas is always kept while the metal bath is held in the furnace. It is necessary to continue blowing, which increases the operating cost, lowers the temperature of the metal bath, prevents clogging and wear of the blowing pipe, and reduces the required amount of blowing gas. Must be strictly limited-there are problems such as.

As a method of charging the granular material into the bath from above the bath surface,
Conventionally, the following two are known. That is, one is
A method in which a charging port is opened at an upper part of the furnace body wall or a part of the furnace hood, a raw material charging chute is connected to the charging port, and the raw material is dropped by gravity from the charging port. The other method is to inject the raw material together with the transfer gas through a vertical injection lance similar to the oxygen blowing lance in the converter. The above two methods are exemplified in, for example, JP-A-60-2612.

By the way, in the molten metal furnace, in order to keep the temperature of the metal bath high, it is desirable to charge the raw material for the granular material at a temperature as high as possible. This is because, for example, in the converter, the higher the iron bath temperature is, the easier the impurities are burned and refined, and in the smelting reduction furnace, the higher the metal bath temperature is, the more the reduction reaction is promoted. If low-temperature raw materials are charged and the temperature of the metal bath is lowered, the required amount of oxygen and coal will increase accordingly.

From this point, when charging the granular material to the smelting reduction furnace, use the gas (high-temperature gas containing a large amount of CO) generated from the smelting reduction furnace to preheat the raw material (prepare for the ore further. The technique of reducing and then charging is already known (for example, JP-A-62-60805).

[Problems to be Solved by the Invention] When the raw material is dropped by weight from above the metal bath and charged, a part of the raw material is scattered by the gas generated in the metal bath, and the total amount is effectively effective. Not charged inside. Similar to the smelting reduction furnace described above, a large amount of gas (also high-temperature gas containing CO) is generated from the bath in the converter as well, but the above-mentioned inlet is to prevent splashing and thermal deformation of the metal bath. Since it is installed quite above the bath surface, the raw materials that are put into the hood are discharged along with the gas into the hood.

On the other hand, regarding the method of charging the raw material using the injection lance, since the blowing port of the tip part moves up and down,
The raw materials can be charged into the bath from a position close to the bath surface,
Due to the characteristics of the flexible hose for transferring the raw material required to support the raising and lowering, the temperature of the raw material to be charged is limited. In other words, at the present time, there is no flexible hose that can be used to transfer powder (that is, has wear resistance) because it does not have sufficient heat resistance.
Even if an attempt is made to charge the powdered or granular material into the molten metal furnace through this, the material cannot be sufficiently preheated.
Therefore, the promotion of the reaction in the furnace by the preheating of the raw material cannot be expected so much. As described above, when the ore is preliminarily reduced and charged into the smelting reduction furnace, the ore must be cooled once before being charged, resulting in waste of energy and process.

When the raw material is blown together with the gas from the bottom or the side of the furnace body to the bottom of the bath, there are problems such as those mentioned above.

[Object of the Invention] The present invention was made in order to solve the above-mentioned problems, and in addition to reliably charging a granular material having a wide particle size distribution into the bath from a position above the metal bath surface, An object of the present invention is to provide an apparatus for charging a granular material in a molten metal furnace, which enables high-temperature transfer and charging of the raw material.

[Means for Solving the Problems] A charging device of the present invention for achieving the above object is a device for charging a powdery or granular material from a metal bath surface into a metal bath of a molten metal furnace. In addition, a fixed and inflexible (that is, flexible hose-free) raw material transfer pipe with heat resistance (service temperature of around 700 ° C or more) is fixedly installed from above the molten metal furnace to just above the opening of the furnace. In addition, an inflexible raw material charging pipe of the water cooling structure (same as above) is externally fitted to the raw material transfer pipe so that it can be moved up and down from the upper part of the molten metal furnace to the inside thereof, and a cooling water hose for water cooling is provided. Is connected to the upper part of the raw material charging pipe, and the upper part is held by a carriage (so to speak, a carrier) provided so as to move up and down along a vertical guide rail.

Further, as described in claim 2, the raw material charging pipe is filled with a sealing member inside the upper part of the raw material charging pipe and pressed from above, and the inner surface of the sealing member is in contact with the outer peripheral surface of the raw material transfer pipe. It is also possible to fit the above into the raw material transfer pipe so that the raw material for granular material is transferred from the upstream of the raw material transfer pipe with a transfer gas and is sprayed from the raw material charging pipe onto the bath surface.

According to a third aspect of the present invention, the raw material charging pipe is a triple pipe having a partition pipe inside and continuous inner and outer flow paths, and the cooling water hose is an inner side of the partition pipe of the triple pipe. It is advisable to connect a plurality of (one or more for each of the inner and outer channels) so as to communicate with each of the outer and outer channels.

Furthermore, as described in claim 4, the inner tube of the raw material charging tube may be made of a wear resistant material.

[Operation] According to the charging device of the present invention, the powdery material is charged into the bath from above the metal bath surface through the raw material transfer pipe and the raw material charging pipe. Since the raw material charging pipe moves up and down below the raw material transfer pipe, if the tip of the charging pipe is lowered close to the bath surface according to the height of the bath surface, the rate of charging the raw material into the bath becomes extremely high. Therefore, by appropriately setting the inner diameters of the transfer pipe and the insertion pipe according to the raw material having the coarse particle diameter, the raw material having a wide particle size distribution from coarse particles to fine powder can be reliably charged into the bath. The raw material charging pipe goes up and down in this way from above the molten metal furnace and enters the high temperature inside the furnace, and the tip approaches the bath surface, but due to the water cooling structure, thermal deformation etc. The inconvenience of does not occur.

Further, since the upper part of the raw material charging pipe is held by a carriage that moves up and down along a vertical guide rail and moves up and down together with the carriage, the above-described lifting and lowering can be performed extremely smoothly. That is, although the raw material charging pipe has a water cooling structure with a cooling water flow path and is heavy with a cooling water hose connected, and it is difficult to balance the weight, the carriage holding it and the carriage are restrained. It is supported by the guide rails that guide it and moves up and down smoothly in the vertical direction without tilting or shaking.

The device of the invention is a structure in which the raw material transfer pipe is fixedly arranged as a heat-resistant and inflexible one, and because of the water cooling structure, the heat-resistant and inflexible raw material charging pipe is externally fitted below the transfer pipe to move up and down. However, since the flexible hose is not used for transferring the granular material, there is practically no temperature limitation for transferring and charging the high temperature material. Regarding the cooling water hose for water cooling the rising and falling raw material charging pipe, heat resistance becomes a problem due to the temperature of the cooling water (supplied at room temperature and the temperature rise width is within several tens of degrees Celsius). There is no such thing.

According to the charging device described in claim 2, since the powdery granular material that is blown to the bath surface together with the transfer gas also acts on the inertial force during the transfer, it is possible to more reliably prevent the dispersion of the fine powdery material. The raw material charging rate is further improved. Since the device of the invention is a system in which the raw material is charged from the bath surface, it is not necessary to strictly adjust the flow rate of the transfer gas in this case as well. In particular, when the raw material is not charged, the same gas can be stopped, which is advantageous in terms of operating cost and maintaining the temperature of the metal bath. Since the seal member is attached to the part where the raw material charging pipe is fitted and connected to the raw material transfer pipe as described above, even if the pressure of the transfer gas is high, gas or powder particles may flow from between the connecting parts. Body material does not leak.

In the apparatus according to claim 3, the cooling water sent from a certain cooling water hose first flows into the flow passage inside or outside the partition pipe of the raw material charging pipe and is continuous with the other (outside or inside the partition pipe). ) To another cooling water hose. It is relatively easy to provide a partition tube inside to make the raw material charging tube a triple tube, but as described above, the cooling water smoothly flows through the raw material charging tube. The heat load of the raw material charging pipe entering inside is effectively reduced.

Further, according to the apparatus of claim 4, the raw material charging pipe can be protected from abrasion due to the raw material.

In either case, if the raw material charging pipe is raised, its tip can be retracted to the lower end of the raw material transfer pipe, that is, the position directly above the opening of the molten metal furnace, so the furnace body must be moved (for tapping). This device does not interfere with the tilting of the machine) or maintenance (repair of refractories, etc.).

[Embodiment] As an embodiment of the present invention, FIG. 1 shows a smelting reduction furnace for iron making and a raw material charging apparatus for the same. The smelting reduction furnace 50 holds an iron bath 50a inside, in which iron ore (preliminary reduced iron below) is charged together with coal, lime, etc., and oxygen (and nitrogen for stirring) is blown into the iron ore. Is obtained in the molten state to obtain pig iron. Since a high-temperature gas containing CO and having a reducing power is generated from the iron bath 50a, in the present embodiment, this gas is passed from the hood (elevating type) 51 covering the furnace body opening 50b to the die 52, and the iron ore is discharged. It is sent to a stone pre-reduction furnace (not shown). Therefore, the iron ore is brought into contact with the above-mentioned gas in the preliminary reduction furnace to become preliminary reduced high-temperature (around 700 ° C) preliminary reduced iron, and the molten reduction furnace 5
Sent to 0.

In order to charge the powdery granular materials such as the pre-reduced iron and the coal and lime into the iron bath 50a from above, in the present embodiment, the raw material transfer pipe 1 and the raw material charging pipe 2 as shown in FIG. It is arranged above the smelting reduction furnace 50. The raw material transfer pipe 1 is fixedly arranged on the building beam 60 such as by being held by a holder 61. They are connected and continuously provided up to near the opening 50b of the smelting reduction furnace 50. The raw material charging pipe 2 has an upper part connected to the lower part of the transfer pipe 1 so that the tip end thereof reaches the inside of the reduction furnace 50 through the opening of the duct 52. That is, the above-mentioned powdery or granular material is charged into the iron bath 50a through the tip end opening 2a through the transfer pipe 1 and the charging pipe 2 connected thereto. Since the transfer gas is blown into the transfer pipe 1 at the upstream portion (not shown), the raw material is transferred and blown onto the iron melt 50a by the action of gravity and the transfer gas.

The raw material charging pipe 2 can be moved up and down by the elevating means 4 from a position where the front end opening 2a is near the lower end of the raw material transfer pipe 1 to a position very close to the iron bath 50a in the smelting reduction furnace 50. . The charging pipe 2 needs to be retracted upward when charging the initial molten iron (seed water) into the reduction furnace 50, but when charging the above-mentioned raw materials, the raw material with a small particle size should also be scattered. Instead, the tip 2a of the iron bath 5a is placed in the iron bath 5a.
This is because it is desirable to get very close to 0a. For this reason, the upper portion of the charging tube 2 is held by the elevating carriage 41, and the carriage 41 is connected to the hoisting winch 33 via the hanging wire 44. Since the carriage 41 is provided with the guide wheel 41a and is attached to the vertical guide rail 42, the carriage 41 moves up and down in the vertical direction as the winch 33 rotates. Since the charging pipe 2 is exposed to the heat of the iron bath 50a and its generated gas, the entire structure has a water cooling structure, and cooling water pipes 31 and 33 and cooling water hoses 32 and 34 (31 and 32 are the forward side, 33 and 34 are connected to the return side).

FIG. 2 shows the details (cross-sectional view) of the connecting portion between the raw material transfer pipe 1 and the raw material charging pipe 2.

As shown in the figure, the upper portion of the charging pipe 2 is fitted onto the straight portion of the transfer pipe 1 and is held by the carriage 41. In this embodiment, since the internal pressure becomes high due to the above-mentioned transfer gas, the transfer pipe 1 and the charging pipe 2 are hermetically connected so as to prevent the gas (and the fine powdery raw material) from leaking. That is, the upper end of the charging pipe 2 is formed into a stuffing box 25, and a gland packing (sealing member) 27 is packed between the stuffing box 25 and the transfer pipe 1 and is fixed by a packing presser 26.

The raw material charging pipe 2 has a triple pipe structure capable of circulating cooling water, and is an integrally formed unit by concentrically combining an outer pipe 21, a partition pipe 22 and an inner pipe 23. The cooling water supplied from the pipe 31 passes through between the partition pipe 22 and the inner pipe 23 to reach the tip portion of the charging pipe 2 (see FIG. 3), and further between the partition pipe 22 and the outer pipe 21. It flows through to the pipe 33.

Although the cross-sectional structure of the raw material transfer pipe 1 is also shown in FIG. 2, the transfer pipe 1 is equipped with a ceramic liner 12 having high wear resistance and heat resistance inside an outer pipe 11 made of steel pipe. Inside the transfer pipe 1, a powdered granular material such as pre-reduced iron at a high temperature (around 700 ° C. as described above) passes at a considerable speed together with the transfer gas, so the above causes thermal inconvenience and wear. This is a treatment for preventing For the same reason, the inner pipe 23 of the charging pipe 2 is made of a material having excellent wear resistance.

FIG. 3 is a sectional view showing the tip of the raw material charging pipe 2.
The outer pipe 21 and the inner pipe 23 of the above-mentioned triple pipe are joined at this portion, and the partition pipe 22 is extended to a position close to the inner side thereof and a cooling water flow path can be secured. The portion 21a from the vicinity of the tip of the outer pipe 21 to the end of the inner pipe 23 was formed of a copper alloy material having high thermal conductivity. This is because the heat from the iron bath 50a acts most strongly on this portion 21a, and it is necessary to improve the heat transfer.

This charging device configured as described above is operated as follows to charge the powdery or granular material into the iron bath 50a of the smelting reduction furnace 50. That is, first, the cooling water is circulated in the raw material charging pipe 2 and the winch 33 is driven to lower the charging pipe 2 together with the carriage 41 while blowing some transfer gas from the upstream side of the raw material transfer pipe 1. Tip opening 2a of charging tube 2
When approaching the iron bath 50a, various raw materials of granular material are simultaneously or individually supplied into the transfer pipe 1 and sprayed onto the iron bath 50a together with the transfer gas. As shown in FIG. 1, the portion of the iron bath 50a facing the tip opening 2a of the charging pipe 2 is lowered, and accordingly the charging pipe 2 is further lowered.
In this way, or if the state of is continued, the granular material is securely in the iron bath 50a without being agitated by the generated gas from the iron bath 50a due to the action of gravity and the inertial force blown out by the transfer gas. Is charged to.

When the operation of the smelting reduction furnace 50 is finished and the reduction furnace 50 is tilted or the inside thereof is maintained, the raw material charging pipe 2 is raised together with the carriage 41, and the position of the tip opening 2a is set near the duct 52. Raise to. If the elevating hood 51 described above is also raised at the same time, the tilting of the reduction furnace 50 will not be hindered, and the opening 50b will be opened widely.

FIG. 4 shows an example in which the tip of the raw material charging pipe is made slightly thin, apart from the above embodiment. Set the diameter of the inner pipe 23 'to the tip opening
2a 'is squeezed to 1/2 or less, and the partition tube 2
The tips of 2'and the outer tube 21 'are also thin. When the raw material is charged, the bath iron may be repelled from the iron bath 50a. However, if the tip opening 2a ′ is made thin in this way, the action of the transfer gas blown out from this (this action also applies to the above-mentioned embodiment). In addition to the above, the adhesion of metal to the inside of the inner pipe 23 'can be prevented more reliably.

The embodiments of the present invention have been introduced above with reference to the drawings. However, the present invention can be embodied by using expansion joints as a seal member between the raw material transfer pipe and the charging pipe. . On the other hand, when the raw material is transferred and charged only by the action of gravity without using the transfer gas, such a seal member is unnecessary. Further, the charging device of the present invention is not limited to the smelting reduction furnace but can be widely applied to a molten metal furnace in which gas is generated from inside the furnace such as a converter. Needless to say, it is not limited to the molten metal furnace for iron making.

[Effects of the Invention] The apparatus for charging the raw material of the granular material in the molten metal furnace of the present invention charges the raw material after bringing the tip opening of the raw material charging pipe connected to the raw material transfer pipe close to the bath surface. Therefore, not only coarse-grain raw materials but also fine-powder raw materials can be reliably charged into the bath. Therefore, there is an advantage that the particle size adjustment and the classification of the charging raw material are unnecessary. In connection with this, the raw material charging pipe does not undergo thermal deformation or the like because it has a water-cooling structure, even though it enters the high temperature furnace and its tip approaches the bath surface. Since it is held at, it goes up and down smoothly (that is, approaches and leaves the bath surface, etc.).

Since the device of the present invention is a system in which the raw material is charged from the bath surface, the gas for transferring (or blowing) the raw material is not essential. Even when such a gas is used, it is not necessary to strictly adjust the flow rate, and the gas can be stopped when the raw material is not charged, which is advantageous in terms of operating cost and maintaining the temperature of the metal bath.

In addition, since a flexible material hose with inferior heat resistance is not used in the transfer route of the granular material, a heat resistant and inflexible material transfer tube / material charging tube is used, so the material preheated to a considerably high temperature is used. Can be transferred and loaded. If a transfer tube with a particularly high heat resistance is used, the preheating temperature can be raised within a range in which the powder or granular material does not cause welding. Therefore, it can be said that there is practically no temperature limitation on the charging material. Therefore, the reaction efficiency of the molten metal furnace can be improved by suppressing the temperature decrease of the metal bath that receives the raw material.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention.
FIG. 1 is an overall view showing a smelting reduction furnace for iron making and a raw material charging device for the furnace, FIG. 2 is a detailed sectional view of a connecting portion between a raw material transfer pipe and a raw material charging pipe, and FIG. 3 is a raw material charging pipe. FIG. 4 is a detailed sectional view showing the tip portion, and FIG. 4 is a detailed sectional view showing another example relating to the tip portion of the charging pipe. 1 ... Raw material transfer pipe, 2 ... Raw material charging pipe, 27 ... Gland packing (sealing member), 4 ... Elevating means, 41 ... Carriage, 50 ... Melt reduction furnace, 50a ... Iron bath.

Claims (4)

[Scope of utility model registration request] 1. An apparatus for charging a granular material into a metal bath of a molten metal furnace from the surface of the metal bath, which is heat-resistant and inflexible from above the molten metal furnace to just above the opening of the furnace. The raw material transfer pipe is fixedly installed, and the inflexible raw material charging pipe having a water-cooling structure is fitted below the raw material transfer pipe so that it can be moved up and down from the upper part of the molten metal furnace to the inside thereof. Then, a cooling water hose for water cooling is connected to the upper part of the raw material charging pipe, and the upper part is held by a carriage provided so as to move up and down along a vertical guide rail. Charging device for raw material of granular material in furnace. 2. A raw material charging pipe is filled with a sealing member inside the upper part of the raw material charging pipe and pressed from above, and the raw material charging pipe is connected to the raw material transferring pipe with the inner surface of the sealing member being in contact with the outer peripheral surface of the raw material transferring pipe. The molten metal furnace according to claim 1, wherein the raw material powder is externally fitted, and the raw material transfer pipe is transferred from the upstream of the raw material transfer pipe with a transfer gas, and is sprayed from the raw material charging pipe onto the metal bath surface. Charger for powdered and granular materials. 3. The raw material charging pipe is a triple pipe having a partition pipe inside and continuous flow passages on the inside and outside thereof, and the cooling water hose is the inside and outside of the partition pipe of the triple pipe. 3. A charging device for a powdered or granular material in a molten metal furnace according to claim 1, wherein a plurality of materials are connected so as to communicate with each of the flow paths. 4. An apparatus for charging a granular material in a molten metal furnace according to claim 1, wherein the inner tube of the material charging tube is made of a wear resistant material.