JP6917037B2 - Blast furnace tuyere - Google Patents

Description

The present invention relates to a tuyere for a blast furnace, which is used in a blast furnace used in steelmaking and the like and has high resistance to heat of the blast furnace.

In iron making, a blast furnace is used in which iron ore, which is a raw material, is reduced to obtain molten iron. Iron ore as a raw material is charged from an inlet provided in the blast furnace, and heat for raising the melting temperature inside the blast furnace is supplied from another inlet of the blast furnace. The molten iron is taken out inside the blast furnace, and the necessary processing is performed after that.

Hot air, which is a heat source, and fine powder of coal are charged into the inlet that supplies this heat. A member called a tuyere is attached to this inlet, and hot air and fine coal powder are injected from the tuyere.

The tuyere is the entrance where hot air and fine coal powder are introduced, and it becomes an environment where molten iron and slag generated inside the blast furnace come into contact. In this environment, the dripping molten iron, slag, etc. are in a state where mechanical wear is likely to occur on the tuyere.

In addition, since the tuyere is used by inserting a part of it inside the blast furnace, it is exposed to high heat and is highly affected by heat. The tuyere is exposed to the potential for wear due to mechanical wear under thermal influence.

The thermal effect causes the tuyere itself to become hot, which increases the effect of mechanical wear on the tuyere. This may lead to damage to the tuyere. In order to prevent the tuyere itself from becoming too hot, a structure that circulates cooling water inside the tuyere has been adopted, and tuyere with a cooling water circulation function has come to be used. It's coming.

The blast furnace requires continuous operation such as 24 hours and long-term operation such as continuing this continuous operation for a predetermined period. In operation for a long period of time, there is regular or irregular maintenance, but if the tuyere is significantly worn during this maintenance, it is necessary to replace the tuyere.

In an environment that is highly affected by mechanical wear and heat as described above, the tuyere is often worn and often needs to be replaced. Frequent replacement of tuyere has the problem of increasing the running cost of the blast furnace. Furthermore, if it takes time to replace the tuyere, the operation suspension period may be longer than the predetermined period during maintenance of the blast furnace, which may reduce the operating capacity of the blast furnace.

On the other hand, before replacing the tuyere that is worn during maintenance, that is, while the tuyere is being inserted into the blast furnace and in operation, the tuyere is damaged by mechanical wear and thermal effects. It is possible that it will be damaged and part of it will be damaged. If the tuyere is damaged and this leads to fatal destruction, the tuyere cannot continue its role and may adversely affect the steelmaking process in the blast furnace.

Of course, it may affect the processes before and after steelmaking in the blast furnace, and it may also affect the quality of steelmaking in the blast furnace.

It is appropriate to replace the tuyere with a tuyere to deal with such destruction of the tuyere, but it is not easy to replace the tuyere while the blast furnace is in operation. On the other hand, it is not preferable to stop or decelerate the operation of the blast furnace due to the destruction of the tuyere from the viewpoint of the operating efficiency of the factory.

Naturally, it takes time to slow down the operation of the blast furnace and prepare other tuyere before the tuyere can be replaced.

Therefore, even if the tuyere is damaged by mechanical wear or thermal influence, it is preferable that the tuyere can maintain the minimum function for a certain period after the damage. At this time, as described above, in recent years, a tuyere in which cooling water circulates has been used. By circulating the cooling water, the thermal effect on the tuyere can be reduced, but if the tuyere is damaged, the cooling water circulation path provided inside the tuyere will be destroyed, and the cooling water will circulate. Can't be done. As a result, the influence of further heat increases, the tuyere is likely to be fatally destroyed, and the function of the tuyere cannot be maintained until the tuyere can be replaced.

The tuyere that is inserted into the blast furnace and used is more susceptible to the heat inside the blast furnace as it is on the surface. Therefore, the tuyere is easily damaged from the surface, and the damage generated on the surface often destroys the cooling water circulation path. Focusing on such a point, a technique in which the cooling water circulation path is doubled has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-153973

Patent Document 1 is a tuyere for an iron-making industrial furnace including a body portion having a blower line pierced in the center, and the body portion is a headed conical body portion having a main body flow path inside. The cover portion is connected to the protruding portion so that the tip body flow path is formed between the protruding portion protruding from the body portion and the outer peripheral surface of the protruding portion, and the outer cooling flow is formed inside. Disclosed is a tuyere for an industrial furnace in which a path is formed and an outer shell portion is connected so as to surround the cover portion.

The tuyere of Patent Document 1 is characterized in that a cold water circulation path having two or more layers is provided inside a body portion that is an outer circumference at the center of a ventilation line. By providing two or more layers of cooling water circulation path, even if the surface is damaged due to thermal influence inside the blast furnace or mechanical wear and the outer cooling water circulation path is destroyed, the inner cooling water circulation path remains. , It is possible to maintain the function as a tuyere having a cooling function.

However, as is clear from the descriptions of FIGS. 2 and 4, claim 2 and the like of Patent Document 1, in the tuyere of Patent Document 1, two or more layers of cooling water circulation passages are laminated in order from the inside. It is configured. That is, as shown in FIG. 12, the cooling water circulation passages of a plurality of layers are formed by sequentially laminating the outer layer members having the protrusions directed inward on the inner members.

FIG. 12 is a schematic view showing a mode of forming a plurality of cooling water circulation paths in the prior art represented by Patent Document 1. FIG. 12 shows a simplified state of the main cooling portion of the tuyere as viewed from the side cross section. In the prior art as in Patent Document 1, in forming a cooling water channel having a plurality of layers (here, the first layer and the second layer), the base member, the first layer member, and the second layer member are formed from the inside. , Laminated.

The first layer member is laminated on the outside of the base member. At this time, the base member has a plurality of protrusions toward the outside (toward the first layer member), and each of the protrusions is in close contact with the first layer member. This stacking forms an inner first layer cooling channel. Here, the reason why there are a plurality of protrusions is that the cooling water circulates in a spiral shape inside the tubular tuyere.

Similarly, the second layer member is laminated on the outside of the first layer member. The first layer member also has a plurality of protrusions toward the outside (second layer member), and each of the protrusions is in close contact with the second layer member. By this stacking, a second layer cooling water channel that circulates in a spiral shape is formed.

Here, the part surrounded by the ellipse in FIG. 12 is the place where the protrusion and the inner member are in close contact with each other. By bringing these points into close contact with each other, a cooling water channel having a plurality of layers is formed. Further, the part filled with the triangle in FIG. 12 is a welded part, and by this welding, each member is connected and the close contact is fixed.

However, the prior art as in Patent Document 1 has the following problems because it has the above-mentioned configuration.

(Problem 1) Since there are many welded parts and the number of members is large, manufacturing costs such as work cost and member cost increase.
(Problem 2) Since there are many welded parts, the structural strength against thermal stress when inserted into a blast furnace and used is weakened, and the resistance to breakage is lowered.
(Problem 3) The second layer member is damaged, and when the first layer member is exposed in the furnace, the resistance to mechanical wear and damage due to thermal influence is weakened.

Due to such a problem, the tuyere of the prior art has a problem that the manufacturing cost is increased, and the structural strength against thermal stress and the resistance to breakage due to mechanical wear and thermal influence are insufficient.

In view of these problems, it is an object of the present invention to provide a tuyere having a plurality of cooling water channels which reduces the cost of tuyere production and improves the structural strength against mechanical wear and thermal stress inside the blast furnace. do.

In view of the above problems, the tuyere for a blast furnace of the present invention includes an inner cylinder that forms a through hole from the root to the tip.
An outer cylinder provided on the outside of the inner cylinder and forming a space for a water channel between the inner cylinder and the inner cylinder.
A separation wall that divides the waterway space into an inner first layer cooling waterway and an outer second layer cooling waterway.
The first supply port that supplies cooling water to the first layer cooling water channel,
The first discharge port that discharges the cooling water that circulates in the first layer cooling water channel,
A second supply port that supplies cooling water to the second layer cooling water channel,
It is equipped with a second outlet that discharges the cooling water that circulates in the second layer cooling water channel.
The inner cylinder and the outer cylinder are connected at the tip,
The separation wall has one or more inner protrusions that project toward the surface of the inner cylinder, which is the inner side, and one or more outer protrusions that protrude toward the inner surface of the outer cylinder, which is the outer side.
The inner protrusions are in close contact with the surface of the inner cylinder, and the outer protrusions are in close contact with the inner surface of the outer cylinder, so that the inner first layer cooling water channel and the outer second layer cooling water channel are provided.
The first layer cooling water channel circulates the cooling water supplied from the first supply port to the first discharge port inside.
The second layer cooling water channel circulates the cooling water supplied from the second supply port to the second discharge port outside the first cooling water channel.
The separation wall is integrated with the inner and outer protrusions,
The first layer cooling water channel and the second layer cooling water channel are separated from each other independently of each other.
By welding the connecting portions where the three members of the inner cylinder, the outer cylinder and the separation wall come into contact with each other, the inner protrusion and the surface of the inner cylinder are brought into close contact with each other, and the outer protrusion and the inner surface of the outer cylinder are brought into close contact with each other .

The tuyere for a blast furnace of the present invention has a cooling water channel inside, and even when it is inserted into a blast furnace and used by the cooling water circulating in the cooling water channel, high heat resistance can be realized and wear can be reduced. ..

In addition, by having two or more layers of cooling water channels from the inside to the outside, the function of the inner cooling water channels is maintained even if the outer cooling water channels are damaged, and the function of the blast furnace tuyere can be maintained. You can continue.

In addition, the separation wall has protrusions on the inside and outside, so that the cross-sectional area and the section coefficient of the separation wall are increased, the structural strength of the separation wall is improved, and the separation wall is less likely to be damaged. Further, since both of these protrusions are in close contact with the inner cylinder and the outer cylinder, the strength balance between the inner and outer cylinders is improved, and the durability is improved.

Further, due to the integral formation of the separation wall with the inner cylinder, when the second layer member is damaged and the first layer member is exposed in the furnace, local melting damage, mechanical wear, and damage due to heat are less likely to occur. Further, since the separation wall forming the inner cooling water channel and the outer cooling water is integrated, the first layer member that directly receives heat does not reduce the strength against stress, and is less likely to be damaged in this respect as well.

Naturally, the cost is also low.

As a result, a tuyere for a blast furnace with high durability can be realized when used in a blast furnace.

It is a photograph of the tuyere for a blast furnace in the first embodiment of the present invention. It is a side sectional view of the tuyere for a blast furnace in Embodiment 1 of this invention. It is a front view of the tuyere for a blast furnace in Embodiment 1 of this invention. It is a 2nd layer cooling water channel development view of the tuyere for a blast furnace in Embodiment 1 of this invention. It is a 1st layer cooling water channel development view of the tuyere for a blast furnace in Embodiment 1 of this invention. It is a schematic diagram which shows the comparison with the prior art in Embodiment 1 of this invention. It is a schematic diagram explaining the merit compared with the prior art in Embodiment 1 of this invention. It is a side sectional view of the tuyere for a blast furnace in Embodiment 2 of this invention. The cross-sectional view at the same position as FIG. 2 is shown. It is a schematic diagram explaining the merit over the prior art in Embodiment 2 of this invention. It is a schematic diagram explaining the merit over the prior art in Embodiment 2 of this invention. It is a schematic diagram explaining the merit over the prior art in Embodiment 2 of this invention. It is a schematic diagram which shows the formation mode of a plurality of cooling water circulation passages in the prior art represented by Patent Document 1.

The tuyere for a blast furnace according to the first invention of the present invention includes an inner cylinder forming a through hole from the root to the tip.
An outer cylinder provided on the outside of the inner cylinder and forming a space for a water channel between the inner cylinder and the inner cylinder.
A separation wall that divides the waterway space into an inner first layer cooling waterway and an outer second layer cooling waterway.
The first supply port that supplies cooling water to the first layer cooling water channel,
The first discharge port that discharges the cooling water that circulates in the first layer cooling water channel,
A second supply port that supplies cooling water to the second layer cooling water channel,
It is equipped with a second outlet that discharges the cooling water that circulates in the second layer cooling water channel.
The inner cylinder and the outer cylinder are connected at the tip,
The separation wall has one or more inner protrusions that project toward the surface of the inner cylinder, which is the inner side, and one or more outer protrusions that protrude toward the inner surface of the outer cylinder, which is the outer side.
The inner protrusions are in close contact with the surface of the inner cylinder, and the outer protrusions are in close contact with the inner surface of the outer cylinder, so that the inner first layer cooling water channel and the outer second layer cooling water channel are provided.
The first layer cooling water channel circulates the cooling water supplied from the first supply port to the first discharge port inside.
The second layer cooling water channel circulates the cooling water supplied from the second supply port to the second discharge port outside the first cooling water channel.

With this configuration, inner and outer channels can be formed by the separation barrier with increased section modulus. Since this separation wall has a large geometrical moment of area, the structural strength can be increased, and even if the outer cylinder is damaged, it is possible to suppress an increase in thermal stress, and high durability can be realized.

In the blast furnace tuyere according to the second invention of the present invention, in addition to the first invention, the first layer cooling water channel and the second layer cooling water channel have a spiral shape or a ring shape between the inner cylinder and the outer cylinder. The second layer cooling water channel circulates outside the first layer cooling water channel.

With this configuration, the main body of the blast furnace tuyere can be cooled efficiently and as a whole.

In the tuyere for a blast furnace according to the third invention of the present invention, in addition to the first or second invention, the separation wall is integrated with the inner protrusion and the outer protrusion.

With this configuration, the section modulus of the separation wall can be increased to improve durability.

In the blast furnace tuyere according to the fourth invention of the present invention, in addition to any one of the first to third inventions, at least a part of the connecting portion of the inner cylinder, the outer cylinder and the separation wall is welded. ,
The inner protrusion and the surface of the inner cylinder are in close contact with each other, and the outer protrusion and the inner surface of the outer cylinder are in close contact with each other.

With this configuration, the unity of the tuyere as a whole can be realized.

In the tuyere for a blast furnace according to the fifth invention of the present invention, in addition to any one of the first to third inventions, the inner cylinder and the separation wall are integrated, and the inner protrusion and the inner cylinder are integrated. ..

With this configuration, the manufacturing cost is reduced and the structural strength is improved. As a result, the durability of the tuyere increases.

In the tuyere for a blast furnace according to the sixth invention of the present invention, in addition to the fifth invention, the inner cylinder and the separation wall are integrated as a casting.

With this configuration, an integrated structure can be reliably realized.

In the tuyere for a blast furnace according to the seventh invention of the present invention, in addition to the fifth invention, only the outer protrusion and the inner surface of the outer cylinder are in close contact with each other.

With this configuration, the number of contact points is reduced, and the structural strength of the separation wall and the cooling water channel is improved.

In the tuyere for a blast furnace according to the eighth aspect of the present invention, in addition to any one of the first to seventh inventions, a third layer cooling channel is further provided in addition to the first layer cooling channel and the second layer cooling channel. Provided.

With this configuration, the cooling performance is further improved. Moreover, even if the cooling water channel is damaged, the ability to respond is enhanced.

In the blast furnace tuyere according to the ninth aspect of the present invention, in addition to any one of the first to eighth inventions, the first supply port, the first discharge port, the second supply port and the second discharge port are It is provided on the surface on the root side between the inner cylinder and the outer cylinder.

This configuration facilitates the supply and discharge of cooling water.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)

(Overview)
An overall outline of the blast furnace tuyere according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a photograph of a tuyere for a blast furnace according to the first embodiment of the present invention. It is a photograph of the appearance of the tuyere 1 for a blast furnace actually manufactured by the inventor taken in a perspective view. As shown in the photograph of FIG. 1, the blast furnace tuyere 1 has a tubular shape as a whole. By having this tubular shape, a part of the blast furnace tuyere 1 can be inserted from the outer wall of the blast furnace.

FIG. 2 is a side sectional view of the tuyere for a blast furnace according to the first embodiment of the present invention. FIG. 2 shows a state in which the blast furnace tuyere 1 is viewed from the side surface, and shows a cross-sectional view in the side surface direction so that the internal structure can be seen. FIG. 3 is a front view of the tuyere for a blast furnace according to the first embodiment of the present invention. FIG. 3 shows a state seen from the front, which is the root side of the blast furnace tuyere 1.

In FIG. 2, the left side is the root (front direction) of the blast furnace tuyere 1, and the right side is the tip of the blast furnace tuyere 1. The blast furnace tuyere 1 includes an inner cylinder 3, an outer cylinder 4, a separation wall 6, a first supply port 71, a first discharge port 72, a second supply port 81, and a second discharge port 82.

The inner cylinder 3 forms a through hole 2 from the root to the tip. In FIG. 2, a through hole 2 is formed along the direction of the tip. When the tuyere 1 for the blast furnace is inserted into the blast furnace, hot air, pulverized coal, or the like is introduced into the blast furnace through the through hole 2.

The outer cylinder 4 is provided on the outside of the inner cylinder 3 and forms a water channel space 5 with the inner cylinder 3. In FIG. 2, a state in which the water channel space 5 is separated into the first layer cooling water channel 7 and the second layer cooling water channel 8 is shown, but the water channel space 5 is separated regardless of the presence or absence of this separation. The space formed between the inner cylinder 3 and the outer cylinder 4 is shown. That is, the space including the first layer cooling water channel 7 and the second layer cooling water channel 8 is the water channel space 5. The water channel space 5 is separated by a separation wall 6 to form a first layer cooling water channel 7 and a second layer cooling water channel 8.

The separation wall 6 is provided in the water channel space 5. Provided in the water channel space 5, as described above, the water channel space 5 is separated into an inner first layer cooling water channel 7 and an outer second layer cooling water channel 8.

The first supply port 71 supplies cooling water to the first layer cooling water channel 7. The first discharge port 72 discharges the cooling water circulating in the first layer cooling water channel 7. That is, the first supply port 71 to the first discharge port 72 are connected via the first layer cooling water channel 7.

The second supply port 81 supplies cooling water to the second layer cooling water channel 8. The second discharge port 82 discharges the cooling water circulating in the second layer cooling water channel 8. That is, the second supply port 81 to the second discharge port 82 are connected via the second layer cooling water channel 8. Through these circulation systems, the cooling water circulates inside the structure of the blast furnace tuyere 1.

FIG. 3 shows the first supply port 71, the first discharge port 72, the second supply port 81, and the second discharge port 82. FIG. 3 shows a state in which these first supply ports 71 to 2 second discharge ports 82 are provided in front of the blast furnace tuyere 1. Since cooling water is supplied and discharged, it is preferable that these are provided in front of the blast furnace tuyere 1. Of course, it does not exclude that it is provided other than the bottom surface.

As shown in FIG. 2, the inner cylinder 3 and the outer cylinder 4 are connected by a tip. By connecting at the tip, the waterway space 5 is closed. Since the water channel space 5 becomes a closed space, the first layer cooling water channel 7 and the second layer cooling water channel 8 formed by being separated by the separation wall 6 are also closed except for the supply port and the discharge port. It becomes a waterway. In addition, the first layer cooling water channel 7 and the second layer cooling water channel 8 are separated water channels.

The separation wall 6 has a single or a plurality of inner protrusions 61 projecting toward the surface of the inner cylinder 3 which is the inner side, and a single or a plurality of outer protrusions 62 projecting toward the inner surface of the outer cylinder 4 which is the outer side. .. FIG. 2 shows the inner protrusion 61 and the outer protrusion 62.

The inner protrusion 61 is in close contact with the inner surface of the inner cylinder 3. The outer protrusion 62 is in close contact with the inner surface of the outer cylinder 4 which is the outer side. Due to these close contact, the separation wall 6 separates the water channel space 5 into an inner side and an outer side, and an inner first layer cooling water channel 7 and an outer second layer cooling water channel 8 are formed.

At this time, the first layer cooling water channel 7 and the second layer cooling water channel 8 are independent. The first layer cooling water channel 7 circulates the cooling water supplied from the first supply port 71 to the first discharge port 72, and the second layer cooling water channel 8 circulates the cooling water supplied from the second supply port 81. , Circulate to the second outlet 82. Since each is independent, cooling water is not mixed.

Each cooling water channel cools the blast furnace tuyere 1 by circulating cooling water to reduce the thermal influence when it is inserted into the blast furnace and used. Further, since the first layer cooling water channel 7 is provided on the inner side and the second layer cooling water channel 8 is provided on the outer side, each of them can be cooled. In addition, even if the outer second layer cooling water channel 8 is damaged, the inner first layer cooling water channel 7 remains and cooling can be continued.

Further, the separation wall 6 is a member of the separation wall 6 by the inner protrusion 61 inward and the outer protrusion 62 outward, and the inner first layer cooling water channel and the outer second layer cooling water channel are separated from each other. Can be formed. The cross-sectional area of the separation wall 6 is increased, and the strength is improved.

Further, since the separation wall 6 is provided with protrusions toward the inside and the outside to support the inner inner cylinder 3 and the outer outer cylinder 4, the separation wall balances the stress inside and the stress outside. 6 is easy to take. With this balance, the shapes of the first layer cooling water channel 7 and the second layer cooling water channel 8 can also be maintained.

(Details of each part)
Details of each part will be described.

FIG. 4 is an internal development view of the first layer cooling water channel 8 of the blast furnace tuyere according to the first embodiment of the present invention. FIG. 4 shows a development view of FIG. 2A in AA. As shown in FIG. 4, the first-layer cooling water channel 7 and the second-layer cooling water channel 8 form the water channel space 5 in a spiral shape or a ring shape. The second layer cooling water channel 8 circulates outside the first layer cooling water channel 7.

FIG. 5 is an internal development view of the second layer cooling water channel 7 of the blast furnace tuyere according to the first embodiment of the present invention. FIG. 5 shows a development view of FIG. 2 BB. Similarly, FIG. 5 shows that the first layer cooling water channel 7 is formed in a spiral or a ring shape.

In this way, the first layer cooling water channel 7 circulates inside, and the second layer cooling water channel 8 circulates outside.

The separation wall 6 is integrated with the inner protrusion 61 and the outer protrusion 62. Due to this integral formation, the separation wall 6 itself does not have a close contact portion (except for the tip of the protrusion). As a result, when the first layer cooling water channel 7 and the second layer cooling water channel 8 are formed inside and outside the separation wall 6, the separation wall 6 is only in close contact with the inner cylinder and the outer cylinder.

As shown in FIG. 2, the separation wall 6 includes an inner protrusion 61 and an outer protrusion 62. The inner protrusion 61 is in close contact with the surface of the inner cylinder 3. The outer protrusion 62 is in close contact with the inner surface of the outer cylinder 4. The inner cylinder 3 and the outer cylinder 4 are connected by welding, and this connection ensures close contact.

By having such a structure, the tuyere 1 for the blast furnace in the first embodiment can form the first layer cooling water channel 7 and the second layer cooling water channel 8.

(Advantage 1 compared to the conventional technology)
The merits of the tuyere 1 for a blast furnace in the first embodiment having such a structure as compared with the prior art will be described. FIG. 6 is a schematic view showing a comparison with the prior art according to the first embodiment of the present invention. The separation wall in the prior art is shown in the upper part of FIG. 6, and the separation wall 6 of the blast furnace tuyere 1 of the first embodiment is shown in the lower part of FIG. In the prior art, cooling water channels are formed layer by layer by stacking members layer by layer. Due to such a structure, as shown in the upper part of FIG. 6, the separation wall, which is a member forming the water channel, has only outer protrusions.

On the other hand, the separation wall 6 in the blast furnace tuyere 1 of the first embodiment includes an inner protrusion 61 and an outer protrusion 62. It is as shown on the lower side of FIG.

That is, the separation wall 6 in the first embodiment has a larger cross-sectional area than the separation wall of the prior art. This is because the cross-sectional area increases as the number of inner protrusions 61, which are protrusions, increases.

As the cross-sectional area increases, the moment of inertia increases. When the member is bent, the stress is calculated by the moment of inertia. The stress decreases as the geometrical moment of inertia increases. That is, the force applied per unit area is reduced, and as a result, the load on the member is reduced.

Due to the increase in the section modulus due to the increase in the cross-sectional area, the separation wall 6 becomes more durable than the member serving as the separation wall of the prior art. As a result, it is more resistant to thermal stress than prior art.

(Advantage 2 compared to the conventional technology)
FIG. 7 is a schematic diagram illustrating the merits of the first embodiment of the present invention as compared with the prior art. The upper part of FIG. 7 shows the state after the outer cylinder is damaged in the prior art, and the lower part of FIG. 7 shows the state after the outer cylinder is damaged in the first embodiment.

As described above, the tuyere for the blast furnace is used by being inserted into the blast furnace. For this reason, mechanical wear and thermal stress are applied to the tuyere for the blast furnace, which imposes a heavy burden. When this mechanical wear or thermal stress is applied, the outer cylinder outside the blast furnace tuyere may be damaged. FIG. 7 shows a state after the outer cylinder is damaged.

There is an outer cooling water channel (second layer cooling water channel 8) between the outer cylinder and the separation wall. If the outer cylinder is damaged, this outer cooling water channel will be exposed. At this time, an inner cooling water channel (first layer cooling water channel 7) exists inside the separation wall. Even if the outer cooling channel is exposed, it is desirable that the separation wall becomes the outer wall of the inner cooling channel and the function of the inner cooling channel is maintained.

However, in the prior art, the separation wall is only a protrusion directed outward and is only in close contact with the outer separation wall. Therefore, as shown in the upper part of FIG. 7, water leaks from the inner cooling water channel from between the protrusion of the inner cooling water channel and the outer separation wall which are only in close contact with each other. This is because water leaks from the gap between the protrusion and the separation wall.

On the other hand, the separation wall of the first embodiment includes an outer protrusion 62 and an inner protrusion 61. Even if the outer cylinder 4 is damaged and the second layer cooling water channel 8 is exposed, there is no close contact portion between the exposed region and the first layer cooling water channel 7. This is because the separation wall 6 is integrated.

As a result, even if a part of the outer protrusion 62 is damaged as shown in the lower side of FIG. 7, the outer protrusion 62 is not connected to the close contact portion. As a result, the water in the first layer cooling water channel 7 does not leak. If there is no water leakage, the blast furnace will not be adversely affected, and the function of the first layer cooling water channel 7 can be maintained.

This point is also a merit (superiority) of the tuyere 1 for a blast furnace in the first embodiment over the prior art.

As described above, the tuyere 1 for a blast furnace in the first embodiment can realize high durability and high function maintenance even after damage as compared with the prior art.
(Embodiment 2)

Next, the second embodiment will be described. In the second embodiment, a blast furnace tuyere in which the inner cylinder and the separation wall are integrally formed will be described. FIG. 8 is a side sectional view of the tuyere for a blast furnace according to the second embodiment of the present invention. The cross-sectional view at the same position as FIG. 2 is shown.

The blast furnace tuyere 1 of the second embodiment has the same elements as the blast furnace tuyere 1 of the first embodiment, but the inner cylinder 3 and the separation wall 6 are integrated. Also in FIG. 8, it is shown that the inner cylinder 3 and the separation wall 6 are integrated. Integral means that the inner cylinder 3 and the separation wall 6 are integrally formed. For example, it may be manufactured as one member, and the inner cylinder 3 and the separation wall 6 may be integrally formed. At this time, the inner cylinder 3 and the separation wall 6 may be integrally formed as a casting.

As described above, in the second embodiment, the inner cylinder 3 and the separation wall 6 are integrated.

Although it is integrated with the inner cylinder 3, it is sufficient if it is grasped as an element as a separation wall 6, and there is no intention other than the fact that the two are defined as different element names.

The separation wall 6 includes an inner protrusion 61 and an outer protrusion 62, as described in the first embodiment. Here, since the inner protrusion 61 is integrated with the inner cylinder 3, a combination portion that is in close contact with the surface of the inner cylinder is not formed as in the first embodiment. The inner protrusion 61 is a structure integrally with the inner cylinder 3 as it is.

The outer protrusion 62 projects toward the outside of the separation wall 6. The fact that the outer protrusion 62 projects outward is the same as in the case of the first embodiment. The outer protrusion 62 projects toward the outer cylinder 4 and is in close contact with the inner surface of the outer cylinder 4. On the other hand, since the inner protrusion 61 is integrated with the inner cylinder 3, no combination such as close contact occurs.

As described above, the first layer cooling water channel 7 is formed by the inner cylinder 3 and the separation wall 6 which are integrated. Since it is integrated, the first layer cooling water channel 7 is formed by the voids of the integrated members. The second layer cooling water channel 8 is formed by the separation wall 6 and the outer cylinder 4. The outer protrusion 62 of the separation wall 6 and the inner surface of the outer cylinder 4 are in close contact with each other, and the combination of these close contact forms the second layer cooling water channel 8.

FIG. 8 shows such a structure.

The first layer cooling water channel 7 and the second layer cooling water channel 8 have a spiral shape or a ring shape as in the first embodiment. With such a form, the entire blast furnace tuyere 1 can be cooled evenly.

Further, cooling water circulates through the first layer cooling water channel 7 from the first supply port 71 to the first discharge port 72, and through the second layer cooling water channel 8 from the second supply port 81 to the second discharge port 82. The circulation of the cooling water is the same as in the first embodiment. By this cooling, the mechanical wear and thermal stress of the blast furnace tuyere 1 are dealt with.

(Advantage 1 compared to the conventional technology)
As shown in FIG. 8, the separation wall 6 and the inner cylinder 3 are integrated. This integration has the advantage of reducing the manufacturing cost of the tuyere 1 for the blast furnace. In the prior art, in order to form the inner first layer cooling water channel and the outer second layer cooling water channel similar to those in FIG. 8, three different members, an inner cylinder, an inner member, and an outer cylinder, are combined and manufactured. I needed it. On the other hand, in the blast furnace tuyere 1 in the second embodiment, it is only necessary to combine the two members of the inner cylinder 3 and the outer cylinder 4 in which the separation wall 6 is integrated.

Therefore, there is an advantage that the manufacturing cost is lower than that of the conventional technique.

(Advantage 2 compared to the conventional technology)
FIG. 9 is a schematic diagram illustrating the merits of the second embodiment of the present invention over the prior art. FIG. 9 shows a state in which the outer cylinder is damaged and the second layer cooling water channel is exposed as in FIG. 7. The upper part of FIG. 9 shows a state in which the outer cylinder is damaged and the outer cooling water channel is exposed by the tuyere of the prior art. The lower part of FIG. 9 shows a state in which the outer cylinder 4 is damaged and the second layer cooling water channel 8 is exposed in the blast furnace tuyere 1 of the second embodiment.

In the prior art, as described with reference to FIG. 7, since the inner cooling water channel and the separation wall are in close contact with each other, a gap is generated between the protrusion and the separation wall in this combination portion. , If the contact part of the separation wall is damaged, water will leak from the inner cooling water channel. If a part of the close contact portion is damaged, such water leakage will occur.

On the other hand, in the blast furnace tuyere 1 of the second embodiment, the inner first layer cooling water channel 7 is formed by an inner cylinder 3 and a separation wall 6 which are integral members. Therefore, even if the second layer cooling water channel 8 is exposed, there is no portion where the first layer cooling water channel 7 is connected to the outside. As a result, water leakage from the first layer cooling water channel 7 does not occur. Since no water leakage occurs, the function of the first layer cooling water channel 7 is maintained after the second layer cooling water channel 8 is exposed. The adverse effect on the blast furnace due to water leakage can also be reduced.

As described above, the blast furnace tuyere 1 of the second embodiment in which the separation wall 6 and the inner cylinder 3 are integrated has an advantage that the function can be maintained even after the outer cylinder 4 is damaged.

(Advantage 3 compared to the conventional technology)
FIG. 10 is a schematic diagram illustrating the merits of the second embodiment of the present invention over the prior art. FIG. 10 shows the side surface of the separation wall and the member integrated with the separation wall. The upper part of FIG. 10 shows a member as a separation wall of the prior art, and the lower part of FIG. 10 shows the separation wall according to the second embodiment and the inner cylinder 3 integrally with the separation wall. As described with reference to FIG. 6, the separation wall 6 of the second embodiment has a large cross-sectional area. In particular, by being integrated with the inner cylinder 3, the cross-sectional area as a whole becomes large.

When the cross-sectional area is large, the cross-sectional coefficient also increases, the structural stress is reduced, and the durability as a member is improved. Due to this improvement in durability, the durability of the tuyere 1 for the blast furnace is also increased.

Further, since the separation wall 6 is integrated with the inner cylinder 3, the contact portion between the inner protrusion 61 and the inner cylinder 3 is eliminated. That is, in the member forming the first layer cooling water channel 7 and the second layer cooling water channel 8, the contact portion is reduced. By reducing the number of contacted parts, the structural strength is also increased.

As the structural strength is increased, naturally, the stress applied to the separation wall of the blast furnace tuyere 1 is reduced, and there is an advantage that the strength against thermal stress is increased.

(Advantage 4 compared to the conventional technology)
FIG. 11 is a schematic diagram illustrating the merits of the second embodiment of the present invention over the prior art. FIG. 11 compares the number of welded portions of the blast furnace tuyere of the prior art and the second embodiment. The upper part of FIG. 11 shows the welded part of the member for forming the cooling water channel of the prior art, and the lower part of FIG. 11 shows the welded part of the member for forming the cooling water channel in the second embodiment. There is.

In the prior art, it is necessary to combine three members, an inner cylinder, a separation wall, and an outer cylinder, in order to form the inner cooling water channel and the outer cooling water channel. Welding 1 is required to fix the outer cylinder and the inner cylinder, and welding 2 is required to fix the outer cylinder and the separation wall (via the inner cylinder). In addition, welding at two locations, welding 3 and welding 4, is required to fix the separation wall and the inner cylinder.

As a result, four welding points are required.

On the other hand, in the blast furnace tuyere 1 of the second embodiment, the inner cylinder 3 and the separation wall 6 are integrated, so that the inner cylinder 3 and the outer cylinder 4 are fixedly connected to each other and welded. Welding in 2 places is enough. That is, only two welding points are required, which is less than that of the conventional technique.

Since the number of welded parts is small, the structural strength of the structure forming the first layer cooling water channel 7 and the second layer cooling water channel 8 is improved. In addition, the structural strength of the blast furnace tuyere 1 itself is also improved. As a result, there is an advantage that the strength of the tuyere 1 for the blast furnace is increased.

The tuyere is used by being inserted into a blast furnace. Therefore, the temperature of the welded portion of the weld 1 is likely to rise due to the heat in the blast furnace. The welded portions of the welds 2 and 3 are in a state of receiving heat from the hot air at the center of the tuyere 1 for the blast furnace. When the outer cylinder is damaged and the separation wall is exposed, the temperature of the welded portion of the welding 4 is likely to rise due to the heat in the blast furnace.

Here, the welded portion has a lower thermal conductivity than the main body portion of the tuyere. When the thermal conductivity is low, it is easily softened by heat from the outside and easily leads to deterioration or breakage. That is, the welded portion is more vulnerable to heat than the tuyere body. Therefore, having many welded parts is not preferable for the durability of the tuyere. In other words, the tuyere 1 of the second embodiment is resistant to thermal deterioration during use because it has few welded parts.

The fact that the temperature of the welded portion tends to rise indicates a state in which the welded portion is softened or weakened to cause mechanical wear, damage due to heat, or mechanical damage.

In the conventional technique in which there are many welded parts, there is a problem that damage to the welded parts due to this heat reduces the strength and durability of the tuyere. On the other hand, the tuyere 1 for the blast furnace of the second embodiment has few welded parts, so that such a problem can be reduced.

As described above, the blast furnace tuyere 1 of the second embodiment has the advantage that the number of welded parts is small.

As described above, in the blast furnace tuyere 1 of the second embodiment, the strength against structural thermal stress can be increased by integrating the inner cylinder 3 and the separation wall 6.

(Embodiment 3)

Next, the third embodiment will be described. In the third embodiment, other ingenuity will be described.

(Cooling channel outside the second layer cooling channel)
In the first and second embodiments, the inner first layer cooling water channel 7 and the outer second layer cooling water channel 8 have been described. In addition to the first layer cooling water channel and the second layer cooling water channel, it is also preferable that a third layer cooling water channel is further provided. For example, by further providing the separation wall on the outside of the separation wall 6, the third layer cooling water channel may be formed on the outside of the second layer cooling water channel 8. By increasing the number of layers of the cooling water channel, there are merits such as improvement of cooling capacity and improvement of responsiveness to damage of the outer layer.

Alternatively, the structure of the separation wall 6 may form a third layer cooling water channel inside the first layer cooling water channel.

Further, not only the third layer cooling water channel but also the cooling water channel outside the third layer cooling water channel may be further provided. In this case, a cooling water channel with the fourth layer and the fifth layer may be formed.

(1st supply port to 2nd discharge port)
As shown in FIG. 3, each of the first supply port 71, the first discharge port 72, the second supply port 81, and the second discharge port 82 may be provided in front of the root side of the blast furnace tuyere 1. This is because the cooling water can be easily supplied and discharged by being provided in front of the root.

Alternatively, at least a part of the first supply port 71 to the second discharge port 82 may be provided on the side surface of the blast furnace tuyere. It suffices if it is provided on the side surface and the cooling water is supplied and discharged.

The tuyere for a blast furnace described in the first to third embodiments is an example for explaining the gist of the present invention, and includes deformation and modification within a range not deviating from the gist of the present invention.

1 Blast furnace tuyere 2 Through hole 3 Inner cylinder 4 Outer cylinder 5 Waterway space 6 Separation barrier 7 First layer cooling water channel 8 Second layer cooling water channel

Claims (5)

An inner cylinder that forms a through hole from the root to the tip,
An outer cylinder provided on the outside of the inner cylinder and forming a space for a water channel between the inner cylinder and the inner cylinder.
A separation wall that divides the space for the water channel into a first layer cooling water channel on the inside and a second layer cooling water channel on the outside.
A first supply port that supplies cooling water to the first layer cooling water channel,
A first discharge port that discharges cooling water that circulates in the first layer cooling water channel, and
A second supply port that supplies cooling water to the second layer cooling water channel,
A second discharge port for discharging the cooling water circulating in the second layer cooling water channel is provided.
The inner cylinder and the outer cylinder are connected at the tip,
The separation wall has one or more inner protrusions that project toward the surface of the inner cylinder, which is the inner side, and one or more outer protrusions that protrude toward the inner surface of the outer cylinder, which is the outer side.
The inner protrusion is in close contact with the surface of the inner cylinder, and the outer protrusion is in close contact with the inner surface of the outer cylinder, and the inner first layer cooling water channel and the outer second layer cooling water channel are provided. Be,
In the first layer cooling water channel, the cooling water supplied from the first supply port is circulated inside to the first discharge port.
The second layer cooling water channel circulates the cooling water supplied from the second supply port to the second discharge port outside the first cooling water channel.
The separation wall is integrated with the inner protrusion and the outer protrusion.
The first layer cooling water channel and the second layer cooling water channel are separated from each other independently of each other.
By welding the connecting portions where the inner cylinder, the outer cylinder, and the three members of the separation wall come into contact with each other, the inner protrusion and the surface of the inner cylinder are brought into close contact with each other, and the outer protrusion and the inner surface of the outer cylinder are brought into close contact with each other. A tuyere for blast furnaces that is in close contact with. The blast furnace tuyere according to claim 1, wherein the connecting portion is located inside the blast furnace tuyere. The first layer cooling water channel and the second layer cooling water channel are formed in a spiral shape or a ring shape between the inner cylinder and the outer cylinder.
The blast furnace tuyere according to claim 1 or 2, wherein the second layer cooling water channel circulates outside the first layer cooling water channel. The tuyere for a blast furnace according to any one of claims 1 to 3 , wherein a third layer cooling water channel is further provided in addition to the first layer cooling water channel and the second layer cooling water channel. The first supply port, the first discharge port, the second supply port, and the second discharge port are provided on a surface on the root side between the inner cylinder and the outer cylinder, according to claims 1 to 4 . One of the described tuyere for blast furnace.

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