JPH0995709A - Water cooled slag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-cooling molten slag trough capable of preventing thermal deformation, erosion, etc., and having high safety by using the surface formed of refractory layer on a thick plate steel-made main material as the molten slag side and the surface formed of cooling layer incorporated with a water-cooling pipe in the main material as the non-molten slag side for the trough bottom and the side walls of the molten slag trough. SOLUTION: The molten slag trough branched from an iron tapping large runner for a blast furnace is constituted of the water-cooling wall 1 forming the trough bottom and both side walls and the brick wall 2 forming the outer wall of the water-cooling wall 1. The water-cooling wall 1 is uses the side formed of the refractory layer on the thick plate steel-made main material as the surface in contact with the molten slag 3 and the side formed of the cooling layer incorporated with the cooling pipe 9 connected to a connection pipe 8 at the outside as the non-molten slag side. By this constitution, the water- cooling molten slag trough improved in molten slag proofing property, erosion resistance, etc., is obtd. at a low cost.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a blast furnace ladle gutter.

[0002]

2. Description of the Related Art In blast furnace operation, molten pig iron and slag are regularly tapped from the taphole of the blast furnace, and separated into hot metal and molten slag by a skinmer damper of the tap iron large gutter. It flows down through the molten slag gutter branched from the slag, and is converted into slag by a slag facility and is carried out. A conventional molten slag gutter has been constructed by a refractory brick forming side walls and a gutter bottom, and a gutter material installed inside the refractory brick.

As a new technology of the molten slag structure, there are technologies described in "Jitsuko Sho 61-29716" and "Kaikaihei 2-51244". The former technique is a water-cooled molten sluice in which a plurality of hollow U-shaped cooling pipes are arranged in the gutter longitudinal direction and installed around the gutter, and water is passed through the U-shaped pipe.
Further, the latter technique is a plurality of casting blocks connected in the longitudinal direction forming both side walls of the molten slag, a cooling pipe embedded inside the casting block, and a refractory brick forming a bottom of the molten sluice. A flowmeter consisting of an irregular shaped refractory applied to the upper part of the refractory bricks, which further monitors the flow rate difference between the water supply amount and the drainage amount of the cooling pipe, and an alarm transmitter which issues an alarm when the flow rate difference is abnormal. It is a water-cooled molten slag gutter equipped with.

[0004]

Since the slag flowing down in the slag gutter is a high temperature melt of about 1500 ° C., the gutter material of the slag gutter is subject to thermal and chemical erosion by the slag. receive. The renewal of the trough material in the conventional molten slag trough is performed when the trough material is eroded and the thickness is reduced to a certain thickness. Slag is 150
Since it is a high-temperature melt of about 0 ° C and a small amount of hot metal called "hot metal" is mixed in the molten slag, the erosion of the gutter progresses normally even if a gutter of a fairly high quality refractory is used, It was necessary to renew the gutter every week. Since the gutter material is expensive and its consumption is large, it has been regarded as a problem as a cause of increasing the hot metal production cost of the blast furnace. The renewal of the gutter is performed by removing the remaining gutter with a breaker, filling it with new grate, and then forming and staking it into the shape of a gutter, but all work is done in a gutter heated to high temperature. Therefore, there is a problem of 3K work that is usually said, and there is also a strong demand for reducing the work cost.

The technique described in the above publication, which is considered to be a new technique of the molten slag structure, may have the following problems in implementation. The former technique is a hollow U
A plurality of V-shaped cooling pipes are arranged in the longitudinal direction of the gutter, installed around the gutter, and a water-cooled slag that allows water to flow through the U-shaped pipe, but in this configuration, the cooling pipe group directly contacts the slag. The cooling pipe group is subjected to a sudden and enormous heat load at the beginning of operation, causing thermal deformation due to a sudden temperature change, and after a certain period of time, the cooling pipes are in direct contact with the molten slag and the hot metal. It is envisaged that the wall may be melted and cause a steam explosion that occurs when the hot melt comes into direct contact with the cooling water.

In the latter technique, a plurality of casting blocks which are connected in the longitudinal direction to form both side walls of the molten sluice, a cooling pipe embedded in the casting block, and a refractory which forms a bottom of the molten sluice are used. It is a water-cooled slag gutter consisting of bricks and irregular refractory material applied to the upper layer of refractory bricks. In this technology, when cast steel is used as the casting of the casting block that forms both side walls of the molten sluice, the technology of casting the cooling pipe inside has problems such as carburizing and welding of the cooling pipe, and the countermeasure technology is established. However, it is not limited to cast iron blocks for which a manufacturing technique for casting a cooling pipe inside has been established.

Since the melting point of cast iron is about 1100 ° C., when the cast iron cast block is brought into direct contact with the molten slag which is a high-temperature melt at about 1500 ° C., the molten slag and the hot metal melt the cast block, It is assumed that after a certain period of time, the cooling pipe buried inside the casting block is melted and damaged, causing the steam explosion.

In this technique, the casting block is not applied to the bottom of the molten slag gutter, and the gutter bottom is composed of the refractory brick and the irregular-shaped refractory applied to the upper layer of the refractory brick.
The reason is that the hot metal, which has a much larger ability to melt the casting block than the molten slag, gathers at the bottom of the gutter due to gravity.
It is supposed to prevent the melt loss of the casting block from rapidly expanding and further increasing the risk of steam explosion due to melt loss of the cooling pipe.

In view of the above problems, the present invention improves the resistance to molten slag and the melt damage to hot metal, reduces the cost of gutter material, reduces the cost of updating gutter material, and avoids the risk of steam explosion. The purpose is to provide sludge.

[0010]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention relates to a molten metal gutter branched from a tap iron gutter of a blast furnace, in which the gutter bottom and side wall of the molten metal gutter are made of thick plate steel main material. And a refractory layer formed on the surface side of the main material in contact with the slag and a cooling layer having a water-cooled cooling pipe built in on the anti-slag side of the main material, which are integrally formed. . Further, a frame metal object is welded to a thick plate steel main material, a high thermal conductive refractory brick having a semicircular groove is arranged in the frame metal object, and a cooling pipe is embedded in the semicircular groove, and the frame metal object It is characterized in that a highly heat-conducting amorphous refractory material is filled therein, and the cooling layer is formed so as to incorporate the cooling pipe therein.

[0011]

The melting point of steel is about 1530 ° C, which is about 430 ° C higher than the melting point of cast iron, which is about 430 ° C, because the main material of the gutter bottom and side walls of the molten slag is about 430 ° C. Is less likely to melt. When the main material is cooled by a cooling layer containing a water-cooled cooling pipe provided on the anti-slag side,
Since steel has a higher thermal conductivity than cast iron, it is easily cooled, and the temperature of the steel main material can be kept lower than in the case of cast iron, so the heat effect on the main material is reduced. The refractory layer formed on the surface side of the thick plate steel main material in contact with the slag has a thickness of 50
When formed with a gutter material of mm, the surface temperature of the main material on the slag side is from about 1200 ° C without a refractory layer to about 600 ° C.
Since the temperature is lowered by about 600 ° C., troubles such as thermal deformation and melting loss of the main material are prevented.

After the refractory layer is melted by the molten slag and the refractory layer is thinned, the refractory layer reduces the heat insulating effect and the molten slag is cooled strongly, so that the refractory layer is cooled to the operating surface. As a result, a solidified slag adhering layer that is solidified is generated, and the solidified slag adhering layer has a heat insulating effect, so that the surface temperature of the main material on the slag side is kept low. A frame metal object is welded to a thick plate steel main material, a high thermal conductive refractory brick having a semi-circular groove is arranged in the frame metal object, and a cooling pipe is embedded in the semi-circular groove, and in the frame object. The cooling layer filled with a highly heat-conductive amorphous refractory material and formed so as to include the cooling pipe realizes a water-cooled cooling layer having a large cooling capacity.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The water-cooled molten slag of the present invention is composed of a water-cooled wall 1 forming a trough bottom and both side walls and a brick wall 2 forming an outer wall of these water-cooled walls 1 as shown in FIG. 1, and a molten slag 3 is a water-cooled wall. Run down the inside of 1. The water cooling wall 1 forming the gutter bottom and both side walls is divided into appropriate lengths in the longitudinal direction of the molten slag gutter, and is cooled by flowing cooling water through a cooling pipe 9 built in the water cooling wall 1. The cooling pipe 9 is connected to the outside of the water cooling wall 1 at each divided position of the water cooling wall 1 by a connecting pipe 8, and cooling water is continuously flowed to each water cooling wall.

FIG. 2 shows a sectional view of the water cooling wall in the embodiment of claim 2 of the present invention. The structure on the slag side is a thick steel plate main material 5.
Amorphous refractory 4 is fixedly held by a support rod 6 which is welded to the slag and protrudes to the slag side and an enclosure 7 which is welded to the outer periphery of the main material 5 and protrudes to the slag side to form a refractory layer. There is. The anti-slag side is a cooling layer, and a high heat conductive refractory brick 11 such as carbon having a semicircular groove for welding the frame metal 10 to the thick plate steel main material 5 and burying the cooling pipe 9 in the frame metal. A brick is arranged, the cooling pipe 9 is embedded in the semicircular groove of the high thermal conductive refractory brick 11 with the heat resistant and high thermal conductive mortar 12, for example, a carbon paste densely, and fixed by the cooling pipe retainer 13. Further, the highly heat-conductive amorphous refractory material 1 is placed in the frame metal 10.
4 is filled with the cooling pipe 9.

[0015]

In the water-cooled slag gutter of the present invention, the water-cooled walls forming the gutter bottom and both side walls are made of a thick steel main material, and an amorphous fireproof material is fixedly held on the side in contact with the slag. It has a structure, and the anti-slag side of the main material is water-cooled by a cooling layer equipped with a cooling pipe, so the problems such as thermal deformation and melting damage of the water-cooled slag gutter are solved and the safety is high. Providing water-cooled slag, it is possible to reduce the cost of the slag and the amount of refilling work. The following effects can be realized by the water-cooled molten slag of the present invention.

1. Since the main material of the water-cooled molten slag is made of thick plate steel, the melting point of the steel is about 1530 ° C and the melting point of cast iron is 1
Since it was about 430 ° C higher than about 100 ° C, it was less likely to be melted by the molten slag. In addition, when the gutter bottom and side wall main materials are cooled by a cooling layer containing a water-cooled cooling pipe provided on the anti-slag side, steel has a higher thermal conductivity than cast iron and is easily cooled. Can be kept lower than in the case of cast iron, so the heat effect is small.

2. Even if the hot metal, which has a much larger capacity to melt than the molten slag, gathers at the bottom of the gutter due to gravity, the main material is a thick steel plate, so the resistance to melting is significantly improved. The period has been greatly extended, and water-cooled molten slag can be applied to the bottom of the gutter. In addition, since the usage period of the main material has been significantly extended, it has become possible to observe and manage the melting loss of the main material for a long time.
The water-cooled molten slag can be replaced with a new one before it is destroyed near the water-cooled cooling pipe, and the risk of steam explosion can be avoided.

3. The refractory layer formed on the surface side of the steel plate main material in contact with the slag, when the refractory layer is formed of a gutter material with a thickness of 50 mm, the refractory layer changes the surface temperature on the slag side of the main material. Since the temperature is lowered by about 600 ° C. from about 1200 ° C. when there is no such component, it is possible to prevent initial troubles such as thermal deformation and melting loss of the main material.

4. When the refractory layer is melted down by the molten slag and the refractory layer becomes thin, the refractory layer reduces the heat insulation effect and the molten slag is cooled strongly. Since the molten slag adhering layer is generated and the solidified slag adhering layer has a heat insulating effect, the surface temperature on the slag side of the main material can be kept low. The refractory layer is protected by the solidified slag adhering layer and can be used for a long period of time, so the consumption of refractory can be reduced, and the cost of the gutter renewal work can be reduced.

[5] In the case of a molten slag gutter formed only by a conventional refractory layer without water cooling, the thickness of the gutter material needs to have a thickness of about 200 mm, but in the case of the water cooling structure of the present invention, the refractory layer thickness is as described above. Since a gutter of 50 mm is sufficient, the amount of refractory used is reduced.

6. Since the outer surface temperature of the water-cooled molten slag is lowered by the water-cooling effect, the need for heat insulation of the cast bed outside the molten sluice is reduced, so that the cast bed structure can be simplified and made compact. 7. Since the temperature of the water-cooled molten sluice is lowered in a short time due to the water-cooling effect, the work of renewing the water-cooled molten sluice is not a high-temperature operation, and the workability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a water-cooled molten slag gutter showing an embodiment of claim 1 of the present invention.

FIG. 2 is an enlarged cross-sectional view of a water cooling wall of a water cooling slag gutter showing an embodiment of claim 2 of the present invention.

[Explanation of symbols] 1 water cooling wall 2 brick wall 3 slag 4 amorphous refractory 5 main material of thick steel plate 6 support rod 7 enclosure metal 8 connecting pipe 9 cooling pipe 10 frame metal 11 high thermal conductivity refractory brick 12 heat resistance high heat Conductive mortar 13 Cooling pipe retainer 14 Highly heat conductive amorphous fireproof material

Claims (2)

[Claims] 1. A refractory gutter branched from a tap iron gutter of a blast furnace, wherein the gutter bottom and side walls of the grate are formed of a thick plate steel main material and a surface side of the main material in contact with the slag. A water-cooled molten sluice, which is integrally formed of a material layer and a cooling layer having a water-cooled cooling pipe provided on the side opposite to the molten slag of the main material. 2. A frame metal product is welded to a thick steel main material, a high thermal conductive refractory brick having semicircular grooves is arranged in the frame metal product, and a cooling pipe is embedded in the semicircular grooves. The water-cooled molten slag according to claim 1, wherein the frame metal material is filled with a highly heat-resistant amorphous refractory material, and the cooling layer is formed so as to include the cooling pipe therein.