RU1813098C - Iron tapping spout - Google Patents

Abstract

SUMMARY OF THE INVENTION: A gutter structure, i.e. the drain chute for the flow of molten iron during the melting out of the blast furnace contains a working lining 2 forming a surface on which those I 1Q 15 16 .A .1 dd even cast iron, a permanent lining 3 outside the working lining and an external lining 6 , 7 with high thermal conductivity outside the permanent lining. The outer lining has a bottom wall or bottom 6 and two opposed side walls 7. To improve the resistance to temperature stresses on the outside and adjacent to at least one, but not all of the walls of the outer lining, at least one refractory insulating lining layer 8, 9, and the other or other walls of the outer lining are associated with heat-dissipating means 10, 11, 12. 5 zp f-ly. 1 ill.

Description

The invention relates to the construction of a shell for the flow of molten iron during the melting out of a blast furnace, and also to a method for cooling such a structure.

The aim of the invention is to eliminate or reduce these problems and, in particular, to design a gutter for molten iron flow that is well adapted to temperature stresses and less prone to cracking.

This is achieved by the fact that the proposed coffer for the flow of molten cast iron during the release of smelting from a blast furnace comprises a working lining forming a gutter-like surface on which cast iron flows, a permanent lining on the outside of the wearing (working) lining, and an external lining with high thermal conductivity outside the constant lining, the outer lining has a bottom wall and two opposed side walls, connected by their lower ends to the bottom wall. Outside and adjacent to the rip at least one year, but not all of the walls of said outer lining, there is at least one insulating lining layer. Other or other of said walls of said outer lining are associated with heat dissipation means. The insulating lining cWpn preferably consists, at least in part, of a Refractory material. It is possible, for example, that the horizontal bottom wall of the outer lining does not directly cool, but directly borders the Outside with an insulating lining, while all the heat to be dissipated through the two side walls of the outer lining is removed by water or air cooling of the said side walls . In this case, to prevent splashing liquid cast iron from the gutter from both sides of the side walls of the gutter structure, horizontal ones are installed on top of the latter; cover plates.

However, it is preferable for the two side walls to be directly adjacent from the outside to the insulating lining layers, and the lower wall to be connected to heat dissipation means which are designed to dissipate heat from the lower wall. Thus, the side walls are cooled through the bottom wall with which they are in contact.

It is desirable that the outer lining have a thermal conductivity higher than 29 W / m K. Then, the outer lining is preferably made

5 from graphite.

To increase the service life of the structures of the gutter, it is desirable that between the permanent lining and. at least part of the outer lining was one or

more layers of compressible material, such as a felt layer, to receive expansion of the structure during operation. Furthermore, for the same reason, it is desirable that the structure of the trough at least partially be provided with a layer of compressible material from the outside of the insulating lining layers.

In addition, the design of the gutter may preferably be provided as

0 external support with steel bottom plate.

The latter serves as a base or

. : the foundation for creating the structure. AT

: in this case, it is desirable that a thin separation layer with a low coefficient

5, the thermal conductivity was located between the steel bottom plate and the outer lining so that the temperature of the steel bottom plate did not exceed the required maximum temperature of 200 ° C in

0 while this thin dividing

; the layer transfers enough heat to the steel

bottom plate to achieve desired

cool outdoor lining. For p. it is sufficient to have a coefficient of thermal conductivity of the order of 1 to 5 W / m K and preferably 1 to 2 W / m K. v, preferably heat dissipating

means designed to disperse

0 heat from the steel bottom plate using forced air cooling. The lower part of the gutter structure, i.e. steel base plate, and the surrounding parts on which the gutter rests may

45 have slots or slots through which cooling air may be supplied to remove heat from the steel bottom plate. It . It can be achieved by connecting the exhaust fan to one side of the mentioned slots. However, the best results are achieved if the heat dissipating agents contain means for generating overpressure on the exhaust side of the cooling air. In this case, it is possible to direct a significantly larger flow of cooling air along the steel bottom plate than when using an exhaust fan.

The drawing shows the proposed gutter, cross section.

On the gutter-shaped surface of the chute 1, molten iron moves, coming from the outlet of the blast furnace, and which is formed by the working lining 2. For the manufacture of the latter, which may consist of several layers capable of moving relative to each other, various types of materials can be used, however, usually refractory concrete is used,

The carbon intermediate lining 3 of amorphous carbon bricks is directly adjacent to the working lining from the outside, forming a permanent lining for the temperature alignment of the working lining. Outside, this intermediate lining is adjacent. insulating layer of refractory concrete. Outside the insulating layer .4, there is a brick outer lining consisting of two opposed side walls 7 and a lower wall 6. The insulating layer 4 prevents the temperature of the liner 6, .7 from rising above 600 ° C. .-; . ;: / .: l.: D, In order to adapt to the thermal expansion of the design of the gutter during operation, it is equipped with compressive and ceramic materials and felt layers 15, 16 located between the side walls 7 of the outer lining and the insulating layer 4 and the intermediate lining 3 respectively.,.:.

The outer lining 6, 7 consists of a heat-conducting material. The bricks are laid out to provide a good heat flow, without insulating layers between them. If there are gaps, they are filled with a highly conductive solution. When using carbon, graphite or semi-graphite, but preferably graphite, for bricks of the outer lining 6, 7, sufficient thermal conductivity is achieved therein, in particular at the junctions of the side walls 7 with the lower wall 6, whereby insulating lining layers 8 can be laid. 9. directly adjacent to the side walls 7, the heat is removed only through the bottom wall 6. Layer 8 is refractory and made of concrete with a high content of alumina, Layer 9 may not be refractory and is made of high insulating properties without refractory properties.

To allow expansion, it is also desirable that the downcomer is provided with a layer 14 of compressible material which is located on the outside of the lining layers 8, 9 from the side of the side walls. Layer 14 is made of ceramic felt.

A bearing steel lower plate 10 is installed on the lower side of the chute, and a separation layer 11 is formed between it and the lower wall 6 of the outer lining, made in the form of a thin insulating layer, for example, of refractory concrete. The thickness and thermal conductivity of this layer are chosen so that it conducts enough heat to the steel plate 10, but would prevent the temperature of the plate from rising above 200. ° C .;

This thin layer 11c with low thermal conductivity is important. The gutters suffer, for example, cracking of the wearing out, i.e. working and permanent linings. This probability increases when molten iron reaches the lower parts of the gutters. In this case, the graphite layer 6, 7 performs protective functions by freezing molten iron into a solid state. If this layer did not exist, then there would be a strong and local thermal load on the steel plate 10 adjacent to the graphite layer. This would lead to a rapid exit from the steel plate. Layer 11 provides the distribution of the thermal load of the graphite layer and, as a result, the service life of the steel plate is increased. . . . ;,. The cooling of the gutter is accomplished by forced air cooling or otherwise by means of a steel bottom plate. In the design and construction, forced air cooling is used. Cooling air is blown through slots 12 between the steel bottom plate 10 and the structure on which the drain chute (sections 13) rests, to dissipate heat from the steel bottom plate 10. Blowing means, such as a fan, are located upstream of the slots 12 , Steel plate 10 has a thickness of the order of 0.7 cm, but may be thicker .... L. :

As noted, layers b and 7 are made of brick. The remaining layers 2, 4, 8, 9, 11 are made of cast material. As noted above, the thermal conductivity of the various layers is selected according to their purpose as good or low heat conductors. In the described construction, the thermal conductivities of the selected materials are in the ranges given below, which are preferred:

Layer Thermal Conductivity, W / m K

2about 2

35-15

A1-5

6,750-100

81-5

90.5-1:

111-5 in particular

about 2

The trough shown in the drawing also has lids 17 located on each side thereof and made of cast concrete with a high alumina content, which is intended to prevent the contact of molten iron spilling from the trough with layers 3, 4,7. 8, 9. In particular, layers 8, 9 with a high insulating property may not have refractory properties and may not withstand contact with molten iron. To further protect them, a layer 18 is provided over them, made of cast concrete with a high alumina content. Thus, outside the described gutter structure, a concrete structure 19 is shown, which in practice may be an existing structure in which the gutter is integrated. On its inside there is a concrete layer 20 and thin layers 21 and 22 of mortar and concrete with a high content of alumina to form a smooth surface for mounting the gutter.

Formula 1. The trough for the release of cast iron from a blast furnace containing a working lining, which is constant outside

a lining and an outer lining having high thermal conductivity and covering the bottom and side walls, as well as a cooling system, characterized in that, in order to increase the service life, at least one of the walls of the outer lining is provided with at least one insulating layer, and other or other walls have the ability to remove heat by the cooling system.

2. The trough according to claim 1, with the exception that the side walls of the outer lining have insulating layers on the outside and the bottom has the ability to remove heat by the cooling system.

3. The trough according to claim 1, with the fact that the outer lining has a thermal conductivity of 29-100 W / micron.

4. The trough according to claim 1, with the exception that at least one layer of thermal expansion compensation is made between the permanent lining and at least part of the external lining.

5. The trough according to claim 1, characterized in that at least one layer of thermal expansion compensation is made outside of at least part of the insulating layers.

6. The trough according to claims 1 and 2, characterized in that the cooling system comprises a steel plate, as well as a thin intermediate layer with lower thermal conductivity than that of the external Lining, located between the external lining and the Steel plate, the thermal conductivity of the intermediate layer is 1–5 W / μ.