CN103509899A - Long-life blast furnace hearth - Google Patents

Abstract

The invention discloses a long-lived blast furnace hearth, which comprises ring-built carbon bricks. The volume in the blast furnace hearth from the furnace bottom to the iron mouth is spherical; the spherical center is located on the central axis of the blast furnace. The radius of the missing sphere is R = (A ² +4B ² )/(8B), where A is the diameter of the hearth, and B is the height of the spherical segment, that is, the total height of the carbon bricks surrounding the hearth. It can greatly suppress the "elephant foot" erosion of the blast furnace hearth, and avoid the hearth burn-through as much as possible. Moreover, in the daily operation of the blast furnace, it can cancel the input of vanadium-titanium ore and other protective materials into the furnace, so it can reduce the cost of pig iron , to promote the development of steel varieties.

Description

A long-lived blast furnace hearth

technical field

The invention belongs to the technical field of ironmaking blast furnaces, and in particular relates to an inner shape of a blast furnace hearth.

Background technique

The internal shape of blast furnace plays an important role in blast furnace smelting. A reasonable internal shape can promote the improvement of economic and technical indicators of blast furnace, otherwise it will be affected. A reasonable internal shape must be compatible with the conditions of the furnace material, the air supply system, the habitual operation system and the law of motion in the furnace in order to obtain the best smelting effect.

The reasonable inner shape comes from production practice. In fact, the selection of the size of each part of the inner shape of the blast furnace in each factory is based on the calculation results and the inner shape analysis and comparison of the same type of blast furnace, and is selected according to the specific conditions of the factory.

Due to the improvement of raw materials and fuel conditions and operation, the internal shape of blast furnaces in my country has gradually evolved from a relatively slender blast furnace in the 1950s to a relatively short and fat internal shape that meets the raw material conditions and operating systems.

The invention patent of patent publication number CN87105170 proposes to expand the hearth diameter D of the small and medium-sized blast furnace to more than 0.29 times the effective height H of the blast furnace, so as to achieve the effect of energy saving and production increase.

However, no matter how the inner shape of the blast furnace evolves, the inner shape of the hearth of the blast furnace is always a flat-bottomed cylinder. With the increase of the age of the blast furnace, the hearth of the blast furnace is prone to "elephant foot" erosion, which eventually leads to burn-through of the hearth.

In order to avoid hearth burn-through, people have applied copper staves at the hearth, and built "ceramic cups" in the hearth, etc., but hearth burn-through accidents still happen from time to time.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a hearth inner shape suitable for blast furnace longevity. The blast furnace hearth built according to the inner shape can greatly reduce the impact of molten iron on the hearth side wall. The impact force can avoid burn-through of blast furnace hearth as far as possible, and prolong the life of blast furnace.

The object of the invention is achieved by the following technical solutions:

A long-lived blast furnace hearth of the present invention, comprising ring-built carbon bricks, is characterized in that: the volume from the furnace bottom to the taphole in the blast furnace hearth is spherical, rather than the usual cylindrical shape;

The spherical center of the spherical segment is located on the central axis of the blast furnace, and the radius of the spherical segmental sphere is R = (A ² +4B ² )/(8B). In the above formula, A is the hearth diameter, and B is the spherical segment Height, that is, the total height of the hearth ring carbon bricks.

In the hearth of a common blast furnace, the ring-shaped carbon bricks built around the hearth are 9 to 12 layers, and the thickness of each layer is 400mm to 550mm. There is one ring of carbon bricks for each layer along the radial direction of the hearth, and carbon is built on the cross section of the hearth. The bricks form a circle.

The carbon brick masonry method around the hearth of a long-lived blast furnace hearth of the present invention is that the total height of the hearth ring is 10 to 16 layers, and the thickness of the first layer (bottom layer) and the second layer of carbon bricks is 80 ～120mm, the thickness of carbon bricks from the third to sixth floors is 180～220mm, the thickness of carbon bricks from the seventh to tenth floors is 280～320mm, and the thickness of carbon bricks from the eleventh to thirteenth floors is 380mm ~420mm, the thickness of carbon bricks above the fourteenth floor is above 500mm; the hearth diameter of each layer of carbon bricks is: a = 2(R ² -(Σb) ² ) ^1/2 , in the above formula, R is the radius of the sphere, and b is the thickness of carbon bricks, which is also the thickness of each layer; the determined hearth diameter a can flexibly design the number of rings and the size of carbon bricks in each layer of the hearth to meet the construction requirements.

Generally speaking, 4 to 12 rings of carbon bricks are laid on the first layer along the radial direction of the hearth, and 1 ring of carbon bricks is laid on the highest layer, so that a non-smooth spherical shape is formed around the hearth; finally, carbon bricks are laid on each layer. Special-shaped ceramic bricks are built on the top of the bricks, so that the inner shape of the furnace bottom becomes a relatively smooth spherical shape.

Compared with the prior art, the present invention has the following advantages:

①The blast furnace hearth built with inner shape according to the present invention can greatly suppress the occurrence of "elephant foot" erosion of the blast furnace hearth.

② According to the blast furnace hearth built with inner-shaped masonry provided by the present invention, due to the increase in the thickness of the brick lining, the burn-through of the hearth can be avoided as much as possible.

The blast furnace built by applying the present invention can greatly suppress the occurrence of "elephant foot" erosion of the hearth of the blast furnace, avoid burn-through of the hearth as much as possible, and, in the daily operation of the blast furnace, can cancel the protective materials such as vanadium-titanium ore. into the furnace, so it can reduce the cost of pig iron and promote the development of steel varieties.

Description of drawings

Fig. 1 is the blast furnace hearth schematic diagram of the embodiment of the present invention;

Among them, 1 is the blast furnace hearth, and 2 is ring-built carbon bricks.

Detailed ways

The specific embodiment of the present invention is described below in conjunction with accompanying drawing:

Taking a 3200m ³ blast furnace as an example, the diameter of hearth 1 of the blast furnace is 12.4m, and the height of the spherical section is 4.4m. According to the calculation formula given by the technical plan, R = (A ² +4B ² )/(8B), in the above formula, A is the diameter of the hearth, B is the height of the ball, that is, the total height of the carbon bricks around the hearth, which can be Get the sphere radius R=6.57m;

Then according to the calculation formula given by the technical plan, the diameter of the hearth built by each layer of carbon bricks is: a = 2(R ² -(Σb) ² ) ^1/2 , where R is the radius of the sphere, b is The thickness of the carbon brick is also the thickness of each layer; the hearth diameter of each layer of the ring-built carbon brick 2 of the hearth 1 can be obtained.

Table 1 shows the diameter of hearth determined by laying carbon bricks 2 on each layer of hearth 1, the number of rings of carbon bricks 2 on each layer and the number of carbon bricks in the innermost ring of each layer of carbon bricks.

Table 1

The carbon bricks 2 around the blast furnace hearth 1 build a rough spherical shape, and then use special-shaped ceramic bricks to build a smooth spherical shape on the carbon bricks, which becomes the usual hearth "ceramic cup". "For "ceramic bowl".

Claims (4)

1. A long-lived blast furnace hearth, comprising ring-built carbon bricks (2), characterized in that the volume from the furnace bottom to the taphole in the blast furnace hearth (1) is spherical. 2. The long-lived blast furnace hearth according to claim 1, characterized in that the center of the spherical segment is located on the central axis of the blast furnace, and the radius of the segmental sphere is R = (A ² +4B ² ) / (8B), where A is the diameter of the hearth, and B is the height of the ball, that is, the total height of the hearth ring with carbon bricks (2). 3. The long-lived blast furnace hearth according to claim 1 or 2, characterized in that the total height of the hearth ring carbon bricks (2) is 10 to 16 layers, and the thickness of the first and second layers of carbon bricks is 80-120mm, the thickness of the carbon bricks from the third to the sixth layer is 180-220mm, the thickness of the carbon bricks from the seventh to the tenth layer is 280-320mm, and the thickness of the carbon bricks from the eleventh to the thirteenth layer is 380 ~ 420mm, the thickness of the carbon bricks above the fourteenth floor is above 500mm; the diameter of the hearth built by each layer of carbon bricks is: a = 2(R ² -(Σb) ² ) ^1/2 , where R is a sphere Radius, b is the thickness of the carbon brick, that is, the thickness of each layer. 4. The long-lived blast furnace hearth according to claim 1 or 2, characterized in that special-shaped ceramic bricks are built on the top of each layer of ring-built carbon bricks (2), so that the inner shape of the furnace bottom becomes a relatively smooth spherical segment shape.

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