CN205576184U - Good blast furnace crucibe of heat conduction - Google Patents

Abstract

The present invention discloses a blast furnace hearth with good heat conduction to solve the problem that the carbon ramming material layer of the blast furnace hearth restricts the performance of the heat conduction performance of the hearth. From the inner side to the outer side of the hearth, the inner lining is ceramic cup, large microporous carbon brick layer, small high thermal conductivity carbon brick layer and cooling wall. The cross-section of the microporous carbon brick is arched. In the utility model, since the thermal conductivity of different parts of the furnace lining increases sequentially from the inner side to the outer side of the hearth, there is no thermal resistance layer, the heat conduction efficiency of the hearth of the blast furnace is greatly improved, and the temperature of the hot surface of the hearth carbon brick is reduced, which is conducive to the formation of The slag shell is used to resist the erosion and erosion of the furnace lining by molten iron and slag. At the same time, due to the decrease in the internal temperature of the carbon brick, the thermal stress is correspondingly reduced, and the formation of annular cracks and the erosion of harmful metals can be avoided, thereby effectively slowing down the erosion of the hearth damage, prolong the service life of blast furnace hearth.

Description

A blast furnace hearth with good heat conduction

technical field

The utility model relates to a blast furnace hearth with good heat conduction.

Background technique

How to prolong the service life of the blast furnace is a hot spot in the field of ironmaking technology. The first-generation service life of blast furnaces has been extended from 5 to 8 years in the 1980s to the current 10-15 years, and the first-generation service life of some advanced blast furnaces can reach more than 20 years. Among them, the criterion for evaluating whether the first-generation furnace life of the blast furnace is over is whether the hearth has burn-through, or there is a hidden danger of burn-through. Therefore, improving the service performance of the blast furnace hearth is an important link to prolong the life of the blast furnace.

From the practice of blast furnace ironmaking, the erosion and damage of the hearth lining is mainly caused by the following factors: (1) molten iron penetration damage; (2) molten iron circulation erosion; (3) harmful elements on the hearth carbon brick (4) Excessive heat stress in the furnace hearth leads to annular fracture of carbon bricks. Among them, (1) and (2) depend on the performance of the hearth carbon brick, and (3) and (4) depend on the temperature of the hearth lining. In view of the above influencing factors, the improvement of the blast furnace hearth needs to start from the two aspects of material and structure. Among them, in terms of material, it is necessary to improve the anti-slag iron corrosion performance, thermal conductivity, <1μm micropore volume ratio, and alkali metal resistance of carbon bricks. Corrosion performance and other indicators; in terms of structure, it is necessary to continuously optimize the structure of the blast furnace hearth to maximize the heat conduction efficiency of the hearth, thereby reducing the temperature of the hot surface of the hearth lining and the thermal stress inside the carbon brick, and alleviating the hearth lining erosion damage.

In recent years, with the development and application of high-quality carbon bricks, the performance of hearth lining materials has been continuously optimized, and the performance of carbon bricks has been effectively improved, which can meet the requirements of long-life blast furnaces. However, from the perspective of the hearth structure, from the inner side to the outer side of the hearth, it is generally ceramic cup + carbon brick + carbon ramming material + stave + furnace shell structure; from the perspective of thermal conductivity, there are still deficiencies, although large micropores The thermal conductivity of carbon bricks is generally above 20w/(m·k), and the thermal conductivity of staves varies according to different materials. The thermal conductivity of copper staves is >300w/(m·k), and the thermal conductivity of ductile iron staves is >30w/( m k), however, the thermal conductivity of the carbon ramming material near the furnace shell is only 5-10w/(m k), so in the original hearth structure, there are The thermal conductivity bottleneck of carbon ramming material, especially when the construction quality is not good, the carbon ramming material is not compacted, and there are gaps in the ramming material layer, the thermal conductivity is lower, sometimes lower than 5w/(m·k), It will seriously restrict the thermal conductivity of the hearth, cause the temperature of the carbon brick inside the hearth to rise abnormally, and accelerate the erosion and damage of the hearth lining. In view of the above shortcomings, it is necessary to improve and optimize the existing hearth structure, improve the heat transfer efficiency of the hearth, alleviate the erosion and damage of the hearth, and prolong the service life of the blast furnace.

Contents of the invention

The purpose of the utility model is to overcome the defects of the prior art, provide a blast furnace hearth with good heat conduction, and prolong the service life of the blast furnace hearth.

The technical scheme of the utility model is realized as follows: a blast furnace hearth with good thermal conductivity, which is that, from the inner side of the hearth to the outer side, the inner lining is successively ceramic cups, large microporous carbon brick layers, and small pieces of high thermal conductivity carbon. Brick layers and staves.

Preferably, the cross-section of the large microporous carbon brick is circular arched.

Preferably, the thermal conductivity of the inner lining layers of the ceramic cup, the large microporous carbon brick layer, the small high thermal conductivity carbon brick layer and the stave increases sequentially from the inside to the outside.

The utility model replaces the carbon ramming material with low thermal conductivity between the furnace shell and the carbon brick in the original blast furnace hearth structure with a small piece of high thermal conductivity carbon brick, and cancels the thermal resistance layer in the heat transfer system, so the heat conduction effect can be improved. Greatly improved. The large carbon brick is changed from the original rectangular parallelepiped to the circular arch shape, so the large carbon brick and the small carbon brick can be closely bonded, and there is no need to fill the carbon ramming material with low thermal conductivity, which again avoids the existence of the thermal resistance layer . From the inner side of the hearth to the outer side, the thermal conductivity of each part of the lining increases sequentially, which is conducive to the rapid export of heat, and can effectively reduce the hot surface temperature of the hearth carbon bricks, so that the surface temperature of the furnace lining is always kept below the slag condensation temperature. Molten slag iron forms a protective slag shell on the surface of the furnace lining to resist the erosion of molten iron and slag. At the same time, due to the good thermal conductivity of the hearth, the temperature gradient inside the large carbon brick in the hearth will also be reduced, and the internal thermal stress of the carbon brick will be reduced accordingly, which can effectively avoid the formation of ring cracks in the carbon brick and the formation of harmful metals in the ring. Deposition and erosion in fractures. All of the above can prolong the service life of the hearth.

Description of drawings

Fig. 1 is the front view of existing furnace hearth structure.

Fig. 2 is a top view of the existing hearth structure.

Fig. 3 is a front view of the structure of the utility model.

Fig. 4 is a top view of the structure of the utility model.

In the figure, 1-furnace shell; 2-stave; 3-carbon ramming material layer; 4-large microporous carbon brick layer; 5-ceramic cup; 6-small high thermal conductivity carbon brick layer.

detailed description

Further describe below in conjunction with accompanying drawing:

As shown in Figure 1 and Figure 2, the existing hearth structure is from the inner side to the outer side of the hearth, followed by a ceramic cup 5, a large microporous carbon brick layer 4, a carbon ramming material layer 3, a stave 2 and a furnace shell 1 , in the process of heat conduction from the inside to the outside, there is a heat conduction bottleneck of the thermal resistance layer of carbon ramming material layer 3, which seriously restricts the performance of the heat conduction performance of the hearth, causing the temperature of the carbon brick inside the hearth to rise abnormally, and accelerates the heat transfer in the hearth. Lining erosion damage.

As shown in Figure 3 and Figure 4, the furnace hearth structure of the utility model is from the inner side of the furnace hearth to the outer side, followed by a ceramic cup 5, a large microporous carbon brick layer 4, a small high thermal conductivity carbon brick layer 6, a stave 2 and Furnace shell 1, ceramic cup 5, large microporous carbon brick layer 4, small high thermal conductivity carbon brick layer 6 and cooling stave 2, the thermal conductivity of each inner lining layer increases sequentially from the inside to the outside, and the large microporous carbon brick horizontally The section is rounded.

During construction, a copper stave 2 is installed inside the furnace shell. The thermal conductivity of the copper stave is generally 300w/(m·k), and then several layers of high thermal conductivity small carbon bricks are built close to the copper stave 2 to form a small There are 6 layers of high thermal conductivity carbon bricks. The thermal conductivity of small carbon bricks is generally above 50w/(m·k). The total thickness of small carbon bricks along the radial direction of the hearth is 200mm-300mm. Flexible design of model parameters; on the hot surface of the small high thermal conductivity carbon brick layer 6, the large microporous carbon brick layer 4 is built by masonry. The thermal conductivity of large carbon bricks is generally above 20w/(m·k). The cross-section is round and arched, so it can be built along the hot surface of small carbon bricks. The specific size of large carbon bricks can be set according to the diameter of the hearth and the requirements of different furnace types. In this embodiment, the thermal conductivity of copper stave 2 is 300w/(m·k), and the thickness of copper stave is 120mm; the thermal conductivity of small piece carbon brick is 50w/(m·k), and the small piece of high thermal conductivity carbon brick layer 6 is along the radial direction of furnace hearth The total thickness is 300mm, and the length × width × height of the small carbon bricks is 300mm×100mm×80mm. The total thickness of the block carbon brick along the radial direction of the hearth is 600mm, and the length × width × height of the large block carbon brick is 600mm × 300mm × 300mm.

In the utility model, since the thermal conductivity of different parts of the furnace lining increases sequentially from the inner side to the outer side of the hearth, there is no thermal resistance layer, the heat conduction efficiency of the hearth of the blast furnace is greatly improved, and the temperature of the hot surface of the hearth carbon brick is reduced, which is conducive to the formation of The slag shell is used to resist the erosion and erosion of the furnace lining by molten iron and slag. At the same time, due to the decrease in the internal temperature of the carbon brick, the thermal stress is correspondingly reduced, and the formation of annular cracks and the erosion of harmful metals can be avoided, thereby effectively slowing down the erosion of the hearth damage, prolong the service life of blast furnace hearth.

Claims (2)

1. the blast furnace crucibe that a heat conduction is good, it is characterised in that: to outside inside cupola well, liner is followed successively by ceramic cup, bulk Microporous Carbon brick layer, fritter height heat-conductive carbon brick layer and cooling wall, and bulk microporous carbon brick cross section is dome-shaped.

The blast furnace crucibe that a kind of heat conduction the most according to claim 1 is good, it is characterised in that: ceramic cup, bulk Microporous Carbon brick layer, fritter height heat-conductive carbon brick layer and cooling wall each inner liner heat conductivity increase the most successively.