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The top of the electric arc furnace is an important component of the electric arc furnace. For example, continuous high temperature, mechanical vibration, quenching and heating, slag erosion, dust particle erosion, acid gas corrosion, etc. all cause damage. In particular, the triangular area will be damaged earlier than the surrounding parts. It is often because the triangular area refractory has been used to the limit that the refractory on the top of the furnace will be offline as a whole. If a material is used to make the furnace top, and the triangle area is damaged, which has affected the use of the whole furnace top, the refractory materials in the periphery will be wasted if the line is taken off in advance. Therefore, in this case, the composite electric furnace top came into being. That is, the triangle area is made of high purity materials, and the peripheral part is made of low-grade materials. In this way, the furnace top triangle area and the peripheral life can be synchronized. However, there are great difficulties in the manufacturing process of this composite roof: when more than two kinds of materials are used to make the roof prefabrication, either high-grade materials and low-grade materials are easy to be mixed during molding, which reduces the grade of refractory materials in the triangle area, so that the expected effect cannot be obtained; Or the interface between high-grade materials and low-grade materials is poorly treated, resulting in delamination, crack, peeling, etc. of the two materials at the interface. These two conditions restrict the service life of composite roof prefabricated parts.
In order to solve the above manufacturing difficulties of composite furnace top prefabrication, Rongda Company has designed and developed a composite furnace top structure with detent to meet the mixed prefabrication of various grades of materials.
Triangle area is the key part of the furnace top, and the working environment is the worst. It is necessary to ensure that the material has a high purity, so this piece needs to be prefabricated separately in advance. Demoulding shall be carried out after the molding and curing period expires, and the peripheral parts shall be poured around the prefabricated parts after the prefabricated parts have obtained sufficient strength; The peripheral part can be divided into the lower part of the peripheral part and the upper part of the peripheral part according to the service environment and vulnerability. The lower part of the peripheral part is a hot surface, close to the steel level, the material grade is only inferior to the central triangle area, and the upper part of the peripheral part is a relatively cold surface, so the service environment is basically normal.
The technical key points of the above-mentioned composite clamping type furnace top prefabricated parts are: the triangular area is prefabricated separately, and the thickness (height) is higher than the peripheral part; The upper part of the triangle area is provided with three evenly distributed chucks to prevent falling off when frequently used; The part in contact with the periphery of the triangle area forms an included angle of 3 °~5 ° with the vertical direction; A number of auxiliary clamping holes to prevent falling off are evenly distributed on the contact surface between the triangle area and the periphery; The clamping hole has an included angle of 5 ° with the horizontal direction and is inclined upward; The peripheral materials are divided into upper part and lower part, which are cast in the same batch at one time. The technical advantages are as follows: while ensuring the service life of the furnace top prefabrication, effectively reducing the dependence of the furnace top on the raw materials prepared by high energy consumption and high pollution ways, and reducing the cost of the furnace top prefabrication; It effectively solves the problems that the composite structure of the prefabricated parts on the top of the electric arc furnace is not tight and the triangular area is easy to fall off in advance; The idea that the triangular area on the top of the electric arc furnace can synchronize with the life of the peripheral parts is realized.
Fig. 1 Prefabricated products of the clamping composite electric furnace roof
Fig. 2 Prefabricated parts of the clamping composite electric furnace roof in use
Fig. 3 Topography of Triangle Area on Top of Clamping Composite Electric Furnace
Fig. 4 Schematic Diagram of the Clamping Composite Electric Furnace Top After Forming
(Expert Group of Beijing United Rongda Engineering Materials Co., Ltd.)