RU2094467C1 - Apparatus for cooling part of shaft of blast furnace - Google Patents

Abstract

FIELD: metallurgy, namely, apparatuses for cooling blast furnace. SUBSTANCE: apparatus includes large-block panels with cooled thick-wall tubes laid along inner side of shaft jacket along the whole height of cooled zone. Tubes are inserted through lower portion of furnace jacket and withdrawn through its upper portion, they are welded in places of their inlet and outlet to shaft jacket by strength dense seam. In order to compensate heat elongations tubes are provided with row of bents in plane parallel to jacket. Position of tube relative to jacket is fixed by means of movable supports allowing displacements in plane parallel to jacket. Intertube space is filled by refractory concrete. EFFECT: improved design. 2 dwg

Description

 The invention relates to ferrous metallurgy, in particular to blast furnace production.

 At present, blast furnace mines have been equipped instead of traditional stove refrigerators with large-block panels or thick-walled steel pipe refrigerators with annular space filled with refractory concrete.

 The first stoves with refrigerators from thick-walled steel pipes were blown in 1984 1985. The cooled thick-walled pipes formed a screen. The lower and upper ends of the pipes were connected by collectors to which pipes supplying and discharging cooling water were supplied through the casing.

 A known design in which between the casing of the furnace and the masonry brackets are installed from steel pipes. These brackets with the upper and lower ends are discharged through the casing of the furnace and welded to it with a strong, dense seam. Pipe openings in the casing are spaced apart to reduce weakening of the casing.

 In well-known publications and copyright certificates, it is proposed that the blast furnace shaft be assembled from several large-block panels. Each panel represents a section of the shaft casing from 1/6 and 1/8 of the circumference of the casing and a length equal to the height of the cooled part of the shaft casing (about 10 12 m). Cooled thick-walled pipes in the form of brackets, side bounding walls are welded to this section of the casing. The annulus is filled with refractory concrete. Finished large block panels are welded and form the shaft of the furnace. This design is taken as a prototype.

 In the known invention there are disadvantages: the cooled staples do not have a compensating bend, therefore, they have a small length (up to about 1.2) and their number is large (up to 1250 pcs per oven). This leads to a large number of holes in the casing of the mine (up to 2500), which degrades the strength of the casing and its gas tightness, leads to an increase in the volume of work when installing the cooling system of the mine and increase its cost.

 In order to eliminate these drawbacks, the design of the large-block panel shown in FIG. 1. This panel includes a part of the shaft casing 1. The width of the large block panel is from 1/6 to 1/8 the circumference of the furnace casing. The height of the panel is equal to the height of the cooled part of the shaft and ranges from 10 to 12 m.

 Along the large-block panel, thick-walled steel pipes 5 are installed to the entire height of the cooled part of the shaft of the blast furnace. Thus, the length of these pipes (staples) is 10-12 m. These brackets are inserted through the opening of the casing in the lower part of the shaft and displayed in the upper part of the shaft. Thus, for each pipe, two holes in the casing are required. There are several compensation bends along the length of the cooled pipes (brackets) to reduce the magnitude of thermal stresses arising from the temperature difference between the casing and the brackets. To fix the position of the brackets along in the area of each bend, supports 6 are installed that allow longitudinal (vertical) movements and exclude radial movements. A sketch of the support is presented on the node 2 of FIG. one.

 The annulus is filled with refractory concrete 3. A layer of thermal insulation is laid between the casing and concrete 4. A layer of refractory masonry is erected along the large-block panel 2. The parameters of the compensators are determined by calculating the temperature difference between the casing and the brackets. Based on the theoretical calculation, a graph is obtained for determining the offset of the compensator (Fig. 2). It can be seen from the graph that with an increase in the offset of the compensator, the voltage in the bracket decreases.

 Compensation bends are located in a plane parallel to the furnace shell. The location of the compensation bends in the radial direction is unacceptable, since after the destruction of the refractory masonry and partial destruction of the refractory concrete, the compensation bends will go into the area of the mine, filled with the charge and smelting products. Long brackets are connected to the evaporative or water cooling system of the furnace.

 The cooling device of the mine operates as follows.

 For some time after blowing, the refractory masonry of the shaft 2 protects the large-block panels from heating from the working space of the furnace. After about 1-1.5 g of work, the refractory masonry of the mine collapses and the refractory concrete of the panel comes into contact with charge materials and smelting products. In about half a year of operation, the refractory concrete of large-block panels collapses to the level of the axes of the brackets of the cooled panels. Further destruction stops and the panels in this state are finalized until the end of the campaign.

 In this case (after the destruction of part of the refractory concrete), the largest temperature difference between the brackets and the casing of the shaft is established. However, compensation of temperature elongations in bent brackets ensures the strength of the brackets, and the presence of supports placed along the pipe firmly holds it in place. The supports are sliding, they do not fix the distance of the staples from the casing of the furnace and allow movement along the entire axis. This favors an even distribution of loads on adjacent compensation bends.

Claims (1)

 The device of the cooled mine of the blast furnace, including large-block panels with cooled pipes and annular space filled with refractory concrete, characterized in that the cooled pipes are laid along the casing of the furnace to the entire height of the cooled mine with the input and output welded to the casing, and are made of steel, thick-walled with a number of compensation bends in height, located in a plane parallel to the furnace casing, and strengthened by sliding supports located in each bend, with the possibility of fixing the distance chilled pipes from the casing of the furnace.

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