SU1668838A1 - Electric arc ore-smelting furnace - Google Patents

Abstract

The invention relates to the field of metallurgy, to the design of ore-thermal furnaces with a round stationary bath, in particular, its placement on the foundation and the organization of air cooling of the furnace bottom. The aim of the invention is to reduce the metal capacity of the furnace, reducing the time of its installation. It was proposed to additionally perform diametrically arranged channels on the surface of the foundation, and block the annular opening closest to the center by a horizontal partition at the level of the surface of the channels. It is also envisaged to reinforce the upper support surfaces of the foundation with metal plates, to perform the bottom surface of the channels of the central part of the foundation with a downward slope to the center of the furnace at an angle with a horizontal of 10 - 45 °, and to the inner surface of the bottom to weld the edges radially spaced at uniform pitch with overlapping openings. By performing the diametral channels, the efficiency of cooling the bottom part of the furnace is increased, and the reinforcement of the upper surface of the foundation eliminates the installation of the beam stand between the bottom and the foundation, which reduces the metal consumption and the period of installation of the furnace on the foundation. 3 hp ff, 6 ill.

Description

The invention relates to metallurgy, to the design of ore-thermal furnaces with a round stationary bath, in particular to its placement on the foundation and the organization of air cooling of the furnace bottom.

The aim of the invention is to reduce the metal capacity of the furnace, reducing the time of its installation.

Figure 1 shows a furnace, a general view; figure 2 - section aa in figure 1; fig.Z - node I in figure 1; FIG. 4 is a section BB in FIG. in Fig.5 - section 8-B in Fig.2: in Fig.6 - section G-D in Fig.2.

The arc ore-thermal furnace contains a round, stationary casing 1, lining 2 with a backfill layer 3 above the flat bottom 4, a foundation 5 with a central part 6 with a central vertical channel 7 connected to the bottom blowing system 4 with annular support surfaces 8 and 9. A metal pipe 10 is installed in channel 7. On the surface of the foundation there are diametrically located open channels 11 from above. The annular passage (opening) closest to the center of the furnace is blocked by a horizontal partition 12. In

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Plates 11 are laid by grooves 13, closely adjacent to the walls of channels 11. The supporting surfaces of the foundation are reinforced with metal plates 14c with bolts 15 welded to them, inserted into base 5. The bottom surface 16 of channels 11 of the central part 6 of foundation 5 is inclined downward to the center of the furnace at an angle with a horizontal of 10-45 °.

The inner surface of the bottom 4 of the casing 1 in the backfill layer 3 of the lining 2 is welded by ribs 17, which are radially spaced at regular intervals along the perimeter and overlap the annular openings of the foundation 5. The partition 12 can be made of separate non-metallic sections attached to the foundation 5 with bolts 18. The cross section of the channels 11 is determined by aerodynamic calculation depending on the area of the bottom 4 and the magnitude of the specified heat removal from its surface.

Arc ore-thermal furnace works as follows.

The cooling air through the central channel 7, connected to the blowing system, passes through the channels 11, and then enters the supra-partition wall of the annular opening of the central part 6 of the foundation 5 and blows through the channels 11 the lower (outer) surface of the bottom 4 of the casing 1. Exhaust air through Channels 11 are released into the atmosphere of the workshop (Figures 1 and 2, the exhaust air outlet is shown by arrows). The direction of flow of the cooling air is achieved by installing the partition 12 and the grooves 13.

The blowing efficiency of the bottom 4 is implied by the fact that cold air first enters the center of the bottom 4, where the maximum heat load is observed, and then evenly blows its entire surface along the beams. The slope of the bottom surface of the 16 channels of the central part 6 of the foundation 5 sets the direction of movement air, reducing its turbulence in the area between the exit nozzle of the channel 7 and the bottom 4. The optimal range of the angle of inclination of the bottom surface of the 16 channels of the central part 6 of the foundation 5 is the angle with the horizontal equal to 10-45 °.

At an angle of less than 10 °, the effect of the air flow direction decreases sharply, and it is impractical to perform an inclination angle of more than 45 ° because in this case the bottom section 4 opposite the channel 1 is practically not blown by air, since the main flow is directed along an inclined surfaces 16.

In addition, the inclined surface 16 reduces the aerodynamic resistance

air flow. The presence of metal plates 14 on the upper bearing surfaces of the foundation 5 prevents the foundation concrete from breaking off and drastically reduces the coefficient of friction between the bottom 4 and the supporting surfaces of the foundation 5, which in turn reduces the negative impact of shear forces on the supporting surfaces of the foundation 5 during thermal expansion of the bottom 4 The need to weld the fins 17 in order to prevent the bottom 4 from deforming from the weight of the lining 2, the melt and the cold mixture is determined by mechanical calculation,

In some cases, there is no need to weld the fins 17, since on powerful furnaces, the bottom 4 is made of a sufficiently thick steel sheet of 32 mm. The supporting surfaces of the foundation 5 are a reliable support for the bottom 4 with a sufficient surface and with an optimal arrangement of the supporting surfaces in terms of the distribution of loads that the bottom 4 perceives. The advantage of the proposed arc ore furnace design is that the intermediate beam stand between the bottom 4 and the foundation 5; The absence of the beam stand, which is usually made of I-beams, reduces the metal intensity of the furnace and shortens its installation time.

No beam cage, i.e. when the bottom 4 is directly mounted onto the supporting surfaces of the foundation 5, it reduces by 500 mm the depth of the foundation 5, which reduces the cost of its manufacture.

Raising 500 mm of the supporting surface of the foundation 5 is caused by lowering the casing 1 by 500 mm due to the given level of the drain chute, which is usually located 200-300 mm above the upper edge of the casting ladle.

Claims (4)

Claim 1. Arrow ore-thermal furnace, containing a round stationary lined casing with a flat bottom, mounted on a foundation, in the upper part of which ring openings are made, and in the central part - a vertical channel connected to the bottom blowing system, in order to reduce the metal capacity of the furnace, reduce the time of its installation, diametrically arranged channels are additionally made on the surface of the foundation, and the annular opening closest to the center is blocked by a horizontal partition on the level outside the channel surface 2. Furnish according to claim 1, in accordance with the fact that the upper bearing surfaces of the foundation are reinforced with metal plates. 3. Furnace according to claims 1 and 2, characterized in that the bottom surface of the channels the central part of the basement is made with a slope down to the center of the furnace at an angle with the horizontal, equal to 10-45 °. 4. Furnace PP.1-3. characterized by the fact that edges are radially welded to the inner surface of the bottom, with a uniform pitch along the perimeter with overlapping openings. I Riga.1 eleven n W ± 8-B Fig.Z uva Fig.Z B-B 17 Rygl