ES2357684T3 - METALLURGICAL FUSION AND TREATMENT EQUIPMENT. - Google Patents

Abstract

The unit has a set of injectors (10) extending through an outer metal casing (12) and an inner fire resistant lining (14) for injecting treatment gas i.e. air, on molten metal (50) over respective nozzle openings (10m). Gas flushing devices are arranged beneath the corresponding injectors for injecting the gas on the molten metal, such that the molten metal is raised over the lining and flows through the nozzle openings. The flushing devices have aligned or unaligned porosity, such that cavities with a diameter less than 10 mm are formed in the molten metal over the flushing devices.

Description

The present invention relates to a metallurgical fusion and treatment equipment, in particular an essentially cylinder-shaped container for housing and treating a mass of non-ferrous molten metal.

To these metallurgical equipment / vessels belong in particular the following:

Peirce-Smith converter, Lieutenant converter, Noranda reactor, copper refining furnace.

The fundamental structure of such equipment for the melting of metal as well as for the housing and treatment of a mass of molten metal is described in DE 2521830 and is as follows:

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The vessel / oven essentially has a cylinder shape, the longitudinal axis of the cylinder extending in the essentially horizontal position of the container. In the case of a Peirce-Shmith converter, this is represented in Figure 1.

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The container has a metal shell and a fire resistant inner lining.

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The container is made with several nozzles, which are conducted from the outside through the metal shell of the oven and through the fire-resistant inner lining to the oven chamber itself, in this way to be able to introduce a treatment gas like the air, by means of nozzles, in the mass of molten metal.

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At the same time, the nozzles or the nozzles of the nozzles, are arranged in the longitudinal direction of the longitudinal axis of the remote vessel next to each other, or in other words: the nozzles are at the same time arranged along a line of the envelope of the cylindrical envelope, the line of the parallel envelope being located relative to the axis of the cylinder. The axis of the nozzles is generally located in a plane located perpendicularly with respect to the axis of the cylinder.

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Up to one hundred process nozzles of this type can be arranged in one of the aforementioned equipment.

For example, because of the formation of a disadvantageous circulation profile of the melt in the area of

the nozzles, or because of the variable gas pressure, the melt may penetrate the nozzles. In the area of the nozzle openings / nozzle openings, chemical reactions can lead to the deposition of solids, for example, magnetite depositions (Fe3O4). In this measure, successive "growth" of the process nozzles can occur. In this way, the volumetric flow rate per unit of time is reduced for an available gas pressure. Productivity decreases.

An increase in gas pressure through the use of compressors is not always possible.

In this context, it is known to clean the nozzles, with the help of a pushing device, manually or mechanically. At the same time, the original cross-section for the gas supply is again provided. At the same time, however, damage to the fire-resistant coating around the nozzle openings and with it, premature wear in this area can occur.

The invention poses in this measure the problem of offering a container for the melting of metal, for the housing and treatment of a mass of molten metal, in particular of a mass of non-ferrous molten metal, in which the nozzle area with the nozzles remain fully functional over prolonged time intervals. At the same time, existing facilities should also be able to be retrofitted if possible.

For the solution of this problem the invention starts from the following knowledge:

Figure 2 shows a cross-section through a part of a wall of a Peirce-Smith converter (according to figure 1) in the area of the nozzles, a nozzle 10 can be recognized herein, which extends from the exterior, through a metal shell 12 and a fire-resistant coating 14, to an area of the converter in which the metal melt 50 is located.

Figures 1 and 2 show the converter in a position which is called "working position". Accordingly, the nozzle 10 extends in this position essentially horizontally and in a perpendicular plane with respect to the longitudinal axis L-L of the converter, also oriented essentially horizontally. The opening area 10m protrudes from the fire-resistant coating 14 slightly (in the new coating shown herein by way of example).

A large number of nozzles 10 of this type is arranged on the longitudinal side of the converter, at a distance from each other, along an imaginary line, as schematically represented in Figure 1.

The treatment gas (herein: air) is introduced through nozzles 10, which have an internal diameter of, for example, 5 cm, in the melt 50, leaving in relatively large bubbles 52 the nozzle 10 and ascending upwards. The release of bubbles from the nozzle takes place in the upper area of the mouth of the nozzle. In the course of the treatment process, the formation of a stream of the melt 50 occurs, as indicated by the arrows in Figure 2. The disadvantageous circulation path of the melt in the vicinity of the mouth of the nozzle and the pressure of the molten mass acting on the mouth of the nozzle favor the penetration of molten mass in the nozzle as well as the formation of deposits 10a in the lower area of the mouth of the nozzle, as indicated schematically in Figure 2. Because of the relatively large gas bubbles, the boundary layer between the gas phase and the liquid phase is relatively small. In addition, the residence time of large gas bubbles in the melt is short. Both factors lead to a small degree of utilization of the introduced air. In practice, it is therefore necessary to introduce significant amounts of air through the nozzles in the melt, which, however, implies long process times and higher costs. In case of use of air with an increased proportion of oxygen, although there is a shortening of the processing times, extreme temperature points are provided in the area of the nozzle openings, whereby wear of the resistant coating 14 to fire increases strongly. At the same time, the danger of infiltrating the fire-resistant coating 14 and / or deposits 10a in the mouth area 10m of the nozzles 10 is increased.

These drawbacks can be avoided by a formation such as that shown in Figure 3. While the shape, arrangement and number of nozzles 10 can be essentially unchanged, the equipment for the metal melt according to the invention is equipped with additional gas rinsing devices 20, which are arranged, in the working / operating position of the equipment, under the nozzles

10. The gas rinsing devices 20 serve to introduce a gas, in such a way into the metal melt 50 that rises adjacent to the fire-resistant coating and this in such a way that in the subsequent path it cleans around one or more mouths of 10m nozzle The expression "clean around" means at the same time that the gas leaving the gas rinse devices 20 (for example, inert gas such as argon) flows against the nozzle mouth (s) 10m and at the same time , pass as close as possible in front of or next to the 10m nozzle mouths.

At the same time, it is shown that the appearance of deposits in the nozzle in the area of the mouth of the nozzle is avoided or greatly reduced. The continuous cleaning of the nozzle mouth ensures the formation of a homogeneous velocity profile in the vicinity of the nozzle mouth. The melt circulation is advantageously influenced in such a way that the melt does not reach, or does so to a small extent, inside the mouth of the nozzle and thus is no longer available there or only to a small extent for deposit formation. In addition, the relatively small gas bubbles 54, introduced through the gas rinse device 20, give rise to a mixture of molten mass with gas, the density of which is less than that of the pure melt. In this way, the process gas (air or mixture of air and oxygen), for the same inlet pressure, can penetrate deeper into the melt, which leads to a better distribution of the process gas. This also increases the residence time of the air bubbles in the melt, so that a clearly improved reaction behavior between the air bubbles 52 and the melt is adjusted in total and, consequently, a better use of process gas.

In a most general embodiment, the invention relates to a metallurgical fusion and treatment equipment with the following characteristics:

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A cylinder shape with a longitudinal axis which, in a working position of the equipment, extends essentially horizontally,

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an outer metal shell,

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a fire resistant inner lining,

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several nozzles, driven from the outside through the metal shell and the fire-resistant coating, for the introduction of a treatment gas into the molten metal mass through corresponding nozzle nozzles,

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the nozzles are arranged on the longitudinal side of the equipment at a distance from each other,

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in the working position of the equipment, one or more gas rinsing devices are provided below the nozzles, through which a gas can be introduced, in such a way into the molten metal mass that rises adjacent to the cladding Fire resistant and at the same time flows against one or several nozzle openings.

The arrangement and formation of the nozzles, as well as the gas rinse devices can take place

in different ways and ways. It should be noted that in the known furnaces of the aforementioned type the nozzle openings are normally located along an imaginary line next to each other. In particular, for an arrangement of nozzles of this type, the invention proposes to provide a corresponding gas flushing device under each nozzle. In other words: a rinsing device is associated with its own gas to each nozzle, so that fine gas bubbles can be selectively conducted from a gas rinsing device to the mouth area of a corresponding nozzle.

Alternatively, a gas rinsing device can also be associated with a group of nozzles.

This is offered, in particular, when a gas rinse device is selected which has a front surface on the gas outlet side, which extends along a larger surface area, for example, has a length that covers two or three nozzles arranged next to each other.

In figure 4, an embodiment of this type is shown (a view from the inside towards the fire-resistant coating 14) of a converter according to figure 1, in figure 4 however in the structuring according to the invention with gas-flushed devices 20 below the nozzles 10.

The arrangement of ten nozzles 10 along a horizontal row can be recognized, so that there are a distance between adjacent nozzles 10, in each case.

Approximately one nozzle diameter below the row of nozzles, seven gas rinse devices 20 can be recognized, each gas rinse device 20 having a rectangular front surface 20m on the gas outlet side. The size of the gas rinsed devices 20 is such that the gas supplied from a rinsed device by 20, for example nitrogen, can be selectively supplied to two nozzles 10 disposed thereon.

Obviously, the gas rinsing devices 20 can be formed with another geometry, in particular in the area of the front surface by the gas outlet side, and thus present, for example, a circular front surface. In this case, it is valid, however again, that for example a gas rinse device 20 can be associated with a nozzle 10, but also a gas rinse unit (larger) to several nozzles

10.

The arrangement of gas rinse devices 20 is analogous to the row of nozzles of Figure 1, so that the gas outlet surfaces of the gas rinse devices 20 are arranged along an imaginary line, located parallel with respect to the axis of the converter. Likewise, it is possible to place the gas rinsing devices 20 displaced in height relative to each other in the fire-resistant brick lining 14.

Figure 3 shows that the gas rinse devices 20 are mounted, similarly to the nozzles 10, through the metal casing 12 and the fire-resistant coating 14.

As explained above, the sense and purpose of the gas rinsing devices 20 is to conduct gas bubbles as thin as possible in front of the mouth area of the nozzles 10 to influence there, thereby, the circulation of melt that prevents a melt penetration into the nozzle and deposits in the nozzle, achieving a better use of the process gas.

For this, gas rinse devices 20 can be formed, for example, with the so-called non-directed porosity. An unguided porosity is similar to the structure of a sponge, looking for gas, depending on the structure of pores, an irregular path through the ceramic brick-rinse gas-based material. Gas rinsing devices of this type with non-directed porosity are known and for this reason they are not represented herein in greater detail.

Alternatively, gas rinsing devices 20 can also be formed with an unguided porosity. At the same time, the gas is conducted, through discrete gas channels, with a selective flow direction, through the washing element.

Combinations of directed and non-directed porosity can also be formed within a gas rinse device 20 or within a row of gas rinse devices 20.

In this way, the depth of penetration of the process gas into the melt 50 can be adjusted selectively. The process gas is the gas that is supplied through the nozzles 10.

Because of the arrangement according to the invention, there is a reduction in temperature tips and a broadly homogeneous temperature profile of the melt in the vicinity of the mouth of the nozzle.

Fire resistant wear is clearly reduced. The penetration of the melt into the mouth of the nozzle and the deposits in the mouth of the nozzle is clearly reduced. The entire cross section of the nozzle remains for a long time free of cleaning work and the process gas supply is clearly more constant than in the prior art. Equipment downtimes are minimized.

Costs can be reduced in parallel. This is also true in the scenario of the provision of additional gas rinse devices 20, since they have a remarkable duration and the duration of the nozzles 10 is clearly extended compared to the prior art.

In the horizontal arrangement of the nozzles, explained above, in the working position of the equipment the possibility of disposing the gas rinse devices 20 is offered, such that the projection of the longitudinal axes of the nozzles 10 and the devices of flushed by gas 20 is located in a plane, perpendicular to the longitudinal axis LL of the equipment, forming an acute angle to each other, as shown in Figure 3, the corresponding angle being designated by α and measuring approximately 30 °.

Normally, the nozzles 10 are, equal to the gas rinsing devices 20, arranged in the lower part of the equipment, when the latter is in the working position, as is evident from the representations according to figures 1 to 3.

The gas rinse device 20 according to Figures 3 and 4 is a gas rinse brick, which continuously presents an unguided porosity, the gas (in this case: nitrogen) being conducted through a supply line of gas 22 and a gas distribution chamber 26, located between the gas supply line 22 and the fire-resistant part 24 porous. A gas rinse brick of this type has been part of the state of the art for decades, although for other purposes of use.

In the representation according to FIG. 3, the front surface 20m of the gas outlet side of the gas rinse device 20 extends aligned with respect to the inner side of the fire-resistant coating 14, although it may slightly penetrate the molten metal mass 50. In any case, the front surface 20m of the gas outlet side is in direct contact with the melt 50 during the washing process.

To the extent that reference is made within the scope of the invention to large or small gas bubbles, they can be quantitatively specified, in particular as follows:

Gas bubbles, such as those to be introduced through the gas rinse devices 20 into the molten metal mass 50, typically have bubble diameters <10 mm.

The average diameter of the bubbles supplied through the nozzles 10 with respect to the average diameter of the bubbles supplied by the gas rinse device 20 is normally 10: 1 to 200: 1.

In a newly coated equipment (as in Figure 3), you can measure, on the side of the fire-resistant coating facing the melt, the shortest distance between the nozzles 10 and the corresponding gas rinse devices 20 can measure 2 to 100 cm, for example 5 to 50 cm.

 The angle α between the projection of the nozzle shaft and the projection of the axis of the corresponding gas rinse device on a plane that is perpendicular with respect to the longitudinal axis LL of the equipment can be 10 ° - 80 °, preferably 10 ° - 40 °

Claims (11)

1. Metallurgical fusion and treatment equipment with the following characteristics: 1.1 a cylinder shape with a longitudinal axis (L-L) which, in a working position of the equipment, extends essentially horizontally,  1.2 an outer metal shell (12), 1.3 a fire-resistant inner liner (14), 1.4 several nozzles (10), conducted from the outside through the metal shell (12) and the fire-resistant coating (14), for the introduction of a treatment gas into the molten metal mass (50) through of corresponding nozzle mouths (10m),  1.5 the nozzles (10) are arranged on the longitudinal side of the equipment at a distance from each other, 1.6 in the working position of the equipment, one or more gas rinse devices (20) are provided below the nozzles (10), through which a gas can be introduced, in such a way into the mass of molten metal that rises adjacent to the fire-resistant coating and, at the same time, flows against one or several nozzle nozzles (10m), 1.7 The gas rinse devices (20) are formed with a directed and / or non-directed porosity and in such a way that the gas bubbles, which are introduced through the gas rinse devices (20) in the mass of molten metal (50), have a bubble diameter <10 mm.

2.

Equipment according to claim 1, in which the mouths of the nozzles (10m) are arranged next to each other along an imaginary line.

3.

Equipment according to claim 1, wherein a corresponding gas rinse device (20) is arranged below each nozzle (10).

Four.

Equipment according to claim 1, wherein a gas rinsing device (20) is arranged in each case below a group of nozzles (10).

5.

Equipment according to claim 1, wherein at least one gas rinsing device (20) has, at least in its final section of the gas outlet side, an unguided porosity.

6.

Equipment according to claim 1, wherein at least one gas rinse device (20) has, at least on its front surface (20m) of the gas outlet side, a rectangular cross section.

7.

Equipment according to claim 1, wherein the gas rinsing devices (20) are arranged next to each other along an imaginary line.

8.

Equipment according to claim 1, wherein the gas rinse devices (20) extend, from the outside, through the metal shell (12) and the fire-resistant coating (14), and its front surface ( 20m) on the gas outlet side is, in the working position of the equipment, against the mass of molten metal.

9.

Equipment according to claim 1, wherein the nozzles (10) and the gas rinsing devices (20) are arranged, in such a way next to each other that an acute α angle is formed between their corresponding longitudinal axes.

10.

Equipment according to claim 1, wherein the nozzles (10) extend essentially horizontally in their operating position.

eleven.

Equipment according to claim 1, wherein the nozzles (10) extend, in their operating position, in the lower part of the housing and treatment vessel.