JP5421455B2 - Metallurgical melting and processing unit - 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 metallurgical melting and processing units, and more particularly to an essentially cylindrical container for containing and processing non-ferrous metals.

  These metallurgical units / vessels include, among others, Pierce-Smith converters, Teniente converters, Noranda reactors, and copper smelting furnaces.

The basic design of such a unit that melts metal and is suitable for final processing of the metal melt is as follows.
The vessel / furnace is essentially cylindrical in shape, the longitudinal axis of which is essentially horizontal when the vessel is in the operating position. This is illustrated in FIG. 1 for the Pierce-Smith converter.
The container has an outer metal casing and an inner refractory lining;
-The vessel is equipped with several nozzles, which extend from the outside through the furnace metal casing and through the inner refractory lining to the actual furnace space to allow treatment gases such as air into the metal melt. Allows to erupt.
-In this regard, each of the plurality of nozzles has a nozzle opening, and these openings are arranged adjacent to each other at a predetermined distance in the longitudinal direction of the longitudinal axis of the container. In other words, the plurality of nozzles are arranged along a line of the cylindrical casing, and the line extends parallel to the axis of the cylinder. The axes of these nozzles extend in a plane perpendicular to the axis of the cylindrical body.
-Up to several hundred such processing nozzles can be arranged in one of the units.

If an unfavorable flow profile of the melt is defined in the region of the nozzle or is defined, for example, by varying gas pressure, the melt may enter the nozzle. In the area of the nozzle mouth / nozzle opening, the chemical reaction may lead to solid deposition, for example deposition of magnetite (Fe ₃ O ₄ ). This may result in subsequent “clogging” of the processing nozzle due to the smaller nozzle cross-section where no solid is deposited. At typical gas pressures, this may reduce the gas throughput per hour. Productivity decreases.

  It is not always possible to increase the gas pressure by using a compressor.

  In this regard, a known solution is to clean the nozzle manually or mechanically with a ram device. The initial cross section for gas circulation is restored as a result. However, this causes damage to the refractory lining around the nozzle opening, thereby causing premature wear in this area.

  The object of the present invention is a container for smelting metal and containing and processing metal melts, in particular non-ferrous metal melts, in which the nozzle region incorporating the nozzles continues to function perfectly for a long period of time. Propose a container. In this regard, it is also possible to retrofit existing units.

  In order to achieve this object, the present invention is based on the following knowledge.

FIG. 3 is a view of the Pierce-Smith converter in the operating position. It is sectional drawing through a part of wall part of the nozzle area | region of the Pierce-Smith converter of FIG. It is sectional drawing through a part of wall part of the nozzle area | region of the converter by this invention. FIG. 2 is a diagram of an embodiment of a converter of the type illustrated in FIG. 1 based on the design of the present invention.

  FIG. 2 shows a cross-section through part of the wall of the nozzle area of the Pierce-Smith converter (shown in FIG. 1), where the nozzle 10 passes from the outside through the metal casing 12 and the refractory lining 14 and the metal melt 50 is processed. It can be seen that it extends into the converter area.

  1 and 2 show the converter in a predetermined position called the operating position. Thus, the nozzle 10 extends in this plane in a plane perpendicular to the converter longitudinal axis LL which is essentially horizontally oriented and likewise essentially horizontally oriented. The opening area 10m extends slightly beyond the refractory lining 14 (in the case of the new installation shown here by way of example).

  A plurality of such nozzles 10 are arranged on the longitudinal surface of the converter at a predetermined distance from each other along a virtual straight line 1 as shown in FIG.

  For example, a process gas (air in this embodiment) is introduced into the melt 50 through a nozzle 10 having an inner diameter of 5 cm, in which the air causes the nozzle 10 to be in the form of relatively large bubbles 52. Get out and rise. Foam is released from the nozzle in the top region of the nozzle opening. During the treatment process, a flow of melt 50 is formed, as indicated by the arrows in FIG. The disadvantageous shape of the melt flow in the vicinity of the nozzle opening, and the pressure of the melt acting on the nozzle opening, as shown in FIG. This results in the formation of a solid deposit 10a in the bottom region. Due to the relatively large gas bubbles, the boundary between the gas and the liquid phase is relatively small. Furthermore, the residence time of this large bubble is short. Both of these factors result in a reduction in the level of efficiency of the introduced air. Therefore, it is actually necessary to introduce a large amount of air into the melt through the nozzle, which means a long process time and thereby high costs. Even though the use of air with a high concentration of oxygen shortens the process time, extreme temperatures are provided in the area of the nozzle opening, which results in a significant increase in wear of the refractory lining 14. This simultaneously increases the risk of intrusion into the refractory lining 14 and / or the risk of deposits 10a in the opening area 10m of the nozzle 10.

  These problems can be avoided by the type of design illustrated in FIG. Although the shape, position, and number of the nozzles 10 can be maintained essentially unchanged, the metal melting unit proposed by the present invention is provided with an additional gas jetting device 20, these gas jetting devices. 20 is arranged below the nozzle 10 in the operating / operating position of the unit. The gas jetting device 20 jets gas into the metal smelt 50 so that the gas rises in proximity to the refractory lining and then the gas is jetted around one or more nozzle openings 10m. As used to introduce. “Shooting around” means that the gas exiting the gas ejection device 20 (for example, an inert gas such as argon) flows toward the nozzle opening 10 m and flows in front of the nozzle opening 10 m without leaking as much as possible. This means that the nozzle opening 10m passes through or along the nozzle opening 10m.

  It has been found that the generation of deposits in the nozzle in the area of the nozzle opening is thereby prevented or greatly reduced. The continuous ejection (purge) around the nozzle opening ensures that a uniform velocity profile is generated in the vicinity of the nozzle opening. The flow of the melt is such that no melt enters the nozzle opening or only a small amount, if any, and no more deposits form at the nozzle opening. As affected. Furthermore, the relatively small gas bubbles introduced via the gas blowing device 20 result in a melt-gas mixture whose density is less than the density of the melt itself. Thus, the process gas (air or air-oxygen mixed gas) penetrates deeper into the melt at the same intake pressure, resulting in better dispersion (distribution) of the process gas. Also, the time that the air bubbles are maintained in the melt is increased as a result, so that an overall significantly improved reaction behavior is established between the bubbles 52 and the melt, thus resulting in a more efficient Use of a typical process gas becomes possible.

In its most general embodiment, the present invention relates to a metallurgical melting and processing unit having the following characteristics.
-A cylindrical shape with a longitudinal axis extending essentially horizontally when the unit is in the operating position-Outer metal case-Inner refractory lining-Process gas through a corresponding nozzle opening into the metal melt Several nozzles extending from the outside through a metal casing and a refractory lining for introduction into the plurality of nozzles adjacent to each other and along each other along the longitudinal plane of the unit (in the direction of the longitudinal axis of the unit) Arranged at a predetermined distance-in the operating position of the unit, one or more gas jets are placed under the nozzles, through which the gas is introduced into the metal melt and the gas is refractory lining. Can be introduced so that it rises close to and flows along one or more nozzle openings.

  The arrangement and design of the nozzle and gas ejection device can be realized in various ways. As mentioned above, the nozzle openings in known furnaces of the type described are usually adjacent to one another along a virtual straight line. In the case of such a nozzle arrangement, the present invention proposes that cooperating (corresponding) gas ejection devices are arranged under all nozzles. In other words, every nozzle is assigned a separate gas ejection device, so that fine gas bubbles can be selectively directed from the gas ejection device towards the opening area of the cooperating nozzle.

  Alternatively, the gas ejection device can also cooperate with a plurality of groups of nozzles.

  This is because the selected gas ejection device has an end face at the outlet end of the gas, the outlet end extending over a large cross-sectional area, e.g. extending to two or three adjacently arranged nozzles. This is a special option if you have

  FIG. 4 shows such an embodiment of the converter of the type illustrated in FIG. 1 (from the point of view towards the refractory lining from the inside), but proposed by the present invention with a gas ejection device 20 under the nozzle 10. Based on the designed design.

  It can be seen that ten nozzles 10 are arranged in a horizontal row, and there are gaps between adjacent nozzles 10.

  Seven gas jetting devices 20 are arranged below the nozzle row and are spaced apart from each other by the nozzle diameter, and each gas jetting device 20 has a rectangular end face 20m at the gas outlet end. The size of the gas ejection device 20 is such that gas discharged from the gas ejection device 20, for example, nitrogen, can be selectively guided to the two nozzles 10 disposed above.

  Needless to say, the gas ejection device 20 can have various shapes, particularly in the region of the end face at the gas outlet end, for example, it can have a circular end face. However, also in this embodiment, one gas ejection device 20 can be provided for one nozzle 10 or alternatively, for example, one (larger) gas ejection unit for several nozzles 10 It can also be provided.

  The layout of the gas ejection device 20 is the same as the nozzle row in FIG. 1, whereby the gas outlet surface of the gas ejection device 20 is attached along a virtual straight line that runs parallel to the axis of the converter, Similarly, the gas ejection devices 20 can be positioned offset from each other at various heights in the refractory lining 14.

  As shown in FIG. 3, the gas ejection device 20 is installed so as to extend through the metal case 12 and the refractory lining 14 in the same manner as the nozzle 10.

  As explained above, the purpose and function of the gas ejection device 20 is to introduce as fine a gas bubble as possible to the front of the opening area of the nozzle 10 where it influences the flow of the melt and thus the melt. To enter the nozzle and prevent deposits from forming in the nozzle and to better use the process gas.

In this regard, the nozzle and the gas ejection device are significantly different from each other in structure and function. The nozzle has a large free internal cross-section (eg> 500 mm ² ) through which gas flows, and in the case of a gas jetting device, the gas has a very small internal cross-section (in particular < Conveyed along individual passages having 50 mm ² ) or through the pore structure.

  The pores may be directional or non-directional.

  The non-directional pores are similar to the spongy structure, in which case the gas looks for an irregular path depending on the pore structure through a ceramic-based material consisting of gas-spouting bricks. Such gas ejection devices with non-directional pores are known and will therefore not be described further here.

  In the case of a gas jetting device 20 with directional pores, the gas is directed through the jetting element via separate gas passages in a selective flow direction.

  Also, a combination of directional and non-directional pores inside the gas ejection device 20 or in a row of the plurality of gas ejection devices 20 can be selected.

  In this case, the depth of penetration of the process gas into the smelt 50 can be selectively adjusted. The process gas is a gas supplied through the nozzle 10.

  The structure proposed by the present invention results in a reduced temperature peak and a very uniform temperature profile of the melt in the area around the nozzle opening.

  The consumption of refractories is greatly reduced. Infiltration of the nozzle openings by the melt and deposits at the nozzle openings are greatly reduced. The entire nozzle cross section is maintained for a long time without any influence, no cleaning is required, and the process gas is introduced more consistently than in the prior art. Unit downtime is minimized.

  At the same time, expenses can be reduced. Since the additional gas jetting device 20 has a fairly long service life and the service life of the nozzle 10 is also greatly increased compared to the prior art, the cost savings are achieved when the additional gas jetting device 20 is provided. Also applies.

  When the unit is in the operating position, where the nozzle is positioned horizontally as described above, the gas ejection device 20 is projected from the longitudinal axis of the nozzle 10 and the gas ejection device 20, As shown in FIG. 3, it can be arranged to form an acute angle in a plane perpendicular to the longitudinal axis LL of the unit, where the corresponding angle is indicated by a and is about 30 °. .

  When the nozzle 10 is in the operating position, as is apparent from the description of FIGS.

  The gas ejection device 20 shown in FIGS. 3 and 4 is a gas ejection brick. The gas ejection brick has pores that are non-directional from end to end, and the gas (nitrogen in this example) is a gas. It is led through an intake line 22 and a gas distribution chamber 26 arranged between the gas intake line 22 and the perforated refractory part 24.

  In the description of FIG. 3, the end face 20 m at the gas outlet of the gas ejection device 20 is flush with the inner surface of the refractory lining 14, but may slightly protrude beyond the refractory lining 14 into the metal melt 50. . In any case, the end face 20m at the gas outlet end is in direct contact with the melt 50 during the ejection operation.

  When referring to large or small gas bubbles in the context of the present invention, this quantitatively means specifically:

  The gas bubbles introduced into the metal melt 50 via the gas blowing device 20 usually have <10 mm diameter bubbles.

Gas discharge device 20 having pores of directivity has a gas passage for this purpose, for gas transport, the internal cross-section of any unaffected gas passages, respectively ^{<15mm 2,} <25mm 2 Or <50 mm ² .

A gas jetting device 20 with non-directional pores made from a perforated refractory material can be designed to have the following values that match the gas permeability to EN 993-4 (1995): > 2 × 10 ¹² m ² ,> 15 × 10 ¹² m ² ,> 50 × 10 ¹² m ² , <200 × 10 ¹² m ² .

  The ratio between the average diameter of the bubbles supplied through the nozzle 10 and the average diameter of the bubbles supplied through the gas ejection device 20 is usually 10: 1 to 200: 1.

The amount of gas introduced into the smelt through the gas ejection device 20 and the nozzle 10 is based on a similar relationship. For example, 0.02-0.5 Nm ³ / min of gas is introduced through all gas ejection elements, and 10 and 20 Nm ³ / min are introduced through all nozzles 10.

  In the case of a newly installed unit (as illustrated in FIG. 3), the shortest distance between the nozzle 10 and the cooperating gas blowing device 20 on the side of the refractory lining facing the melt is It can be 2 to 100 cm, for example 5 to 50 cm.

  The angle between the projection of the nozzle axis on the plane perpendicular to the longitudinal axis LL of the unit and the axis of the cooperating gas jetting device is 10 ° to 80 °, preferably 10 ° to 40 °. It can be.

DESCRIPTION OF SYMBOLS 10 ... Nozzle 10m ... Nozzle port 12 ... Outer metal shell 14 ... Inner fireproof lining 20 ... Gas ejection apparatus (gas ejection equipment)
50 ... metal melt 52 ... bubble 54 ... relatively small gas bubble

Claims (11)

A container for metallographic melting and processing,
The following features:
In 1.1 the operating position, a tubular shape having water earnestly extending longitudinal axis (L-L),
1.2 outer metal shell (12),
1.3 Inner fireproof lining (14),
1.4 extending from the outside through the metal shell (12) and the refractory lining (14), process gas corresponding nozzle orifice (10 m) through the metal melt (50) more for introduction into Nozzle (10),
1.5 The nozzle (10) is arranged at a predetermined distance from each other on the longitudinal side of the container,
1.6 In the operating position of the vessel, one or more gas ejection facilities (20) are arranged under the nozzle (10), through which gas is introduced into the metal melt. Is introduced to rise adjacent to the refractory lining and is thus blown toward one or more of the nozzle openings (10 m),
Container that have a.   The said nozzle opening (10m) is arrange | positioned adjacent to each other along the virtual straight line, The container of Claim 1 characterized by the above-mentioned.   2. A container according to claim 1, characterized in that a corresponding gas jetting facility (20) is arranged under each nozzle (10).   A container according to claim 1, characterized in that one gas ejection facility (20) is arranged under the group of nozzles (10).   2. Container according to claim 1, characterized in that the at least one gas ejection facility (20) is provided with irregular holes at least at its gas outlet end.   2. Container according to claim 1, characterized in that at least one gas ejection facility (20) has a rectangular cross section at least in front of the gas outlet end (20m).   The container according to claim 1, wherein the gas ejection facilities (20) are arranged adjacent to each other along a virtual straight line.   The gas ejection facility (20) extends from the outside through the metal shell (12) and the refractory lining (14), and the front surface (20m) of the gas ejection facility (20) at the gas outlet end is operated. The container according to claim 1, wherein the container is in contact with the molten metal at a position.   The nozzle (10) and the gas ejection facility (20) are arranged with respect to each other such that the axes of the nozzle (10) and the gas ejection facility (20) form an acute angle α. The container according to claim 1. It said nozzle in the operating position (10) A container according to claim 1, characterized in that it Mashimashi water earnestly extension. It said nozzle in the operating position (10) A container according to claim 1, characterized in that extends along the bottom of the front Kiyo device.

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