Vacuum lid for a vacuum converter and vacuum converter

Abstract

The invention relates to a cooled vacuum lid (10) for detachable placement – ​​with the aid of a first cooled flange unit (11) – onto the opening of a vacuum vessel of a vacuum converter (1), in particular a vacuum argon-oxygen decarburization (VAOD) converter, for the production of ferrous and non-ferrous alloys. For this purpose, the vacuum lid has a cooled lid section (15) to which a connection for a cooled vacuum line (17) is provided. In order to maintain a vacuum-tight connection, in particular between the vacuum lid and the vacuum vessel, even during process-related movements or forces, a cooled lateral compensator (14) is detachably connected to the lower end of the lid section (15). The vacuum lid is placed onto the opening of the vacuum vessel via this lateral compensator.It serves to absorb movements or forces acting perpendicular to the longitudinal axis (L) and in the direction of the longitudinal axis of the vacuum lid and / or the vacuum converter (1). A second cooled flange unit (16) is provided for the detachable, vacuum-tight connection of the lateral compensator to the lid section.

Description

[0001] The invention relates to a vacuum lid for a vacuum converter, in particular a vacuum argon-oxygen decarburization (VAOD) converter, for sealingly fitting onto the opening of a vacuum vessel of the vacuum converter. The invention also relates to a vacuum converter for the vacuum metallurgical treatment of liquid steel with the vacuum vessel, in particular an RH, VD or VOD vacuum vessel, and with the vacuum lid.

[0002] Melting vessels that can be sealed with lids, such as vacuum converters, are known in various designs. For example, EP 0 921 201 B1 discloses a melting furnace that refines a molten metal in an evacuated, sealed chamber. This chamber is formed by bringing a sealing element attached to a lower end of a sealing lid into close contact with a sealing flange on the outer surface of a conical section extending from the furnace mouth to a straight body section. This sealing element is used to retractably cover the furnace mouth.

[0003] To provide an improved seal, DE 10 2008 027 006 A1 proposes a device for the secondary and vacuum metallurgical treatment of liquid steel, comprising a vacuum vessel, such as an RH, VD, or VOD vessel, which can be sealed and closed for the vacuum process with a liftable and lowerable lid and / or is connected to a sealed, downstream vacuum pipeline. A sealing agent is arranged around the circumference at the upper end of the vacuum vessel and / or the vacuum pipeline, and the lid and / or a connecting end of the downstream vacuum pipeline is / are designed with a collar that can be fitted over the sealing agent. This ensures that the seal is no longer directly exposed to high thermal loads from heat radiation. Furthermore, the seal is located in a space protected from the outside by the fitted collar and is virtually indestructible, as even falling or...Dripping wax or molten steel can no longer reach the seal. Flanges are no longer required at the sealing point, nor is their mechanical processing or water cooling necessary.

[0004] Vacuum vessels, such as an RH, VD or VOD vessel or a converter, such as an LD converter, are used in metallurgical plants for the production of steels from liquid iron, scrap, direct reduced iron, hot briquetted iron (HBI) pressed into briquettes, or for the production of iron alloys under protective gas and vacuum conditions, and the like.

[0005] During the decarburization of steel moltens, in which the carbon and other element content of the pig iron used is reduced, the unwanted components are oxidized. This process, known as refining, takes place partly under atmospheric conditions with oxygen being blown in through a lance. The oxygen blowing process, also known as the Linz-Donawitz process (LD process; English: basic oxygen process, BOP), is a production method for steelmaking by oxidizing high-carbon pig iron into low-carbon steel.

[0006] Unlike atmospheric converters, the vacuum converter is closed by a cooled vacuum lid, and the pressure inside is reduced to the desired level via a cooled connection to an evacuation system. After the pressure is reduced, excess oxygen is injected, which is required for burning metallic fuels during decarburization.

[0007] Since processes such as argon-oxygen decarburization can cause considerable movement of the converter components, particularly due to blowing during metallurgical treatment, the sealed components, such as the vacuum vessel and vacuum lid, must be designed with corresponding stability and be securely connected. However, the converters currently used in metallurgical engineering do not adequately meet these requirements. Vacuum converters are not currently in use.

[0008] The invention therefore aims to further develop a known vacuum lid for a vacuum vessel of a vacuum converter and a known vacuum converter in such a way that the vacuum-tight connection, in particular of the vacuum lid with the vacuum vessel, can be maintained even during process-related movements or process-related forces.

[0009] The problem is solved with respect to the vacuum lid by the subject matter of claim 1. Accordingly, the vacuum lid is characterized in that a cooled lateral compensator is detachably connected to the lower end of the lid section for placement on the opening of the vacuum vessel and for absorbing movements or forces acting perpendicular to and in the direction of the longitudinal axis of the vacuum lid and / or the vacuum converter; and that a second cooled flange unit is provided for detachably connecting the lateral compensator to the lid section.

[0010] The claimed lateral compensator advantageously serves as a vibration damper between the lid section and the vacuum vessel. It absorbs vibrations, movements, and / or forces that occur as disturbances during operation of the vacuum converter, perpendicular to and in the direction of the longitudinal axis of the vacuum lid and / or the vacuum converter. Thus, it ensures a vacuum-tight connection required for vacuum operation between the cooled lid section and the lateral compensator on the one hand, and between the claimed vacuum lid and the vacuum vessel on the other, despite the aforementioned disturbances.

[0011] The cooled first and second flange units have the advantage that the vacuum vessel with the claimed vacuum lid, on the one hand, and the lid section and the lateral compensator, on the other hand, can be sealed by means of conventional gaskets placed between the respective flanges. The gaskets can be made of a rubber-elastic material, such as an elastomer with Shore A hardness, for example, silicone, Teflon, Perbunan, etc. The invention offers the advantage of ensuring the smooth operation of a vacuum converter during metallurgical treatment under vacuum, thus guaranteeing economical operation of the vacuum converter.

[0012] All components described as "cooled" are preferably water-cooled. However, other cooling methods, e.g., using a different coolant, preferably a different cooling fluid, are also conceivable.

[0013] In this description, the term "vacuum cover" includes the cover section, the lateral compensator, and three flanges, two of which are part of the second flange unit and a second flange is located at the lower end of the lateral compensator. A fourth flange, welded to the vacuum vessel of the vacuum converter in the area of ​​the opening, is not part of the vacuum cover.

[0014] The term "vacuum converter" refers to a vacuum vessel and the vacuum lid used for this purpose.

[0015] The terms "bottom" and "top" refer to the representation in the figures. Specifically, the lower end of the lid section faces the upper end of the lateral compensator, and vice versa. The lower end of the lateral compensator is opposite its upper end and faces the opening of the vacuum vessel.

[0016] Further advantageous embodiments of the invention will be found in the dependent claims.

[0017] In one embodiment of the vacuum lid according to the invention, the cooled lateral compensator comprises at least one bellows body with two terminal, thus arranged at its ends, tubular connection pieces for respective connection with a flange.

[0018] Preferably, the lateral compensator comprises two cooled bellows bodies connected by a tube section, with terminal fittings attached at the ends. This improves the compensation of movements or forces that occur perpendicular to the longitudinal axis of the vacuum lid or vacuum converter.

[0019] The terms "longitudinal axis of the vacuum lid", "longitudinal axis of the vacuum converter" and "longitudinal axis of the vacuum vessel of the vacuum converter" are used synonymously.

[0020] As claimed, and as the term "lateral" already suggests, the lateral compensator is specifically designed to absorb vibrations, movements, or forces acting perpendicular to the longitudinal axis of the vacuum lid and / or the vacuum converter. While the lateral compensator also absorbs vibrations, movements, or forces acting in the direction of the longitudinal axis of the vacuum lid, this is limited in magnitude and duration. Particularly due to the harsh environmental conditions prevailing during the operation of the vacuum converter, such as high pressure, high temperature, and corrosive gases, the lateral compensator, by design, cannot withstand longitudinal forces for extended periods.

[0021] To extend the service life of the lateral compensator, the invention therefore optionally provides a safety device specifically designed to absorb forces occurring along the longitudinal axis of the vacuum vessel of the vacuum converter during its operation or to compensate for such movements. For this purpose, the safety device comprises plate elements, in particular ring-shaped plate elements, which surround the connecting pieces of the bellows bodies of the lateral compensator.

[0022] According to one embodiment, the plate elements are connected to each other by axially parallel tie rods provided on opposite sides of the at least one bellows body. This allows movements or forces occurring along the longitudinal axis of the vacuum lid or vacuum converter to be compensated for or absorbed.

[0023] Swivel joints, preferably universal joints, can be attached to the ends of the tie rods and connected to the plate elements.

[0024] According to a further embodiment, the plate elements can be connected additionally or alternatively to the tie rods by axially parallel swivel joints provided on opposite sides of the at least one cooled bellows body. This allows for greater variability when compensating for or absorbing movements or forces occurring along the longitudinal axis of the cooled vacuum lid or vacuum converter.

[0025] A combination of the tie rods and the swivel joint tensioning improves the effectiveness of the securing device.

[0026] The combination of a lateral compensator and a locking device allows for the compensation or absorption of not only lateral movements or forces occurring perpendicular to the longitudinal axis of the vacuum lid or vacuum converter, but also movements or forces occurring along the longitudinal axis of the vacuum lid or vacuum converter. The locking device relieves the lateral compensator of the burden of compensating for movements or forces in the longitudinal direction.

[0027] The at least one bellows body, the connecting pieces, and / or the pipe section are preferably cooled, i.e., designed to allow the passage of a cooling fluid. This makes it possible to use these elements even at temperatures exceeding 300°C. Furthermore, any impairment of the mechanical properties of these elements is largely avoided. Temperature-related expansion of the materials used, such as metals, which can lead to undesirable forces on the mechanical connections of individual components, can thus be avoided or at least largely reduced.

[0028] All flanges must be cooled. Thus, according to the invention, cooling the seals maintains their functionality and therefore the functionality of the entire vacuum converter.

[0029] In a preferred embodiment of the vacuum lid according to the invention, the seals are formed from a rubber-elastic material such as an elastomer with Shore A hardness. A sufficiently good sealing effect can be achieved by using such materials.

[0030] The aforementioned object of the invention is achieved with respect to the vacuum converter by the subject matter of claim 12. Accordingly, the vacuum converter is characterized in that it can be sealed with a cooled vacuum lid according to any one of claims 1 to 11. The advantages of this solution correspond to the advantages previously mentioned with respect to the claimed vacuum lid.

[0031] The invention is explained in more detail below with reference to exemplary embodiments, accompanied by drawings shown at different scales and in some cases in a highly schematic manner. Identical parts in the figures are designated with the same reference numerals. They show: Fig. 1 a schematic view of a vacuum converter and Fig. 2 a view of a vacuum lid according to the invention

[0032] After Fig. Figure 1 comprises a vacuum converter, designated overall by reference numeral 1, comprising a vacuum vessel 2, to the body section 4 of which vessel sections 6 and 8 taper towards both longitudinal ends. While vessel section 6 is closed with a bottom plate 7, vessel section 8 surrounds a (working) opening 9 located away from the body section 4. If a metallurgical treatment for the production of ferrous and non-ferrous alloys under vacuum conditions, in particular the production of stainless steel, is carried out in the vacuum converter 1, which is pivotable about a horizontal axis, the (working) opening 9 is closed with a cooled vacuum lid 10.A first cooled flange unit 11, which detachably connects the conical outer wall 12 of the vessel section 8 of the vacuum vessel 2 and the cooled vacuum lid 10, serves to ensure that an interior 3 of the vacuum converter 1 is sealed to the outside via an inserted seal 13.

[0033] Above the first flange unit 11, the vacuum cover 10 has a [feature / position] in the Fig. Figure 1 schematically depicts a cooled lateral compensator 14. Opposite the first cooled flange unit 11, a second cooled flange unit 16 is provided between the cooled lateral compensator 14 and a cooled cover section 15. A connection for a cooled vacuum line 17 for connecting a vacuum pump device for evacuating the vacuum converter 1 can be provided on the cooled cover section 15 and / or on the vacuum vessel.

[0034] Due to the temperatures above 300°C prevailing during the metallurgical treatment of ferrous and non-ferrous alloys in the vacuum converter 1, as described in Fig. 1. Schematically indicated on the first and second cooled flange units 11, 16 are lines 18 for conveying or circulating a cooling fluid, such as water. Likewise, in a preferred embodiment of the vacuum lid 10 according to the invention, the lateral compensator 14 and the lid section 15 can be designed to be cooled accordingly.

[0035] According to the invention, the seal 13 of the first flange unit 11 and a seal 19 of the second flange unit 16 are preferably each made of a material with rubber-elastic properties, such as an elastomer. The material preferably has a Shore hardness of A.

[0036] According to Fig. In one embodiment of the cooled vacuum lid 10 according to the invention, the first cooled flange unit 11 is formed by a cooled flange 25 of the vacuum vessel 2 and a first flange 26 attached to the lateral compensator 14 of the cooled vacuum lid 10, which is described in detail below. The second cooled flange unit 16 is formed by a second cooled flange 22 attached to the cooled lateral compensator 14 and a flange 21 attached to the cooled lid section 15. As shown by reference numeral 23, the two flanges 21 and 22 are screwable together and are traversed or surrounded by cooling lines 24, which serve to convey a cooling fluid such as water, and are sealed against each other by the circumferential seal 19.

[0037] The vacuum lid 10 is sealed to the conical body section 8 of the vacuum converter 1 using the first cooled flange unit 11.

[0038] For this purpose, the cooled flange 25 is attached to the body section 8 of the vacuum vessel 2. The first cooled flange 26, provided on the cooled vacuum cover 10, is sealed onto this flange, forming the flange unit 11. The vacuum-tight connection is achieved by the gasket 13, which is accommodated by a circumferential channel. The circumferential channel is formed by two annular recesses / grooves that are precisely aligned with each other when the cooled vacuum cover 10 is in place on the vessel section 8. Between the first cooled flange 26 of the first cooled flange unit 11 and the second cooled flange 22 of the second cooled flange unit 16, two cooled bellows bodies 30, 32 are provided, connected to each other via a pipe section 28.

[0039] The bellows bodies 30, 32 are connected to the first flange 26 and the second flange 22, respectively, via cylindrical connecting pieces 34 and 36. The bellows bodies 30, 32, the pipe section 28, and the connecting pieces 34 and 36 are designed to allow the passage of a cooling fluid. For this purpose, the bellows bodies 30, 32, the connecting pieces 34, 36, and the pipe section 28 are double-walled and can be directly permeated by a cooling fluid such as water, or they may have cooling pipes or cooling coils 38 for the passage of the cooling fluid, such as water. This ensures a functional, sealing connection of the cooled vacuum lid 10 to the conical vessel section 8, even at internal operating temperatures above 300°C.

[0040] The cooled bellows bodies 30, 32 can absorb, in particular, or primarily, lateral movements or forces occurring perpendicular to the longitudinal axis L of the vacuum converter 1, which are process-related or caused by thermal expansion or contraction of the material. In contrast, during metallurgical operation, movements or forces occurring along the longitudinal axis L due to movements of any parts of the vacuum converter 1, as well as due to thermal expansion or contraction of the material during cooling, are absorbed by a securing device of the cooled vacuum lid 10 with a tie rod and / or swivel joint clamping arrangement.

[0041] The cooled connecting piece 36 between the second cooled flange 22 and the second bellows body 32 is surrounded by an annular plate element 40, and the cooled connecting piece 34 between the first bellows body 30 and the first cooled flange 26 is surrounded by an annular plate element 42. Between the plate elements 40, 42, which are arranged perpendicular to the longitudinal axis L of the vacuum converter 1, two pairs of rod-shaped elements 43, 45, i.e., tie rods, are attached to the cooled pipe section 28, preferably in diametrically opposed positions, by means of a pair of cross braces 44, 46. The pairs of rod-shaped elements 43, 45 are preferably connected at their longitudinal ends by universal joint elements 48, 50 and 52, 54, respectively, via bolts 47, 49.The universal joint elements 48, 52 are firmly screwed to the ring-shaped plate element 40 via rod-shaped links 56 and the universal joint elements 50, 54 are screwed to the ring-shaped plate element 42 via rod-shaped links 58.

[0042] With the help of the in Fig.The two simplified tie rod elements and / or swivel joints of the securing device can absorb or compensate for movements or forces in the direction of the longitudinal axis L, to which the components of the vacuum converter 1 are subjected, up to a range of, for example, 100 mm. The universal joint elements 48 to 54 or the rod-shaped links 43, 45 prevent forces or movements acting in the direction of the longitudinal axis L of the vacuum converter 1 from causing damage to the cooled bellows bodies 30, 32 and thus from compromising the tightness of the overall system. In this way, the cooled vacuum lid 10 according to the invention can be securely attached to a dynamically operating metallurgical vacuum vessel of the vacuum converter 1 while maintaining the respective set pressure conditions.

[0043] According to the invention, the cooled vacuum lid 10 can be placed on or lifted off the conical vessel section 8 – with the first flange unit 11 detached – using hydraulically, pneumatically or electromechanically operating devices. Reference symbol list 1 vacuum converter 2 vacuum vessels 4 Hull section 6. Vessel segment 7 Base plate 9 Working opening 10 vacuum lids 11 first flange unit 12 Exterior wall 13 Seal 14 Lateral compensator 15 Cover section 16 second flange unit 17 Vacuum line 18 lines for coolant 19 Seal 21 Flange on the cover section 22 second flange on the lateral compensator 24 Cooling line 25 Flange on the vacuum vessel 26 first flange on the lateral compensator 28 pipe sections 30 first bellows body 32 second bellows body 34, 36 connectors 38 cooling pipes 40, 42 ring-shaped plate elements 43 pairs of rod-shaped links 44 pairs of cross braces 45 pairs of rod-shaped links 46 pairs of cross braces 47 bolts 48, 50 universal joint elements 52, 54 Universal joint elements 56 rod-shaped links 58 rod-shaped links L Longitudinal axis QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 0 921 201 B1

[0002] DE 10 2008 027 006 A1

[0003]

Claims

[1] Cooled vacuum lid (10) for detachable placement - with the aid of a first cooled flange unit (11) - onto the opening of a vacuum vessel of a vacuum converter (1), in particular a vacuum argon oxygen decarburization (VAOD) converter, for the production of ferrous and non-ferrous alloys, wherein the vacuum lid comprises: a cooled lid section (15) on which a connection for a cooled vacuum line (17) can be provided; characterized by , that a cooled lateral compensator (14) is detachably connected to the lower end of the lid section (15) for placement on the opening of the vacuum vessel and for receiving movements perpendicular to the longitudinal axis (L) and in the direction of the longitudinal axis of the vacuum lid and / or the vacuum converter (1) or acting forces; and that a second cooled flange unit (16) is provided for detachably connecting the lateral compensator to the cover section. [2] Cooled vacuum lid (10) according to claim 1, characterized by , that the cooled lateral compensator (14) has at least one cooled bellows body (30, 32) with two terminal tubular connection pieces (34, 36) for connection to a cooled flange (26, 22) of the first and / or second flange unit (11, 16). [3] Cooled vacuum lid according to claim 1 or 2, characterized by , that the cooled lateral compensator (14) comprises two cooled bellows bodies (30, 32) connected via a pipe section with cooled connecting pieces (34, 36) attached at the ends. [4] Cooled vacuum lid according to claim 2 or 3, characterized by, that a safety device is provided to absorb movements or forces acting in particular in the direction of the longitudinal axis (L), wherein the safety device has plate elements (40, 42) which surround the connecting pieces (34, 36) of the bellows bodies. [5] Cooled vacuum lid according to claim 4, characterized by , that the plate elements (40, 42) are connected to each other by tie rods (58, 43, 56; 58, 45, 56) provided opposite each other and parallel to the axis outside the at least one cooled bellows body (30, 32). [6] Cooled vacuum lid according to claim 5, characterized by , that initially individual ends of the tie rods (43, 45) are hinged to swivel joints (48, 50; 52, 54) which are connected to the plate elements (40, 42). [7] Cooled vacuum lid according to any one of claims 4 to 6, characterized by, that the plate elements (40, 42) are connected to each other by swivel joints provided outside the at least one cooled bellows body (30, 32) opposite each other and parallel to the longitudinal axis (L). [8] Cooled vacuum lid according to any one of claims 2 to 7, characterized by , that at least one bellows body (30, 32) and / or the connecting pieces (34, 36) are designed to convey a coolant. [9] Cooled vacuum lid according to any one of claims 3 to 8, characterized by , that the pipe section (28) is designed for conveying or routing a cooling fluid. [10] Cooled vacuum lid according to any one of claims 2 to 9, characterized by , that the seals (13, 18) are formed from an elastomer of Shore hardness A. [11] Cooled vacuum lid according to any one of claims 2 to 10; characterized by , that the second flange unit (16) has: a flange (21) attached to the lower end of the cover section (15); and a second flange (22) attached to the upper end of the lateral compensator, wherein the two flanges (21, 22) of the second flange unit (16) are designed for the passage or routing of a cooling fluid and can be detachably connected to each other, e.g. via a screw connection. [12] Cooled vacuum converter (1) for vacuum metallurgical treatment of liquid ferrous and non-ferrous alloys with a vacuum vessel (2) which has a connection (17) for connecting to a pumping device for its evacuation, characterized by , that the vacuum converter (1) with the cooled vacuum lid (10) which can be placed on the vacuum vessel (2) according to one of claims 1 to 11 can be sealed vacuum-tight by means of the first flange unit (11). [13] Vacuum converter (1) according to claim 12, characterized by , that the first flange unit (11) has: a first flange (26) attached to the lower end of the lateral compensator (14); and a flange (25) attached to the opening of the vacuum vessel, wherein the two flanges (25, 26) of the first flange unit (11) are designed for the passage or routing of a cooling fluid and can be detachably connected to each other, e.g. by means of a screw connection.

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