Pneumatic slag damper

Abstract

The invention relates to a pneumatic slag stopper, a metallurgical vessel and a method for pneumatically closing a tapping channel of a metallurgical vessel with respect to the outflow of slag by means of a gas flow provided from at least one gas flow outlet. The gas flow outlet is arranged on a swivel arm which can be swiveled about a swivel axis by means of a swivel drive, the swivel arm having a gas delivery channel which opens into the at least one gas flow outlet, the longitudinal axis of the at least one gas flow outlet being as parallel as possible to the swivel axis. The metallurgical vessel has a tapping channel and the slag stopper which is fixed to the metallurgical vessel, the longitudinal axis of the tapping channel being as parallel as possible to the swivel axis. In the method, the gas flow outlet arranged on the swivel arm is positioned into a sealing position in front of the tapping opening of the tapping channel by swiveling the swivel arm into the sealing position in front of the tapping opening with a swivel movement which is performed in a plane which is as perpendicular as possible to the longitudinal axis of the tapping channel.

Description

TECHNICAL FIELD

[0001] The present application relates to a pneumatic slag stopper for pneumatically closing a tapping channel of a metallurgical vessel with respect to the tapping of slag by means of at least one gas flow introduced into the tapping channel from at least one gas flow outlet, and a method for pneumatically closing a tapping channel. BACKGROUND

[0002] In metallurgical processing steps of a metal melt, besides the liquid metal product, also a liquid slag is produced, which has a lower density than the liquid metal product. The processing steps are carried out in a metallurgical vessel, and when the liquid metal product is removed from the metallurgical vessel, a carryover of slag can occur. This is undesirable, and it is sought to separate the slag and the metal product as completely as possible. It is known to close the tapping channel of the metallurgical vessel as soon as the share of slag in the tapped liquid is unacceptably high. Such a method is based, for example, on a pneumatic closing of the tapping channel by means of a gas blow. Such a method is described, for example, in DE 26 39 712.

[0003] The devices for carrying out such a method are usually arranged on the metallurgical vessel and are thus exposed to extreme environmental conditions. Their service life is limited, and maintenance and replacement must be carried out frequently. In order to successfully carry out the pneumatic closing, the gas should be blown as symmetrically as possible with respect to the tapping channel. The position of the slag stopper device should be aligned accordingly. This makes the maintenance and replacement costs too high. A device is known from AT 40 89 65 B, which simplifies the replacement and maintenance due to the constructional design. However, the constructional design corresponding to the principle of DE 26 39 712 enlarges the rotational outer contour of the metallurgical vessel. The resulting space problems in the surrounding area of the existing metallurgical vessel can limit the usability. SUMMARY

[0004] TECHNICAL TASK

[0005] It is the task of the present application to provide a pneumatic slag stopper and a method for pneumatically closing a tapping channel, which allow an extended usability with respect to the prior art.

[0006] TECHNICAL SOLUTION

[0007] The task is solved by a pneumatic slag stopper for pneumatically closing the tapping channel of a metallurgical vessel with respect to the tapping of slag by means of at least one gas stream directed into the tapping channel from at least one gas stream outlet, wherein the gas stream outlet is arranged on a swivel arm which can be swiveled about a swivel axis by means of a swivel drive and which has a gas delivery channel which opens into the at least one gas stream outlet, characterized in that the longitudinal axis of the at least one gas stream outlet is as parallel as possible to the swivel axis.

[0008] The slag or the metal melt flow with entrained slag flows through the tapping channel or the tapping opening at the end thereof. The pneumatic slag stopper closes the tapping channel or the tapping opening at the end thereof with respect to the tapping of slag, so that the tapping opening at the end of the tapping channel is open when the gas stream blocks the tapping of the slag or the metal melt flow with entrained slag. For this purpose, the gas stream is directed into the tapping channel or the tapping opening at the end of the tapping channel. The gas flows from the at least one gas stream outlet into the tapping channel against the flow direction of the slag or the metal melt flow with entrained slag and thus actually closes the tapping channel with respect to the tapping of slag.

[0009] The tapping channel is suitable for blocking the slag or the metal melt flow with entrained slag by the gas flowing from the gas stream outlet. The gas delivery device comprising the gas delivery channel and the at least one gas stream outlet is suitable for blocking the slag or the metal melt flow with entrained slag flowing through the tapping channel or the tapping opening. The tapping channel extends through the wall of the metallurgical vessel. The metal melt is discharged from the metallurgical vessel through the tapping channel. The tapping channel ends at the outer side of the metallurgical vessel having the tapping opening. The tapping opening is present in a so-called tapping opening support, i.e. a plate which is perpendicular to the longitudinal axis of the tapping channel.

[0010] The metallurgical vessel is for example a steel plant converter, for example for a BOF or LD process.

[0011] The gas stream outlet is arranged on a swivel arm because it is only positioned in front of the tapping opening when the slag is tapped. Before that, it should be in other positions. If it is ready, it should be able to be positioned in front of the tapping opening without problems. This is achieved in that it is arranged on a swivel arm which can be swiveled about a swivel axis by means of a swivel drive.

[0012] The gas outlet is arranged on a swivel arm which can be swiveled about a swivel axis by means of a swivel drive, and the swivel arm has a gas-conducting channel which opens into the at least one gas outlet, characterized in that the longitudinal axis of the at least one gas outlet is as parallel as possible to the swivel axis, and the swivel arm can be swiveled with a swivel movement in a plane which is as perpendicular as possible to the swivel axis.

[0013] The swivel arm can be swiveled into the sealing position about the swivel axis by means of a swivel drive. The swivel arm can be swiveled into the sealing position with a swivel movement in a plane which is as perpendicular as possible to the swivel axis.

[0014] Preferably, the sealing position is reached from the starting position of the swivel arm only by a swivel movement, if necessary, so that no additional movement is added to the swivel movement.

[0015] There must be at least one single gas outlet, but there can also be a plurality of gas outlets.

[0016] The swivel arm has a gas-conducting channel which opens into the at least one gas outlet. By means of this gas-conducting channel, the gas which is necessary for the pneumatic closing is fed to the gas outlet. The guidance in the swivel arm can be produced compactly and easily. According to the invention, the longitudinal axis of the gas outlet is as parallel as possible to the swivel axis. "As parallel as possible" includes not only parallel but also a deviation from the parallelism of up to + / - 5°, which can occur in operation without limiting the functional capability to an unacceptable extent. The deviation of + / - 5° relates to the angle between the longitudinal axis of the gas outlet and the swivel axis in the plane which contains these two axes, if these two axes are arranged intersecting one another after the translation.

[0017] In such a construction, the rotating outer contour is reduced when the skimmer is mounted on the metallurgical vessel compared to DE 26 39 712.

[0018] Advantages of the invention

[0019] Preferably, the spacing of the gas outlet from the axis of rotation is adjustable. This can be achieved, for example, in that a component of a certain length, which serves as the swivel arm and is connected to the swivel drive, can be adjusted in different positions relative to the axis of rotation. Thereby, the alignment of the gas outlet relative to the taphole is made easier, for example, after the replacement of the taphole channel, and the installation on the metallurgical vessel and the maintenance of the stopper are less expensive. With the stopper according to AT 408 965 B, the entire stopper together with the housing has to be adjusted on the metallurgical vessel, which is much more costly. The stopper according to the application therefore offers a comparatively reduced installation time and costs.

[0020] The swivel arm can be swiveled from a starting position up to a maximum swivel angle. Preferably, the maximum swivel angle is settable. This can be done, for example, in that adjustable stop elements for limiting the swivel movement are arranged on the swivel drive.

[0021] Thereby, the alignment of the gas outlet relative to the taphole is made easier, which makes the installation, the maintenance and the replacement of the stopper on the metallurgical vessel less expensive.

[0022] Preferably, the swivel arm comprises at least one arm module and at least one gas outlet module, wherein the gas outlet module contains the at least one gas outlet and is fixed in a releasable manner on the arm module. With such a modular construction, the swivel arm can be produced more easily and the outlay on maintenance is lower, because only the gas outlet module has to be replaced, if necessary.

[0023] According to an advantageous embodiment variant, there are a plurality of gas flow outlets. This can have advantages in terms of the flow behavior of the gas stream after it has flowed out of the slag dam. The better the gas stream is successfully introduced coaxially into the slag outlet channel with respect to the longitudinal axis of the slag outlet channel when the slag outlet channel is pneumatically closed, the better the result with respect to the prevention of the outflow of slag. If a plurality of gas flow outlets are provided, these can have a comparatively small cross section with the same total cross-sectional area as a single, larger gas flow outlet. For very narrow spatial situations, the length that can be achieved for the gas flow outlet can be very short. This can result in the consequence that the gas stream, when flowing out, for example as a result of the sharp one-sided pressure loss that occurs when the flow direction is changed from the gas delivery channel into the gas flow outlet, is diverted with respect to the longitudinal axis of the gas flow outlet and thus becomes difficult to coaxially introduce into the coaxial slag outlet channel. The result with respect to the prevention of the outflow of slag can thereby be suboptimal. In addition, the outflow of the diverted gas stream leads to undesirable noise emissions. If the gas stream, although through the same total cross-sectional area, flows through a number of gas flow outlets with a smaller cross section, it is comparatively less diverted. Accordingly, it becomes easier to introduce it coaxially into the slag outlet channel, the outflow of slag is better prevented, and there are fewer noise emissions.

[0024] According to an advantageous embodiment variant, the gas flow outlet or the gas flow outlets are configured as one or more gas channels in a nozzle head element that can be inserted into the swivel arm or into the gas flow-out module. Thereby, different geometries of the gas flow outlet or a reaction to changing boundary conditions of the problem to be solved or a replacement due to wear can be used if necessary in a simple manner. There can be a single nozzle head element or there can be a plurality of nozzle head elements.

[0025] According to an advantageous embodiment variant, the position of the nozzle head element can be aligned by means of an adjustment element, for example an angle with respect to the longitudinal axis of the gas flow outlet with respect to the swivel axis. The adjustment element can be an adjustment bolt, for example. By means of the alignability, the desired coaxiality of the gas stream with respect to the longitudinal axis of the slag outlet channel, as already described above, can be achieved more easily than with a non-adjustable nozzle head element.

[0026] The following position of the swivel arm, which can also be referred to as the sealing position, is provided for pneumatically closing the slag outlet channel of the metallurgical vessel with respect to the outflow of slag. The swivel axis extends through the swivel shaft. The slag dam is provided with a gas supply line for supplying gas to the gas delivery channel.

[0027] According to an advantageous embodiment variant, the gas supply line is connected to the gas delivery channel in the valveless manner only in the sealing position, at least by means of a connection channel arranged eccentrically in the swivel axis. If necessary, further connection channels can also be present outside the swivel axis for the introduction of gas from the connection channels in the swivel axis into the gas delivery channel.

[0028] The valveless design reduces susceptibility to disturbances and maintenance outlay. The end opening of the gas supply line and the opening of the gas supply line side of the connection channel arranged in the swivel axis coincide with one another only in the sealing position, and the gas can accordingly flow only then. In the starting position, no gas flow is possible, since the swivel axis closes the gas supply line.

[0029] During the movement towards the sealing position and during the pneumatic closure of the taphole channel, splashes of the metal melt or slag can solidify on the swivel arm. This can have a negative effect on the swivel movement and the introduction of the gas flow into the taphole channel. According to an advantageous embodiment variant, a plurality of exhaust openings are present in the swivel arm, preferably in the surroundings of at least one gas outlet opening of the gas outlet module. The exhaust openings are arranged next to the region in which the one or more gas outlet openings are arranged. By "surroundings" is meant the region of the swivel arm or gas outlet module which, in the sealing position, precedes the taphole holder. If the exhaust openings open into the gas delivery channel, the gas which is delivered, for example, by the gas delivery channel, flows through the exhaust openings. The surface is reduced by the exhaust openings, thereby making it difficult for the metal melt or slag to freeze. The metal melt or slag is made difficult to freeze by the gas which flows in operation. The exhaust openings thus contribute to the abovementioned problems being alleviated.

[0030] According to an advantageous embodiment variant, the swivel drive is free of a transmission. This reduces the manufacturing costs, the susceptibility to disturbances and the maintenance outlay which the damper fixed to the metallurgical vessel has to tolerate in the extreme environmental conditions.

[0031] According to an advantageous embodiment variant, the swivel drive comprises at least one crankshaft and at least one pneumatic cylinder for driving the crankshaft. This reduces the susceptibility to disturbances and the maintenance outlay which the damper fixed to the metallurgical vessel has to tolerate in the extreme environmental conditions.

[0032] According to an advantageous embodiment variant, the swivel drive is accommodated in a thermally insulated housing. This reduces the susceptibility to disturbances and the maintenance outlay which the damper fixed to the metallurgical vessel has to tolerate in the extreme environmental conditions. In particular, the service life of the pneumatic cylinders is thereby increased.

[0033] A further subject of the application is a metallurgical vessel with a tapping hole channel and a damper according to the application fixed on the metallurgical vessel, wherein the longitudinal axis of the tapping hole channel is as far as possible parallel to the axis of rotation. For a damper according to the application installed in this way, the advantages described above arise. The damper can be fixed on the metallurgical vessel directly or indirectly. Preferably, the damper is fixed in a releasable manner. It can be fixed on the metallurgical vessel indirectly, for example, via a carrier on the metallurgical vessel. The carrier for the damper according to AT 408 965 B can be used for the damper according to the application, for example. This allows the damper according to AT 408 965 B to be retrofitted as a damper according to the application. In such a case, the connections for the supply lines present on the existing carrier can be used unchanged by the corresponding design of the damper.

[0034] The damper according to the application can of course have a frame similar to the theory of AT 408 965, which carries the damper components, wherein this frame carrying the damper components is itself fixed on the metallurgical vessel in a releasable manner.

[0035] A further subject of the application is a method for pneumatically closing a tapping hole channel of a metallurgical vessel with respect to the outflow of slag by means of a gas flow provided from at least one gas flow outlet, wherein the at least one gas flow outlet arranged on a swivel arm is positioned into a sealing position in front of the tapping hole of the tapping hole channel, characterized in that for this the swivel arm is swiveled into the sealing position in front of the tapping hole with a swivel movement, wherein the swivel movement takes place in a plane as far as possible perpendicular to the longitudinal axis of the tapping hole channel.

[0036] For known dampers as described in DE 26 39 712 and AT 408 965 B, the swivel arm is swiveled in front of the tapping hole in such a way that the distance between the gas flow outlet and the tapping hole decreases continuously along the longitudinal axis of the tapping hole channel until the sealing position is reached.

[0037] The swivel movement takes place here in the plane of the longitudinal axis of the tapping hole channel. The gas flow outlet approaches the tapping hole virtually from the front in the direction of the longitudinal axis of the tapping hole channel.

[0038] In contrast, according to the application, the swivel takes place in such a way that the swivel movement takes place in a plane as far as possible perpendicular to the longitudinal axis of the tapping hole channel. The gas flow outlet approaches the tapping hole or the longitudinal axis of the tapping hole channel virtually from the side.

[0039] "as vertically as possible" includes not only vertical but also deviations from the vertical of up to + / - 5°, such slight deviations from the orthogonal being possible in operation without limiting the functional capability to an unacceptable extent.

[0040] In such a method, the position space required for the realization of the swiveling movement outside the outer contour of the metallurgical vessel is less for a slag stopper arranged on the metallurgical vessel than in DE 26 39 712 and AT 40 89 65 B. Thereby, it is also possible to use in cases in which the operation of the slag stopper according to DE 26 39 712 and AT 40 89 65 B cannot be carried out due to the narrow position space situation between the tapping hole and the tundish.

[0041] The gas flow outlet is positioned in the tapping hole support before the tapping hole, that is to say outside the metallurgical vessel, for example at a distance of 30 to 100 mm. The gas flow outlet is oriented here in the direction of the tapping hole.

[0042] In the sealing position, the longitudinal axis of the tapping hole channel and the longitudinal axis of the gas flow are preferably substantially coaxial. For the best possible aerodynamic closure of the tapping hole channel, it is important that such a gas flow is introduced centrally, symmetrically about the edge of the tapping hole.

[0043] If there is only one gas flow outlet, this is preferably positioned centrally before the tapping hole, with the longitudinal axis of the tapping hole channel and the longitudinal axis of the gas flow outlet being substantially coaxial. The gas flow flowing out of the gas flow outlet, the longitudinal axis of which is substantially coaxial with the longitudinal axis of the gas flow outlet, will then also be substantially coaxial with the longitudinal axis of the tapping hole channel.

[0044] If there are multiple gas flow outlets, these are preferably positioned centrally before the tapping hole in such a way that the gas flow is substantially coaxial with the longitudinal axis of the tapping hole channel.

[0045] Since the swivel arm necessarily enters into the flow of the metal melt and / or the flow of the slag flowing out of the tapping hole before the tapping hole channel can be closed aerodynamically in the swiveling movement, liquid material splashes in the direction beside the longitudinal axis of the tapping hole channel. The splashes can freeze on the equipment components that are hit by the splashes, which is referred to as encrustation. The encrustation can also occur on the slag stopper and in the surroundings of the tapping hole, for example on the tapping hole support. The solid encrustation can cause problems when positioning the gas flow outlet, for example because it limits the swiveling movement before the set sealing position is reached. A so-called horn consisting of encrustation is formed on the tapping hole, for example, which increases in each tapping process in the course of the conventional method.

[0046] Compared with DE 26 39 712 and AT 40 89 65 B, the danger of clogging obstructing the planned positioning of the gas flow outlet from the taphole channel is reduced during the method according to the application. The reason for this is that, for example, a partially formed trumpet is pushed aside and knocked off when approached laterally by the swing arm. Maintenance outlay is thereby reduced and problems caused by clogging when pneumatically closing are mitigated.

[0047] According to a preferred embodiment, during the pneumatically closing of the taphole channel, gas flows from exhaust openings present in the surroundings of at least one gas flow outlet in the swing arm. This prevents clogging in the surroundings of the gas flow outlet.

[0048] A further subject of the application is a signal processing means with machine-readable program code, characterized in that the program code has regulating instructions for carrying out the method according to the application.

[0049] A further subject of the application is a machine-readable program code for a signal processing means, characterized in that the program code has regulating instructions which cause the signal processing means to carry out the method according to the application.

[0050] A further subject of the application is a storage medium with the machine-readable program code according to the application stored thereon. BRIEF DESCRIPTION OF DRAWINGS

[0051] The application is described below by means of the schematic, exemplary drawings of embodiments. Therein:

[0052] Figure 1 and 2 A conventional pneumatic closing of the taphole channel is shown;

[0053] Figure 3 and 4 An embodiment of the pneumatic dam according to the application in the starting position is shown in different views;

[0054] Figure 5 A cross section of an embodiment of the swing arm according to the application is shown;

[0055] Figure 6 An embodiment of the pneumatic dam according to the application in the sealing position is shown in as far as possible similar views; Figure 3 and 4 An embodiment of the pneumatic dam according to the application in the sealing position is shown in as far as possible similar views;

[0056] Figure 7 A swing arm with an arm module and a gas flow-out module is shown schematically;

[0057] Figure 8 A gas outflow module with nozzle head elements and gas outflow openings is shown; and

[0058] Figure 9a and 9b An embodiment of a valveless gas supply concept for a gas delivery channel is shown schematically. DETAILED DESCRIPTION

[0059] Example

[0060] Figure 1 and 2 The pneumatic closing of a tapping channel according to DE 26 39 712 is shown. During tapping, the metal melt 2 flows out of the metallurgical vessel 1, here a steelworks converter, through the tapping channel 3. The tapping opening 4 is in the tapping support 5. The starting position is shown here, since the slag 6 has not yet flowed out. A gas outflow opening 8 is arranged on the swivel arm 7. The swivel arm 7 can be swiveled about the swivel axis 9 by means of the swivel drive 10. The longitudinal axis 11 of the gas outflow opening 8 in the plane of the drawing is perpendicular to the swivel axis 9. In Figure 2 The sealing position occupied by means of the swivel drive 10 is shown in the middle. The longitudinal axis 11 of the gas outflow opening 8 is coaxial with the longitudinal axis of the tapping channel 3. The gas outflow opening 8 is in the tapping opening 4 in the tapping support 5. For the pneumatic closing, gas flows from the gas outflow opening 8 into the tapping channel 3, which is shown by the arrows. This gas flow also entrains air through the annular gap 12 around the gas outflow opening 8 centrally positioned in the tapping opening 4, which is shown by the arrows.

[0061] Figure 3 A pneumatic stopper according to the invention is shown. The swivel arm 13 has a gas outflow opening on its end. The gas delivery channel running in the swivel arm 13 is not shown. The drawn longitudinal axis 14 of the gas outflow opening is parallel to the swivel axis 15. The swivel drive is arranged inside the housing 16 and is not shown additionally. The housing 16 can be thermally insulated.

[0062] Figure 4 A further view of the situation shown in Figure 3

[0063] In the two attached Figure 3 and 4 A tapping support 17 with a tapping opening of a metallurgical vessel on which a stopper according to the invention is arranged is also shown in the two attached

[0064] ​Figure 5 The relationship of the longitudinal axis 14 of the gas outlet in the swivel arm 13 relative to the swivel axis 15 is shown schematically in a sectional view. In the swivel arm 13, a gas-conducting channel 23 extends, which opens into the gas outlet 19.

[0065] In Figure 3 and 4 the slag stopper is in a starting position. Figure 6 The situation is shown schematically in a sectional view in which the slag stopper is in a sealing position after it has been swiveled in a plane that is as perpendicular as possible to the longitudinal axis of the tapping opening 24. In the sealing position, the gas outlet is positioned in front of the tapping opening 24.

[0066] Figure 7 A section of the swivel arm 13 is shown schematically in a sectional view, which section comprises an arm module 26 and a gas-outlet module 27 that is fixed in a releasable manner on the arm module 26.

[0067] Figure 8 A nozzle head element 29 that is built into the gas-outlet module 27 is shown schematically in a sectional view, which nozzle head element has a plurality of gas channels 30a, 30b, 30c as gas outlets. Further gas outlets in the nozzle head element 29 are outlined, but not labeled. Exhaust openings 31a, 31b, 31c are shown in the surroundings of the gas outlets; further exhaust openings in the nozzle head element 29 are outlined, but not labeled.

[0068] Figure 9a It is shown schematically how, in the sealing position, the gas supply line 32 is connected to the gas-conducting channel 23 in the swivel arm 13 via a connecting channel 34 in the swivel shaft 35 that is arranged eccentrically relative to the swivel axis 15, without a valve.

[0069] Figure 9b It is shown schematically how, in the position in which the swivel arm 13 has been swiveled by approximately 90°, the connecting channel 34 is no longer in communication with the gas supply line 32. Figure 9a In a position in which the swivel arm 13 has been swiveled by approximately 135°, the connecting channel 34 is no longer in communication with the gas supply line 32.

[0070] List of reference signs:

[0071] 1 metallurgical vessel

[0072] 2 metal melt

[0073] 3 tapping opening channel

[0074] 4 tapping opening

[0075] 5 tapping opening support

[0076] 6 furnace slag

[0077] 7 swivel arm

[0078] 8 gas flow outlet

[0079] 9 swivel axis

[0080] 10 swivel drive

[0081] 11 longitudinal axis of the gas flow outlet

[0082] 12 annular gap

[0083] 13 swivel arm

[0084] 14 longitudinal axis of the gas flow outlet

[0085] 15 swivel axis

[0086] 16 housing

[0087] 17 slag outlet support

[0088] 18 slag outlet channel

[0089] 19 gas flow outlet

[0090] 23 gas delivery channel

[0091] 24 slag outlet

[0092] 26 arm module

[0093] 27 gas flow-out module

[0094] 29 nozzle head element

[0095] 30a, 30b, 30c gas channel

[0096] 31a, 31b, 31c gas outlet

[0097] 32 gas supply line

[0098] 34 connection channel

[0099] 35 swivel shaft

[0100] CITED LIST:

[0101] PATENT LITERATURE

[0102] AT 408 965 B

[0103] DE 26 39 712

Claims

1. Pneumatic slag stopper for pneumatically closing a tapping channel (18) of a metallurgical vessel with respect to the outflow of slag by means of at least one gas stream directed into the tapping channel (18) from at least one gas stream outlet (19), wherein the gas stream outlet (19) is arranged on a swivel arm (13) which can be swiveled about a swivel axis (15) by means of a swivel drive and which has a gas delivery channel (23) which opens into the at least one gas stream outlet (19), wherein the longitudinal axis (14) of the at least one gas stream outlet is as far as possible parallel to the swivel axis (15), and wherein the gas stream stops the outflow of slag or entrains the flow of a metal melt with slag in the case of an open tapping opening (24) of the tapping channel (18). The distance of the gas stream outlet (19) from the swivel axis (15) can be adjusted. The maximum swivel angle can be set. The swivel arm (13) comprises at least one arm module (26) and at least one gas stream outlet module (27), 2. The aerodynamic skimmer according to claim 1, characterized in that wherein the gas stream outlet module (27) contains the at least one gas stream outlet (19) and is fixed in a releasable manner on the arm module (26).

3. The aerodynamic skimmer according to claim 1 or 2, characterized in that There are a plurality of gas stream outlets (19).

4. The aerodynamic skimmer according to claim 1 or 2, characterized in that One or more gas stream outlets (19) are configured as one or more gas channels in a nozzle head element (29) which can be inserted into the swivel arm (13) or the gas stream outlet module (27). The position of the nozzle head element (29) can be aimed by means of an adjustment element.

5. The aerodynamic skimmer according to claim 1 or 2, characterized in that Only in the sealing position is a gas supply line (32) connected to the gas delivery channel (23) without a valve, at least by means of a connection channel (34) which is eccentrically arranged in the swivel shaft (35).

6. The aerodynamic skimmer according to claim 4, wherein, There are a plurality of exhaust openings in the surroundings of the at least one gas stream outlet (19) in the swivel arm (13).

7. The aerodynamic skimmer according to claim 6, characterized in that The swivel drive is free of a transmission.

8. The aerodynamic skimmer according to claim 1 or 2, characterized in that The swivel drive comprises at least one crankshaft and at least one pneumatic cylinder for driving the crankshaft.

9. The aerodynamic skimmer according to claim 1 or 2, characterized in that The swivel drive is arranged in a thermally insulated housing (16).

10. The aerodynamic skimmer according to claim 1 or 2, characterized in that There are a plurality of exhaust openings in the gas stream outlet module (27).

11. The aerodynamic skimmer according to claim 1 or 2, characterized in that The longitudinal axis of the tapping channel (18) is as far as possible parallel to the swivel axis (15).

12. The aerodynamic skimmer according to claim 1 or 2, characterized in that 15. Method for pneumatically closing a tapping channel (18) of a metallurgical vessel with respect to the outflow of slag by means of a gas stream provided from at least one gas stream outlet (19), 13. The aerodynamic skimmer according to claim 4, wherein, wherein the at least one gas stream outlet (19) which is arranged on a swivel arm (13) is positioned into a sealing position in front of a tapping opening (24) of the tapping channel (18), 14. Metallurgical vessel (1) having a tapping hole channel (18) and a slag dam according to any one of claims 1 to 13 fixed to the metallurgical vessel (1), characterized in that, wherein the swivel arm (13) is swiveled into the sealing position in front of the tapping opening (24) with a swivel movement, wherein the swivel movement takes place in a plane which is as far as possible perpendicular to the longitudinal axis of the tapping channel (18), ​ ​ ​ and wherein the slag tap (24) at the end of the slag tap channel (18) is open for the outflow of slag or the metal melt flow entraining slag to be blocked by a gas flow.

16. The method of claim 15, wherein, During the pneumatic closing of the slag tap channel (18), gas flows from exhaust openings present in the surroundings of the at least one gas flow outlet (19) in the rotary arm (13).

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