EP1054068B1 - Method and apparatus for closing and opening of a tap hole of a tiltable metallurgical vessel - Google Patents

Description

The invention relates to a method for closing and opening a tap hole tiltable metallurgical vessel, in particular a steelworks converter, the Tap hole by means of a closure device with a closure body which is from a Waiting position can be brought into a closed position and back, can be locked, and an apparatus for performing the method.

Oxygen-blowing steelwork converters have for the purpose of parting off the steel bath its own tap hole, which is located far below the mouth of the converter. When tipping of the converter in the tapping position initially slag flows from this tap hole - Erstoder Lead slag - then steel follows, with a certain amount due to the vortex effect Amount of slag - called slag - is carried away, in the end, if the converter is empty of steel, the tail slag until the converter is tipped back.

It is known for closing and opening a tap hole in a steelworks converter (DE 32 08 490 C, AT 350 090 B), a closure body with the release of a Annular gap between the closure body and the wall of the tap hole from one To bring the waiting position into a closed position covering the taphole and back, whereby, at least in the closed position, a pressurized gas in the tap hole against the Outflow direction of a melt contained in the steel plant converter is initiated.

Oxidation reactions make unwanted pig iron into steel Accompanying elements of the iron smelter are bound to oxygen and the formed oxides released in gaseous form or transferred into the slag. After freshening up elements often have to be added to the steel for deoxidation and alloying purposes that have a higher affinity for oxygen than that in the slag tied unwanted accompanying elements. The consequence of this is that such Alloy elements reduce the unwanted accompanying elements from the slag can, slagging themselves. Fresh slag can also be very aggressive compared to the refractory material of the melting pot and ladle. Out For reasons of quality and for reasons of economy, one strives to: Tapping and alloying a melt in the pan, as far as possible with the slag to prevent.

The retention of the slag when tapping the oxygen-blowing As explained above, the steelworks converter is a requirement of the metallurgists: Steel bath is tapped from the converter through the tap hole into the steel ladle, accompanying slag floats on the steel bath in the pan and influences the Steel quality negative.

Methods and devices of the type described in the introduction have been put into practice proven. The closure body leaves an annular gap with respect to the wall of the tap hole free, through the air into the interior of the metallurgical vessel due to the through the Sealing body supplied compressed gas, which is blown into the tap hole, sucked becomes. This prevents the melt from flowing out inside the vessel the tap hole is completely sealed pneumatically. With a facility of this kind you can about 50% of the total slag is retained in the converter. 20% of Total slag flows as first or preliminary slag. 30% of the total slag result from the idling slag - called vortex - that runs along with the tapping and through no facility can be influenced.

Opening and closing the tap hole with one of the above Establishments have proven themselves in practice, but the following disadvantage occurs: With the known devices, the transition from the slag outlet to the steel outlet is by means of of a ratio pyrometer which is observed during the transition from steel to slag or Slag to steel gives an impulse for the swinging in and out of the Closure body is used to close or open the tap hole. The The problem is the uniqueness of the signal. If with a compressed gas, e.g. With Nitrogen, which is blown to retain slag, is blown out of the tap hole itself. If steel also comes to the inside opening of the tap hole, it will become heavier is to enter the tap hole. It is initially mixed with slag and it forms extremely turbulent condition. However, the jet itself is caused by the compressed gas initially held back. As a result, it comes from a certain bath level above the tap hole due to the increasing pressure of the steel bath suddenly one This increasingly unstable condition topples over until there is a surge of steel fluid pours into the tap hole. The signal receiver will then respond, but it is not closed prevent part of this amount from pouring out before the closure body from the tap hole. Steel is already flowing before the tap hole is fully opened through the tap hole on the closure body. The amount of steel flowing out is in of the order of 120 to 250 kg steel and depends on the taphole condition. This Quantity pours over the closure device, which places an extraordinary burden on it and is bearded.

Even if the pivoting movement of the closure body in the known devices is started immediately after the detection of steel leakage, it moves Closure body nevertheless relatively long in the direction of the longitudinal axis of the tap hole, so that it leads to strong bearings of the Breech body comes. Only as long as no steel with the one flowing out of the tap hole Beam is carried away, there is no risk of bear formation for the facility, i.e. a material deposit on the device. Solidified slag falls after cooling relatively easy and hardly impedes the mobility of the facility.

The invention aims to avoid the disadvantages and difficulties of the prior art Technology and set themselves the task, a method and an implementation facility to create the method, which is a tapping with significantly reduced Allow slag discharge and by which a danger of fermentation is essential is reduced.

This object is achieved according to the invention in a method of the type described in the introduction solved in that the activation of the closure device depending on the amount of Metal and / or slag bath level of the metal contained in the metallurgical vessel or slag melt and depending on the tilt angle and the internal volume of the metallurgical vessel is carried out.

According to the invention, observation of the start of the escape of the melt and of the liquid metal directly at the tap hole, because at a certain height of the metal and slag bath level, there is always an escape of slag or liquid metal takes place from a certain tilt angle of the metallurgical vessel. That means with in other words, one can use the level of the bath level contained in the vessel Melt the decanting moment, from which the melt when the vessel is tilted into the Pinhole penetrates, determine; it is only necessary to adjust the height of the bathroom mirror to know the respective tilt angle and the internal volume of the metallurgical vessel in order to to activate the locking device in good time.

However, it is not necessary to measure the metal and slag bath level be, but it is sufficient, the filling weight of the metallurgical vessel or the filling amount to know the metallurgical vessel with molten metal and slag, since that Internal volume of the vessel is known. The burnout is for the internal volume refractory lining of the metallurgical vessel. It has in the Practice has shown that the level of the metal and slag bath level to a large extent from Burnout of the refractory lining of the metallurgical vessel is dependent, etc. also then when it's tipped. For the steelworker, taking the Burnout no effort, especially since the increase in burnout from batch to batch the steelworker is familiar with himself.

A preferred procedure is characterized in that when the metallurgical vessel first the tap hole by means of the closure device just before Drainage of a slag melt is closed that when the open the taphole just before the molten metal runs out and that the tap hole is closed again at the tapping end of the molten metal becomes.

When activating the closure device, the time period for the movement is advantageous the locking device from the waiting position to the closed position and vice versa the closed position into the waiting position.

A device for performing the closing method according to the invention and opening a tap hole of a tiltable metallurgical vessel, in particular one Steelworks converter, with one that can be actuated with an actuating device Closure device that from a waiting position, in which the tap hole is open, in a This results in the closed position in which the taphole is closed and can be moved back characterized in that the metallurgical vessel is equipped with a tilt measuring device, and the actuating device for the closure device with the tilt measuring device is coupled.

A preferred embodiment is characterized by a regulating or control unit, into which the internal volume of the metallurgical vessel and the filling quantities of metal and Data relating to slag can be entered.

The invention is shown below with reference to one in the drawing Embodiment explained in more detail, wherein Fig. 1 is an overall side view of a Steel plant converter trained metallurgical vessel and FIGS. 2 and 3 each illustrate a section through a steelworks converter on an enlarged scale, u.zw. Fig. 2 through a freshly delivered steel mill converter and Fig. 3 is a section through a steel mill converter with severe burnout, i.e. relatively close to one Neuausmauerung.

The steelworks converter 1 shown in FIG. 1 has a refractory inside Lining 2 provided steel jacket 3, which is mounted in a support ring 4. This is with diametrically opposite trunnions 5 supported on the foundation 6 Converter bearings 7 mounted, one of the trunnions 5 with the large one Converter tilt drive gear 8 is provided. For tilting the steelworks converter 1 serve schematically illustrated drive motors 9.

In order to detect the exact tilt angle of the steelworks converter 1, the Steelworks converter equipped with a tilt measuring device 10 which e.g. on the trunnion 5 or on the transmission 8 is provided.

On one side of the steelworks converter 1 in a plane 11 perpendicular to the tilting or A pinhole 13 is arranged in the center between the pivot pin 5 in the center of rotation 12 a closure device 14 can be closed.

For the purpose of closing the tap hole 13, a closure body 15 is below Release of an annular gap 16 between the closure body 15 and the inner wall 17th the tap hole 13 from a waiting position I into a tap hole 13 concealing Locking position II and movable back, as for example in AT 350 090 B. is described. In the closed position II is a compressed gas via line 18 in the Tap hole against the outflow direction contained in the steelworks converter 1 Metal melt 19 and / or slag melt 20 can be introduced, whereby the metal melt 19 or the slag melt 20 can be retained in the steelwork converter 1. An actuating device, for example, is used to move the closure body 15 a pressure medium cylinder 21, which is supplied with pressure medium via lines 22, 23. In Control valves 24, 25, 26 are installed in each of the pressure medium lines 18, 22, 23.

According to the invention, the actuating device 21 for the closure device 14 with the Tilt measuring device 10 coupled, etc. such that when the steel mill converter is tilted 1 initially just before reaching the tap hole 13 through the slag melt 20 Tap hole 13 is closed by means of the closure device 14 and when tilting further of the steelworks converter 1 just before the tap hole 13 is reached by molten steel 19 is opened. At the tapping end of the molten metal, the tap hole 13 is again locked.

For determining the decanting instant, i.e. the beginning of the overflow of slag or steel melt 20 or 19 over the decanting point 27 - this lies on the cutting line the inner wall 28 of the refractory lining 2 with the inner wall 17 of the tap hole 13-is it is important to determine the internal volume of the steelworks converter 1 as well as the filling quantity or the Filling weight or the heights 29, 30 of the bath level 31 of the slag melt 20 and the To know bath level 32 of the molten steel 19. According to the representations in FIGS. 2 and 3, in which the refractory lining 2 once in new condition (Fig. 2) and once after a large number of batches, that is to say with a considerable burnout (FIG. 3) , the height of the steel bath level 32 and the height of the slag level 31 fluctuate compared to the tap hole 13 despite always the same filling quantity or the same Fill weight to a significant extent due to the changing internal volume of the Steelworks converter 1.

2 and 3 additionally show the levels 29 ', 30' of the metal and slag bath levels 32, 31 with the steelwork converter 1 tilted, and it can be seen that both the slag bath level 31 and the steel bath level 32 with a steelworks converter 1 with burnout due to the larger internal volume of the steelworks converter 1 at completely different tilting angles α ₁ ', α ₂ ' the overflow edge, ie the decanting point 17 of the tap hole 13 is reached than in a steelworks converter 1 which has been newly lined.

α₁ = Kippwinkel des Stahlwerkskonverters 1, bei dem der Schlackenbadspiegel 31 den Dekantierpunkt 27 erreicht,

α₂ = Kippwinkel des Stahlwerkskonverters 1, bei dem der Stahlbadspiegel 32 den Dekantierpunkt 27 erreicht.

Fig. 3 - Stahlwerkskonverter 1 mit Ausbrand:

α₁' = Kippwinkel des Stahlwerkskonverters 1, bei dem der Schlackenbadspiegel 31 den Dekantierpunkt 27 erreicht,

α₂' = Kippwinkel des Stahlwerkskonverters 1, bei dem der Stahlbadspiegel 32 den Dekantierpunkt 27 erreicht.

2 and 3 mean
Fig. 2 - newly lined steelwork converter 1:

α ₁ = tilt angle of the steelworks converter 1, at which the slag bath level 31 reaches the decanting point 27,

α ₂ = tilt angle of the steelworks converter 1, at which the steel bath level 32 reaches the decanting point 27.

Fig. 3 - steel mill converter 1 with burnout:

α ₁ '= tilt angle of the steelworks converter 1, at which the slag bath level 31 reaches the decanting point 27,

α ₂ '= tilt angle of the steelworks converter 1, at which the steel bath level 32 reaches the decanting point 27.

In the case of a steelworks converter 1 with burnout, the steelworks converter 1 has to be tilted by the angle α ₁ '> α ₁ or α ₂ '> α ₂ so that the slag melt 20 or the metal melt 19 each reach the decanting point 27.

The coupling of the tilt angle α with the actuator 21 for the Closure body 15 is realized via a regulating or control unit 33, in which the Internal volume of the steelworks converter 1, i.e. the fire of the refractory lining 2, and the fill quantities of molten steel and slag can be entered. At the Tilting the steelworks converter 1, the valves 24, 25 and 26 depending on the in the regulating or control unit 33 entered data relating to the tilt angle, internal volume and filling quantity actuated, so that the closure device at the right time while avoiding unwanted leakage of slag melt 20 or Minimization of slag melt leakage during metal tapping, i.e. Stahlabstich, is operated.

The invention is not limited to the illustrated embodiment, but can be modified in various ways. For example, it is also possible in addition to the activation of the closure device 14 by the control or Control unit 33 the tapping beam, which emerges through the tap hole 13, with a suitable Signal sensor to determine a difference between through the tap hole 13 emerging steel melt 19 and slag melt 20 to observe, and so on electrical and / or electromagnetic path another criterion for activation to have the closure device 14 available. It is also possible that To design taphole closure device 14 in a different way, for example by the Closure body 15 with directions of movement lying in different surfaces the waiting position I is moved to the closed position II and back, thereby the Residence time of the closure body 15 in the immediate vicinity of the through the tap hole 13th emerging beam and in the beam is greatly reduced.

The invention can be used for different tiltable metallurgical vessels with a tap hole deploy; however, the main area of application is steel mill converters.

Claims (8)

1. Method for closing and opening a tapping hole (13) of a tiltable metallurgical vessel (1), in particular a steelworks converter (1), in which method the tapping hole (13) can be closed by means of a closure device (14) having a closure body (15) which can be moved from a waiting position (I) into a closure position (II) and back, characterized in that the closure device (14) is activated as a function of the height (30, 29) of the metal and/or slag bath level (32, 31) of the molten metal or slag (19, 20) contained in the metallurgical vessel and as a function of the tilt angle (α₁, α₂) and the internal volume of the metallurgical vessel (1).
2. Method according to Claim 1, characterized in that the filling weight of the metallurgical vessel (1) is used to determine the height (30, 29) of the metal and/or slag bath level (32, 31).
3. Method according to Claim 1 or 2, characterized in that the quantity of molten metal and slag (19, 20) with which the metallurgical vessel (1) is filled is taken into account for the activation of the closure device (14).
4. Method according to Claim 1, 2 or 3, characterized in that the burn-off from the refractory lining (2) of the metallurgical vessel (1) is taken into account for the activation of the closure device (14).
5. Method according to one or more of Claims 1 to 4, characterized in that, during tilting of the metallurgical vessel (1), firstly the tapping hole (13) is closed by means of the closure device (14) just before molten slag (20) runs out, in that as the metallurgical vessel (1) is tilted further, the tapping hole (13) is opened just before molten metal (19) runs out, and in that, at the end of tapping of the molten metal (19), the tapping hole (13) is closed again.
6. Method according to one or more of Claims 1 to 5, characterized in that, during activation of the closure device (14), the time required for the closure device (14) to move from the waiting position (I) into the closure position (II), or, vice versa, from the closure position (II) into the waiting position (I), is taken into account.
7. Arrangement for closing and opening a tapping hole of a tiltable metallurgical vessel (1), in particular a steelworks converter (1), having a closure device (14), which can be actuated by an actuation device (21) and can be moved out of a waiting position (I), in which the tapping hole (13) is open, into a closure position (II), in which the tapping hole (13) is closed, and back, characterized in that the metallurgical vessel (1) is fitted with a tilt-measuring device (10), and the actuation device (21) for the closure device (14) is coupled to the tilt-measuring device (10).
8. Arrangement according to Claim 7, characterized by a control or regulating unit (33), to which data relating to the internal volume of the metallurgical vessel (1) and the quantities of metal and slag with which the metallurgical vessel is filled can be input.

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