EP1054068A2 - Method for closing and opening of a tap hole of a tiltable metallurgical vessel - Google Patents

Abstract

Process for closing and opening a tap hole (13) of a tilting metallurgical vessel (1) comprises activating the closing unit depending on the height (30, 29) of the metal and/or slag bath mirror (32, 31) of the metal and/or slag melt in the vessel and depending on the tilting angle ( alpha 1, alpha 2) and the inner volume of the vessel.

Description

The invention relates to a method for closing and opening a tap hole tiltable metallurgical vessel, in particular a steel plant converter, the Tap hole by means of a closure device with a closure body, which by 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 tilting of the converter in the tapping position initially slag flows out of this tap hole - first or Lead slag - then steel follows, with a certain amount due to the vortex effect Amount of slag - called moving 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 that covers 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 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 inside the metallurgical vessel due to the through the Sealing body supplied compressed gas, which is blown into the tap hole, sucked becomes. As a result, the melt inside the vessel is prevented from flowing out and 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 along as first or preliminary slag. 30% of the total slag result from the run-on 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 Facilities has proven itself 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 observed which occurs 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 becomes 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 pressurized gas initially held back. As a result, it comes from a certain bath level above the tap hole suddenly due to the increasing pressure of the steel bath This increasingly unstable state 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 swivel movement 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 process, which is a tapping with significantly reduced Allow slag discharge and by which a danger of fading 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 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 beginning 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 instant of decantation, 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, it is sufficient, the filling weight of the metallurgical vessel or the filling amount to know the metallurgical vessel with metal and slag melts, 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 just before the tap hole by means of the closure device 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 is the closed position, in which the tap hole 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 fill quantities of metal and Data relating to slag can be entered.

The invention is illustrated 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, etc. 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 Brick lining.

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 opposed 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 Steel mill 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 Closing 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 steelworks converter 1. An actuating device is used to move the closure body 15, for example 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 reaching the tap hole 13 by molten steel 19th is opened. At the tapping end of the molten metal, tap hole 13 is again locked.

To determine 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 - 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 Knowing the 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 the case of a steelworks converter 1 which has been re-lined.

Fig. 2 - neu ausgemauerter Stahlwerkskonverter 1:

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 a steelworks converter 1 with burnout, the steelworks converter 1 must 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. Steel tapping, 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 pickup to determine a difference between through the tap hole 13 emerging steel melt 19 and slag melt 20, 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 manner, 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)

Method for closing and opening a tap hole (13) of a tiltable metallurgical vessel (1), in particular a steelworks converter (1), the tap hole (13) being closed by means of a closure device (14) with a closure body (15) which extends from a waiting position (I ) can be brought into a closed position (II) and back, can be locked, characterized in that the activation of the locking device (14) depending on the height (30, 29) of the metal and / or slag bath level (32, 31) of the metallurgical vessel contained metal or slag melt (19, 20) and depending on the tilt angle (α ₁ , α ₂ ) and the internal volume of the metallurgical vessel (1) is carried out. A method according to claim 1, characterized in that for the determination of the Height (30, 29) of the metal and / or slag bath level (32, 31) the filling weight of the metallurgical vessel (1) is used. Method according to claim 1 or 2, characterized in that for the activation the closure device (14) the filling quantity of the metallurgical vessel (1) with metal and Slag melt (19, 20) is taken into account. A method according to claim 1, 2 or 3, characterized in that for the Activation of the closure device (14) the burnout of the refractory lining (2) of the metallurgical vessel (1) is taken into account. Method according to one or more of claims 1 to 4, characterized characterized in that when the metallurgical vessel (1) is tilted first the tap hole (13) by means of the closure device (14) just before a slag melt escapes (20) is closed, that when the metallurgical vessel (1) tilts further just before Drainage of molten metal (19), the tap hole (13) is opened, and that at Tapping the molten metal (19) the tap hole (13) is closed again. Method according to one or more of claims 1 to 5, characterized characterized in that when the closure device (14) is activated, the time period for the Movement of the closure device (14) from the waiting position (I) to the closed position (II) or vice versa from the closed position (II) to the waiting position (1) is taken into account. Device for closing and opening a tap hole of a tiltable metallurgical vessel (1), in particular a steelworks converter (1), with a an actuating device (21) actuatable locking device (14), which consists of a Waiting position (I), in which the tap hole (13) is open, in a closed position (II), in the the tap hole (13) is closed and can be moved back, characterized in that the metallurgical vessel (1) is equipped with a tilt measuring device (10), and the Actuating device (21) for the closure device (14) with the tilt measuring device (10) is coupled. Apparatus according to claim 7, characterized by a regulating or control unit (33), into which the internal volume of the metallurgical vessel (1) and the filling quantities of Data relating to metal and slag can be entered.

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