EP0621097B1 - Set of ceramic elements for a casting gate and method of changing this set - Google Patents

Abstract

Set of ceramic (refractory) elements for a casting gate (10), comprising a metallic reinforcement (12) mounted on a metallurgical vessel (1), a stationary ceramic plate (14) including a port (14a), a movable ceramic plate (16) including a port (16a), a collector nozzle (42), displacement means for displacing the movable plate (14) with respect to the stationary plate (16) so as to control the covering-over of the port of the stationary plate by the port of the movable plate. Pressure means (26) make it possible to press the movable plate against the stationary plate, a stationary ceramic plate (14) and a movable ceramic plate (16) and the collector nozzle (42) are capable of being linked together so as to constitute a set which may be introduced into and/or removed from the casting gate (10) in a single operation. <IMAGE>

Description

The invention relates to a set of refractory elements, in particular for a shutter of casting, said casting shutter comprising a metal frame mounted on a metallurgical container, at least one fixed refractory plate, comprising at least one pouring orifice, at least one movable refractory plate, comprising at least one pouring orifice, at least one collecting nozzle made integral with the movable plate, displacement means for displacing said at least one movable plate by relative to said at least one fixed plate so as to control the recovery of the orifice of the fixed plate and the movable plate; means of pressure which allow to clamp said at least one movable plate against said at least one fixed plate (known for example by: Stahl und Eisen 94 (1974) No. 2, pages 70-72).

In a device of this type, the metal parts of the shutter (frame metallic in particular) generally have a lifespan of several hundred or even of several thousand flows. However, the refractory elements (fixed plates and mobile, as well as the pouring nozzle) have a lifetime of a few pourings and therefore must be changed frequently.

Two methods are currently used to change these refractories.

According to a first method, each refractory element is changed individually. In certain embodiments, the collecting nozzle can be reached from outside the metal frame but access to the plates to be changed requires opening this metal frame. For example, the flow shutter has a door mounted on hinges. This door can be opened to give access to the refractories. Each refractory plate is removed individually and replaced with a new plate (with or without metal casing). This method is well suited when the elements refractories to handle are light enough to be easy to replace manually and provided that the access and ambient conditions allow the operator has easy and safe access.

On the other hand, in the case of large shutters, such as those used for steel furnaces, converters or large ladles, each element refractory can reach a weight of several tens of kilos. Moreover, particularly in the case of ovens and converters which, unlike pockets and distributors, cannot be moved outside their working environment, the change of refractory elements must be carried out on site under conditions very painful for the operator, especially due to the temperature. These conditions are further exacerbated because one cannot usually wait for the cooling of the shutter because the time required to change plates, which involves a production stoppage, therefore a loss, must be minimized. The conditions of work are therefore particularly strenuous.

We could consider assisting operators with tools such as robots or manipulators. For such tools, the weight is not a disadvantage. The postman critical consists of the number of manipulations to perform. Time to handling required to change plates using a manipulator would be far superior to what an operator would need to make the same change manually. Each gripper must be adapted to the object to handle. Such a solution would therefore be extremely expensive, complex and long.

According to a second known method, the complete casting shutter is removed from the container and replaced by a new shutter containing new refractories. This method also has many disadvantages. Indeed the complete shutter weighs much more than the refractory to exchange, for example twenty times more. So, if the refractories weigh 100 kg, it will be necessary to handle a two-ton element, which requires powerful tools and increased handling time.

It is also necessary to disconnect and reconnect the cylinder which is used to the moving plate drive, remove and replace the various shields of protection, etc ... In total, the time required and the number of operations are increased. On the other hand, the shutter containing the used refractories must be transported in a workshop where used refractories are replaced by refractories new. The working conditions are then easier, in particular as regards temperature and accessibility. Time is also a less critical factor because that production can continue during this time. However the number of operations to be carried out to exchange the refractory elements remains the same and more transport and the workshop must be financed.

The present invention relates to a set of refractory elements comprising the refractory elements to be exchanged in a flow shutter which remedies disadvantages of the two methods described above. Its purpose is also a method for replacing this set of refractory elements.

The set of refractory elements according to the invention is characterized in that the nozzle collector is secured to the movable plate and in that said at least one plate fixed refractory and said at least one movable refractory plate are capable of being linked between them so as to constitute a set which can be introduced into and / or removed from the shutter in a single operation.

The method of replacing the set of refractory elements of a flow shutter, said shutter comprising a metal frame mounted on a container metallurgical, at least one fixed refractory plate comprising at least one orifice, at the at least one movable refractory plate comprising at least one orifice, means for movement to move the movable plate relative to the fixed plate so as to order the covering of the orifice of the fixed plate and of the movable plate; of pressure means which allow the movable plate to be clamped against the fixed plate characterized in that one sets up and / or removes the refractory clearance in a single surgery.

In a first step, the set of used refractories is removed in a single operation, and in a second step we put back a new set of new refractories. he it follows that a single gripper and a single movement are sufficient, whereas according to the prior art, a gripper and a specific movement by refractory element were necessary. The handling time is greatly reduced because the handling of each of the elements is replaced by a single overall handling. Automation is made easier by the uniqueness of the movement. The number of manipulations to be performed is reduced in a ratio of 2 to 3.

Because handling is faster and simpler, it is possible to perform it on site (in situ) without having to use the second method of the prior art previously described in which the entire shutter is removed for be dismantled in a special workshop. As a result, the benefit of the first method is retained. The weight of the part to be handled is limited to the weight of the refractory elements possibly associated with a metal casing directly mounted on each of these elements. This is advantageous because the handling must not be adapted to an excessively heavy load.

• la figure 1 est une vue d'ensemble d'un convertisseur et d'un obturateur à tiroir monté sur ce convertisseur ;
• la figure 2 est une vue d'ensemble en coupe longitudinale d'un obturateur de coulée, tel que celui représenté sur la figure 1 ;
• la figure 3 est une vue en coupe selon a plan perpendiculaire à celui de la figure 1 et qui montre le détail des moyens de liaison de la plaque réfractaire fixe et de la plaque réfractaire mobile ;
• la figure 4 est une vue de l'obturateur des fig. 2 et 3 représenté dans une autre position.
• la figure 5 est une vue schématique d'une variante de réalisation dans laquelle les moyens de liaison sont disposés sur l'enveloppe des plaques réfractaires ;
• la figure 6 est une variante de réalisation dans laquelle les moyens de liaison sont situés sur l'enveloppe métallique de la plaque fixe et sur un cadre dans lequel est enchâssée la plaque mobile ;
• la figure 7 est une vue de l'extrémité d'un préhenseur destiné à être utilisé dans une variante du procédé de l'invention ;

Other characteristics and advantages of the present invention will appear on reading the following description of embodiments given by way of illustration and in no way limitative with reference to the appended figures in which:

• Figure 1 is an overall view of a converter and a slide valve mounted on this converter;
• Figure 2 is an overall view in longitudinal section of a flow shutter, such as that shown in Figure 1;
• Figure 3 is a sectional view along a plane perpendicular to that of Figure 1 and showing the detail of the connecting means of the fixed refractory plate and the movable refractory plate;
• Figure 4 is a view of the shutter of Figs. 2 and 3 shown in another position.
• Figure 5 is a schematic view of an alternative embodiment in which the connecting means are arranged on the envelope of the refractory plates;
• Figure 6 is an alternative embodiment in which the connecting means are located on the metal casing of the fixed plate and on a frame in which is embedded the movable plate;
• FIG. 7 is a view of the end of a gripper intended for use in a variant of the method of the invention;

FIG. 1 shows an overview of a converter 1 for the development of steel. A drawer shutter, designated by the general reference 10, is fixed under the converter 1. The steel contained in this converter is poured into a pocket 3 through a tap hole.

There is shown in Figure 2 a sectional view of the drawer shutter 10 mounted on the converter 1. This shutter consists of a metal frame 12 fixed on the outside wall of the converter. In this frame we find a set of two plates, namely a fixed plate 14 and a movable plate 16. Each of these plates has an orifice, respectively 14a, 16a for the passage of the metal. Of pressure means press the movable plate 16 against the fixed plate 14 and this one against a plate 36 mounted in a recess of the frame 12. These pressure means will be described in more detail with reference to FIG. 3.

The fixed plate is placed in a frame, said frame for driving the fixed plate 20, and the movable plate in a drive frame 22 of the movable plate 16. The rod 44 of the cylinder is retained in a housing of the drive frame of the movable plate 22. The jack allows the movable plate to be moved on the fixed plate.

This displacement makes it possible, in a known manner, to vary the overlap of the orifices 14a and 16a of the two plates so as to control or completely stop the passage metal. It will be noted that, in the example shown, the shutter comprises in all three plates, namely the junction plate 36, the fixed plate 14 and the plate mobile 16. But only the fixed plates 14 and mobile 16 are working plates which support erosion on contact with liquid metal. On the contrary, the junction plate 36 does not see steel in the sense that it is only changed when converter 1 is empty. Although, in the example shown, the drawer shutter has two work plates only in addition to the junction plate, it could include more, for example three or more.

By set of refractory elements is meant, in the example shown, the fixed plate 14, possibly surrounded by a metal casing 38, and the associated movable plate 16 to the casting nozzle 42, the plate 16 and the casting nozzle 42 being mounted in a metal casing 40. On the other hand, the refractory set does not include the junction plate 36 fixed to the internal nozzle 36a.

The envelope 40 assembles the movable plate 16 and the nozzle 42. It provides the assembly sufficient rigidity to serve as a bearing surface for pressure means which will be described later. It further comprises a shield 40a which protects against radiation and projections.

The weight of the refractory set is reduced to the minimum compatible with these functions. There is shown in Figure 3, a sectional view of the embodiment of Figure 2 along a perpendicular plane. This figure shows the detail of the pressure means, generally designated by the general reference 26. They include a lever 100. At one end the lever is fixed to a torsion bar 102 shown in section transverse. At its other end, the lever 100 is applied to a slide 104. The slide 104 is fixed to the metal casing 40. The force of the lever is transmitted to the plate 16, then to plate 14 which is supported on the junction plate 36. A static sealing is thus ensured between the fixed plate 14 and the junction plate 36 and a dynamic seal is ensured between the plates 14 and 16. It will be noted that the means for clamping the fixed plate against the junction surface of the pouring orifice are the same as the pressure means for pressing the fixed plate 14 against the movable plate 16. The same means therefore fulfill two distinct functions.

According to the invention, the metal casing 38 which surrounds the fixed plate 14 has a housing 38a. A tongue 106 is fixed to the metal casing 40 which surrounds the movable plate 16 and the collecting nozzle 42. This tongue 106 comes lock in the housing 38a. The tongue 106 and the housing 38 constitute the means for linking the refractory elements so that they form a clearance which can be inserted and / or removed in a single block, and therefore in a single operation of the shutter 10. More specifically, in the example shown, the game comprises no only the fixed and movable plates themselves, but also the envelopes 38 and 40 and the nozzle 42. It is this assembly which is introduced and / or removed in a single surgery. It is true that the weight to be handled is increased compared to the weight of refractory only. However, this increase in weight remains reasonable.

Returning to FIG. 2, we will now describe in detail the means for securing the frame 20 for driving the fixed plate either with the frame 1 or with the frame for driving the movable plate 22. These means consist of a lock with 2 positions 50. This lock is mounted on the frame 20 for driving the fixed plate. In a first position, shown in Figure 1, it enters a housing 51 of the frame 2. In its other position it enters a housing 3 provided in the drive frame 22 of the movable plate. In the first position it immobilizes the drive frame of the fixed plate relative to the frame and, in its second position, relative to the drive frame of the movable plate. The cylinder presents sufficient travel to move the set of two frames 20 and 22 sufficiently to release the set of refractory elements from the grip of the pressure means of the fixed plate against the junction surface of the pouring orifice.

Thanks to the two-position lock, the same means, namely the cylinder achieves successively two distinct functions. On the one hand it allows to move the plate movable on the fixed plate (first position of the latch 50). On the other hand it is used during the extraction of the part to be changed from the installation of a new fixed plate. For this the lock is placed in its second position, which allows to move with one blocks the fixed plate drive frame and the plate drive frame mobile joined together by the bolt 50. The set of refractory to be changed is moved at the same time as frames 20 and 22.

There is shown in Fig 4, the drawer of Fig 3 in the open position. We notice that the latch 50 is placed in said second position in which it secures the frame drive 20 of the fixed plate 14 with the drive frame 22 of the plate mobile 16. the jack 28, the rod 44 of which is connected to the block 22 for driving the movable plate, was used to push the assembly constituted by the two frames drive (fixed and mobile) and the plates housed in the openings of these frames (fixed plate 14 and movable plate 16). This movement was continued enough to that the set of refractories be entirely freed from the action of pressure means 26.

The openings of the frames 20 and 22 being superimposed, the set of refractories can be freely removed without having to open a door as is generally done in prior art devices. No connection or disconnection is required because the cylinder rod remains fixed to the frame during these operations drive plate. The set to change, constituted as we said previously of the fixed refractory plate 14, of the movable refractory plate 16, of the casing 38 of the fixed plate 14 and the casing 40 of the movable plate 16 is evacuated in a single operation by means of a gripper. A set of replacement, comprising new refractories, is then brought by means of the same different manipulator or gripper.

The jack is then actuated to pull the assembly which penetrates laterally relative to to the pouring opening under the locking means 26, which positions the two plates without further operation. The fixed plate 14 is slid under pressure means 30 before the fixed plate 14 begins to cover the pouring opening.

We see that this embodiment has a double advantage. On the one hand it allows, according to the invention, to change the set of refractories in a single operation at instead of having to successively manipulate the various refractory plates. this is an important advantage in the case where the set of refractories has two plates as in the example shown. This characteristic saves time important. This time saving is increased when two grippers are used, one for remove the used refractories, the other to install a set of new refractories. The two grippers do not perform the same function because it is easier to remove the set of used refractories than to install a new set of refractory. The gripper used for removal therefore does not need to be very sophisticated.

The fact of using two grippers makes it possible to keep ready that of the two which is used for putting in place of the new set of refractories. It can go into action as soon as the refractory used cars have been evacuated. This saves precious time, especially in the case converters for which it is desirable that the time required for the exchange refractory remains less than a few minutes.

On the other hand, the embodiment shown has yet another advantage.

Indeed, in the prior art casting shutters, access to the refractory exchanging is obtained by means of a pivoting door mounted on hinges. Before to be able to access the refractories, it is necessary to open this door. When the refractories have been changed, you must close the door before you can replace the shutter in operation. These two additional operations take time time. Furthermore, they cannot be easily automated.

It can be seen that, according to the embodiment shown, it is not necessary to open and to close a door to access the refractories. These are evacuated and put in place by sliding the whole to change which removes a step. Else apart from that this operation can be performed easily because it does not require manual intervention but can on the contrary be carried out in a simple manner thanks to a cylinder. It will also be noted that this cylinder is the same as that which serves, so conventional, to the regulation of the casting. It is therefore not necessary to plan additional equipment.

FIG. 5 shows an alternative embodiment of the invention. In this variant the fixed refractory plate 14 is surrounded by a metal casing 110, by example in sheet steel. The mobile refractory plate 16 is also surrounded by a metal casing made of sheet steel 112. In the example shown a nozzle is integral with this fixed refractory plate. The metal envelope of the plate fixed retractor is folded so as to constitute a flange 114. The envelope metal 112 of the movable refractory plate is folded over the flange 114 of the metal casing of the fixed refractory plate so as to constitute a slide 116. This slide constitutes the connection which makes it possible to set up and / or remove the fixed refractory plate and the movable refractory plate in a single operation of the flow shutter. It goes without saying in the case where the set of refractory plates has more than two plates, each of these plates may have an envelope clean metal, each refractory plate being made integral with the plate neighboring refractory by means of a slide similar to that which has just been described.

In a vertical handling position, the slide could allow both plates to dissociate. This disadvantage is overcome, in accordance with the invention, by fitting the runners with end-of-travel stops limiting the travel of the sliding movement. This race must however remain sufficient to allow normal operation of the shutter when the plates have been placed in place.

There is shown in Figure 6 an alternative embodiment of the device shown in Figure 5. In this variant the fixed refractory plate 14 comprises an envelope metallic 110, in an identical manner to what has been described with reference to FIG. 5.

On the other hand, the mobile refractory plate 16 and the pouring nozzle 42 are placed in a rigid metal frame 120. This metal frame has a groove 122in which houses the flange 114 of the metal casing 110 of the plate fixed refractory so as to constitute a slide, as described above.

Of course, this slide can also be equipped with limit stops.

When introducing a new set of refractories, it is necessary to maintain precisely the fixed plate in a predetermined position relative to the plate mobile. This is easily obtained, in accordance with the invention, by bonding the two plates. This bonding is destroyed by the drive means of the fixed plate during the first time the shutter is put into operation. The relative position predetermined can also be obtained by ensuring a mechanical setting strong enough to maintain the relative positions of the two plates during the handling and low enough to be destroyed by means of drives (wedge in the slide, pin between the metal frames ...).

FIG. 7 shows an alternative embodiment of the invention. In this

FIG. 7 shows an alternative embodiment of the invention. In this variant the frame is constituted by a fixed frame 60 and by a door 62 mounted on articulated hinges 64 on the fixed frame 60. The set of refractories to be exchanged is consisting of a fixed refractory plate 14 and a movable refractory plate 16. These plates have through holes arranged in alignment with each other. A manipulator 66 includes a gripper 68, the end of which can be inserted into the holes. The gripper 68 constitutes the means which makes it possible to link the plates 14 and 16 constituting the game so that they can be inserted and / or removed in one surgery. Note that in this embodiment the means which allow to link the plates together are external to the set of refractories. This is however sufficient because it is only necessary that the plates are linked together only during their handling.

Claims (16)

1. Set of refractory components, particularly for slide gate valve (10) comprising

   a metallic frame (12) mounted on a metallurgical vessel (1);

   at least one fixed refractory plate (14) having at least one opening (14a);

   at least one movable refractory plate (16) having at least one opening (16a);

   at least one pouring nozzle (42);

   means for displacing the movable plate (14) with respect to the fixed plate (16) in order to control an overlap between the openings of the fixed and movable plate;

   compression means (26) for locking the movable plate against the fixed plate;
   characterized in that said at least one fixed refractory plate (14) and said at least one movable refractory plate (16) and said at least one pouring nozzle (42) can be interconnected so as to form a set which can be introduced and/or removed with respect to the slide gate valve (10) in a single operation.
2. Set according to claim 1, characterized in that the refractory components constituting the set are interconnected by means permitting a movement of said at least one fixed refractory plate (14) relative to said at least one movable refractory plate (16), the amplitude of said movement being adequate for the operation of the slide gate valve (10).
3. Set according to one of the claims 1 or 2, characterized in that said at least one fixed refractory plate (14), said at least one movable refractory plate (16) and said pouring nozzle (42) have metal shells (38, 40), the connection between the plates being provided by said shells (38, 40).
4. Set according to claim 3, characterized in that the connection between said plates (14, 16) is ensured by sliding mechanisms fixed to said metal shells (38, 40).
5. Set according to any one of the claims 2 to 4, characterized in that it has means for locking the relative movement of said fixed refractory plate relative to said movable refractory plate in a predetermined and in particular superimposed position, said means being destroyed during the first movement of the slide gate valve.
6. Set according to claim 1, characterized in that the connection between said at least one fixed refractory plate (14) and said at least one movable refractory plate (16) is ensured by bonding, the connection by bonding being destroyed by the first movement of the slide gate valve (10).
7. Set according to claim 1, characterized in that said plates have means making it possible to maintain them in a predetermined, particularly superimposed, relative position by connecting means external of the sets of refractory plates (14, 16).
8. Set according to claim 7, characterized in that the external connection means are constituted by a gripping manipulator (66) able to grasp and/or lock the refractory component set in a relative position.
9. Method for the replacement of the set of refractory components of a slide gate valve, the latter comprising a metallic frame (12) mounted on a metallurgical vessel (1), at least one fixed refractory plate (14) having at least one opening (14a), at least one movable refractory plate (16) having at least one opening (16a), at least one pouring nozzle (42), displacement means for displacing the mobile plate (14) relative to the fixed plate (16), so as to control the overlap of the opening of the fixed plate by the opening of the movable plate, compression means (26) making it possible to lock the mobile plate against the fixed plate, characterized in that said refractory component set is installed and/or removed in a single operation.
10. Replacement method according to claim 9, characterized in that use is made of a handling tool (66) incorporating a gripper (68), which ensures a connection of the components of the refractory set at the time of the installation and/or deposition of said plates.
11. Replacement method according to either of the claims 9 and 10, characterized in that use is made of a handling tool for removing the used refractory component set and another handling tool for installing a new refractory component set, so as to reduce the time necessary for replacing the plates.
12. Replacement method according to any one of the claims 9 to 11, characterized in that the used refractory components are discharged by gravity, the components of the refractory set being connected only on their introduction into the slide gate valve.
13. Method for the replacement of refractory plates according to any one of the claims 9 to 12, characterized in that the metal shells (38, 40) are replaced at the same time as the refractory set respectively surrounding each of said plates.
14. Replacement method according to any one of the claims 9 to 13, characterized in that use is made of displacement means (28, 44) of the movable refractory plate (16) for displacing the set of refractory components into a position where it is no longer subject to the action of the compression means (26) making it possible to lock the movable plate (16) against the fixed plate (14), which frees any attachment to the slide gate valve (10), so as to permit access to the handling manipulator without opening the metallic frame (12) of the valve.
15. Replacement method according to claim 14, characterized in that use is made of a carrying frame (20) for the fixed plate (14) and a carrying frame (22) for the movable plate (16), the fixed plate carrying frame and movable plate carrying frame being joinable by means of a bolt (50) having two positions mounted on said fixed plate carrying frame (20).
16. Replacement method according to claim 15, characterized in that the fixed plate carrying frame (20) has a central opening into which is introduced the fixed plate (14), and in that the movable plate carrying frame (22) has a central opening into which is introduced the movable plate (16), the central opening of the fixed plate carrying frame and the central opening of the movable plate carrying frame being superimposed during the extraction and insertion of the refractory component set.

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