CN111480047B

CN111480047B - Door system for opening and closing a container opening of a furnace

Info

Publication number: CN111480047B
Application number: CN201880063464.3A
Authority: CN
Inventors: 麦克斯·施密特; 拉斐尔·奥尔利克
Original assignee: Strikowestofen GmbH
Current assignee: Strikowestofen GmbH
Priority date: 2017-09-28
Filing date: 2018-09-26
Publication date: 2022-07-08
Anticipated expiration: 2038-09-26
Also published as: DK3688395T3; ES2893158T3; EP3688395A1; PL3688395T3; CN111480047A; MX2020004820A; EP3462118A1; EP3688395B1; WO2019063643A1

Abstract

The invention relates to a furnace, in particular a melting and/or holding furnace, comprising: a container for receiving a melt, the container having an opening; and a door for closing and opening the opening. The oven further includes at least two first door hinges fixedly disposed relative to the door and defining a first door axis of rotation. The oven also has at least one, preferably exactly one, second door hinge, which is fixedly arranged relative to the door and at a distance from the first door rotation axis. The furnace further comprises: a first coupling device movably connecting the door to the container via a first door hinge; and a second coupling device movably connecting the door to the container via a second door hinge. It is particularly advantageous to provide exactly two first door hinges and exactly one second door hinge on the door. In this way, exactly three hinges can be used to install and guide the door.

Description

Door system for opening and closing a container opening of a furnace

The present invention relates to a furnace, and in particular to a melting and/or holding furnace for melting and/or holding metal at a desired temperature, comprising a door system for opening and closing the opening of the vessel.

Industrial furnaces, such as melting furnaces, typically include a container having a container opening to ensure accessibility to the interior of the furnace, for example for cleaning the melting chamber. Door systems provided for industrial furnaces to facilitate opening and closing of these container openings are known from the prior art. The door system must achieve a good sealing action and the container opening is closed as free as possible of any gaps, for example to ensure the efficiency of the furnace and a certain quality of the metal being melted, and to avoid heat escaping from the furnace via the container opening.

Especially when the container opening is large, the door size rises, which has a door weight, which necessitates a drive for opening and closing the door and/or a supporting door guide. In this respect, various guiding and/or driving mechanisms are known from the prior art which move the furnace door in an upwardly guided manner or vertically along guide rails by means of levers arranged on both sides during opening.

Due to thermal influences, such furnace door systems are often subjected to high loads during furnace operation. The hot molten material within the oven can cause deformation of the oven door and/or deformation of the door support surface surrounding the container opening. In addition, the solidifying molten material (such as liquid metal) or particles in the region of the vessel opening can lead to impurities and irregularities in the sealing region between the furnace door and the furnace. These deformations and impurities can cause the sealing surface of the furnace door to no longer sealingly abut the door bearing surface and can create a gap between the furnace and the closed door. The width of the resulting gap may be several centimeters and the gap may make it possible for ambient air to be undesirably sucked in or the furnace atmosphere to be undesirably discharged depending on the pressure prevailing in the furnace. This may reduce the efficiency of the process occurring in the furnace (e.g., the melting process), as increased energy consumption may be necessary to heat the furnace interior.

In view of the above, it is an object of the present invention to provide a furnace comprising a door system that minimizes leakage and maximizes furnace efficiency.

This object is achieved by a door system according to the subject matter of claim 1.

The furnace according to the invention, in particular for melting and/or maintaining metal at a desired temperature, comprises a container having an opening, for example for receiving molten material, and at least one door for closing and opening said opening. The furnace typically comprises a melting chamber, in which the metal can be melted, and/or a holding chamber, in which the molten mass can be heated to the temperature required for the process and/or held at this temperature. The furnace comprises at least one door comprising at least two first door-side joints, which are fixedly arranged with respect to the door and define, for example, a first door-side axis of rotation. The oven further comprises at least one and preferably exactly one second door-side joint, which is fixedly arranged with respect to the door. The at least one second door-side joint or exactly one second door-side joint may be provided on the door spaced from the line defined by the first door-side joint. The furnace further comprises: a first coupling device movably connecting the door to the container through a first door-side joint; and a second coupling device movably connecting the door to the container by at least one and preferably by exactly one second door-side joint. In particular, it is advantageous if exactly two first door-side connections and exactly one second door-side connection are provided on the door. In this way, the door can be installed and guided by exactly three joints. This three-point mounting has the advantage that the mounting of the door in the closed position is statically determinate. Since the sum of the forces and moments in the door and in the bearings or joints therein (which are exerted, for example, by the weight of the door) is always zero in the statically determinate configuration, stresses in the door and/or in the seat of the door are avoided. The service life of the door and the bearings can thus be increased.

Still further, the furnace may comprise: at least one first container-side connection, which is arranged fixedly in relation to the container; and at least one second container-side connection which is fixedly arranged relative to the container. The first coupling means usually comprise at least one first coupling arm which in each case connects at least one of the first door-side fittings, for example rigidly, to at least one of the at least one first container-side fittings. The second coupling means may comprise at least one second coupling arm, which connects at least one and preferably exactly one second door-side joint, for example rigidly, to at least one second container-side joint.

The at least one second door-side joint and preferably exactly one second door-side joint may define a second door-side rotation axis or center of rotation. The at least one first container-side joint may define a first container-side axis of rotation. The at least one second container-side adapter generally defines a second container-side axis of rotation. The first door-side joint, the at least one second door-side joint (preferably exactly one second door-side joint), the at least one first container-side joint and the at least one second container-side joint may be arranged and designed such that the first door-side rotational axis, the first container-side rotational axis and the second container-side rotational axis are oriented substantially parallel to one another in pairs, for example at least in one design position. In one design position, the second door-side axis of rotation is preferably also oriented parallel to the described axis of rotation. The deviation from parallelism can be no more than 10 °, preferably no more than 8 °, and particularly preferably no more than 5 °. This may have the advantage that the door system comprising the door and the articulated arm articulated thereto (which is additionally articulated to the container) is designed as a linkage, and preferably as a planar linkage. The linkage arm may be designed to have a fixed length and to swing on the container. The link arm may be further hinged to the door such that the door may be pivoted by a swinging motion. The door can thus close or open the container opening.

The at least one second door-side joint (preferably exactly one second door-side joint) may be designed as a ball-and-socket joint. This may be advantageous because the door may in this way be mounted in a statically indeterminate manner in the open state and only in the closed state become statically determinate by abutting against the container. In this way, the door in the open state can be pivoted by at least one undefined degree of freedom, and the position of the door can be adapted to the deformation of the container side. In the closed state, the door can thus substantially sealingly abut against the container.

Within the meaning of the present application, the term "ball-and-socket joint" should preferably be understood to mean a joint which allows a free movement with three independent rotational degrees of freedom. This includes, for example, articulated joints between two machine parts, in which the ball can rotate in all directions in a hollow sphere or at least partially in a hollow sphere. Within the meaning of the present application, a ball-and-socket joint is therefore to be understood in particular as a bearing which has three independent degrees of rotational freedom, i.e. with rotational freedom with respect to three independent axial or spatial directions. For example, they may be implemented as bearings with spherical friction pairs, cardan bearing designs, bearings with increased bearing clearance that allow angular offset, or made of other elements of this nature.

The joints described in this application may each be designed as ball and socket joints. It may be particularly advantageous to design the at least two first door-side joints and the at least one first container-side joint in each case as ball-and-socket joints. Preferably, at least two first container-side joints can be provided, which are preferably both designed as ball-and-socket joints. Additionally or alternatively, the at least one second door-side joint may be designed as a ball-and-socket joint and the at least one second container-side joint may be designed as a ball joint. In order to prevent uncontrolled rocking back and forth or lateral tilting of the door during the displacement movement, it may be useful for the at least one second container-side connection to have only two degrees of rotational freedom, and preferably only one or exactly one degree of rotational freedom. In particular, it may be advantageous if at least one first door-side joint, at least one or exactly one second door-side joint and one first container-side joint or a plurality of first container-side joints are each designed as a ball-and-socket joint.

The coupling arms of the first and/or second coupling means may comprise, for example, levers, braces or bars, or may be in another form. Regardless of the form, the linkage arm can establish, for example, a rigid or substantially rigid connection between the respective container-side and door-side joints. The linkage arms may each be variable or adjustable in terms of their length.

One or more of the linkage arms may be arranged and designed such that the door has an additional degree of freedom. For example, at least one or more of the linkage arms may each comprise a resilient element, such as a spring or a pneumatic cylinder. The spring element can then in each case be arranged and designed such that by varying the load of the spring element, the length of the respective coupling arm, which is defined by the distance between the joints connected to one another by means of the coupling arm, can be varied.

The coupling arm or coupling arms may additionally each comprise a pretensioning device for pretensioning the specific elastic element. When the elastic element is subsequently pretensioned by the pretensioning device, the length of the respective coupling arm can be changed with the respective elastic element pretensioned only if the load of the elastic element exceeds a first threshold value which is not equal to zero. In this way it is possible, for example, to ensure that the coupling arm has the necessary minimum stiffness during displacement of the door.

The pretensioning device may be adjustable in order to vary the pretensioning of the elastic element and to vary the described threshold value. For example, the resilient element of the coupling arm may comprise at least one spring. The pretensioning device may then comprise a stop element configured to limit the movement of the spring, in particular by the spring abutting against the stop element. For adjusting the pretensioning of the spring, the stop element can then be displaceable relative to the strut of the respective coupling arm. For example, the stop element and the strut of the coupling arm may comprise complementary and mutually engaging threads, such that the stop element may be displaced relative to the strut by a rotational movement of the stop element.

The first and second coupling means may be designed such that a first distance defined by the first coupling means between the first door-side rotational axis and the first container-side rotational axis is different from a second distance defined by the second coupling means between the second door-side rotational axis and the second container-side rotational axis. When the second door-side joint comprises only exactly one joint, for example a ball-and-socket joint, and thus defines the aforementioned centre of rotation, the second distance may also be defined as the distance between the second container-side axis of rotation and the centre of rotation defined by exactly one second door-side joint. In the case where the first door-side rotation axis and the first container-side rotation axis deviate from parallelism, the first distance may be a minimum distance between the first door-side joint and the first container-side rotation axis. The first distance may be, for example, at least 1.1 times, at least 1.2 times, or at least 1.5 times the second distance.

During the door from a closed position, in which the door closes the container opening, to an open position, in which the door at least partially exposes the container opening, an opening angle between a door-side plane spanned by the door-side rotation axis and a container-side plane spanned by the container-side rotation axis may increase. This may be particularly advantageous to facilitate cleaning of the door in the open position, in particular the inside of the door facing the container. The plane spanned by the container-side axis of rotation preferably extends parallel to the vertical direction.

The planes spanned may be oriented such that gravity acting on the door body generates a force component that causes the door to self-align and also acts as a sufficiently high sealing force.

The opening angle is generally at least 20 °, preferably at least 30 °, and particularly preferably at least 40 °. The opening angle is generally not more than 80 °, preferably not more than 70 °, and particularly preferably not more than 60 °. When the second door-side joint comprises only exactly one joint, for example a ball-and-socket joint, and defines the aforementioned door-side centre of rotation, the door-side opening angle can also be defined by a line which is perpendicular to the first door-side axis of rotation and which extends through the described door-side centre of rotation, which can be determined by exactly one second door-side joint.

If one or more of the door-side and/or vessel-side joints are designed as ball-and-socket joints, the parallel position of the axes can be changed to an "approximately parallel only" position. This allows for additional spatial swinging or tilting movement of the door, for example, with respect to a swinging or tilting axis. The swing or tilt axis may for example lie in a plane, or may be movable in a plane, which is perpendicular to the rotation axis spanned by the first container-side joint and/or perpendicular to the rotation axis spanned by the second container-side joint. In a design position, the aforementioned door-side plane and container-side plane may be, for example, parallel, while these planes may deviate from parallelism during operation of the door. This is advantageous because the door can adapt to varying geometries of the door-side or container-side sealing surface as a result of the described swinging or tilting movement.

It may also be provided that the distance ratio of the first distance to the second distance is less than 1. In this case, the opening angle described may become smaller during the movement of the door from the closed position to the open position.

The container opening is typically located in a plane spanned by the edges of the container defining the container opening. In the closed position, the door is then oriented, for example, vertically. The container opening may also lie in a plane which forms an angle with the vertical plane which is not equal to zero. Such an inclination angle of the container opening plane may be, for example, at least 10 °. The sealing surface of the door (which in the closed position surrounds the container opening and which abuts against the door-bearing surface of the container and preferably seals the container opening) is generally oriented in the closed position substantially parallel to the container opening plane. When the container opening lies in a plane which forms an angle of inclination different from zero with the vertical, the door in the closed position normally likewise has this angle of inclination with respect to the vertical plane. The gravitational force acting on the door, which is applied to the centre of gravity of the door and directed vertically downwards, can thus be used to achieve a closing and sealing effect. The door is thus able to seal the container opening in the closed state, e.g. without an additional actuator providing additional sealing force.

It may be advantageous if the container-side and door-side joint is arranged and designed such that the first plane (which is spanned by the first door-side axis of rotation and the first container-side axis of rotation) is oriented parallel to the second plane (which is spanned by the second door-side axis of rotation and the second container-side axis of rotation) in the closed position of the door-closed container opening. In case the second door-side joint comprises only exactly one joint, for example a ball-and-socket joint (which then defines the aforementioned door-side centre of rotation), the second plane described may also be spanned by the door-side centre of rotation and the second container-side axis of rotation instead of the second door-side axis of rotation and the second container-side axis of rotation. This may have the advantage that forces (which may be introduced into the door by the at least two first door-side joints and by the at least one second door-side joint) are also oriented parallel to each other at least in the closed position of the door, so that, for example, when the door is closed, the door may be prevented from rotating independently about the door center of gravity. The sealing force by which the sealing surface of the door in the closed position is urged against the door bearing surface of the container can thus be distributed substantially evenly across the sealing surface of the door. In particular, it may be advantageous that the force acting on the door is exerted by the force of gravity acting on the door, for example by the above-described inclined configuration of the container opening plane or by a guided movement direction comprising a vertical component.

The first coupling means may comprise first adjustment means for varying the first distance. The second coupling means may comprise second adjustment means for varying the second distance. In the closed position, undesirable gaps may occur between the door and the container opening, as already described above, due to deformations of the door bearing surface and/or of the door-side sealing surface or due to deposits. The first and/or second distance may be variable by means of an adjustment device, such that the orientation of the door relative to the container opening may be readjusted. The first and/or second distances may be adjustable such that the first and second distances have different lengths after adjustment. Further, the first and/or second distance may be adjustable such that the first and/or second door-side rotation axis may be adjusted from a parallel position relative to the first and/or second container-side rotation axis to an oblique position relative to the first and/or second container-side rotation axis. The guide design implemented by the first and second coupling means can thus be adjusted and sealing can be achieved despite impurities or deformations of the door-side or container-side sealing surface. In the case of a statically determinate guiding situation of the door, which is implemented by means of the three-point mounting described above, such an adjustment procedure can be carried out relatively easily, for example, because changing the first and/or second distance does not result in any stress, as is the case, for example, with the overdetermined systems of the prior art, which are implemented by means of a four-point mounting. For example, the adjustment device can be implemented relatively easily according to the turnbuckle principle. In this process, the right-hand and left-hand threads are combined so that the first and/or second distances can be changed, for example, by turning an internal thread that receives the left-hand and right-hand threads. The thread may be provided on, for example, the attachment arm.

As an alternative or in addition to the adjusting device, the first coupling device and/or the second coupling device may comprise a spring device, preferably a spring device each. The spring means may give the door an additional degree of freedom, which contributes to the self-sealing of the door. This reduces the need for readjustment by the adjusting device, since the door can assume the function of longitudinal adjustment within the spring travel possible under design.

Doors are generally substantially rigid components that may be exposed to strong thermal influences or temperature differences. For example, the interior of the vessel is typically much warmer than the environment outside the furnace. The interior of the vessel is typically heated to above 800 c and typically predominates at a temperature of about 50 c in the environment outside the furnace. This may result in, for example, deformation or a change in shape due to changes in the refractory material.

The at least one second container-side connector can optionally further comprise at least two connectors. In this way, the weight of the door can be distributed among the different container side connections.

When the second door-side joint comprises only exactly one joint, the at least two second container-side joints can be arranged such that the position of exactly one second door-side joint to a vertical projection on a second container-side rotation axis defined by the second container-side joint is preferably located centrally between two of the at least two second container-side joints along the second container-side rotation axis. Further, the distance between each of the at least two first door-side joints and exactly one second door-side joint may in this case be the same. This symmetrical arrangement allows the forces absorbed by the support to be distributed substantially uniformly to the second container-side connection.

In one embodiment, at least one of the at least one first container-side joint may comprise a ball-and-socket joint. It is also possible that a plurality of the at least one first container-side joint comprises a ball-and-socket joint. In this way, the oven door can be provided with an additional degree of freedom, which can allow the door to be automatically aligned by means of swinging. If no driving force is applied to the door, the door may automatically align until it remains in the unloaded position. In the unloaded position, a force equilibrium is generally established and the door bears with its sealing surface against the door bearing surface.

Further, the oven may comprise a fixing means for locking the door in the open state of the door and/or in the closed state of the door. In this way it can be ensured that the door is securely anchored when someone cleans the door or when the interior of the furnace is cleaned.

As mentioned above, the door can exert sufficient sealing force on the door bearing surface surrounding the container opening by its weight alone, so that the container opening is adequately sealed in the closed position of the door. Additionally or alternatively, the oven may further comprise a drive for moving the door from the open state to the closed state and/or vice versa. The door is movable by a driving force. In addition, the actuator may exert a force on the door in the direction of the door bearing surface, preferably perpendicular to the door bearing surface, when the door is already in the closed position, thereby increasing the sealing effect. The drive may also, for example, support only an opening movement or a closing movement. For example, the drive may comprise an electric motor and a winch connected thereto, wherein the door can be raised or lowered again on the drum by winding or unwinding a chain or wire rope. The drive can also be embodied in the form of an actuator which is integrated into the second coupling arm, for example.

An exemplary embodiment of the present invention will be described below based on the drawings.

In the drawings:

FIG. 1 shows a portion of an oven in perspective view with a door in an open position;

FIG. 2 shows a portion of the oven of FIG. 1 in perspective view with the door in a closed position;

FIG. 3 shows a schematic of a four-member linkage;

figure 4 shows a schematic front view of a door comprising first and second coupling means;

figure 5 shows a schematic side view of a door comprising a first and a second coupling device; and is

Fig. 6 schematically shows an embodiment of the coupling device according to fig. 5 in a perspective view.

Fig. 1 and 2 each show in perspective a part of a furnace 1, for example for melting metal. The furnace comprises a vessel 2 for containing molten metal. The container 2 has an opening 3. The furnace further comprises a door 4 designed to open and close the opening 3. Two first door-side connections 5 and 5' are provided on the door 4, which are arranged fixedly with respect to the door 4. The joint 5, 5' is here designed as a rotary joint and defines a first door-side axis of rotation 5 d. Exactly one second door-side joint 6 is fixedly arranged with respect to the door 4 and spaced apart from the rotation axis 5 d. The exactly one second door-side joint 6 is designed, for example, as a ball-and-socket joint and defines a centre of rotation 6 d. In an alternative embodiment, it is also conceivable that two or more second door-side joints are fixedly arranged on the door instead of the exactly one second door-side joint shown here. They may then define a second door-side rotation axis, which is oriented, for example, parallel to the first door-side rotation axis 5 d.

The first coupling means 7 movably connects the door 4 to the container 2 by means of two first door-side joints 5 and 5'. The second coupling means 8 movably connects the container 2 to the door 4 by exactly one door-side joint 6. The two first container-side connections 9 and 9' are arranged fixedly with respect to the container 2. The first tank-side connections 9 and 9' are designed here, for example, as ball-and-socket connections. The two second container-side connections 10 and 10' are arranged fixedly with respect to the container 2. (the container side fittings 9 'and 10' are not visible in fig. 1, but are clearly visible in fig. 2.) the second container side fitting 10 is spaced apart from the first container side fitting 9. For example, the joint is disposed above the joint 9 in the vertical direction.

The first coupling means 7 comprise first coupling arms 7' and 7 ". The coupling arm 7' connects the first door-side joint 5', for example rigidly, to the first container-side joint 9 '. The coupling arm 7 "connects the first door-side joint 5, for example rigidly, to the first container-side joint 9. The second coupling means 8 comprise a second coupling arm 8 'which connects exactly one second door-side joint 6, for example rigidly, to the container-side joints 10 and 10'. The second coupling arm 8' is designed as a steel bracket. The two first container-side joints 9 and 9' define a first container-side rotation axis 9 d. The two second container-side fittings 10 and 10' define a second container-side axis of rotation 10 d. The door-side rotational axis 5d and the container-side

rotational axes

9d and 10d are oriented parallel to one another, for example, in pairs, at least in one design position.

In the example shown, the first distance a1 between the first container-side axis of rotation 9d and the first door-side axis of rotation 5d describes the respective length of the first linkage arm 7 ", 7'. The first distance a1 is for example 45 cm. The second container-side rotation axis 10d is for example only 30cm in comparison to the second distance a2 between the centers of rotation defined by exactly one second door-side joint 6. In the exemplary embodiment shown here, the first distance a1 defined by the first linkage arms 7' and 7 "is therefore greater than the second distance a 2. As a result, when the door 4 is opened, the opening angle α between the container-side plane spanned by the container-side rotation axes 9d and 10d and the door-side plane spanned by the door-side rotation center 6d defined by exactly one door-side joint 6 and the first door-side rotation axis 5d increases. Instead of the described door-side plane, the angle α can also be defined on the door side by a straight line which intersects the door-side axis of rotation 5d perpendicularly and which extends through the center of rotation defined by exactly one second door-side joint 6. In the closed position, in which the door 4 closes the opening 3, the angle α 1 is, for example, 20 °, and in the open position, in which the door 4 exposes the opening 3, the angle α 2 is, for example, 30 °, as can be readily seen from fig. 5. Since the first linkage arms 7' and 7 "are designed to be longer than the second distance a2, the door can be viewed and cleaned particularly well from the side facing the opening 3. Nevertheless, the door does not tilt so much that the operator is exposed to the radiation of the heated inner surface of the door.

The first coupling means 7 and the second coupling means 8 each comprise, for example, an adjusting means. For example, the turnbuckles are integrated on the first coupling arms 7', 7 ", so that the lengths of the first coupling arms 7' and 7" can be adjusted independently of each other. A further adjustment means may be provided between the second coupling arm 8' and the second door side joint 6 such that the second distance a2 may be adjusted by the further adjustment means.

As an alternative or in addition to the adjusting device, the furnace 1, in particular the first and/or second coupling means 7, 8, may comprise a spring device, which gives the door 4 an additional degree of freedom to seal itself. This reduces the need for readjustment, since the door 4 can assume the function of longitudinal adjustment within the spring travel possible under design.

In the exemplary embodiment shown here, the second door-side joint 6 is arranged exactly in the vertical door center plane. At least one chain is engaged on the door body, which chain can be wound and unwound by means of the drum 11. The drum 11 may be driven by an electric motor 12. Winding the chain onto and unwinding it from the drum, pulls the door up (thereby exposing the door 4 to the opening 3) or lowers the door 4 (thereby closing the opening 3). The door 4 can be fixed in any arbitrary position between the open position and the closed position. The door 4 can also be driven in another way, for example by an actuator, which forms or is comprised by the second coupling arm 8'.

Fig. 3 schematically shows a linkage mechanism. The illustrated linkage substantially corresponds to the linkage used to move the door 4 in fig. 1 and 2. The door 4 is connected in an articulated manner to the container 2 by a first door-side joint, by a first coupling means 7 and by a first container-side joint 9. The door 4 is further connected to the container 2 by a second door-side connection 6, by a second coupling means 8 and by a second container-side connection 10. The distances a1 and a2 are shown in a simplified manner in fig. 3 with the same length. The distances a1 and a2 of fig. 1 and 2 are different.

Figure 4 illustrates a schematic diagram of a door system corresponding to the door system of figures 1 and 2.

In a schematic perspective view, fig. 6 shows an embodiment of the coupling arm 7' of the oven 1 shown in fig. 2 and 4, which connects the door-side joint 5' to the container-side joint 9 '. The remaining coupling arms 7 "and 8 'can be designed in the same way as the coupling arm 7' shown here. The attachment arm 7' defines a longitudinal direction 15. The coupling arm 7' has: a first coupling point 11 comprising an eyelet for receiving a pin of the door-side joint 5'; and a second coupling point 12 comprising an eyelet for receiving a pin of the container side coupling 9' (see fig. 4). The first coupling point 11 and the second coupling point 12 are arranged on opposite ends of the coupling arm 7' in the longitudinal direction 15. The coupling arm 7' further comprises a hollow stay 13, which is rigidly connected to the first coupling point 11. The hollow stay 13 encloses a cavity 14, which is open at the end of the cavity 14 facing the second coupling point 12.

The second coupling point 12 is in contrast rigidly connected to a further strut 16. The struts 16 are at least partially housed in the cavities 14 formed by the hollow struts 13. The end of the stay 16 connected to the second coupling point 12 at least partially protrudes from the cavity 14. The struts 16 can be displaced along the longitudinal direction 15 within the cavity 14 and relative to the hollow struts 13. By displacement of the strut 16 within the cavity 14, the specific length of the coupling arm 7' along the longitudinal direction 15 can be varied, which length is defined by the distance of the coupling points 11, 12 or the distance of the joints 5', 9' relative to each other.

Further, springs 17a and 17b are disposed within the cavity 14. At the end of the spring 17a facing the first coupling point 11, the spring 17a abuts against a stop element 18a, and at the end of the spring 17a facing the second coupling point 12, the spring abuts against, for example, an arcuate stop element 18c, which is fixedly connected to the hollow stay. The stop element 18c may, for example, partially protrude into the cavity 14. The stop element 18c is preferably arranged in the center of the cavity 14 along the longitudinal direction 15. The spring 17a is therefore pretensioned or pretensioned between the

stop elements

18a, 18 c. In contrast, at the end of the spring 17b facing the second coupling point 12, the spring 17b abuts against a stop element 18b, and at the end of the spring 17b facing the first coupling point 11, the spring abuts against a stop element 18 c. The spring 17b is therefore pretensioned or pretensioneable between the

stop elements

18b, 18 c. The stop element 18c is arranged and designed to avoid impairing the movability of the stay 16 and the stop 19 relative to the hollow stay 13 in the longitudinal direction 15.

The stop element 18a is at least partially housed within the cavity 14. The position of the stop element 18a relative to the hollow strut 13 is variable along the longitudinal direction 15. For example, the inner wall of the hollow strut 13 surrounding the cavity 14 and the stop element 18a may comprise mutually engaging threads (which are complementary to each other) such that the stop element 18a is movable by a rotational movement along the longitudinal direction 15 relative to the hollow strut 13. The stop element 18b is accommodated in a corresponding manner at least partially within the cavity 14. The position of the stop element 18b relative to the hollow strut 13 is variable along the longitudinal direction 15. Furthermore, the inner wall of the hollow strut 13 surrounding the cavity 14 and the stop element 18b may comprise mutually engaging threads (which are complementary to each other) such that the stop element 18b is movable by a rotational movement along the longitudinal direction 15 relative to the hollow strut 13.

An arcuate stop 19 partially surrounding the strut 16 is fixedly disposed on the outside of the strut 16. The stop 19 may be designed integral with the strut 16 or attached to the strut 16. The stop 19 is housed together with the strut 16 in the cavity 14 and is movable relative to the hollow strut 13 along the longitudinal direction 15. The stop 19 and the

springs

17a, 17b may be designed and arranged such that at least one of the

springs

17a, 17b is always in contact with the stop 19 and abuts against the stop 19. At the same time, the

springs

17a, 17b, which do not come into contact with the stop 19 due to the deflection of the stay 16, are prevented by the stop 18c from changing their length.

For example, the stop 19 and the spring 17a can be designed and arranged such that the spring 17a in the unloaded state of the coupling arm 7' abuts against the stop element 18a at the end of the spring 17a facing the first coupling point 11 and against the stop 19 at the end of the spring 17a facing the second coupling point 12, such that the spring 17a is pretensioned between the first stop element 18a and the stop 19. Accordingly, the spring 17b can be pretensioned between the stop 19 and the stop element 18 b.

The pretensioning of the

springs

17a, 17b and the length of the coupling arm 7' can then be set, for example, by changing the position of the

stop elements

18a, 18b relative to the hollow strut 13 in the longitudinal direction 15. Due to the settable pretensioning of the

springs

17a, 17b, a change in the length of the coupling arm 7' and, for example, an elastic movement of the strut 16 relative to the hollow strut 13 can only be brought about if the force exerted by the strut 16 on the hollow strut 13 or by the hollow strut 13 on the strut 16 is greater than a threshold value which is predetermined by the pretensioning of the

springs

17a, 17b and is not equal to zero. This value may be, for example, hundreds or thousands of newtons.

Fig. 6 shows the coupling arm 7 'in a position in which the strut 16 and the second coupling point 12 fixedly connected to the strut 16 are offset out of the unloaded state of the coupling arm 7', in which the

springs

17a, 17b are equally tensioned, for example. In fig. 6, the spring 17b is loaded (here compressed) more strongly than in the unloaded state of the coupling arm 7'. In contrast, the spring 17a in fig. 6 can be loaded less strongly than in the unloaded state of the coupling arm 7', for example. In fig. 6, in which the strut 16 is offset in the direction away from the first coupling point 11 along the longitudinal direction 15, the stop element 18c prevents the first spring 17a from following the offset of the strut 16. In contrast, when the strut 16 is biased in the longitudinal direction 15 towards the first coupling point 11 (not shown), the stop element 18c prevents the second spring 17b from following the bias of the strut 16. In an alternative embodiment, it is also possible to provide a separate stop element for each

spring

17a, 17b instead of providing a stop element 18c to limit the movability of the

springs

17a, 17 b.

Pretensioning the

springs

17a, 17b by means of the

adjustable stop elements

18a, 18b provides good stability of the door 4 during displacement, since the

pretensioned springs

17a, 17b impart sufficient stiffness to the linkage arm 7'. At the same time, the pretensioning of the

springs

17a, 17b may allow a swinging or tilting movement of the door 4 relative to the container 2 if the closing or sealing force between the door 4 and the container 2 is sufficiently high. In the closed position of the door 4, in which the door 4 closes the opening 3 of the container 2, the position of the door 4 with respect to the container 2 may be adapted to impurities in the region of the container 2 surrounding the opening 3, so that the door 4 always ensures a tight sealing of the opening 3. As described, additionally at least the first door-side and tank-side connections 5, 5', 9' and the second door-side connection 6 are preferably each designed as a ball connection for this purpose.

Claims

1. A furnace (1) comprising:

a container (2) having an opening (3) for receiving a molten substance;

a door (4) for closing and for opening the opening (3);

at least two first door-side joints (5, 5') which are fixedly arranged relative to the door (4);

at least one second door-side joint (6) fixedly arranged with respect to the door (4);

-first coupling means (7) to movably connect the door (4) to the container (2) through a first door-side joint (5, 5');

-second coupling means (8) movably connecting the door (4) to the container (2) by means of the at least one second door-side joint (6);

at least one first container-side connection (9) which is arranged fixedly in relation to the container (2); and

at least one second container-side connection (10) which is arranged fixedly in relation to the container (2);

the first coupling device (7) comprises at least one first coupling arm (7', 7 ") which connects in each case at least one of the first door-side connections (5, 5') to at least one of the at least one first container-side connections (9, 9 '); and is

The second coupling arrangement comprises a second coupling arm (8') connecting the at least one second door-side connection (6) to at least one second container-side connection (10, 10');

it is characterized in that the preparation method is characterized in that,

at least one of the at least one first container-side joint (9, 9') comprises a ball-and-socket joint and/or the at least one second door-side joint is designed as a ball-and-socket joint.

2. Oven (1) according to claim 1, characterized in that the two first door-side joints are designed as ball-and-socket joints.

3. Oven (1) according to claim 2,

the first linkage arm (7') comprises at least one first elastic element (17a, 17b) arranged and designed such that the length of the first linkage arm (7') can be varied by varying the load of the first elastic element, the length of the first linkage arm (7') being defined by the distance between the joints connected to each other by the first linkage arm (7'); and/or

The second linkage arm (8') comprises a second elastic element arranged and designed such that the length of the second linkage arm (8') can be varied by varying the load of the second elastic element, the length of the second linkage arm (8') being defined by the distance between the joints connected to each other by the second linkage arm (8').

4. Oven (1) according to claim 3,

the first coupling arm (7') comprises a first pretensioning device for pretensioning the first elastic element (17a, 17b) such that the length of the first coupling arm (7') can only be changed if the load of the first elastic element (17a, 17b) exceeds a first threshold value which is not equal to zero if the first elastic element is pretensioned; and/or the second coupling arm (8') comprises a second pretensioning device for pretensioning the second elastic element such that the length of the second coupling arm (8') can only be changed if the load of the second elastic element exceeds a second threshold value which is not equal to zero if the second elastic element is pretensioned.

5. Oven (1) according to claim 4,

the first pre-tensioning device is adjustable so as to vary the pre-tensioning of the first elastic element (17a, 17b) and to vary the first threshold value; and/or

The second pretensioning device is adjustable in order to vary the pretension of the second elastic element and to vary the second threshold value.

6. Oven (1) according to claim 4,

the first elastic element comprises at least one first spring (17a, 17b) and the first pre-tensioning device comprises a first stop element (18a, 18b) configured to limit the movement of the first spring (17a, 17b), the first stop element (18a, 18b) being displaceable relative to the strut (13) of the first coupling arm (7') for adjusting the pre-tensioning of the first spring; and/or

The second elastic element comprises at least one second spring and the second pre-tensioning device comprises a second stop element configured to limit the movement of the second spring, the second stop element being displaceable relative to the strut of the second linkage arm (8') for adjusting the pre-tensioning of the second spring.

7. A furnace (1) according to any of the claims 1-6, wherein the at least one second door-side joint (6) is spaced apart from the line defined by the at least two first door-side joints and comprises one second door-side joint (6) for reducing mechanical stress.

8. A furnace (1) according to claim 7, wherein the at least two first door-side joints (5, 5') define a first door-side rotational axis (5 d).

9. Oven (1) according to claim 8,

the at least one second door-side joint (6) defines a second door-side rotation axis (6d) or a door-side rotation center;

the at least one first container-side joint (9) defining a first container-side axis of rotation (9 d); and is

The at least one second container-side fitting (10) defining a second container-side axis of rotation (10 d);

the first door-side connection (5, 5'), the at least one second door-side connection (6), the at least one first container-side connection (9, 9') and the at least one second container-side connection (10, 10') are arranged and designed in such a way that the first door-side rotational axis (5d), the first container-side rotational axis (9d) and the second container-side rotational axis (10d) are oriented parallel to one another in pairs.

10. A furnace (1) according to claim 9, wherein the first coupling means (7) and the second coupling means (8) are designed such that a first distance (a1) defined by the first coupling means (7) between the first door-side axis of rotation (5d) and the first container-side axis of rotation (9d) is different from a second distance (a2) defined by the second coupling means (8) between the second door-side axis of rotation or the door-side center of rotation and the second container-side axis of rotation (10d), such that a door-side plane spanned by the first and second door-side axes of rotation or a straight line perpendicular to the first door-side axis of rotation and extending through the center of rotation defined by the one second door-side joint, and the first and second containers during a movement of the door (4) from a closed position, in which the door (4) closes the opening (3) of the container (2), to an open position, in which the door (4) at least partially exposes the opening (3) of the container (2) The opening angle (alpha) between the container side planes spanned by the side rotation axes is increased in order to facilitate inspection and cleaning of the door inner side in the open position.

11. A furnace (1) according to claim 10, characterized in that the first coupling means (7) comprise first adjusting means for changing the first distance (a1) and/or the second coupling means (8) comprise second adjusting means for changing the second distance (a 2).

12. A furnace (1) according to any of the claims 1-6, wherein said at least one second vessel side connection (10) comprises at least two connections.

13. A furnace (1) according to claim 9, wherein the one second door-side joint (6) and the at least two second container-side joints (10, 10') are arranged such that the position of the vertical projection of the one second door-side joint (6) onto the second container-side axis of rotation (10d) defined by the second container-side joints (10, 10') is located along the second container-side axis of rotation (10d) between two of the at least two second container-side joints (10, 10 ').

14. Oven (1) according to claim 9, characterized in, that the first and second door-side joints and the first and second container-side joints are designed and arranged such that in the closed position of the door (4) closing the container opening (3), a plane spanned by the first door-side rotational axis (5d) and by the first container-side rotational axis (9d) is oriented parallel to a plane spanned by the second door-side rotational axis or by the rotational center defined by the one second door-side joint and by the second container-side rotational axis (10 d).

15. Oven (1) according to claim 7, characterized in, that the respective distances between at least two of the at least two first door-side joints (5, 5') and the one second door-side joint (6) are the same.

16. A furnace (1) according to any of the claims 1-6, characterized by fixing means for locking the door (4) in the open and/or closed state.

17. A furnace (1) according to any of the claims 1-6, characterized by a drive (12) for moving the door (4) from an open position to a closed position and/or vice versa.