DE102021103168A1 - Knife gate valve and method - Google Patents

Abstract

The invention relates to a knife gate valve (10) for industrial plants, comprising a slide rod (11) which is operatively connected to a first drive element (A1) in order to bring about an axial movement of the slide rod (11) in such a way that at least one slide plate (12) is subjected to an axial force can be acted upon and moved into a closed and open position, and at least one pressing element (13) in order to press the slide plate (12) against a sealing seat (14), the slide rod (11) comprising a lifting mechanism (15) which is designed for this is to apply a pressing force and/or a release force to the pressing element (13), the pressing force of the lifting mechanism (15) being independent of the axial force of the slide rod (11) which moves the slide plate (12) into the closed position, and/ or the lifting mechanism (15) can be actuated independently of the axial movement of the slide rod (11).

Description

The invention relates to a knife gate valve according to the features of the preamble of claim 1. The invention also relates to a method for operating a knife gate valve.

Out of DE 20 2016 102 559 U1 a plate valve with two slide plates is known, which are arranged in a plate basket. In these so-called double slide gate valves, the slide gates are pressed apart in the shut-off position by a wedge arrangement between the slide gates and pressed against the corresponding housing sealing seats. The wedge assembly is actuated directly by the pusher rod which moves the plate basket containing the pusher plates. In order to control the pressing force during the opening and closing process, the wedge arrangement is subjected to a release force which is applied by a spring element which is arranged between the plate cage and a clamping element on the slide rod and relieves the wedge arrangement.

With knife gate valves, a good sealing effect must be created. It is therefore important that when opening and closing, the point in time at which the pressing element is subjected to a release force or a pressing force can be precisely determined. The contact pressure is adjusted depending on the pressure conditions that prevail in the pipelines connected to the gate valve in order to achieve sufficient tightness.

Although spring elements have proven themselves, there is still a need for improvement, since the closing time can vary under certain conditions (heavy soiling, chemical or thermal loads).

The invention is therefore based on the object of specifying a knife gate valve of the type mentioned in the introduction, in which the parameters when opening and closing the knife gate valve can be set and controlled better. Furthermore, it is the object of the invention to specify a method for operating a knife gate valve.

According to the invention, this object is achieved by a knife gate valve according to claim 1. With a view to the method for operating a knife gate valve, the object is achieved by the subject matter of claim 16 and the subject matter of claim 17.

Specifically, the object is achieved by a slide gate valve for industrial plants, comprising a slide rod which is operatively connected to a first drive element in order to bring about an axial movement of the slide rod in such a way that at least one slide plate can be subjected to an axial force and can be moved into a closed and open position, and at least a pressing element, in order to press the slide plate against a sealing seat, is released, the slide rod comprising a lifting mechanism which is designed to apply a pressing force and/or a releasing force to the pressing element, the pressing force of the lifting mechanism being independent of the axial force of the slide rod which moves the slide plate into the closed position, and/or the lifting mechanism can be actuated independently of the axial movement of the slide rod.

The term knife gate valve includes different types of knife gate valves. For example, it can be a double knife gate valve, a single knife gate valve or a wedge-in-wedge knife gate valve. Other types of knife gate valves are also possible, for example from the iron and steel industry, from the chemical and petrochemical industry, from energy and environmental technology and from the glass industry.

The slide rod can be moved axially. The slide rod is moved in the longitudinal direction, for example by an electric motor which drives a rotating output nut or spindle nut which interacts with a thread on the slide rod. Alternatively, other types of drive can be used.

In the closed position it is possible to press the slide plate against the sealing seats by the lifting mechanism or to reduce the pressing force during the transition from the closed position to the open position and to release the slide plate from the sealing seats again.

According to the invention, the pressing force is independent of the axial force with which the slide rod moves the slide plate into the closed position. This means that the contact pressure does not result from the axial force of the slide rod which is applied to move the slide plate axially to the open or closed position. The pressing force of the lifting mechanism thus remains unaffected by the axial force of the slide rod for axially driving the slide plate. In other words, the pressing force of the lifting mechanism and the axial force of the slide rod are decoupled from one another.

In addition or as an alternative to the above force-decoupled actuation, the lifting mechanism can be actuated independently of the axial movement of the slide rod. This means that the lifting mechanism can be operated without the Actuation of the lifting mechanism must be preceded by an axial movement of the slide rod. The axial movement of the pusher rod is therefore not a condition that must be met in order to actuate the lifting mechanism. In other words, the lifting mechanism is not actuated by the axial movement of the slide rod, but can be actuated independently of the axial movement.

In the plate slide according to the invention, the movement of the at least one slide plate into the closed position by the slide rod and the pressing of the at least one slide plate against the sealing seats by the lifting mechanism are two separate processes in terms of force and/or movement.

The knife gate valve according to the invention consequently has the advantage that, in contrast to knife gate valves with spring and clamping elements, the opening and closing parameters of the knife gate valve can be better controlled. The parameters include, among other things, the amount of contact pressure with which the slide plates are pressed against the sealing seats, the stroke that is generated by the lifting mechanism for pressing the at least one slide plate, and the time from which the at least one slide plate is pressed against the sealing seats is pressed.

The pressing element can be subjected to a pressing force and/or a releasing force by the lifting mechanism. A spring element and a clamping element, as they are described in the prior art, can consequently be dispensed with entirely. This is advantageous for the following reasons. For example, the material of the spring element and the clamping element can become brittle as a result of thermal and chemical loads, so that cracks can form. This reduces the clamping force of the clamping element and the releasing force of the spring element. During the closing process, the spring force counteracts the movement of the slide rod. If, for example, the spring stiffness of the spring element has changed due to embrittlement, this means that the stroke, the contact pressure force and the point in time at which the contact pressure takes place can no longer be reliably determined.

Preferred embodiments of the invention are given in the subclaims.

In a particularly preferred embodiment, the lifting mechanism can be actuated by a second drive element, in particular can be actuated separately. As a result, the pressing force of the lifting mechanism can be generated without the first drive element of the slide rod influencing the pressing force. Furthermore, the lifting mechanism can be actuated by the first drive element independently of an axial movement of the slide rod. To put it more precisely, the lifting mechanism and the slide rod can be actuated separately.

In a further particularly preferred embodiment, the plate pusher comprises a switching unit, the switching unit being adapted to connect the first drive element to the lifting mechanism, or to switch between the first drive element and the second drive element, which is operatively connected to the lifting mechanism. The switching unit can be configured, for example, to change the way in which a movement and/or force is introduced or transmitted into the slide rod. In other words, the switching unit can be configured to switch between two types of movement of the slide rod. Alternatively, the switching unit can be configured to switch between the two drive elements. This makes it possible to decouple the axial force of the slide rod and the pressing force of the lifting mechanism from one another, or the lifting mechanism can thus be actuated independently of the axial movement of the slide rod.

In a preferred embodiment, the slide rod can be rotated about its own central longitudinal axis, at least in the closed position. This means that the slide rod is rotatably mounted. In other words, the slide rod can rotate about its own central longitudinal axis. For example, it is possible that the switching unit is configured to switch between the axial movement and the rotating movement of the slide rod.

In one embodiment with a rotatable slide rod, it is advantageous if the lifting mechanism comprises a rotary element, which is non-rotatably connected to the slide rod, and a push element, which is connected to the pressing element, the rotary element and the push element being connected to one another in this way by a screw connection are that the pusher element can be moved axially by rotating the pusher rod.

Thus, the lifting mechanism here comprises at least two elements. The rotating element, which is non-rotatably connected to one of the at least one slide plate facing axial end of the slide rod, and the thrust element, which is connected to the pressing member. The rotating element and the pushing element are operatively connected to one another by a screw connection. In other words, the pushing element is screwed into the rotating element or vice versa. The rotating element and the pushing element are preferably designed in one piece, in particular monolithically. The lifting mechanism can include other elements.

The slide rod can be rotated at least in the closed position or is rotated at least in the closed position. Alternatively, the slide rod can be or can be rotated in the open position or in an intermediate position. When the pusher rod rotates, the rotary element rotates together with the pusher rod. The rotation of the rotating element causes an axial movement of the pushing element through the thread of the screw connection. This makes it possible for the pushing element to be screwed in or out as a result of the rotation of the rotary element. In this way, the thrust element can be moved axially and moved toward the pressing element or away from the pressing element. In other words, the pressing member can be subjected to a pressing or releasing force.

The screw connection is preferably designed in the opposite direction to the rotation of the slide rod in the closed position, so that the rotation of the slide rod in the closed position causes a stroke of the push element in the direction of the pressing element. For example, the screw connection has a left-hand thread. In the case of a left-hand thread, the thrust element is moved away from the rotary element and towards the pressing element when the rotary element rotates counter to the direction of the thread. If the rotation element rotates with the sense of the thread, the position of the pushing element shifts in the direction of the rotation element.

In a further particularly preferred embodiment, the switching unit is adapted to switch between a rotation and a linear movement of the slide rod. The switching unit makes it possible to switch between the two possible types of movement of the slide rod. As a result, the exact point in time can be selected when the at least one slide plate is to be pressed against the sealing seat. The slide rod preferably performs either an axial movement or a rotational movement. This means that preferably both types of movement are not carried out at the same time.

The switching unit particularly preferably comprises a clutch, in particular a multi-plate clutch or a claw clutch, or a locking unit. A coupling or a locking unit makes it possible to transfer a rotational movement to the slide rod. For example, the slide rod can be coupled to an output nut or spindle nut. During the linear movement, the spindle nut can move the slide rod in the axial direction. In the coupled state, the rotational movement of the spindle nut is no longer converted into an axial movement, but is instead transmitted directly to the slide rod, so that the slide rod rotates with the spindle nut.

In a further embodiment, the screw connection comprises an internal thread of the rotating element and an external thread of the pushing element. This allows the pushing element to be screwed into the rotating element.

It is advantageous if the rotating element has a collar and the collar forms a stop. In other words, the collar forms a stop for the movement of the slide rod into the closed position. The stop is subjected to a force during the axial movement of the slide rod. In other words, the at least one slide plate or the plate cage is moved into the closed position by the collar.

In one embodiment, the thrust element is positively connected to the pressing element at least in the axial direction. As a result, the pressing element can move with the thrust element in the axial direction. The thrust element is preferably connected in a form-fitting manner to the pressing element in both axial directions of the slide rod. In this way, the slide plate can be pressed against the sealing seat and released from it again.

It is particularly advantageous if the pushing element comprises an essentially hammer-shaped geometry. As a result, the thrust element is positively connected to the pressing element in both axial directions of the slide rod. Furthermore, the hammer-shaped geometry prevents the pushing element from rotating with the rotating element when the pusher rod rotates. This means that the thrust element is positively connected or can be connected to the pressing element by the hammer-shaped geometry in a direction of rotation of the slide rod.

In a particularly preferred embodiment, the slide rod comprises an outer tube and the lifting mechanism comprises an inner rod, the inner rod being arranged coaxially in the outer tube and being connected to the pressing element. As a result, the inner rod can be moved in the outer tube. For example, the inner rod can be movable or rotatable in an axial direction. Thus, a separation of the way is possible, on each of the axial force of the slide rod and the Contact pressure of the lifting mechanism can be generated. The inner rod in the outer tube also enables a compact design of the lifting mechanism. Such a system can be referred to as a rod-in-rod system, for example.

In the rod-in-rod system it is advantageous if the first drive element comprises a spindle with a spindle nut and the second drive element comprises a cylinder/piston arrangement. Alternatively, other drive elements can be used. The cylinder/piston arrangement enables a sufficiently large stroke and a high contact pressure force to be implemented in order to press the inner rod against the contact pressure element.

Within the scope of the invention, a method for operating a plate slide is disclosed and claimed, in which a slide rod is moved axially in the direction of the pressing element into a closed position, when the closed position is reached the axial movement of the slide rod is stopped and the slide rod is rotated in the closed position a central longitudinal axis is displaced and the rotational movement of the slide rod is converted into a linear movement by a lifting mechanism in the region of an axial end of the slide rod.

As described above, the lifting mechanism includes a rotating element and a pushing element. The rotating element and the pushing element each have corresponding threads which engage in one another when installed. When the rotary element rotates, the position of the push element is shifted in the axial direction of the push rod.

When the axial movement of the pusher rod is stopped, the pusher rod is preferably immobile in the axial direction. This allows the pusher to be moved axially.

A method for operating a knife gate valve, in particular with a rod-in-rod system, is also disclosed and claimed within the scope of the invention, in which a slide rod, which includes an outer tube, is moved axially in the direction of a pressing element into a closed position when it is reached the closed position, the axial movement of the slide rod is stopped and the pressing element is subjected to a pressing force by a lifting mechanism, which comprises an inner rod guided coaxially in the outer tube.

It is advantageous if, in the method described above, the outer tube is connected to the first drive element and the inner rod is connected to the second drive element.

When the closed position is reached, the slide rod is preferably immovable or fixed in the axial direction. This makes it possible to operate the lifting mechanism independently of the axial movement. It is not excluded that, for example in the case of the rod-in-rod system, the movement of the outer tube and the movement of the slide rod take place at the same time, at least in sections.

The invention is explained in more detail below using exemplary embodiments with reference to the attached schematic drawings.

• 1 einen Schnitt durch ein Ausführungsbeispiel eines erfindungsgemäßen Plattenschiebers, der als Doppelplattenschieber ausgebildet ist;
• 2 einen weiteren Schnitt durch den Doppelplattenschieber gemäß 1;
• 3 eine detaillierte Ansicht des Doppelplattenschiebers gemäß 1;
• 4 einen Schnitt durch ein Ausführungsbeispiel eines erfindungsgemäßen Plattenschiebers, der als Keil-im-Keil Plattenschieber ausgebildet ist;
• 5 eine detaillierte Ansicht des Keil-im-Keil Plattenschiebers gemäß 4;
• 6 eine perspektivische Ansicht des Keil-im-Keil Plattenschiebers gemäß 4;
• 7 einen Schnitt durch ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Plattenschiebers mit einem Stange-in-Stange System.

In these show:

• 1 a section through an embodiment of a knife gate valve according to the invention, which is designed as a double knife gate valve;
• 2 another section through the double knife gate valve according to 1 ;
• 3 a detailed view of the double knife gate valve according to 1 ;
• 4 a section through an embodiment of a knife gate valve according to the invention, which is designed as a wedge-in-wedge knife gate valve;
• 5 see a detailed view of the wedge-in-wedge knife gate valve 4 ;
• 6 a perspective view of the wedge-in-wedge knife gate valve according to FIG 4 ;
• 7 a section through another embodiment of a knife gate valve according to the invention with a rod-in-rod system.

the 1 , 2 and 3 show a double knife gate valve. The double plate gate valve comprises a housing 21 on which two pipe sockets 22 are arranged. In the installed state, the pipe sockets are connected to corresponding lines (not shown), in particular flanged onto them.

In the housing 21, a slide rod 11, a plate cage 23 and a pipe bridge 24 are arranged, which are connected to each other, the plate cage 23 being arranged between the pipe bridge 24 and the slide rod 11. The pipe bridge 24 and the plate basket 23 are movable by the push rod 11 in a longitudinal direction of the push rod 11 . Through the slide rod 11, the pipe bridge 24 and the plate basket in an open and in a closed position be moved. In the closed position shown, the plate basket 23 is arranged between the pipe sockets 22 and in the open position the pipe bridge 24 is arranged between the pipe sockets 22 .

Slider plates 12 are arranged in the plate cage 23, in particular loosely inserted. The slide plates 12 are arranged concentrically and parallel to one another.

A pressing element 13 is arranged between the two slide plates 12 . The pressing member 13 includes two wedges 13a, 13b. A centering ball 26 is arranged between the two wedges 13a, 13b. The wedges 13a, 13b each rest against an outer wedge 25a, 25b. The outer wedges 25a, 25b are arranged between the slide plates 12 and the wedges 13a, 13b.

The wedge arrangement of the wedges 13a, 13b and the outer wedges 25a, 25b makes it possible for the slide plates 12 to be pressed orthogonally to the axial direction of movement of the slide rod 11 against the sealing seats 14.

The pressing element 13 and the slide rod 11 are connected to one another by a lifting mechanism 15 . To put it more precisely, the pressing element 13 and the slide rod 11 are operatively connected to one another by the lifting mechanism 15 .

The lifting mechanism 15 comprises a rotating element 16 and a pushing element 17. The rotating element 16 is arranged on the end of the slide rod 11 facing the pressing element 13. The rotating element 16 is rotatably connected to the slide rod 11, for example welded. The rotating element 16 has an essentially hollow-cylindrical shape.

The rotating element 16 has a first section and a second section. The two sections adjoin one another in the axial direction.

The first section comprises a collar 20 and a bore with an internal thread I'. The collar 20 is arranged on an outer surface, in particular a lateral surface, of the rotation element 16 . The collar 20 extends continuously in the circumferential direction of the rotation element 16. In the direction of the disk cage 23, the collar 20 has a surface which runs perpendicular to the central longitudinal axis of the slide rod 11. The surface is ring-shaped in plan view. A sliding disk, for example, is arranged between the surface of the collar 20 facing the pressing member 13 and the disk cage 23 in order to reduce the friction when the rotary element 16 rotates. On the side facing away from the pressing element, the collar 20 has a surface that is inclined in the direction of the slide rod 11 . In other words, the surface of the collar 20 facing away from the pressing member 13 is conical.

The internal thread I′ is arranged in a bore on the axial end of the rotary element 16 facing the pressing member 13 . The bore extends in the direction of the slide rod 11. The internal thread I' extends along an inner surface of the bore to the second section of the rotary element 16.

The second section of the rotating element 16 has a smaller inside diameter than the first section. The second section engages in a recess in the slide rod 11 . The recess is adapted to the smaller inside diameter of the rotating element 16 .

The first section is connected to the pusher element 17 when installed, and the second section is connected to the pusher rod 11 when installed.

The pushing element 17 has a first area and a second area. The first portion is cylindrical and has an external thread A'. The external thread A' corresponds to the internal thread I' of the first section of the rotary element 16. This means that the external thread A' and the internal thread I' have the same winding direction and pitch. The threads are formed in the opposite direction to the rotation of the slide rod 11 in the closed position.

At least in sections, the second area has a rectangular or cuboid geometry and is arranged at least in sections between the wedges 13a, 13b and connected to them in a form-fitting manner. More precisely, the wedges 13a, 13b enclose the rectangular area in both axial directions of movement of the slide rod 11. The first and the second area together form a hammer-shaped geometry. Alternatively, the second area can have polygonal geometries.

In 1 and 2 a first drive element A1 is shown. The slide rod 11 is connected or coupled to the first drive element A1. The first drive element A1 can comprise an electric motor, for example. For example, a spindle nut of the first drive element A1 can interact with the slide stay 11 in order to generate an axial movement of the slide rod 11 .

The plate slide 10 includes a switching element 19. The switching element 19 is arranged in the area of the first drive element A1. The switching element 19 enables a detachable connection of the slide rod 11 and the spindle nut. When the slide rod 11 and the spindle nut are connected, the rotation of the spindle nut is transmitted directly to the slide rod 11 . This means that the rotation of the spindle nut is not converted into an axial movement, but the slide rod 11 rotates together with the spindle nut. Other constructions and mechanisms by which the switching element 19 transmits rotation to the slide rod 11 are possible.

The switching element 19 can, for example, comprise a multi-plate or claw clutch in order to transmit a rotation to the slide rod 11 . Other types of coupling are also conceivable. Alternatively, a locking unit is possible.

4 , 5 and 6 show a wedge-in-wedge knife gate valve. The wedge-in-wedge knife gate valve differs from the double knife gate valve described above. The wedge-in-wedge knife gate valve comprises two pipe sockets 22 and a guide housing 28 which is connected to the pipe sockets 22. The wedge-in-wedge knife gate valve thus has no pipe bridge 24 and no plate cage 23.

The wedge-in-wedge plate slide includes two slide plates 12 which are directly connected to the wedges 13a, 13b of the pressing member 13 or bear against them. The pressing element 13 is connected to the slide rod 11 by a lifting mechanism 15, which is essentially identical in construction to the lifting mechanism according to FIG 1 until 3 is. The differences in the lifting mechanism 15 described above will be discussed below.

In 5 It can be clearly seen that the rotating element 16 is pushed onto the slide rod 11 and is connected to the slide rod 11 in a rotationally fixed manner by a bolt or a screw. The rotation element 16 is connected to the slide rod 11 with the second section. The inner diameter of the second section is larger than the inner diameter of the first section in order to prevent the slide rod 11 from being pushed in too far, in particular being pushed onto the internal thread I'.

The collar 20 of the rotating element rests against the slide plates 12 in the wedge-in-wedge knife gate valve. To put it more precisely, the slide plates 12 have an extension or a step 29 on the surface facing the respective other slide plate 12 . The slide rod 11 and the lifting mechanism 15 are connected to the slide plates 12 by the step 29 . A sliding disk is preferably arranged between the step 29 and the collar 20 in order to reduce the friction when the rotary element 16 rotates.

The guide housing 28 has a guide 30 for the slide plates 12 on or in an inner surface. The slide plates are arranged in the guide housing 28 in the open position. In the closed position, the slide plates 12 are arranged between the pipe sockets 22 and close them.

6 shows an external view of the wedge-in-wedge knife gate valve. It is easy to see here that the pressing element 13 is surrounded by the slide plates 12 .

In the closed position, the slide plates 12 are arranged in a tapering manner at the end remote from the slide rod 11 . In other words, the distance between the slide plates 12 is smaller at the end remote from the slide rod 11 than at the end near the slide rod 11 .

In the open position, the slide plates 12 are arranged in the guide housing 28 . In the guide housing 28, the slide plates 12 are arranged parallel and concentrically to one another.

7 shows a knife gate valve 10, which is essentially the double knife gate valve according to 1 until 3 is equivalent to. the inside 7 However, the knife gate valve 10 shown has a lifting mechanism 15 which comprises a rod-in-rod system. The rod-in-rod system includes a slide rod 11 which has an outer tube 31 . The outer tube 31 is designed as a hollow cylinder. The outer tube 31 is connected to the disc cage 23 at one axial end and to the first drive member A1 at another axial end.

An inner rod 32 is arranged in the outer tube 31 . The inner rod 32 is guided in the outer tube 31 . The inner rod 32 is part of the lifting mechanism 15 of the plate slide 10. For this purpose, the inner rod 32 is arranged with one axial end on the pressing element 13 and is connected with another axial end to a second drive element A2. The inner rod 32 is preferably connected to the pressing element 13 in a form-fitting manner. For this purpose, the inner rod 32 can be connected with a hammer-shaped geometry on the axial end facing the pressing element 13 . The hammer-shaped geometry allows a positive connection in both axial directions of the inner rod 32. This enables the slide plates 12 to be pressed on and released.

The second drive element A2 includes a cylinder/piston arrangement. More precisely, the inner rod 32 is connected to the piston rod of a piston arranged coaxially in the cylinder. When a force is applied to the piston, the force is transmitted to the inner rod 32 . The effect of this is that the inner rod 32 can be moved axially in the outer tube 31 and the pressing element 13 can be subjected to a pressing force or a release force.

The slide rod 11 or the outer tube 31 can be moved by the drive element A1 and the inner rod 32 can be moved by the drive element A2. The inner rod 31 can thus be moved independently of the slide rod 11 . This has the advantage that the pressing element 13 can be subjected to a pressing force and/or a release force, the pressing force of the lifting mechanism 15 being independent of the axial force of the slide rod 11 which moves the slide plate 12 into the closed position. Furthermore, it is possible that the lifting mechanism 15 can be actuated independently of the axial movement of the slide rod 11 .

The outer pipe 31 and the first drive element A1 have the function of moving the plate cage 23 with the slide plates 12 and the pipe bridge 24 and of converting them into the closed or open position. The inner rod 32 and the second drive element A2 serve to apply a pressing force to the pressing element 13 in order to press the slide plates 12 against the sealing seats 14 .

It should be pointed out here that possible combinations of the described embodiments fall under the subject matter of the invention. For example, a rod-in-rod system is conceivable, in which the inner rod 32 as in the embodiment according to 1 is rotatably mounted and causes a pressing force on the pressing element 13 through the interaction of the rotating element 16 with the pushing element 17 .

The slide rod 11 generally functions to move the slide plates 12 to an open and closed position. For this purpose, the slide rod 11 is connected to the first drive element A1. In order to move the slide plates axially, they are subjected to an axial force by the slide rod 11 .

The slide plates 12 are loosely arranged in such a way that they can be pressed against the sealing seats 14 by the pressing element 13, in particular by the wedges 13a, 13b or the outer wedges 25a, 25b, during an axial movement of the lifting mechanism 15.

The lifting mechanism 15 allows in the embodiments according to 1 until 6 to convert a rotation of the push rod 11 into a linear movement without changing the position of the push rod 11 in the axial direction. Furthermore, the stroke or the pressing force and the point in time from which the slide plates 12 are pressed tightly against the sealing seats can be easily adjusted by the lifting mechanism 15 .

The rotation element 16 is non-rotatably connected to the slide rod 11 in order to be able to rotate with the slide rod 11 . The collar 20 of the rotary member 16 serves as a stop for the closed position.

The thrust element 17 is positively connected to the wedges 13a, 13b by the hammer-shaped geometry. Furthermore, the hammer-shaped geometry prevents the pushing element 17 from rotating with the rotating element 16 . As a result, the movement space of the pusher element 17 is limited to axial movement directions. The pushing element 17 acts on the slide plates 12 in the closed position or during the closing process with a pressing force and when opening or during the transition to the open position with a release force.

The threads are formed in the opposite direction to the rotation of the slide rod 11 in the closed position. Due to the opposing thread, the thrust element 17 can be moved in the direction of the pressing element 13 in the closed position. A gear effect is possible through different threads in order to control the parameters during closing and opening, in particular the contact pressure.

In the following, an exemplary closing process of a knife gate valve 10 according to FIG 1 until 6 described.

At the beginning of the closing process, the gate valve 10 is in the open position.

The first drive element A1 is activated. The first drive element A1 moves the slide rod 11 in the direction of the pressing element 13. During the closing process, the axial movement of the slide rod 11 is transmitted to the slide plates 12 by the lifting mechanism 15.

When the closed position is reached, the axial movement of the slide rod 11 stops. The slide rod 11 is fixed or immovable in the axial direction in the closed position. The switching unit 19 is then activated and the slide rod 11 changes from the axial movement to a rotational movement.

The lifting mechanism 15 converts the rotation of the pusher rod 11 into a linear movement through the interaction of the rotary element 16 and the pushing element 17 and the pushing element 17 is moved in the direction of the pressing element 13 . The slide plates 12 are subjected to a contact pressure by the contact pressure element 13 so that they lie tightly against the sealing seats 14 .

In order to move the gate valve 10 back into the open position, the above steps can be carried out in reverse order. When opening, the axial movement of the slide rod 11 is transmitted to the slide plates 12 by the push element 17 .

A further closing process of a plate slide 10 is shown in accordance with FIG 7 described.

First, the first drive element A1 is actuated. The first drive element A1 causes the outer tube 31, which is connected to the disc basket 23, to move axially. When the closed position is reached, the first drive element A1 is stopped. The outer tube 31 and the plate cage 23 are immovable or fixed in the closed position in the axial direction.

The second drive element A2 is then actuated. The second drive element A2, for example a cylinder/piston arrangement, moves the inner rod 32 in the direction of the pressing element 13. The pressing element 13 is subjected to a pressing force and presses the slide plates 12 against the sealing seats 14, so that the plate slide 10 is tightly closed . To open the plate slide 10, the steps mentioned can be carried out in reverse order.

Reference List

A1

First drive element

A2

Second drive element

A'

external thread

I'

inner thread

10

knife gate valve

11

slide rod

12

slide plate

13

pressure element

13a, 13b

wedge

14

tight fit

15

lifting mechanism

16

rotation element

17

sliding element

18

screw connection

19

switching unit

20

collar

21

Housing

22

pipe socket

23

plate basket

24

pipe bridge

25a, 25b

outer wedges

26

centering ball

28

guide housing

29

Step

30

guide

31

outer tube

32

inner rod

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 202016102559 U1 [0002]

Claims (17)

Knife gate valve (10) for industrial plants, comprising a slide rod (11) which is operatively connected to a first drive element (A1) in order to bring about an axial movement of the slide rod (11) in such a way that at least one slide plate (12) can be subjected to an axial force and can be converted into a closed and open position, and at least one pressing element (13) in order to press the slide plate (12) against a sealing seat (14), characterized in that the slide rod (11) comprises a lifting mechanism (15) which is designed for this purpose to apply a pressing force and/or a release force to the pressing element (13), the pressing force of the lifting mechanism (15) being independent of the axial force of the slide rod (11) which moves the slide plate (12) into the closed position, and/or the lifting mechanism (15) can be actuated independently of the axial movement of the slide rod (11). plate slide after claim 1 , characterized in that the lifting mechanism (15) can be actuated by a second drive element (A2)), in particular can be actuated separately. plate slide after claim 1 or 2 , characterized in that the plate pusher comprises a switching unit (19), the switching unit (19) being adapted to connect the first drive element (A1) to the lifting mechanism (15), or between the first drive element (A1) and the second Drive element (A2), which is operatively connected to the lifting mechanism (15), switch. Slab slide according to one of the preceding claims, characterized in that the slide rod (11) is rotatable about its own central longitudinal axis, at least in the closed position. plate slide after claim 4 , characterized in that the lifting mechanism (15) comprises a rotary element (16) which is non-rotatably connected to the slide rod (11) and a thrust element (17) which is connected to the pressing element, the rotary element (16) and the pusher element (17) is connected to one another by a screw connection (18) in such a way that the pusher element (17) can be moved axially by rotating the pusher rod (11). plate slide after claim 5 , characterized in that the screw connection (18) is designed in the opposite direction to the rotation of the slide rod (11) in the closed position, so that the rotation of the slide rod (11) in the closed position causes a stroke of the push element (17) in the direction of the pressing element (13). . Knife gate valve after one of Claims 4 until 6 , characterized in that the switching unit (19) for switching between a rotation and a linear movement of the slide rod (11) is adapted. plate slide after claim 7 , characterized in that the switching unit (19) comprises a clutch, in particular a multi-plate clutch or a claw clutch, or a locking unit. Knife gate valve after one of Claims 4 until 8th , characterized in that the screw connection (18) comprises an internal thread of the rotating element (16) and an external thread of the pushing element (17). Knife gate valve after one of Claims 4 until 9 , characterized in that the rotation element (16) has a collar (20) and the collar (20) forms a stop. Knife gate valve according to one of the preceding claims, characterized in that the thrust element (17) is positively connected to the pressing element (13) at least in the axial direction. Knife gate valve according to one of the preceding claims, characterized in that the thrust element (17) comprises an essentially hammer-shaped geometry. Knife gate valve after one of Claims 1 until 3 , characterized in that the slide rod (11) comprises an outer tube (31) and the lifting mechanism (15) comprises an inner rod (32), the inner rod (32) being arranged coaxially in the outer tube (31) and being connected to the pressing member (13 ) connected is. plate slide after Claim 13 , characterized in that the outer tube (31) is connected to the first drive member (A1) and the inner rod (32) is connected to the second drive member (A2). plate slide after Claim 14 characterized in that the first drive element (A1) comprises a spindle with a spindle nut and the second drive element (A2) comprises a cylinder/piston arrangement. Method for operating a knife gate valve (10), in particular according to one of Claims 1 until 12 , in which a. a slide rod (11) is moved axially in the direction of a pressing element (13) into a closed position, b. when the closed position is reached, the axial movement of the slide rod (11) is stopped and the slide rod (11) is rotated in the closed position about a central longitudinal axis of the slide rod (11), c. the rotational movement of the slide rod (11) is converted into a linear movement by a lifting mechanism (15) in the region of an axial end of the slide rod (11) facing the pressing member (13). Method for operating a knife gate valve, in particular according to one of Claims 1 until 3 and 13 until 15 , where a. a slide rod (11), which comprises an outer tube (31), is moved axially in the direction of a pressing element (13) into a closed position, b. upon reaching the closed position, the axial movement of the slide rod (11) is stopped and c. by a lifting mechanism (15), which comprises an inner rod (32) guided coaxially in the outer tube (31), the pressing element (13) is subjected to a pressing force.

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