System for sealing a fluid passage from a first component to a second component

Abstract

System for sealing a fluid passage from a first component (1) to a second component (2), wherein the first component (1) and the second component (2) radially limit the fluid passage, the first component (1) and the second component (2) are arranged side by side in the flow direction, and are designed in a connection area where the first component (1) and the second component (2) are in contact during fluid passage, to receive a sealing device, wherein the sealing device comprises: at least a first sealing element (3), which is annularly designed for the passage of fluid and radially limits the fluid passage in the connection area, the first sealing element (3) having at least one expansion slot (4) and being sealed to the first component (1) with a first sealing surface (5) and being sealed to the second component (2) with a second sealing surface (8), characterized in thatthat at least one first sealing element (3) is flexible, the expansion slot (4) allows radial movement, the first sealing surface (5) is inclined against the flow direction and interacts with a counter-sealing surface acting on the first component (1) in such a way that, due to radial movement of the first sealing element (3) caused by radial pressure of the fluid passing through the connection area, the first sealing element (3) expands in the radial direction, presses radially towards the first component (1), and, in addition, the first sealing surface (5) seals with the expansion slot (4) by bearing towards the first component (1), and presses the first sealing element (3) axially towards the second component (2), wherein the second sealing surface (8) with the expansion slot (4) is sealed against the second component (2) by bearing towards it.wherein at least one expansion slot (4) extends in an arc shape from an inner wall (10) of the first sealing element (3) to the second sealing surface (8).

Description

[0001] The invention relates to a system for sealing a fluid passage from a first component to a second component, in particular for use in plastic melt processing systems, such as a melt filter according to the preamble of claim 1.

[0002] Such a system for sealing a fluid passage comprises a first component and a second component. The first component and the second component radially delimit the fluid passage. The first component and the second component are arranged next to one another in the flow direction and are designed to accommodate a sealing device in a connecting region where the first component and the second component lie against one another during the fluid passage. The sealing device comprises at least one first sealing element which is annular in design for the passage of fluid, preferably low-viscosity plastic melt, and which radially delimits the fluid passage in the connecting region. In addition, the first sealing element has at least one expansion slot. The at least first sealing element is assigned to a first component with a first sealing surface in a sealing manner and to a second component with a second sealing surface in a sealing manner.

[0003] Generally, according to the state of the art, annular seals made of PTFE material are used, for example, in flat slide screen changers. Very high temperatures occur, especially in the area of ​​highly viscous plastic melts. However, the PTFE seals known from the state of the art only function up to temperatures of approximately 2500°C and are generally prone to leakage.

[0004] European patent application EP 2 900 350 B1 describes a filter device for molten plastic material, which utilizes an annular sealing element with an expansion slot. However, this sealing element is designed in such a way that relatively large free slot widths occur in the area of ​​at least one expansion slot. This makes reliable sealing difficult, since the seal design in this case allows molten plastic to permanently penetrate the area of ​​the expansion slot.

[0005] DE 10 2009 035 790 A1 and US 5 507 498 A each disclose a sealing element with a sealing surface inclined relative to the flow direction.

[0006] From DE 201 21 504 U1 a seal of a piston in a cylinder is known, which is pressed by the fluid pressure directly in the radial and axial direction onto a radial surface and an axial surface of the sealing element.

[0007] It is therefore the object of the present invention to provide a system for sealing a fluid passage from a first component to a second component according to the type specified in the preamble of claim 1, in particular for use with low-viscosity plastic melt at higher temperatures, which enables reliable sealing in a structurally simple manner and overcomes the disadvantages of the prior art.

[0008] This object is achieved according to the invention by features of the characterizing part of patent claim 1 in conjunction with its preamble features.

[0009] Advantageous embodiments of the sealing device are defined in the subclaims.

[0010] According to the invention, the at least one first sealing element is flexible, the expansion slot enables radial movement, the first sealing surface is inclined against the flow direction and interacts with a counter-sealing surface interacting on the first component such that a radial movement of the first sealing element (3) due to radial pressure of the fluid passing through the connection region causes the first sealing element to expand in the radial direction, press radially against the first component, and moreover the first sealing surface is sealed by the expansion slot by bearing in the direction of the first component. Furthermore, the first sealing element is pressed axially against the second component, wherein the second sealing surface is sealed against the second component by bearing in the direction of the second component.According to the invention, the flexible design with the expansion slot of at least the first component enables, in a structurally simple manner, a three-dimensional alignment of the first sealing element in the radial direction due to the corresponding pressure of the passing fluid and the resulting axial direction, to ensure reliable sealing both against the first component and against the second component. Due to the pressure of the passing fluid, the at least one first sealing element is thus expanded in the radial direction and pressed in the axial direction against the first component or second component to be sealed.

[0011] In a particularly simple design, the application of pressure in the radial and resulting axial directions is preferably achieved by sloping the first sealing surface in the manner of a conical surface against the flow direction. This can be an outer cone.

[0012] Particularly preferably, a sealing surface inclined in the opposite direction, associated with the first component or the second component, can be provided, by means of which the resulting axial pressure can be built up when the inclined first sealing surface is in contact.

[0013] According to a preferred embodiment, the first sealing surface and the second sealing surface can be arranged at an angle to one another. However, it is particularly preferred that the first sealing surface and the second sealing surface form a uniform sealing surface of the first sealing element.

[0014] The construction according to the invention is particularly simple in the case in which the first sealing element is formed in one piece and the at least one expansion slot is provided continuously through the first sealing element.

[0015] In this case, according to one embodiment of the invention, the at least one expansion slot can be arranged in an arc shape extending from an inner wall of the first sealing element to the second sealing surface.

[0016] In order to introduce the pressure of the passing fluid through the sealing device as easily as possible, the expansion slot runs radially at least in the area of ​​the inner wall of the first sealing element.

[0017] In order to reliably seal and prevent the penetration or permeation of fluid through the expansion slot according to the invention in a particularly simple manner, the at least one expansion slot preferably has a tangential extension at least in the region of the second sealing surface of the first sealing element. Thus, the resulting pressure compresses the expansion slot particularly reliably in this area, so that essentially no or very little melt penetrates and remains there. This further enhances the sealing effect according to the invention.

[0018] The sealing effect according to the invention can be achieved particularly reliably if the device according to the invention or the corresponding system has a separate, annular sealing seat in the region of the first component assigned to the first sealing element, into which the first sealing element fits. Similarly, according to a preferred embodiment, to achieve a better sealing result, the device according to the invention or the system according to the invention can be designed such that the second component assigned to the first sealing element has a second sealing element, designed in annular shape for the passage of fluid. The second sealing element can have a third sealing surface assigned to the second component in a sealing manner, adjacent to the second component, and a fourth sealing surface assigned to the first sealing element in a sealing manner, adjacent to the second sealing surface.In this way, a particularly reliable seal is also possible towards the second component.

[0019] Preferably, the second sealing element has a thermal expansion coefficient that compensates for flexible deformation of the first sealing element due to the pressure of the fluid passing through, particularly in the range of higher temperatures at or above 2500°C. In this way, material tolerances, which are particularly pressure- and temperature-induced, can be compensated particularly reliably, which can further improve the sealing effect of the sealing device or sealing system according to the invention. Particularly preferably, the first sealing element can be made of a stainless steel alloy and the second sealing element of a copper alloy.

[0020] Preferably, the first component is a melt filter device or a perforated plate of a melting device, and the second component is a flat slide valve of a melting device. The advantages of the sealing device or the corresponding sealing system according to the invention are particularly evident when used in a melting device, especially when processing low-viscosity plastic melts, as explained above.

[0021] Further advantages, features and possible applications of the present invention will become apparent from the following description in conjunction with the embodiments shown in the drawings.

[0022] In the description, claims, and drawings, the terms and associated reference symbols used in the list of reference symbols below are used. In the drawings, the following definitions apply: Fig. 1a to e views of the first sealing element of the sealing device of the system according to the invention according to a preferred embodiment thereof; Fig. 2a to c show representations of a second sealing element of the sealing device of the system according to the invention according to a preferred embodiment thereof; and Fig. 3 a sealing device of a system according to the invention for sealing a fluid process with a first component and a second component in the assembled state in a sectional side view according to the preferred embodiment of the invention.

[0023] The Fig. 1a shows a plan view of at least one first sealing element 3 of the sealing device of the system according to the invention for sealing a fluid passage from a first component 1 to a second component 2, wherein the two components are only Fig. 3. It can be clearly seen in the illustration that the first sealing element 3 is annular for the passage of fluid therethrough and has at least one expansion slot 4. Furthermore, it has a first sealing surface 5, which is inclined in the axial direction in the manner of a conical surface, as is shown, for example, in the sectional view of Fig. 1b or in the side views of the Fig. 1c and Fig. 1d and in the perspective view of the Fig. 1e can be clearly seen. The first sealing element 3 is formed in one piece and the expansion slot 4 is provided continuously therethrough, wherein the expansion slot 4 runs in an arc shape from an inner wall 10 of the first sealing element 3 to the second sealing surface 8. The course of the expansion slot 4 is radial at least in the region of the inner wall 10 of the first sealing element 3 and then continues in an arc shape up to the region of the tangential run-out in the region of the second sealing surface 8 of the first sealing element 3. Thus, in a simple manner according to the invention, it can be achieved that the applied melt pressure both a radial pressurization of the first sealing element 3 and, as a result, a resulting axial pressure of the sealing element 3 ensures that as little as possible or even no melt at all is located in the expansion slot 4 in the clamped state between the first component to be sealed and the second component to be sealed.

[0024] In the representations of the Fig. 1a to 1e clearly show that the first sealing surface 5 and the second sealing surface 8 are adjacent to one another, but are arranged at an angle different from one another. According to the invention, it would also be conceivable, although not shown in the figures, for the first sealing surface 5 and the second sealing surface 8 to form a uniform sealing surface of the first sealing element 3, for example, if the sealing surface 8 were directly adjacent to the first sealing surface 5 at an identical cone angle.

[0025] The Fig. 2a to 2c show a second sealing element 6 associated with the second component and the first sealing element 3, which is also designed in a ring shape for the passage of fluid. The second sealing element 6 shown has a third sealing surface 7 associated with the second component in a sealing manner, which in the assembled state of the device according to the invention abuts the second component, and a fourth sealing surface 9 associated with the first sealing element 3 in a sealing manner, which in the assembled state of the device according to the invention abuts the second sealing surface 8 of the first sealing element 3. The first sealing element is inserted into the resulting recess of the second sealing element 6. It should be noted that in the edge region, for example in Fig. As can be clearly seen in Figure 2b of the sectional side view of the second sealing element 6, the second sealing element has beveled edges which, in the assembled state, essentially continue the edges of the conical surface of the first sealing element 3. According to the invention, the second sealing element 6 preferably has a thermal expansion coefficient that enables flexible deformation of the first sealing element 3 due to the pressure of the fluid passing through it in the temperature range that provides the application area of ​​the sealing device according to the invention. This preferably enables an improved sealing effect by compensating for tolerances.

[0026] The Fig.3 shows, in a sectional side view, the sealing system according to the invention with the sealing device according to the invention in an assembly situation with the first component 1 and the second component 2. A further separate annular sealing seat 11, assigned to the first sealing element 3 and the first component 1, can also be clearly seen, wherein the sealing seat 11 there forms a contact element which is conically shaped in the opposite direction to the conically shaped part of the first sealing element. According to the invention, the radially occurring compressive force can thus be deflected particularly easily in the axial direction by the respective sealing surfaces bearing against one another, as a result of which the first sealing element 3 is clamped against the second sealing element 6 and thus the second sealing element 6 against the second component 2. The first sealing element 3 is also clamped against the first component 1 orpressed against the corresponding sealing seat 11 and sealed accordingly.

[0027] According to the embodiment of the present invention shown, a particularly simple and reliable sealing of a fluid passage between two components is thus possible according to the invention, in particular when used in melting devices for low-viscosity plastic melts at higher temperatures in the range of 2500 °C and higher. List of reference symbols 1 first component 2 second component 3 first sealing element 4 expansion slot 5 first sealing surface 6 second sealing element 7 third sealing surface 8 second sealing surface 9 fourth sealing surface 10 inner wall 11 annular sealing slot

Claims

[1] A system for sealing a fluid passage from a first component (1) to a second component (2), wherein the first component (1) and the second component (2) radially delimit the fluid passage, the first component (1) and the second component (2) are arranged next to one another in the flow direction, and are designed to receive a sealing device in a connecting region at which the first component (1) and the second component (2) lie against one another during the fluid passage, the sealing device comprising: at least one first sealing element (3), which is annularly designed for the passage of fluid and radially delimits the fluid passage in the connecting region, the first sealing element (3) has at least one expansion slot (4) and is sealingly associated with the first component (1) by means of a first sealing surface (5) and is sealingly associated with the second component (2) by means of a second sealing surface (8), characterized bythat the at least one first sealing element (3) is flexible, the expansion slot (4) allows a radial movement, the first sealing surface (5) is inclined against the flow direction and cooperates with a counter-sealing surface cooperating on the first component (1) in such a way that, due to a radial movement of the first sealing element (3) due to radial pressure of the fluid passing through the connection area, the first sealing element (3) expands in the radial direction, presses radially against the first component (1), furthermore, the first sealing surface (5) seals with the expansion slot (4) by bearing in the direction of the first component (1), the first sealing element (3) presses axially against the second component (2), wherein the second sealing surface (8) with the expansion slot (4) is sealed against the second component (2) by bearing in the direction of the second component (2),wherein the at least one expansion slot (4) extends in an arc from an inner wall (10) of the first sealing element (3) to the second sealing surface (8). [2] System according to claim 1, characterized by that at least the first sealing surface (5) is inclined in the manner of a conical surface against the flow direction. [3] System according to one of claims 1 or 2, characterized by that the first sealing surface (5) and the second sealing surface (8) form a uniform sealing surface of the first sealing element (3). [4] System according to one of the preceding claims, characterized by that the first sealing element (3) is formed in one piece and the at least one expansion slot (4) is continuous. [5] System according to one of the preceding claims, characterized by that the at least one expansion slot (4) extends radially therefrom at least in the region of the inner wall (10) of the first sealing element (3). [6] System according to one of the preceding claims, characterized by that the at least one expansion slot (4) runs tangentially outward at least in the region of the second sealing surface (8) of the first sealing element (3). [7] System according to one of the preceding claims, characterized by that the first component (1) has a separate, annular sealing seat (11) associated with the first sealing element (3). [8] System according to one of the preceding claims, characterized by in that the second component (2) has a second sealing element (6) assigned to the first sealing element (3) and formed in a ring shape for the passage of fluid, wherein the second sealing element (6) has a third sealing surface (7) sealingly assigned to the second component (2) and adjacent to the second component (2), and a fourth sealing surface (9) sealingly assigned to the first sealing element (3) and adjacent to the second sealing surface (8). [9] System according to claim 8, characterized by that the second sealing element (6) has a thermal expansion coefficient which compensates for a flexible deformation of the first sealing element (3) due to the pressure of the fluid passing through. [10] System according to one of the preceding claims, characterized by that the first component (1) is a perforated plate of a melting device and the second component (2) is a flat slide of a melting device. [11] System according to one of the preceding claims, characterized by that the fluid is a low-viscosity plastic melt.

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