Non-uniform porous medium mechanical end face sealing structure

Abstract

The non-uniform porous medium mechanical end face sealing structure comprises a movable ring and a static ring which are used for mechanical sealing, the outer diameter side of the movable ring or the static ring is a high-pressure side, and the inner diameter side of the movable ring or the static ring is a low-pressure side; the high-pressure side of the moving ring or the static ring is a porous medium sealing ring, the porous medium sealing ring comprises a first porous medium sealing material and a second porous medium sealing material, and the first porous medium sealing material and the second porous medium sealing material are periodically and alternately arranged in the circumferential direction of the high-pressure side; a solid sealing ring is arranged on the low-pressure side of the moving ring or the static ring, the porous medium sealing ring and the solid sealing ring are integrally formed in a sintering mode, and the outer circumference of the porous medium sealing ring makes contact with a sealing medium. The invention has the remarkable characteristics of keeping the end surfaces of the movable and static rings non-contact during starting and stopping, large bearing capacity in the operation process, small abrasion and long service life.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical seals, and in particular relates to a non-uniform porous medium mechanical end face sealing structure. Background Art

[0002] Mechanical seals are key basic components of rotating power machinery in chemical equipment and are widely used in rotary shaft seals of chemical machinery such as centrifugal pumps, compressors, and mixing kettles. The long life and reliable operation of mechanical seals are related to the safety and stability of the entire chemical equipment system. Traditional contact mechanical seals often have technical problems such as difficulty in film formation, easy contact wear, and poor lubrication performance.

[0003] Porous medium material is a solid medium material containing interconnected tiny pores. The sealing fluid can flow through the pores of the porous medium material into the sealing end face. The flow rate entering the sealing end face is determined by the end face sealing liquid film pressure, and the end face sealing liquid film pressure distribution is affected by the sealing medium seepage behavior. A large number of research results have proved that sliding bearings made of porous medium materials have good lubrication characteristics, greater bearing capacity and stiffness.

[0004] Therefore, it is urgent to design a mechanical end face sealing structure using porous medium materials. Summary of the invention

[0005] In order to solve the technical problem that the low viscosity of the medium makes it difficult for the existing contact mechanical seal to form a complete sealing liquid film 4 on the sealing end face, resulting in poor lubrication effect and easy contact wear of the sealing ring, the present invention provides a non-uniform porous medium mechanical end face sealing structure, which can be used in low viscosity medium conditions to improve the problem of difficult film formation in the contact mechanical seal.

[0006] The technical solution adopted by the present invention is:

[0007] A non-uniform porous medium mechanical end face sealing structure, comprising a dynamic ring and a static ring for mechanical sealing, wherein the outer diameter side of the dynamic ring or the static ring is the high-pressure side, i.e., the upstream, and the inner diameter side of the dynamic ring or the static ring is the low-pressure side, i.e., the downstream; characterized in that the high-pressure side of the dynamic ring or the static ring is a porous medium sealing ring, and the porous medium sealing ring comprises a first porous medium sealing material and a second porous medium sealing material, and the first porous medium sealing material and the second porous medium sealing material are periodically alternately arranged along the circumferential direction of the high-pressure side; the low-pressure side of the dynamic ring or the static ring is a solid sealing ring, and the porous medium sealing ring and the solid sealing ring are integrally formed by sintering, and the outer circumference of the porous medium sealing ring is in contact with the sealing medium.

[0008] Furthermore, the first porous medium sealing material and the second porous medium sealing material are prepared from porous medium materials with different permeabilities.

[0009] Furthermore, the distribution ratio of the first porous medium sealing material to the second porous medium sealing material in the circumferential direction ranges from 0.25 to 4.

[0010] Furthermore, the radial widths of the first porous medium sealing material and the second porous medium sealing material are the same, and the ratio of the radial widths to the sealing end surface width is in the range of 0.5 to 0.8; the heights of the first porous medium sealing material and the second porous medium sealing material are in the range of 5 to 20 mm.

[0011] Furthermore, the entity sealing ring is a sealing dam, and the ratio of the width of the sealing dam to the width of the sealing end face is in the range of 0.5 to 0.2.

[0012] Furthermore, the periodic number of the first porous medium sealing material and the second porous medium sealing material in the circumferential direction is 6 to 12.

[0013] Furthermore, the materials of the first porous medium sealing material, the second porous medium sealing material and the solid sealing ring are all silicon carbide.

[0014] The working principle of the present invention is:

[0015] When the mechanical seal is in operation, the sealing medium enters the sealing end face through two porous medium material areas with different permeabilities to form a static pressure effect. At the same time, due to the different elastic moduli of the porous medium materials with different permeabilities, the degree of deformation of the end face under the action of the sealing pressure is different, thereby forming a certain dynamic pressure effect on the sealing end face.

[0016] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0017] 1. The unique porous medium material on the sealing ring of the present invention enables the mechanical seal to have good lubrication properties, greater bearing capacity and rigidity.

[0018] 2. Due to the different elastic moduli of porous media materials with different permeabilities, the degree of deformation of the end face under the action of sealing pressure is different, thus forming a certain dynamic pressure effect on the sealing end face, which can further ensure full film lubrication of the sealing end face, reduce friction and wear, and extend service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a geometrical schematic diagram of the end face of the mechanical seal porous medium of the present invention.

[0020] Figure 2 It is a cross-sectional view of the mechanical seal end face.

[0021] Figure 3 It is the pressure distribution diagram of the sealing liquid film on the sealing end face of the non-uniform porous medium.

[0022] Figure 4 It is the pressure distribution diagram of the fluid in the porous medium material sealed at the end face of the non-uniform porous medium. DETAILED DESCRIPTION

[0023] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] The present invention will be described in detail below in conjunction with exemplary embodiments with reference to the accompanying drawings.

[0026] Reference Figure 1 The present invention discloses a non-uniform porous medium mechanical end face sealing structure, comprising a dynamic ring and a static ring for mechanical sealing, wherein the outer diameter side of the dynamic ring or the static ring (5) is a high-pressure side, i.e., upstream, and the inner diameter side of the dynamic ring or the static ring is a low-pressure side, i.e., downstream; the high-pressure side of the dynamic ring or the static ring is a porous medium sealing ring, and the porous medium sealing ring comprises a first porous medium sealing material 1 and a second porous medium sealing material 2, and the first porous medium sealing material 1 and the second porous medium sealing material 2 are periodically arranged alternately along the circumferential direction of the high-pressure side; the low-pressure side of the dynamic ring or the static ring is a solid sealing ring 3, and the porous medium sealing ring and the solid sealing ring 3 are integrally formed by sintering, and the outer circumference of the porous medium sealing ring is in contact with the sealing medium.

[0027] In one embodiment, the first porous medium sealing material 1 and the second porous medium sealing material 2 are made of porous medium materials with different permeabilities.

[0028] Specifically, in this embodiment, the permeability of the first porous medium sealing material 1 is higher than the permeability of the second porous medium sealing material 2 .

[0029] In one embodiment, the distribution ratio range A of the first porous medium sealing material 1 and the second porous medium sealing material 2 in the circumferential direction is 1 / A 2 It is 0.25~4.

[0030] In one embodiment, the radial widths of the first porous medium sealing material 1 and the second porous medium sealing material 2 are the same, and the ratio of the radial widths to the sealing end surface widths is in the range of 0.5 to 0.8; the heights of the first porous medium sealing material 1 and the second porous medium sealing material 2 are in the range of 5 to 20 mm.

[0031] In one embodiment, the physical sealing ring 3 is a sealing dam, and the ratio of the width of the sealing dam to the width of the sealing end surface is in the range of 0.5 to 0.2.

[0032] In one embodiment, the periodic number of the first porous medium sealing material 1 and the second porous medium sealing material 2 in the circumferential direction is 6 to 12.

[0033] In one embodiment, the materials of the first porous medium sealing material 1 , the second porous medium sealing material 2 and the solid sealing ring 3 are all silicon carbide.

[0034] Reference Figure 2 The first and second porous medium materials and the solid sealing ring 3 are integrally formed by sintering, and the outer circumference of the porous medium sealing ring on the high-pressure side contacts the sealing medium. When the mechanical seal is in operation, the sealing medium enters the sealing end face through two porous medium material areas with different permeabilities to form a static pressure effect. At the same time, due to the different elastic moduli of the porous medium materials with different permeabilities, the deformation degree of the end face under the sealing pressure is different, thereby forming a certain dynamic pressure effect.

[0035] Reference Figure 3 The pressure distribution of the porous medium mechanical end face sealing liquid film 4 gradually decreases from the outer diameter to the inner diameter. Under the effect of this pressure distribution, the sealing medium flows into the material from the outer diameter side of the porous medium material, and then precipitates from the porous medium material sealing end face to the sealing gap, generating fluid static pressure between the sealing end faces. The liquid that permeates from the gap of the porous medium material not only strengthens the lubrication of the sealing end face, but also improves the static pressure effect of the end face, improving the lubrication performance during low-speed startup.

[0036] Reference Figure 4 , the porous medium end face seal porous medium area pressure distribution, in the porous medium material with higher permeability, the porous medium pressure is higher, while in the porous medium material with lower permeability, the porous medium area pressure distribution gradually increases from the inner diameter to the outer diameter, and gradually decreases from the bottom surface of the porous medium to the upper bottom surface, and the minimum pressure appears at the intersection of the porous medium material and the ordinary sealing ring material. The pressure difference caused by the different permeabilities can cause the mechanical seal to produce a certain dynamic and static pressure effect. As the permeability of the porous medium material increases, the amount of fluid entering the sealing gap through the porous medium ring gradually increases, and the dynamic and static pressure effects it produces are also stronger, thereby enhancing the performance of the mechanical seal.

[0037] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0042] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A non-uniform porous medium mechanical end face sealing structure, comprising a dynamic ring and a static ring for mechanical sealing, wherein the outer diameter side of the dynamic ring or the static ring is a high pressure side, i.e., upstream, and the inner diameter side of the dynamic ring or the static ring is a low pressure side, i.e., downstream; characterized in that: The high-pressure side of the dynamic ring or the static ring is a porous medium sealing ring, and the porous medium sealing ring includes a first porous medium sealing material and a second porous medium sealing material, and the first porous medium sealing material and the second porous medium sealing material are periodically arranged alternately along the circumferential direction of the high-pressure side; the low-pressure side of the dynamic ring or the static ring is a solid sealing ring, and the porous medium sealing ring and the solid sealing ring are integrally formed by sintering, and the outer circumference of the porous medium sealing ring is in contact with the sealing medium.

2. A non-uniform porous medium mechanical end face sealing structure as claimed in claim 1, characterized in that: The first porous medium sealing material and the second porous medium sealing material are made of porous medium materials with different permeabilities.

3. A non-uniform porous medium mechanical end face sealing structure as claimed in claim 1, characterized in that: The distribution ratio of the first porous medium sealing material to the second porous medium sealing material in the circumferential direction ranges from 0.25 to 4.

4. A non-uniform porous medium mechanical end face sealing structure as claimed in claim 1, characterized in that: The radial widths of the first porous medium sealing material and the second porous medium sealing material are the same, and the ratio of the radial widths to the sealing end surface width is in the range of 0.5 to 0.8; the heights of the first porous medium sealing material and the second porous medium sealing material are in the range of 5 to 20 mm.

5. The non-uniform porous medium mechanical end face sealing structure according to claim 1, characterized in that: The entity sealing ring is a sealing dam, and the ratio of the width of the sealing dam to the width of the sealing end surface is in the range of 0.5 to 0.

2.

6. A non-uniform porous medium mechanical end face sealing structure as claimed in claim 1, characterized in that: The periodic number of the first porous medium sealing material and the second porous medium sealing material in the circumferential direction is 6 to 12.

7. A non-uniform porous medium mechanical end face sealing structure as claimed in claim 1, characterized in that: The materials of the first porous medium sealing material, the second porous medium sealing material and the solid sealing ring are all silicon carbide.

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