Air distribution structure of dry mechanical seal

Abstract

The utility model relates to a gas distribution structure of a dry type mechanical seal, and belongs to the technical field of dry type mechanical sealers.The gas distribution structure of the dry type mechanical seal comprises a dry type mechanical seal structure and a cavity assembly, a sealing cavity is formed in the cavity assembly, the dry type mechanical seal structure is located in the sealing cavity, and a gas distribution ring is arranged in the sealing cavity; the gas distribution ring and the sealing cavity are concentrically arranged, the gas distribution ring divides the sealing cavity into an outer cavity body and an inner cavity body, the dry type mechanical sealing structure is located in the inner cavity body, a plurality of through holes are formed in the gas distribution ring, a gas inlet used for being communicated with external cooling fluid is formed in the cavity assembly, the gas inlet is communicated with the outer cavity body, and the through holes are communicated with the inner cavity body. The cavity assembly is provided with an exhaust port used for being communicated with an external pipeline, and the exhaust port is communicated with the inner cavity. The temperature of the end face of the friction pair in the dry type mechanical sealing structure is controlled within a certain range, and the service life of the sealing structure is effectively prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of dry mechanical seals, and in particular to an air distribution structure of dry mechanical seals. Background Art

[0002] The polyethylene extrusion granulator is a device used to extrude polyethylene plastic particles to produce moldings. A sealing mechanism is usually required at the extrusion screw position of the extrusion granulator to improve the sealing performance at the barrel interface.

[0003] At present, the seal of the extrusion granulator usually adopts dry mechanical seal, that is, the sealing method without using lubricant or liquid sealant. The dry mechanical seal operates under the state of gas lubrication and dry friction. The dry mechanical seal structure has two friction pair end faces. During long-term use, the temperature at the friction pair end faces is easy to exceed the safe working temperature, affecting the operating life of the sealing structure. Utility Model Content

[0004] In order to help control the temperature of the friction pair end surface in a dry mechanical seal structure within a certain range and effectively extend the service life of the seal structure, the present application provides an air distribution structure for a dry mechanical seal.

[0005] The air distribution structure of the dry mechanical seal provided in this application adopts the following technical solution:

[0006] An air distribution structure for a dry mechanical seal comprises a dry mechanical seal structure and a cavity assembly, wherein the cavity assembly has a sealed cavity, the dry mechanical seal structure is located in the sealed cavity, an air distribution ring is provided in the sealed cavity, the air distribution ring is concentrically arranged with the sealed cavity, the air distribution ring divides the sealed cavity into an outer cavity and an inner cavity, the dry mechanical seal structure is located in the inner cavity, a plurality of through holes are provided on the air distribution ring, an air inlet for communicating with an external cooling fluid is provided on the cavity assembly, the air inlet is communicated with the outer cavity, an exhaust port for communicating with an external pipeline is provided on the cavity assembly, and the exhaust port is communicated with the inner cavity.

[0007] Preferably, the plurality of through holes are arranged in a plurality of rows along the axial direction of the air distribution ring.

[0008] Preferably, the through holes in each row are arranged at intervals along the circumference of the air distribution ring.

[0009] Preferably, the diameter of the through hole is 2 mm-4 mm.

[0010] Preferably, the air distribution ring is an aluminum ring.

[0011] Preferably, the air distribution ring comprises two semicircular arc pieces which are arranged relatively in the sealing cavity, the two semicircular arc pieces are in contact with each other, and the cross-sectional plane of the semicircular arc piece is in the same direction as the cross-sectional plane of the cavity assembly.

[0012] Preferably, a flow guide pipe is provided on the air distribution ring, one end of the flow guide pipe is connected to the inner cavity, and the other end of the flow guide pipe is connected to the exhaust port, and the exhaust port is connected to the inner cavity through the flow guide pipe.

[0013] Preferably, the diameters of the air inlet and the air outlet are both 11 mm-13 mm.

[0014] In summary, this application includes the following beneficial technical effects:

[0015] The external cooling fluid enters the outer cavity through the air inlet, and then is guided from the multiple through holes on the air distribution ring to the friction pair end face of the dry mechanical seal structure for cooling and heat exchange. The setting of multiple through holes can guide the cooling fluid to the friction pair end face from multiple directions, which helps to make the heat exchange more uniform. Then, after the heat exchange, the cooling fluid is discharged through the exhaust port for recovery, thereby helping to control the temperature of the friction pair end face within a certain range during the long-term use of the dry mechanical seal structure, effectively extending the operating life of the sealing structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the air distribution structure applied to the dual-axis structure in the embodiment of the present application.

[0017] Figure 2 yes Figure 1 Enlarged view of part A.

[0018] Figure 3 It is a partial structural cross-sectional view of an embodiment of the present application.

[0019] Explanation of the reference numerals: 1. dry mechanical seal structure; 2. cavity assembly; 3. sealing cavity; 31. outer cavity; 32. inner cavity; 4. air distribution ring; 41. semicircular arc piece; 5. through hole; 6. air inlet; 7. exhaust port; 8. flow guide tube. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1-3 This application is described in further detail.

[0021] The embodiment of the present application discloses a gas distribution structure of a dry mechanical seal. Figure 1 and Figure 2The air distribution structure of the dry mechanical seal includes a dry mechanical seal structure 1 and a cavity assembly 2. The cavity assembly 2 has a sealing cavity 3, and the dry mechanical seal structure 1 is located in the sealing cavity 3. The dry mechanical seal structure 1 is mainly composed of two pairs of friction pairs, compensation elements and rubber sealing rings; the cavity assembly 2 is mainly a circular metal assembly placed outside the dry mechanical seal structure 1, which is used to provide an independent closed chamber for the dry mechanical seal structure 1; the specific structures of the dry mechanical seal structure 1 and the cavity assembly 2 belong to the prior art and will not be described in detail here.

[0022] Reference Figure 1 and Figure 2 An air distribution ring 4 is fixedly arranged in the sealing cavity 3. The cross section of the air distribution ring 4 is circular. The air distribution ring 4 is concentrically arranged with the sealing cavity 3. Specifically, the air distribution ring 4 is an aluminum ring. The aluminum ring is light in weight and can achieve a lightweight design. It also has good thermal conductivity, which facilitates the cooling of the end face of the friction pair. The air distribution ring 4 divides the sealing cavity 3 into an outer cavity 31 and an inner cavity 32. The outer cavity 31 is located outside the inner cavity 32, and the dry mechanical seal structure 1 is located in the inner cavity 32. A plurality of through holes 5 are opened on the air distribution ring 4, and the outer cavity 31 is connected with the inner cavity 32 through the plurality of through holes 5.

[0023] Reference Figure 2 and Figure 3 The cavity assembly 2 is provided with an air inlet 6 for communicating with an external cooling fluid, and the air inlet 6 is connected to the outer cavity 31; the cavity assembly 2 is provided with an exhaust port 7 for communicating with an external pipeline, and a guide tube 8 is fixedly penetrated on the air distribution ring 4, and the guide tube 8 has a diameter of 12 mm. The guide tube 8 is located in the outer cavity 31, and the guide tube 8 is arranged along the radial direction of the air distribution ring 4. One end of the guide tube 8 is connected to the inner cavity 32, and the other end is connected to the exhaust port 7, so that the exhaust port 7 is connected to the inner cavity 32 through the guide tube 8. Among them, the diameters of the air inlet 6 and the exhaust port 7 are both 11 mm-13 mm. Preferably, the diameters of the air inlet 6 and the exhaust port 7 are both 12 mm, which helps to ensure the cooling and heat exchange effect on the end faces of the friction pairs in the dry mechanical seal structure 1. In the embodiment of the present application, the external cooling fluid uses low-temperature nitrogen.

[0024] When in use, the external cooling fluid enters the outer cavity 31 through the air inlet 6, and then the cooling fluid is guided to the friction pair end face in the dry mechanical seal structure 1 through the multiple through holes 5 on the air distribution ring 4 to cool the friction pair end face, and the setting of the multiple through holes 5 can guide the cooling fluid to the friction pair end face from multiple directions, ensuring uniform cooling and heat exchange at all parts of the friction pair end face, and then the fluid after heat exchange is discharged from the exhaust port 7 through the guide pipe 8 for recovery, so that during the long-term use of the dry mechanical seal structure 1, it helps to control the temperature of the friction pair end face within a certain range, effectively prolong the operating life of the sealing structure, and ensure the long-term stable operation of the equipment. The setting of the guide pipe 8 helps to separate the fluid discharged after heat exchange from the cooling fluid that has just entered the outer cavity 31, ensuring the heat exchange cooling effect.

[0025] Reference Figure 2 and Figure 3 , multiple through holes 5 are arranged in multiple rows along the axial direction of the air distribution ring 4, and multiple through holes 5 in each row are arranged at intervals along the circumferential direction of the air distribution ring 4. In the embodiment of the present application, multiple through holes 5 are arranged in two rows along the axial direction of the air distribution ring 4. In other embodiments, the number of rows of multiple through holes 5 arranged along the axial direction of the air distribution ring 4 can be set according to actual needs. Among them, the diameter of the through hole 5 is 2mm-4mm, preferably 3mm. By designing the diameter of the through hole 5 to be smaller, more through holes 5 can be arranged in the circumferential direction of the air distribution ring 4 to ensure uniform cooling and heat exchange at various ends of the friction pair.

[0026] The through holes 5 are designed to have multiple rows, and each row is arranged at intervals along the circumference of the air distribution ring 4, so that within the limited structural size space, the cooling fluid entering the outer cavity 31 can be evenly guided to the friction pair end surface through the multiple through holes 5, further ensuring uniform cooling and heat exchange at various locations on the friction pair end surface, helping to make the temperature of the friction pair end surface consistent, controlling the temperature of the friction pair end surface within a certain range, and effectively extending the service life of the sealing structure.

[0027] Reference Figure 2 and Figure 3 Specifically, the air distribution ring 4 includes two semicircular arc pieces 41, which are relatively fixedly arranged in the sealing cavity 3. The cross-sectional surfaces of the two semicircular arc pieces 41 abut against each other to form a circular ring. The cross-sectional surface of the semicircular arc piece 41 is in the same direction as the cross-sectional surface of the cavity assembly 2 to facilitate the installation and disassembly of the air distribution ring 4.

[0028] The implementation principle of the embodiment of the present application is as follows: when in use, the external cooling fluid is introduced into the outer cavity 31 from the air inlet 6 through the external pipeline and the valve, and then the cooling fluid enters the inner cavity 32 evenly from the multiple through holes 5 on the circumference of the air distribution ring 4, so that it can flow evenly to the friction pair end face in the dry mechanical seal structure 1, which helps to ensure uniform cooling and heat exchange at all parts of the friction pair end face, and then the fluid after heat exchange is discharged from the exhaust port 7 through the guide pipe 8 for recycling and treatment, so that during the long-term use of the dry mechanical seal structure 1, the temperature of the friction pair end face can be controlled within a certain range, effectively extending the service life of the sealing structure and ensuring the long-term stable operation of the equipment.

[0029] The air distribution structure of the dry mechanical seal in the present application can be used in the seal of a single-axis extrusion granulator or a double-axis extrusion granulator. The seal in the double-axis structure is an independent cavity, and there is no connection between the air distribution structures.

[0030] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. The air distribution structure of dry mechanical seal is characterized by: The invention comprises a dry mechanical seal structure (1) and a cavity assembly (2), wherein the cavity assembly (2) has a sealed cavity (3), the dry mechanical seal structure (1) is located in the sealed cavity (3), an air distribution ring (4) is arranged in the sealed cavity (3), the air distribution ring (4) is arranged concentrically with the sealed cavity (3), the air distribution ring (4) divides the sealed cavity (3) into an outer cavity (31) and an inner cavity (32), the dry mechanical seal structure (1) is located in the inner cavity (32), a plurality of through holes (5) are provided on the air distribution ring (4), an air inlet (6) for communicating with an external cooling fluid is provided on the cavity assembly (2), the air inlet (6) is communicated with the outer cavity (31), and an exhaust port (7) for communicating with an external pipeline is provided on the cavity assembly (2), the exhaust port (7) is communicated with the inner cavity (32).

2. The air distribution structure of the dry mechanical seal according to claim 1, characterized in that: The plurality of through holes (5) are arranged in a plurality of rows along the axial direction of the air distribution ring (4).

3. The air distribution structure of the dry mechanical seal according to claim 2, characterized in that: The through holes (5) in each row are arranged at intervals along the circumference of the air distribution ring (4).

4. The air distribution structure of the dry mechanical seal according to claim 1, characterized in that: The diameter of the through hole (5) is 2 mm-4 mm.

5. The air distribution structure of the dry mechanical seal according to claim 1, characterized in that: The air distribution ring (4) is an aluminum ring.

6. The air distribution structure of the dry mechanical seal according to claim 5, characterized in that: The air distribution ring (4) comprises two semi-circular arc pieces (41) arranged relatively in the sealing cavity (3), the two semi-circular arc pieces (41) abut against each other, and the cross-sectional plane of the semi-circular arc piece (41) is in the same direction as the cross-sectional plane of the cavity assembly (2).

7. The air distribution structure of the dry mechanical seal according to claim 1, characterized in that: The air distribution ring (4) is provided with a flow guide tube (8), one end of the flow guide tube (8) is in communication with the inner cavity (32), and the other end of the flow guide tube (8) is in communication with the exhaust port (7), and the exhaust port (7) is in communication with the inner cavity (32) via the flow guide tube (8).

8. The air distribution structure of a dry mechanical seal according to any one of claims 1 to 7, characterized in that: The diameters of the air inlet (6) and the air outlet (7) are both 11 mm to 13 mm.

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