Contact-type gas seal device

Abstract

To provide a contact-type gas seal device for the rotating shaft of equipment. [Solution] The gland assembly includes a front cover 2 and a rear cover 1, and a seal assembly provided within the gland assembly and arranged to rotate together with a pivot shaft 9. The inner end face of the front cover and the end face of the first seal ring 4 of the seal assembly form a first friction pair, and the inner end face of the rear cover and the end face of the second seal ring 5 of the seal assembly form a second friction pair. A cylindrical space 16 is formed between the inner circumferential surface of the gland assembly, the inner end face of the front cover, the inner end face of the rear cover, and the outer circumferential surface of the seal assembly. The gland assembly is provided with a gas inlet 10 that communicates with the cylindrical space and is connected to an external gas source. At least one contact end face of the first friction pair is provided with a guide groove 14 that extends from the radial center of the first friction pair to the friction outer diameter and guides the pressurized gas in the cylindrical space to the contact surface of the first friction pair.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of sealing, and particularly relates to a contact gas sealing device for a rotating shaft of equipment for processing solid, semi-solid or high-viscosity fluid materials. [Background Art]

[0002] In chemical industry, food, pharmaceutical industry and other industries, equipment such as agitators, mixers, screw conveyors are widely used for processing solid powder, granular materials or high-viscosity fluids. Where the rotating shaft of such equipment penetrates the equipment casing, a reliable seal is required to prevent leakage of internal materials and block entry of external contaminants.

[0003] At present, the general operating condition of such equipment is low rotation speed, with large axial play and radial runout. Commonly used sealing methods include packing seals, rubber lip seals and contact mechanical seals. However, these sealing methods have obvious defects: the packing seal is prone to wear of the rotating shaft, requires frequent adjustment of pressing force, and has a short service life; the rubber lip seal also has limited service life and has high requirements for the surface finish of the shaft. These two sealing methods have serious leakage, are prone to cause environmental pollution, bring potential hazards to production and personal safety, and are only applicable to simple cases where sealing requirements are not high.

[0004] Conventional mechanical seals for fluids have excellent sealing performance, but usually require high installation accuracy of the equipment, are difficult to adapt to the large shaft runout and play in the above operating conditions, and have limited applications. On the other hand, the principle of non-contact dry gas seal is to use the gas dynamic pressure effect to form a non-contact gas film between the sealing end faces at high speed rotation, which is not applicable to the contact end face seal under the low-speed and heavy-load operating conditions described in the present technical field.

[0005] Several improvements have emerged to enhance the performance of contact seals. For example, there are techniques to adapt to shaft eccentricity and rattle by using an elastic member to drive the seal ring and allow its float, techniques to increase the seal prepressure with an external gas source, and techniques to improve the ambient temperature of the seal assembly by installing a gas ring inside the seal cavity.

[0006] However, the improvements in the above-mentioned conventional technologies share a common flaw: although the externally connected pressurized gas enters the seal cavity, it only acts on the space outside the seal friction pair, and is used to provide seal prepressurization and create isolation from the medium on the outer circumference of the friction pair. This method is indirect cooling, and the pressurized gas is not accurately guided into the contact area of ​​the seal end face that is directly subjected to friction, and effective gas convection cannot be formed between the friction pairs. Therefore, when the operating temperature fluctuates or the rotational speed of the equipment is high, the heat generated by the friction pair increases rapidly, and because there is no direct and effective cooling means, seal wear becomes severe and the service life is shortened. Frequent stoppages and replacements not only affect production efficiency but also increase maintenance costs.

[0007] Therefore, assuming reliable sealing can be guaranteed, a new type of contact gas sealing device is needed that can accurately transport cooling gas to the contact surface of the friction pair and form effective gas convection at the friction surface, thereby solving the problem of severe heat generation, rapid wear, rapid failure, and the need for frequent shutdowns and maintenance of sealing friction pairs in powder and slurry stirring and transport equipment. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The objective of this invention is to provide a contact-type gas sealing device that overcomes the shortcomings of the prior art, guarantees a reliable seal, accurately transports cooling gas to the contact surfaces of friction pairs, and forms effective gas convection on the friction surfaces. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides a contact gas seal device for sealing solid or high-viscosity materials inside a rotating machine, which is installed between the case of the rotating machine and a pivot shaft that penetrates the case, and includes a gland assembly comprising a front cover and a rear cover, wherein the front cover and the rear cover are axially connected by fasteners, and the front cover is fastened to the case by connecting bolts; and a seal assembly provided within the gland assembly, comprising a first seal ring, an elastic seal ring seat and a second seal ring, wherein the three are formed as a whole by insert or friction connection and are arranged to rotate with the pivot shaft, wherein the inner end face of the front cover and the end face of the first seal ring The present invention provides a contact-type gas seal device characterized in that a first friction pair is formed by the inner end face of the rear end cover and the end face of the second seal ring, a cylindrical space is formed between the inner circumferential surface of the gland assembly, the inner end face of the front cover, the inner end face of the rear end cover and the outer circumferential surface of the seal assembly, the gland assembly is provided with a gas inlet communicating with the cylindrical space and is used to inject pressurized gas into the cylindrical space by connecting an external gas source, and at least one contact end face of the first friction pair is provided with a guide groove that extends from the radial middle of the first friction pair to the friction outer diameter, is distributed symmetrically in the circumferential direction, and guides the pressurized gas in the cylindrical space to the contact surface of the first friction pair.

[0010] According to a selectable embodiment, a ventilation passage is provided on the end face of the seal ring or the end face of the tip cover, and the ventilation passage is arranged to partially communicate with the guide groove at least for a portion of the rotation of the pivot shaft, and at the same time communicate with the cylindrical space or the gas inlet.

[0011] According to a selectable embodiment, the air guide groove is provided on the end face of the first seal ring facing the tip cover.

[0012] According to a selectable embodiment, the air guide groove is provided on the end face of the tip cover facing the first seal ring.

[0013] According to a selectable embodiment, the guide groove partially or completely penetrates the first friction pair along the axial direction.

[0014] According to a selectable embodiment, the ventilation passages are arranged symmetrically along the circumferential direction.

[0015] According to a selectable embodiment, the pressure of the pressurized gas is at least 0.5 BAR greater than the pressure of the material inside the device.

[0016] According to an optional embodiment, a valve opening / closing device and / or a pressure and flow velocity adjustment and detection device are installed between the external gas source and the gas inlet.

[0017] According to a selectable embodiment, the pressurized gas is nitrogen, carbon dioxide, or air.

[0018] According to a selectable embodiment, the elastic seal ring seat is made of a rubber-plastic material, and its hardness is less than the material hardness of the first seal ring and the second seal ring.

[0019] According to a selectable embodiment, the seal assembly is positioned to float axially and radially relative to the gland assembly.

[0020] According to a selectable embodiment, an adjustment gasket is provided between the front cover and the rear cover for adjusting the axial length of the gland assembly.

[0021] According to a selectable embodiment, the components of the contact gas seal device are molded to be an integral structure, a divisible structure, or a combination of both, and the divisions are connected via gaskets or transition members.

[0022] According to an alternative embodiment, the cylindrical space is configured to provide a collection and storage space when material leaks instantaneously. [Effects of the Invention]

[0023] Unlike the indirect cooling method in the prior art in which gas acts only on the outer space of the sealing friction pair, the present invention provides an air guide groove extending from the radial middle portion to the outer diameter on the friction sealing surface, so that the pressure-receiving gas can directly enter the contact surface of the friction pair. The flowing gas forms convection on the friction surface, continuously absorbs heat generated by friction, performs cooling directly at the heat source, effectively controls the temperature of the sealing surface, and fundamentally solves the problem of low cooling efficiency in the prior art.

[0024] The pressure-receiving gas is guided by the air guide groove closer to the sealing interface where the movable ring, the stationary ring and the particle medium contact each other, forming an annular gas isolation, which makes the purging of the sealing material more direct and effective. The pressure-receiving gas with a pressure higher than the material pressure can prevent solid particles or high-viscosity materials in equipment from intruding into the friction surface, which fundamentally avoids abrasive wear and extends the service life of the seal.

[0025] The symmetrical distribution of the air guide grooves along the circumferential direction allows the cooling gas to flow uniformly on the sealing surface, so as to avoid local overheating. When the air passage is provided, the air passage engages with the air guide groove to form dynamic communication during the rotation of the rotating shaft, further improving the transport efficiency of gas to the friction surface. With this structure, the contact type gas sealing device can adapt to severe conditions such as temperature fluctuation under operating conditions or high rotation speed of equipment.

[0026] When the air passage is provided, the air passage ensures smooth flow of gas, and can provide a collection and storage space when the sealing material leaks instantaneously, reducing the progress of wear caused by materials entering the friction sealing surface, and improving the safety and reliability of the seal.

[0027] The seal assembly of the present invention is connected to the rotating shaft via an elastic seal ring seat, has axial and radial floating performance, and can well compensate radial runout and axial play of the shaft. At the same time, the pressure applied by the pressure-receiving gas to the seal ring combines with the elastic pre-pressure of the elastic seal ring seat, which makes the adhesion of the seal surface more stable, and can maintain reliable sealing even at the moment of pressure fluctuation or start-stop.

[0028] The gland assembly of the present invention adopts a structure in which a front end cover and a rear end cover can be disassembled. After stopping the rotation of the device and closing the external gas source, the fastener can be loosened to separate the rear end cover from the front end cover along the axial direction, which makes it easy to replace the internal seal assembly, there is no need to remove the main shaft of the device, and the difficulty and cost of maintenance are reduced.

[0029] As described above, in the present invention, by providing an air guide groove on the friction seal surface, pressure-receiving gas is directly introduced into the friction contact surface to perform convective cooling and material purging, which effectively reduces frictional heat generation, reduces wear of the friction pair, prolongs the service life of the seal, improves production efficiency, and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0031] [Figure 1] It is a cross-sectional view of the overall structure in which the contact type gas seal device according to the first embodiment of the present invention is attached to a device case, wherein an air guide groove is provided on an end face of a first seal ring. [Figure 2] It is a schematic perspective structural view of the first seal ring in the first embodiment of the present invention, showing the air guide groove provided on the end face thereof. [Figure 3] It is a cross-sectional view of the overall structure in which the contact type gas seal device according to the second embodiment of the present invention is attached to a device case, wherein an air guide groove is provided on an end face of a front end cover. [Figure 4]This is a front view of the sealing surface of the tip cover in the second embodiment of the present invention, showing the air guide groove provided on the end face of the tip cover. [Figure 5] This is a cross-sectional view of the overall structure of a contact-type gas seal device according to the third embodiment of the present invention, which is attached to an equipment case. An air guide groove is provided on the end face of the first seal ring, and an annular ventilation passage is provided inside the tip cover. [Figure 6] This is a front view of the sealing surface of the tip cover in the third embodiment of the present invention, showing the annular ventilation passage provided inside the tip cover. [Figure 7] This is a schematic diagram of the three-dimensional structure of the first seal ring in the third embodiment of the present invention, showing the air guide groove and annular air passage at its end face. [Figure 8] This is a cross-sectional view of the overall structure of a contact-type gas seal device according to the fourth embodiment of the present invention, which is attached to an equipment case, and a through-type gas guide groove is provided on the end face of the first seal ring. [Figure 9] This is a schematic diagram of the three-dimensional structure of the first seal ring in the fourth embodiment of the present invention, showing a through-type air guiding groove.

[0032] Further objectives and features of the embodiments of this invention will become clear when you follow the detailed description accompanied by the following drawings. However, it should be understood that the drawings are designed for illustrative purposes only and do not limit the scope of this invention. [Modes for carrying out the invention]

[0033] Hereinafter, the technical proposal in the embodiments of the present invention will be clearly and completely described with reference to the drawings of the embodiments of the present invention. Needless to say, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention fall within the scope of protection of the present invention.

[0034] In the following drawings, similar reference numerals and letters indicate similar items; therefore, once an item is defined in one drawing, it is not necessary to further define or explain that item in subsequent drawings.

[0035] In describing this invention, it should be understood that the directions or positional relationships indicated by terms such as "axial direction," "radial direction," "circumferential direction," "inside," and "outside" are based on the directions or positional relationships shown in the drawings, and are merely for the purpose of making the description of this invention easier and simpler. They do not indicate or imply that the shown device or component has a specific direction or must be configured and operated in that specific direction, and therefore should not be understood as limitations on this invention.

[0036] Furthermore, terms such as "first" and "second" are merely descriptive and should not be understood as indicating or suggesting relative importance, or implicitly referring to the number of technical features shown.

[0037] Figure 1 is a cross-sectional view of the overall structure of a contact-type gas seal device according to the first embodiment of the present invention, attached to a device case, and an air guide groove is provided on the end face of the first seal ring. Figure 2 is a schematic diagram of the three-dimensional structure of the first seal ring in the first embodiment of the present invention, showing the air guide groove provided on its end face. Referring to Figures 1 and 2, the contact-type gas seal device of the present invention is installed as a whole between the case 8 of a rotating device and the pivot shaft 9 that passes through it, and is intended to seal solid powder, particulate material, or high-viscosity fluid inside the device to prevent leakage of internal material to the outside and entry of external impurities.

[0038] As shown in Figure 1, the contact gas seal device mainly comprises a gland assembly and a seal assembly located inside it. The gland assembly includes a front cover 2 and a rear cover 1, which are axially connected via fasteners 6 and an adjustment gasket 15. The front cover 2 is fastened to the equipment case 8 by connecting bolts 11 and an auxiliary seal ring 7, providing connection to the equipment, positioning, and static sealing. After stopping the rotation of the equipment and turning off the external gas source, the fasteners 6 can be loosened to separate the rear cover 1 from the front cover 2 axially, facilitating replacement of the internal seal assembly.

[0039] The seal assembly includes a first seal ring 4, an elastic seal ring seat 3, and a second seal ring 5. The elastic seal ring seat 3 is made of a rubber-plastic material such as rubber or polyurethane, and its hardness is lower than that of the cemented carbide or ceramic materials of the first seal ring 4 and the second seal ring 5. The three components, the first seal ring 4, the elastic seal ring seat 3, and the second seal ring 5, constitute the entire seal assembly by fitting or friction connection, and provide axial and radial floating. The inner bore of the elastic seal ring seat 3 tightly embraces the pivot shaft 9, and during normal operation, frictional force causes the entire seal assembly to rotate together with the pivot shaft 9.

[0040] The inner end face of the front cover 2 is provided opposite the end face of the first seal ring 4 that faces the material side, forming the first friction pair. The inner end face of the rear cover 1 is provided opposite the end face of the second seal ring 5 that is opposite to the material side, forming the second friction pair.

[0041] A cylindrical space 16 for containing pressurized gas is formed between the inner circumferential surface of the ground assembly, the inner end surface of the tip cover 2, the inner end surface of the rear end cover 1, and the outer circumferential surface of the seal assembly.

[0042] A gas inlet 10 is provided in either the front cover 2 or the rear cover 1. A screw connection port for connecting to an external gas source is provided at the outer end of the gas inlet 10. A valve opening / closing device and a pressure and flow velocity adjustment and detection device can be installed between the external gas source and the gas inlet 10. A pressurized gas (e.g., nitrogen, carbon dioxide, or clean air) with a constant pressure can be injected into the cylindrical space 16 through the gas inlet 10. The pressure of the pressurized gas should be at least 0.5 BAR greater than the pressure of the materials inside the device.

[0043] In the first embodiment, as shown in Figures 1 and 2, an air guide groove 14 is provided on the end face of the first seal ring 4 facing the tip cover 2.

[0044] The guide groove 14 extends from the radial center of the first friction pair to the outer friction diameter and is distributed symmetrically along the circumferential direction. Because the guide groove 14 extends to the outer friction diameter and is in direct communication with the cylindrical space 16, the pressurized gas injected from an external gas source can enter the central region of the contact surface of the first friction pair without obstruction via the guide groove 14.

[0045] When the equipment is in operation, the pivot shaft 9 rotates the seal assembly together with it, while the gland assembly remains stationary. Simultaneously, an external gas source injects pressurized gas into the cylindrical space 16 through the gas inlet 10. The pressurized gas fills the cylindrical space 16 and applies axial pressure to the first seal ring 4 and the second seal ring 5, causing the first seal ring 4 to press against the front cover 2 and the second seal ring 5 to press against the rear cover 1, thereby achieving a rotary contact seal.

[0046] Importantly, because the guide groove 14 extends from the center to the outer diameter of the friction surface, the pressurized gas in the cylindrical space 16 is directly guided to the contact surface of the first friction pair through the guide groove 14. The flowing pressurized gas forms convection on the friction surface, constantly removing heat from the friction and achieving direct cooling of the friction pair. At the same time, the pressurized gas creates a purging effect on the seal surface, preventing material from penetrating the friction surface, reducing wear, and extending the seal's service life.

[0047] Figure 3 is a cross-sectional view of the overall structure of the contact-type gas seal device according to the second embodiment of the present invention, attached to an equipment case, and shows that an air guide groove is provided on the end face of the tip cover. Figure 4 is a front view of the sealing surface of the tip cover in the second embodiment of the present invention, showing the air guide groove provided on the end face of the tip cover. Referring to Figures 3 and 4, the difference between the second embodiment and the first embodiment is that the installation position of the air guide groove 14 is different.

[0048] In the second embodiment, the air guide groove 14 is provided not on the first seal ring 4, but on the end face of the tip cover 2 facing the first seal ring 4. As shown in Figure 4, the air guide groove 14 extends from the radial center of the end face of the tip cover 2, beyond the outer diameter edge of the contacting first seal ring 4, directly communicates with the cylindrical space 16, and is distributed symmetrically along the circumferential direction.

[0049] The operating principle of the second embodiment is the same as that of the first embodiment. The pressurized gas is guided to the contact surface of the first friction pair by a guide groove 14 provided in the stationary tip cover 2, thereby achieving convective cooling and material purging. By providing the guide groove 14 in the stationary tip cover 2, the machining process for the rotating seal ring can be simplified.

[0050] Figure 5 is a cross-sectional view of the overall structure of a contact-type gas seal device according to the third embodiment of the present invention, mounted on an equipment case. An air guide groove is provided on the end face of the first seal ring, and an annular ventilation passage is provided inside the tip cover. Figure 6 is a front view of the sealing surface of the tip cover in the third embodiment of the present invention, showing the annular ventilation passage provided inside the tip cover. Figure 7 is a schematic diagram of the three-dimensional structure of the first seal ring in the third embodiment of the present invention, showing the air guide groove and annular ventilation passage on the end face. Referring to Figures 5, 6, and 7, the third embodiment includes a ventilation passage 12 in addition to the first embodiment.

[0051] As shown in Figures 5 and 7, an air guide groove 14 is provided on the end face of the first seal ring 4 facing the tip cover 2, and a ventilation passage 12 is further provided inside the ring of the first seal ring 4. Alternatively, as shown in Figure 6, the ventilation passage 12 may be provided inside the main body of the tip cover 2.

[0052] The ventilation passage 12 has one end that communicates with the cylindrical space 16 or directly with the gas inlet 10, and the other end that opens near the contact surface of the first friction pair.

[0053] The ventilation passages 12 are distributed symmetrically in the circumferential direction. During the rotation of the pivot shaft 9, the ventilation passages 12 partially communicate with the guide grooves 14 at least at some timings, thereby further enhancing the efficiency of gas transport to the friction surface at the base of the guide grooves 14.

[0054] In addition to enhancing gas flow, the ventilation passage 12 provides a collection and storage space for material when it leaks momentarily, reduces wear progression due to material entering the friction seal surface, and improves the safety reliability of the seal.

[0055] Figure 8 is a cross-sectional view of the overall structure of the contact-type gas seal device according to the fourth embodiment of the present invention, mounted on an equipment case, and a through-type gas guide groove is provided on the end face of the first seal ring. Figure 9 is a schematic diagram of the three-dimensional structure of the first seal ring in the fourth embodiment of the present invention, showing the through-type gas guide groove. Referring to Figures 8 and 9, the difference between the fourth embodiment and the first embodiment is the difference in the depth of the gas guide groove 14.

[0056] In the fourth embodiment, the guide groove 14 provided on the end face of the first seal ring 4 partially or completely penetrates the first friction pair along the axial direction. As shown in Figure 9, the depth of the guide groove 14 is large, and the guide groove 14 penetrates the entire thickness of the friction surface.

[0057] The through-type gas guide groove 14 further increases the cross-sectional area and flow rate of the gas flow, enhancing the convective cooling effect, and is particularly applicable when the operating temperature is high or the rotation speed of the equipment is high.

[0058] To facilitate adjustment of the seal prepressure, one or more sets of adjustment gaskets 15 may be provided between the front cover 2 and the rear cover 1, as shown in Figures 1-8. By increasing or decreasing the thickness of the gaskets, the overall axial length of the gland assembly 20 can be finely adjusted, thereby changing the initial compression amount against the elastic seal ring seat 3 and achieving the objective of precisely adjusting the seal prepressure.

[0059] To accommodate different mounting and maintenance needs, the components of this contact gas seal device, particularly the gland assembly 20 and the seal ring, may be designed as a single integrated structure, a divisible structure divided along the axial or radial direction, or a combination structure that is partially whole and partially divided. The divisions are connected by gaskets or transition members to facilitate mounting and replacement without removing the equipment spindle.

[0060] As described above, this invention fundamentally improves the operating environment of contact seals by providing an air guide groove 14 extending from the radial center to the outer diameter on the friction seal surface, adding a ventilation passage 12 as needed, and directly introducing pressurized gas to the friction contact surface for convection cooling and material purging. This solves the drawbacks of conventional technology, such as insufficient cooling and severe wear, extends the service life of the seals, and reduces production and maintenance costs.

[0061] While some specific embodiments of the present invention have been described in detail by means of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not intended to limit the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the present invention is indicated by the claims.

Claims

1. A contact-type gas seal device, installed between the case (8) of a rotating machine and a pivot shaft (9) that penetrates the case (8), for sealing solid or high-viscosity materials inside the machine, A gland assembly comprising a front cover (2) and a rear cover (1), wherein the front cover (2) and the rear cover (1) are axially connected by fasteners (6), and the front cover (2) is fastened to the case (8) by connecting bolts (11), A seal assembly provided within the ground assembly, comprising a first seal ring (4), an elastic seal ring seat (3), and a second seal ring (5), the three of which are connected by inserts or friction connections, and which is arranged to rotate in conjunction with the pivot shaft (9), The inner end face of the front cover (2) and the end face of the first seal ring (4) form a first friction pair, and the inner end face of the rear cover (1) and the end face of the second seal ring (5) form a second friction pair. A cylindrical space (16) is formed between the inner circumferential surface of the ground assembly, the inner end surface of the front cover (2), the inner end surface of the rear cover (1), and the outer circumferential surface of the seal assembly. The ground assembly is provided with a gas inlet (10) that communicates with the cylindrical space (16), and is used to connect an external gas source and inject pressurized gas into the cylindrical space (16). A contact-type gas seal device characterized in that at least one contact end face of the first friction pair is provided with a guide groove (14) that extends from the radial center of the first friction pair to the friction outer diameter, is distributed symmetrically in the circumferential direction, and guides the pressurized gas in the cylindrical space (16) to the contact surface of the first friction pair.

2. A ventilation passage (12) is provided on the end face of the first seal ring (4) or the end face of the tip cover (2). The contact-type gas seal device according to claim 1, characterized in that the ventilation passage (12) is arranged to communicate partially with the guide groove (14) at least a portion of the timing when the pivot shaft (9) rotates, and at the same time communicate with the cylindrical space (16) or the gas inlet (10).

3. The contact-type gas seal device according to claim 1, characterized in that the air guide groove (14) is provided on the end face of the first seal ring (4) facing the tip cover (2).

4. The contact-type gas seal device according to claim 1, characterized in that the air guide groove (14) is provided on the end face of the tip cover (2) facing the first seal ring (4).

5. The contact-type gas seal device according to claim 1, characterized in that the air guide groove (14) partially or completely penetrates the first friction pair along the axial direction.

6. The contact-type gas seal device according to claim 2, characterized in that the ventilation passage (12) is arranged symmetrically along the circumferential direction.

7. The contact-type gas seal device according to claim 1, characterized in that the pressure of the pressurized gas is at least 0.5 BAR greater than the pressure of the material inside the device.

8. The contact-type gas seal device according to claim 1, characterized in that a valve opening / closing device and / or a device for adjusting and detecting atmospheric pressure and flow velocity are installed between the external gas source and the gas inlet (10).

9. The contact-type gas seal device according to claim 1, characterized in that the pressurized gas is nitrogen, carbon dioxide, or air.

10. The contact-type gas seal device according to claim 1, characterized in that the elastic seal ring seat (3) is made of a rubber plastic material and its hardness is less than the material hardness of the first seal ring (4) and the second seal ring (5).

11. The contact-type gas seal device according to claim 1, characterized in that the seal assembly is arranged to float axially and radially relative to the gland assembly.

12. The contact-type gas seal device according to claim 1, characterized in that an adjustment gasket (15) for adjusting the axial length of the gland assembly is provided between the front cover (2) and the rear cover (1).

13. The contact gas seal device according to claim 1, characterized in that the components of the contact gas seal device are formed into an integrated structure, a divisible structure, or a combination of both, and the divided portions are connected via gaskets or transition members.

14. The contact gas seal device according to claim 2, characterized in that the cylindrical space (16) is arranged to provide a collection and storage space when material leaks instantaneously.

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