CN102278475A - Dynamic sealing structure for reciprocating movement shaft between high temperature gas and high temperature liquid - Google Patents

Abstract

The invention discloses a dynamic sealing structure of a reciprocating shaft between high-temperature gas and high-temperature liquid. Install the small end of the stepped flange with a central hole in the central hole of the other flange. The two flanges are separated by fillers at the radial joints, and separated by heat insulating material plates at the joints of the end faces. The reciprocating motion shaft The top is coated with heat-insulating ceramic coating and installed coaxially in the two flange holes; the reciprocating shaft on the side of the shoulder surface in the stepped flange hole is provided with three kinds of soft fillers of different materials in sequence from the inside to the outside, and then locked with threads , the outside of which is the high-temperature gas end; the reciprocating shaft on the other side of the shoulder surface in the stepped flange hole is sequentially provided with a combined sealing ring and a snap ring to limit the position of the oblique spring, and the outside is a high-temperature liquid end. In the present invention, the soft packing mainly plays the role of insulating and sealing the high-temperature gas, and the combined sealing ring mainly plays the role of sealing the high-temperature liquid, and the sealing performance can be improved by adjusting the locking device after the packing is worn out.

Description

Dynamic seal structure of reciprocating shaft between high temperature gas and high temperature liquid

technical field

The invention relates to a dynamic sealing structure of a reciprocating shaft, in particular to a dynamic sealing structure of a reciprocating shaft between high-temperature gas and high-temperature liquid.

Background technique

The sealing of high-temperature gas or liquid is a key problem among the problems to be solved in hydraulic and pneumatic systems working under high temperature conditions. If this problem cannot be solved well, it will affect the normal operation of the system, and even produce accidents, with disastrous consequences. At present, there is no effective solution and device for high-temperature dynamic sealing, especially in the working condition where high-temperature gas and high-temperature liquid exist at the same time.

In some specific environments, the gas temperature is within 500-700°C, and the liquid temperature is within 200-300°C. It is difficult for the existing sealing ring products to ensure a good sealing effect for a long time.

Contents of the invention

The purpose of the present invention is to provide a dynamic sealing structure for a reciprocating shaft between high-temperature gas and high-temperature liquid, which can seal the reciprocating shaft when the gas temperature reaches 500-700°C and the liquid temperature reaches 200-300°C.

The technical solution adopted by the present invention to solve its technical problems is:

Install the small end of the stepped flange with a center hole in the center hole of the other flange. The two flanges are separated by heat-insulating asbestos filler at the radial connection, and the large end faces of the two flanges are at the axial connection. Separated by a heat insulating material plate and fixed with bolts and nuts, the reciprocating motion shaft is coated with heat insulating ceramic coating and installed coaxially in the two flange holes; the reciprocating motion on the side of the shoulder surface in the stepped flange hole The shaft is provided with soft fillers of three different materials, expanded graphite filler, copper alloy strip-wound metal filler and ceramic fiber sealing filler, from the inside to the outside, and then the external thread locking device is used to limit and lock the position. The outside of the external thread locking device is high temperature. Gas end; the reciprocating shaft on the other side of the shoulder surface in the stepped flange hole is provided with high temperature resistant plastic, graphite fiber, and metal locking ring pressed into a ring combination seal ring from the inside to the outside, and used in conjunction with the oblique spring , the metal locking ring is in contact with the snap ring and is limited, and the outer side of the snap ring is the high-temperature liquid end.

The expanded graphite filler and the ceramic fiber sealing filler are cylindrical rings, and the copper alloy strip-wound metal filler is a frustum-shaped ring with a small inside and a large outside, and its generatrix is a straight line or a curve.

The stepped flange, flange, external thread locking device, snap ring, bolt and nut are all made of the same high temperature resistant alloy material.

The beneficial effects that the present invention has are:

1 The combined seal can form a temperature gradient and a pressure gradient, so that each sealing packing can work in an appropriate pressure and temperature range, ensuring the life of the sealing packing and sealing effect, and reducing leakage.

2 Sealing rings are used for liquid and gas respectively, which can play a sealing role under the conditions of different temperatures and pressures of gases and liquids.

3 After working for a period of time, when the sealing packing has a small amount of wear, it can be compressed by adjusting the external thread locking device to continue to use.

4 The flanges of the gas part and the flanges of the liquid part are separated by heat insulating materials to reduce the heat exchange between gas and liquid and cause further increase of liquid temperature.

Description of drawings

Accompanying drawing is the structural principle schematic diagram of the present invention.

In the figure: 1. Reciprocating motion shaft, 2. High temperature gas, 3. External thread locking device, 4. Ceramic fiber sealing packing, 5. Copper alloy tape winding metal packing, 6. Thermal insulation asbestos packing, 7. Expanded graphite packing , 8. Flange, 9. Bolt, 10. Heat shield, 11. Nut, 12. High temperature resistant plastic, 13. Graphite fiber, 14. Metal locking ring, 15. Inclined spring, 16. Thermal insulation ceramic coating, 17 , High temperature liquid, 18, snap ring, 19, flange.

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

As shown in the drawings, install the small end of the stepped flange 8 with a central hole in the central hole of another flange 19, and the two flanges are separated by heat-insulating asbestos filler 6 at the radial connection. The large end face of the flange is separated by a heat-insulating material plate 10 at the axial connection, and fixed with bolts 9 and nuts 11, and the reciprocating motion shaft 1 is coated with heat-insulating ceramic coating 16 and coaxially installed in two flange holes; The reciprocating motion shaft 1 on the side of the shoulder surface in the 8 holes of the stepped flange is provided with soft packing of three different materials such as expanded graphite packing 7, copper alloy tape winding metal packing 5 and ceramic fiber sealing packing 4 from the inside to the outside. The external thread locking device 3 is limited and locked, and its outer side is the high-temperature gas end; the reciprocating motion shaft 1 on the other side of the shoulder surface in the 8 holes of the stepped flange is sequentially provided with high-temperature-resistant plastic 12 from the inside to the outside. Graphite fiber 13 and metal locking ring 14 are pressed together with oblique spring 15 to form a combined sealing ring. Metal locking ring 14 is in contact with snap ring 18 to limit the position. The outer side of snap ring 18 is the high-temperature liquid end.

The ceramic fiber sealing packing 4 is made of high temperature resistant material mainly for heat insulation and proper sealing of the gas. The metal packing 5 wrapped with copper alloy tape and the expanded graphite packing 7 are used to seal and isolate the very small amount of gas leaked from the ceramic fiber sealing packing 4, thereby Play a sealing role. When the filler is used for a long working time to wear and become loose, the external thread locking device 3 can be adjusted to compress. The high-temperature liquid part is sealed by a combined sealing ring composed of high-temperature-resistant plastic 12, graphite fiber 13 and metal locking ring 14, and the contact surface is locked by an oblique spring. The flange in contact with the ultra-high temperature gas and the flange in contact with the high-temperature liquid are isolated and sealed by heat insulating materials, so that the heat of the ultra-high temperature gas cannot be directly transferred from the flange to the flange of the high-temperature liquid part, which will cause further increase in the temperature of the high-temperature liquid. raised. In order to ensure that the shaft is not heated up by the heat transfer of ultra-high temperature gas, the ceramic coating is applied on the reciprocating axis of the shaft to play a heat insulating role.

The expanded graphite filler 7 and the ceramic fiber sealing filler 4 are cylindrical rings, and the metal filler 5 wrapped with a copper alloy tape is a frustum-shaped ring with a small inside and a large outside, and its generatrix is a straight line or a curve, forming a wedge shape to ensure the sealing effect .

The stepped flange 8, flange 19, external thread locking device 3, snap ring 18, bolt 9 and nut 11 are all made of the same high temperature resistant alloy material to ensure the same deformation under high temperature environment.

Claims (3)

1. the movable sealing structure of reciprocating shaft between high-temperature gas and high-temp liquid, it is characterized in that: the small end that has the ladder flange (8) of center hole in inciting somebody to action is installed in another flange (19) center hole, two flanges separate with heat insulation asbestos packing (6) in joint radially, the large end face of two flanges separates with thermal-protective material plate (10) in axial joint, and affixed with bolt (9) and nut (11), be coated with on the reciprocating shaft (1) that insulating ceramic coating (16) is coaxial to be installed in two flange holes; The reciprocating shaft (1) of circular bead surface one side in ladder flange (8) hole from inside to outside is provided with the spacing and locking with outside thread locking device (3) after the soft packing that expanded graphite packing (7), copper alloy belt twine metallic stuffing (5) and (4) three kinds of different materials of ceramic fiber stuffing box packing successively, is the high-temperature gas end outside the outside thread locking device (3); The reciprocating shaft (1) of the circular bead surface opposite side in ladder flange (8) hole from inside to outside is provided with successively by high-temperature resistance plastice (12), seal ring that graphite fiber (13) and metal locking ring (14) are pressed into and oblique heart spring (15), metal locking ring (14) contacts with snap ring (18) and carries out spacingly, and snap ring (18) outside is the high-temp liquid end.

2. the movable sealing structure of reciprocating shaft between a kind of high-temperature gas according to claim 1 and high-temp liquid, it is characterized in that: described expanded graphite packing (7) and ceramic fiber stuffing box packing (4) are for being cylindrical ring, copper alloy belt twine metallic stuffing (5) for inner small and outside big be the frustoconic shape ring,, its bus is straight line or curve.

3. the movable sealing structure of reciprocating shaft between a kind of high-temperature gas according to claim 1 and high-temp liquid, it is characterized in that: described ladder flange (8), flange (19), outside thread locking device (3), snap ring (18), bolt (9) all adopts identical high-temperature alloy material with nut (11).

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