A high-temperature magnetic fluid seal assembly for a steam turbine drain riser

Abstract

The utility model relates to a sealing assembly technical field especially is a kind of high-temperature magnetic fluid sealing assembly for steam turbine drainage riser, including two drainage pipes, the outer wall one end of two drainage pipes is equipped with first flange plate, and the outer wall of two first flange plates is provided with eight thread holes around the axis forty-five degrees equidistance, the thread hole of first flange plate is connected with connecting disc by hexagon bolt thread, and the outer wall one end of hexagon bolt is connected with nut, the left side of connecting disc is equipped with second flange plate, and the outer wall of connecting disc is provided with eight thread holes, and the inner wall is consistent with the structure size of first flange plate and corresponding, the connecting disc is connected with closed assembly by inner wall thread thread. The device can be rotated and screwed on the thread at the both ends of shaft sleeve by connecting disc, connected by hexagon bolt and nut and pipeline etc. flange, use two sets of pole piece magnetic pole opposite to drive high-temperature magnetic fluid to form sealing ring in shaft sleeve, high-temperature resistance long life, maintenance frequency is low.

Description

Technical Field

[0001] This utility model relates to the field of sealing component technology, specifically to a high-temperature magnetic fluid sealing component for steam turbine drainage risers. Background Technology

[0002] A sealing assembly is a complete functional unit that forms an effective barrier between two or more mechanical parts to prevent or control the leakage of working media (such as liquids or gases) and to prevent the intrusion of external contaminants (such as dust, moisture, and impurities). It consists of one or more sealing elements (such as O-rings, gaskets, mechanical seals, etc.) and their matching support structures (such as grooves, glands, bushings, fasteners, etc.). As one type, the high-temperature magnetohydrodynamic sealing assembly for turbine drain risers is a special device specifically installed on turbine drain risers to achieve an absolute seal between the rotating drain valve stem and the fixed valve body under high temperature and high pressure environments.

[0003] Chinese utility model patent CN221683039U discloses a steam turbine sealing device, which includes "an outer sealing ring and a plurality of inner sealing rings equidistantly disposed on the rotor, with a sealing cavity formed between two adjacent inner sealing rings, the outer sealing ring being disposed around the inner sealing ring, and an arc-shaped sealing strip that can be embedded in the sealing cavity being connected to the outer sealing ring"; however, it is affected by the operating environment during long-term use, wears out quickly, requires frequent maintenance, causes leakage, and increases production costs. Utility Model Content

[0004] The purpose of this invention is to provide a high-temperature magnetic fluid sealing assembly for steam turbine drain risers to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a high-temperature magnetic fluid sealing assembly for a steam turbine drain riser, comprising two drain pipes, each drain pipe having a first flange at one end of its outer wall, and the outer walls of the two first flanges having eight threaded holes equidistantly spaced around the axis at 45 degrees. The threaded holes of the first flanges are threaded to a connecting plate via hexagonal bolts, and one end of the outer wall of the hexagonal bolts is threaded to a nut. A second flange is provided on the left side of the connecting plate, and the outer wall of the connecting plate has eight threaded holes with an inner wall size consistent with and corresponding to the first flange. The connecting plate is threaded to a sealing assembly via its inner wall thread.

[0006] The enclosed assembly includes a bushing with threaded interfaces at both ends, and the bushing is threadedly connected to the connecting disc through the threaded interfaces. A liquid storage tube is provided at the center of the outer wall of the bushing, and multiple heat dissipation fins are provided on the outer wall of the liquid storage tube. The inner wall of the bushing has two first grooves and a labyrinth-type sealing rings arranged sequentially from both sides to the middle. A first pole shoe is provided at the inward end of the two sets of labyrinth-type sealing rings. A permanent magnet is fixedly installed at the inward end of the two first pole shoes, and a second pole shoe is fixedly installed at the inward end of the two sets of permanent magnets.

[0007] The beneficial effects of this utility model are as follows: the device can be rotated and screwed onto the threads at both ends of the bushing via the connecting disc, and connected to the flange of the pipe or other flange via hexagonal bolts and nuts. It utilizes the opposite magnetic poles of the two sets of pole shoes to drive the high-temperature magnetic fluid to form a sealing ring inside the bushing, which has high temperature resistance, long service life, and low maintenance frequency.

[0008] To ensure adequate replenishment of the high-temperature magnetic fluid within the storage tube and extend the sealing time:

[0009] The further configuration is as follows: the outer wall of the liquid storage tube is provided with an injection port, and an injection plug is threadedly connected to the injection port. The outer wall of the injection plug is provided with two anti-overflow gaskets.

[0010] By adopting the above technical solution, the high-temperature magnetic fluid is injected into the storage tube by unscrewing the injection plug and using a tool. This appropriately replenishes the high-temperature magnetic fluid consumed in the tube, which helps to extend the sealing time and reduce the maintenance frequency.

[0011] To ensure that the connection between the drainage riser and the pipe remains aligned at all times, avoid vibration and misalignment during installation, and improve the sealing effect:

[0012] The design further includes: flexible graphite sealing rings are engaged with the inner rings of both first grooves.

[0013] By adopting the above technical solution, the inner rings of the two first grooves contact equipment such as drainage risers through the snap-fit ​​flexible graphite sealing rings. Utilizing their own elasticity, they automatically compensate for radial runout and installation eccentricity during installation, while reducing friction and vibration offset between them and the bushing, thus improving the sealing effect.

[0014] To ensure the high-temperature magnetic fluid does not evaporate or carbonize at high temperatures, thus maintaining a good seal:

[0015] The further configuration is as follows: the side wall of the liquid storage tube is provided with two water-cooled liquid exchange ports, which can be connected to cooling water, and the inside of the liquid storage tube is hollow, storing a high-temperature magnetic fluid using perfluoropolyether or other fluorocarbon oils as the base fluid.

[0016] By adopting the above technical solution, cooling water is connected to the liquid exchange port through two water-cooled outlets to cool the high-temperature magnetic fluid stored inside the liquid storage tube. The high-temperature magnetic fluid circulates and carries away heat under the action of two sets of pole shoes with opposite magnetic poles, which avoids the evaporation and carbonization of the magnetic fluid and the influence of the magnetic pole shoes, thus improving the sealing effect.

[0017] To extend the service life of the first and second pole shoes and improve the fixation effect of the two sets of pole shoes on the high-temperature magnetofluid:

[0018] Further configuration: the first pole piece is the positive pole, the second pole piece is the negative pole, and both are made of samarium cobalt magnet material. The inner wall is provided with multiple sets of annular concave and convex toothed channels, and the upper and lower parts of the interior are provided with pipes connected to and communicating with the liquid storage pipe.

[0019] By adopting the above technical solution, the first and second pole shoes, using samarium cobalt magnets, can work stably in environments above 350°C, ensuring that the magnetic field strength does not decay. They also firmly fix the high-temperature magnetic fluid in the toothed grooves of the two pole shoes, forming a seal and improving the fixing and sealing effect.

[0020] To reduce wear and erosion of the bushings and lower maintenance frequency:

[0021] Further configuration: The bushing is made of a robust alloy steel housing material.

[0022] By adopting the above technical solution and using bushings made of robust alloy steel with durable outer shell material, corrosion and erosion can be avoided at high temperatures, which helps to reduce the frequency of maintenance.

[0023] The parts of the device not covered herein are the same as or can be implemented using existing technologies. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the main view of this utility model;

[0025] Figure 2 This utility model Figure 1 Unfolding diagram;

[0026] Figure 3 This is a schematic diagram of the sealing assembly of this utility model;

[0027] Figure 4 This utility model Figure 3 Cross-sectional view.

[0028] In the diagram: 1. Drain pipe; 2. First flange; 3. Hex bolt; 4. Connecting plate; 5. Sealing assembly; 501. Bushing; 502. Liquid storage pipe; 503. Heat sink; 504. First groove; 505. Labyrinth seal; 506. First pole shoe; 507. Permanent magnet; 508. Second pole shoe. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0030] Please see Figures 1 to 4 A high-temperature magnetic fluid sealing assembly for a steam turbine drain riser includes two drain pipes 1. Each drain pipe 1 has a first flange 2 at one end of its outer wall. The outer walls of the two first flanges 2 are provided with eight threaded holes at equal intervals around the axis at 45 degrees. The threaded holes of the first flanges 2 are threaded to a connecting plate 4 by hexagonal bolts 3. A nut is threaded to one end of the outer wall of the hexagonal bolts 3. A second flange is provided on the left side of the connecting plate 4. The outer wall of the connecting plate 4 has eight threaded holes with an inner wall that are the same size and correspond to the structure of the first flanges 2. The connecting plate 4 is threaded to a sealing assembly 5 by the inner wall thread.

[0031] The closed assembly 5 includes a bushing 501. The bushing 501 has threaded interfaces at both ends and is threadedly connected to the connecting plate 4 through the threaded interfaces. The outer wall of the bushing 501 has a liquid storage tube 502 at its center and multiple heat sinks 503 on its outer wall. The inner wall of the bushing 501 has two first grooves 504 and labyrinth seals 505 arranged sequentially from both sides to the middle. The labyrinth seals 505 have a first pole shoe 506 at one end facing inward. The two first pole shoes 506 are fixedly installed with permanent magnets 507 at one end facing inward. The two permanent magnets 507 are fixedly installed with a second pole shoe 508 at one end facing inward.

[0032] In this embodiment, as Figure 2 and Figure 3 As shown, the outer wall of the liquid storage tube 502 is provided with an injection port, and an injection plug is threadedly connected to the injection port. The outer wall of the injection plug is provided with two anti-overflow gaskets.

[0033] In this embodiment, as Figure 3 and Figure 4 As shown, the inner rings of the two first grooves 504 are both fitted with flexible graphite sealing rings.

[0034] In this embodiment, as Figure 2 and Figure 3As shown, the side wall of the liquid storage tube 502 is provided with two water-cooled liquid exchange ports, which can be connected to cooling water. The interior of the liquid storage tube 502 is hollow and stores a high-temperature magnetic fluid using perfluoropolyether or other fluorocarbon oils as the base fluid.

[0035] In this embodiment, as Figure 4 As shown, the first pole piece 506 is the positive pole and the second pole piece 508 is the negative pole. Both are made of samarium cobalt magnets. The inner wall is provided with multiple sets of annular concave and convex toothed channels, and the upper and lower parts of the inner wall are provided with pipes that are connected to and communicate with the liquid storage pipe 502.

[0036] In this embodiment, as Figure 3 and Figure 4 As shown, bushing 501 is made of a robust alloy steel housing material.

[0037] The working process of this high-temperature magnetic fluid sealing assembly for steam turbine drain risers is as follows:

[0038] First, rotate the connecting plate 4 onto the threads at both ends of the bushing 501. Then, by unscrewing the injection plug, inject the high-temperature magnetic fluid into the storage pipe 502 using a tool to replenish the consumed high-temperature magnetic fluid. The high-temperature magnetic fluid uses perfluoropolyether or other fluorocarbon oils as the base fluid. Next, snap the four flexible graphite sealing rings into the two first grooves 504 at both ends of the bushing 501 in pairs. Connect them to the first flange 2 of the pipeline or other equipment using hexagonal bolts 3 and nut flanges. According to the contact sequence, the four flexible graphite sealing rings inside the bushing 501 automatically compensate for radial runout and installation eccentricity during installation using their own elasticity, while reducing friction and vibration offset between them and the bushing 501. Then, through the labyrinth seal ring 505, a certain degree of sealing is maintained without contact with the pipe body or other equipment. The first pole shoe 506 and the second pole shoe 508, using samarium cobalt magnets, can work stably in environments above 350℃, similar to permanent magnets. Iron 507 together ensures that the magnetic field strength does not decay and firmly fixes the high-temperature magnetic fluid in the toothed grooves of the two sets of pole shoes. The toothed grooves of the two sets of pole shoes are equipped with pipes that connect to the storage area inside the liquid storage tube 502. The multiple heat sinks 503 of the liquid storage tube 502 can remove some of the heat of the high-temperature magnetic fluid during operation, forming an O-ring seal and thus constructing multiple sets of sealing rings. This achieves non-contact, reduces friction, and maintains a seal. The samarium cobalt magnet material is high-temperature resistant and has a long service life. The bushing 501 is made of a robust alloy steel durable shell material to avoid rapid corrosion in high-temperature environments. Cooling water can be connected through two water-cooling exchange ports to cool the high-temperature magnetic fluid stored inside the liquid storage tube 502. The high-temperature magnetic fluid circulates and removes heat under the action of the two sets of pole shoes with opposite magnetic poles, preventing the magnetic fluid from evaporating, carbonizing, and affecting the magnetism of the pole shoes, thereby reducing maintenance frequency, extending sealing time, reducing maintenance frequency, and improving sealing effect.

[0039] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0040] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0041] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The above examples are only for the purpose of helping to understand the method and core ideas of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that due to the limitations of textual expression, there are objectively infinite specific structures. For those skilled in the art, several improvements, modifications, or changes can be made without departing from the principles of this utility model, and the above technical features can also be combined in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without modification, should all be considered within the protection scope of this utility model.

Claims

1. A high-temperature magnetic fluid sealing assembly for a steam turbine drain riser, comprising two drain pipes (1), characterized in that: Each of the two drainage pipes (1) has a first flange (2) at one end of its outer wall, and the outer walls of the two first flanges (2) are provided with eight threaded holes at equal intervals around the axis at 45 degrees. The threaded holes of the first flanges (2) are connected to a connecting plate (4) by hexagonal bolts (3), and a nut is threaded to one end of the outer wall of the hexagonal bolts (3). A second flange is provided on the left side of the connecting plate (4), and the outer wall of the connecting plate (4) has eight threaded holes with the same inner wall size as the first flange (2) and corresponding to it. The connecting plate (4) is connected to a sealing component (5) by the inner wall thread. The closed assembly (5) includes a bushing (501), both ends of which are provided with threaded interfaces, and the bushing (501) is threadedly connected to the connecting disc (4) through the threaded interfaces. The outer wall of the bushing (501) is provided with a liquid storage tube (502), and the outer wall of the liquid storage tube (502) is provided with multiple heat sinks (503). The inner wall of the bushing (501) is provided with two first grooves (504) and a labyrinth seal ring (505) from both sides to the middle. The labyrinth seal ring (505) is provided with a first pole shoe (506) at one end facing inward. The two first pole shoes (506) are fixedly installed with permanent magnets (507) at one end facing inward. The two permanent magnets (507) are fixedly installed with a second pole shoe (508) at one end facing inward.

2. The high-temperature magnetic fluid sealing assembly for a steam turbine drain riser as described in claim 1, characterized in that: The outer wall of the liquid storage tube (502) is provided with an injection port, and an injection plug is threadedly connected to the injection port. The outer wall of the injection plug is provided with two anti-overflow gaskets.

3. The high-temperature magnetic fluid sealing assembly for a steam turbine drain riser as described in claim 1, characterized in that: The inner rings of both first grooves (504) are fitted with flexible graphite sealing rings.

4. The high-temperature magnetic fluid sealing assembly for a steam turbine drain riser as described in claim 1, characterized in that: The side wall of the liquid storage tube (502) is provided with two water-cooled liquid exchange ports, which can be connected to cooling water, and the interior of the liquid storage tube (502) is hollow.

5. The high-temperature magnetic fluid sealing assembly for a steam turbine drain riser as described in claim 1, characterized in that: The first pole piece (506) is the positive pole, and the second pole piece (508) is the negative pole. Both are made of samarium cobalt magnet material. The inner wall is provided with multiple sets of annular concave and convex toothed channels, and the inner upper and lower parts are provided with pipes connected to and communicating with the liquid storage pipe (502).

6. The high-temperature magnetic fluid sealing assembly for a steam turbine drain riser as described in claim 1, characterized in that: The bushing (501) is made of a robust alloy steel housing material.

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