Dry gas sealing device for central cylinder of air pre-heater

Abstract

The utility model relates to the field of air pre-heaters, in particular to an air pre-heater center cylinder dry gas sealing device which comprises an air pre-heater truss and a guide end shaft, the air pre-heater truss comprises two semi-circular plates, end plates are fixed to the tops of the opposite ends of the two semi-circular plates, the end plates are fixedly installed through first fixing bolts, and the guide end shaft is fixedly connected with the air pre-heater truss. A connecting plate is fixed to the surface of the guide end shaft, a sealing sleeve is arranged on the surface of the guide end shaft in a sleeved mode, the connecting plate and the sealing sleeve are fixedly connected through a second fixing bolt, and a dry gas sealing assembly is arranged between the sealing sleeve and the two semicircular plates. The air leakage at the central cylinder of the air pre-heater can be improved, and the influence on a bearing system and the pollution to the environment around the air pre-heater are reduced.

Description

Technical Field

[0001] This utility model relates to the field of air preheaters, specifically to a dry gas sealing device for the central cylinder of an air preheater. Background Technology

[0002] An air preheater is a device used to increase the temperature of air in a boiler or other heat exchange equipment. It recovers waste heat from the flue gas emitted by the boiler and transfers it to the air entering the boiler, thereby increasing the air temperature, improving combustion efficiency and thermal efficiency, and reducing fuel consumption and pollutant emissions.

[0003] The existing design of the air preheater center cylinder seal uses a packing-type seal structure, which consists of an air seal cylinder and packing, a pressure ring, a base plate, and a primary air positive pressure cooling duct. However, this design has drawbacks: the packing is prone to wear and aging, especially at the hot end of the air preheater shaft where temperatures often reach 350-400℃. This high temperature further shortens the packing's lifespan. With an air preheater speed of 1 rpm and a typical shaft diameter of 350 mm, the wear linear velocity is 0.02 m / s. Based on 4000 hours of annual operation, the wear amount is no less than... The packing is 288 meters long, but its actual thickness is only about 15mm, so wear through is inevitable. After the packing ages and wears, the sealing effect is lost. Hot air is ejected from the packing and pressure ring positions under positive pressure, causing ash to accumulate at the center end shaft of the hot-end truss. The ash spreads and accumulates further. The leaking hot air will also affect the bearing oil temperature at the guide bearing position. At the same time, due to the positive pressure and hot air, the temperature is too high, which does not meet the conditions for safe production. The ash leakage problem cannot be dealt with when it is hot, and the furnace can only be shut down for repair. This is often a temporary solution and cannot completely solve the problem.

[0004] Therefore, it is necessary to invent a dry gas sealing device for the central cylinder of an air preheater. Utility Model Content

[0005] Therefore, this utility model provides a dry gas sealing device for the central cylinder of an air preheater to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a dry gas sealing device for the central cylinder of an air preheater, comprising an air preheater truss and a guide end shaft. The air preheater truss includes two semicircular plates, and end plates are fixed to the top of the opposite ends of the two semicircular plates. The end plates are fixedly installed by a first fixing bolt. A connecting plate is fixed to the surface of the guide end shaft, and a sealing sleeve is sleeved on the surface of the guide end shaft. The connecting plate and the sealing sleeve are fixedly connected by a second fixing bolt. A dry gas sealing assembly is provided between the sealing sleeve and the two semicircular plates.

[0007] Preferably, the dry gas sealing assembly includes a sealing chamber, which is composed of two sealing shells. The bottoms of the two sealing shells are respectively fixed to the tops of two semicircular plates. When the two semicircular plates are fixedly installed, the opposite ends of the two sealing shells abut against each other.

[0008] Preferably, the sealed chamber is provided with a plurality of dynamic pressure air storage slots, and a plurality of layers of sealing copper rings are symmetrically fixed on both sides of the sealing sleeve. The plurality of layers of sealing copper rings correspond one-to-one with the plurality of dynamic pressure air storage slots, and the sealing copper rings are located in the corresponding dynamic pressure air storage slots.

[0009] Preferably, a cold primary air duct interface is fixedly installed on the side end of any one of the sealed housings, and a ventilation hole is opened on the side end of the sealed housing, the ventilation hole being connected to the cold primary air duct interface.

[0010] Preferably, each of the two sealing housings has a plurality of reinforcing ribs fixed to its side ends, and the bottom ends of the plurality of reinforcing ribs are fixed to the top of the two semicircular plates.

[0011] The beneficial effects of this utility model are as follows: through the coordinated use of the air preheater truss, guide end shaft, connecting plate, sealing sleeve, and dry gas sealing assembly, the dry gas sealing assembly is composed of multiple layers of sealing copper rings and sealing chambers. The sealing copper rings are installed on the guide end shaft through the sealing sleeve and rotate synchronously with the guide end shaft in the radial direction. The sealing chamber is installed on the air preheater truss and does not rotate. This results in a multi-layer pressure-reducing labyrinth design between the multiple layers of sealing copper rings and the sealing chamber, which provides a good sealing effect and a long service life. It can improve air leakage at the center cylinder of the air preheater and reduce the impact on the bearing system and pollution of the environment around the air preheater. Attached Figure Description

[0012] Figure 1 A structural cross-sectional view provided for this utility model;

[0013] Figure 2 A partial structural schematic diagram of the sealing chamber provided by this utility model;

[0014] Figure 3 A top view of the structure provided for this utility model.

[0015] In the diagram: 1. Guide end shaft; 2. Semicircular plate; 3. End plate; 4. First fixing bolt; 5. Connecting plate; 6. Sealing sleeve; 7. Second fixing bolt; 8. Sealing shell; 9. Dynamic pressure air storage tank; 10. Sealing copper ring; 11. Cold primary air duct interface; 12. Ventilation hole; 13. Reinforcing rib. Detailed Implementation

[0016] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0017] Please refer to the appendix. Figures 1-3 The dry gas sealing device for the central cylinder of the air preheater provided by this utility model includes an air preheater truss and a guide end shaft 1. The air preheater truss includes two semi-circular plates 2. Each of the two semi-circular plates 2 has an end plate 3 fixed at its top opposite end. The end plate 3 is fixedly installed by a first fixing bolt 4, which makes the air preheater truss easy to disassemble and assemble. A connecting plate 5 is fixed on the surface of the guide end shaft 1. A sealing sleeve 6 is sleeved on the surface of the guide end shaft 1. The connecting plate 5 and the sealing sleeve 6 are fixedly connected by a second fixing bolt 7, which means that the sealing sleeve 6 is fixed on the guide end shaft 1. A dry gas sealing assembly is provided between the sealing sleeve 6 and the two semi-circular plates 2.

[0018] The dry gas sealing assembly includes a sealing chamber, which is composed of two sealing shells 8. The bottoms of the two sealing shells 8 are respectively fixed to the tops of two semi-circular plates 2. When the two semi-circular plates 2 are fixedly installed, the opposite ends of the two sealing shells 8 abut against each other. The sealing chamber is provided with several dynamic pressure air storage grooves 9. Several layers of sealing copper rings 10 are symmetrically fixed on both sides of the sealing sleeve 6. The layers of sealing copper rings 10 correspond one-to-one with the several dynamic pressure air storage grooves 9. The sealing copper rings 10 are located in the corresponding dynamic pressure air storage grooves 9. Specifically, the dry gas seal is composed of multiple layers of sealing copper rings 10 and a sealing chamber. The sealing copper rings 10 are installed on the guide end shaft 1. The direction and guide shaft 1 rotate synchronously. The sealing chamber is installed on the air preheater truss and does not rotate. This allows the sealing copper ring 10 and the sealing chamber to adopt a multi-layer pressure-reducing labyrinth design, so that the two relatively moving equipment surfaces are separated by a layer of air film, realizing non-contact operation of the sealing end face, with good sealing effect and long service life. It can improve air leakage at the central cylinder, reduce the impact on the bearing system and pollution of the environment around the preheater. It should be noted that the multiple sets of dynamic pressure air storage tanks 9 opened in the sealing chamber are all precision machined by laser engraving process with a machining accuracy between 0.25mm and 0.5mm, and are heat treated as a whole to eliminate internal stress.

[0019] A cold primary air duct interface 11 is fixedly installed on the side end of any one of the sealed housings 8, and a ventilation hole 12 is opened on the side end of the sealed housing 8. The ventilation hole 12 is connected to the cold primary air duct interface 11. Specifically, using the existing cold primary air air seal duct, a cold air is drawn from the cold primary air duct interface 11 and injected into the air seal through the side interface. The air film pressure prevents air leakage.

[0020] Several reinforcing ribs 13 are fixed to the sides of both sealing shells 8. The bottom ends of the reinforcing ribs 13 are fixed to the top of the two semi-circular plates 2. Specifically, under the action of the reinforcing ribs 13, the stability of the sealing shell 8 and the semi-circular plates 2 can be effectively increased, that is, the stability between the sealing chamber and the air preheater truss can be effectively increased.

[0021] The above description is merely a preferred embodiment of this utility model. Any person skilled in the art can modify this utility model or modify it into an equivalent technical solution using the technical solution described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solution of this utility model are within the scope of protection claimed by this utility model.

Claims

1. A dry gas sealing device for the central cylinder of an air preheater, comprising an air preheater truss and a guide end shaft (1), wherein the air preheater truss comprises two semi-circular plates (2), characterized in that: Both of the two semicircular plates (2) are fixed with end plates (3) at their opposite tops. The end plates (3) are fixedly installed by the first fixing bolt (4). A connecting plate (5) is fixed on the surface of the guide shaft (1). A sealing sleeve (6) is sleeved on the surface of the guide shaft (1). The connecting plate (5) and the sealing sleeve (6) are fixedly connected by the second fixing bolt (7). A dry gas sealing assembly is provided between the sealing sleeve (6) and the two semicircular plates (2). The dry gas sealing assembly includes a sealing chamber, which is composed of two sealing shells (8). The bottoms of the two sealing shells (8) are respectively fixed to the tops of two semi-circular plates (2). When the two semi-circular plates (2) are fixedly installed, the opposite ends of the two sealing shells (8) abut against each other. The sealed chamber is provided with several dynamic pressure air storage grooves (9), and several layers of sealing copper rings (10) are symmetrically fixed on both sides of the sealing sleeve (6). The several layers of sealing copper rings (10) correspond one-to-one with the several dynamic pressure air storage grooves (9), and the sealing copper rings (10) are located in the corresponding dynamic pressure air storage grooves (9). A cold primary air duct interface (11) is fixedly installed on the side end of any of the sealing housings (8), and a ventilation hole (12) is opened on the side end of the sealing housing (8), and the ventilation hole (12) is connected to the cold primary air duct interface (11).

2. The dry gas sealing device for the central cylinder of the air preheater according to claim 1, characterized in that: Both of the sealing shells (8) have several reinforcing ribs (13) fixed to their sides, and the bottom ends of the reinforcing ribs (13) are fixed to the top of the two semicircular plates (2).

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