Floating sealing device

Abstract

The invention discloses a floating sealing device, and belongs to the field of rotary air preheaters of boilers, the floating sealing device is mounted on a bin grid plate of an air preheater, and a dynamic and static sealing structure is formed between the floating sealing device and a static sector plate of the air preheater during operation of the air preheater; the sealing device is characterized in that the sealing device has a self-adaptive clearance compensation function capable of changing along with temperature change and comprises the movable module and the static module, the movable module conducts position compensation under limiting of the static module, the sealing effect is improved, and meanwhile the sealing device has the advantages of being simple in structure, convenient to install and the like.

Description

Technical Field

[0001] The invention relates to the technical field of radial sealing of a rotary air preheater for a boiler, and in particular to a floating sealing device. Background Art

[0002] According to the expansion characteristics of the rotary air preheater rotor, the rotating shaft expands and stretches upward along the axis, while the outer edge of the rotor radially outward will tilt downward due to the temperature difference between the cold and hot ends, that is, the upper end surface of the bin partition plate tilts outward at an angle, that is, angular displacement, showing a large axial displacement of the outer edge of the rotor and a small axial displacement at the center; this phenomenon is the mushroom deformation of the air preheater rotor; the mushroom deformation of the rotary air preheater rotor from cold to hot state seriously affects the sealing system of the air preheater. The dynamic and static sealing structures on the wind side and the flue gas side are required to ensure the sealing performance of the air preheater during the entire cold and hot state process. Therefore, a sealing structure is required to adapt to the cold and hot deformation conditions. Summary of the invention

[0003] The purpose of the present invention is: to address the above-mentioned problems, the present invention provides a floating sealing device, based on the function of the thermal actuator, a functional component that can generate a displacement driving force as the temperature changes, so that the sealing plate of the air preheater can be compensated for displacement as the temperature changes, which can effectively compensate for the change of the sealing gap with the temperature, ensure that the sealing gap does not change with the temperature, and improve the sealing effect.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A floating sealing device, comprising:

[0006] An active module, the active module comprising a front sealing plate and a main sealing plate, the front sealing plate and the main sealing plate are stacked and connected, and the front sealing plate and the main sealing plate are isolated by a gasket;

[0007] A stationary module, the stationary module comprising a guide plate, the guide plate extending between the front sealing plate and the main sealing plate, a U-shaped groove being provided on one side of the guide plate body, a gasket being embedded in the U-shaped groove and movably matched with the U-shaped groove, and a pressure plate being provided on the side of the guide plate away from the front sealing plate;

[0008] The device also includes a fireproof cloth, one end of which is connected to the front sealing plate, and the other end of which is connected between the guide plate and the pressure plate;

[0009] An elastic card is also connected between the movable module and the static module to provide a lifting force when the movable module is displaced;

[0010] Thermal actuators are respectively arranged on both sides of the connection between the movable module and the static module. Both ends of the thermal actuators are respectively connected with arched plates, which are arranged between the movable module and the static module along the displacement direction of the movable module.

[0011] Furthermore, a rear sealing plate is laid on a side of the front sealing plate away from the main sealing plate, and a sealing filler layer is filled between the front sealing plate and the rear sealing plate.

[0012] Furthermore, the fireproof cloth is located at one end of the front sealing plate and is connected to the sealing filler layer.

[0013] Furthermore, the fireproof cloth is bent to reserve a certain length and then connected between the guide plate and the pressure plate.

[0014] Furthermore, the main sealing plate, the rear sealing plate and the front sealing plate are all long strip-shaped structures with folded edges.

[0015] Furthermore, a plurality of washers are sequentially arranged side by side along the axial direction of the long front sealing plate, and a plurality of U-shaped grooves are sequentially opened on one side of the guide plate corresponding to the plurality of washers.

[0016] Furthermore, the sealing filler layer is a refractory fiber layer containing graphite.

[0017] Furthermore, a long hole is provided at one end of the elastic card, and the long hole is used to adjust the tightness of the elastic card and thus adjust the elastic force of the elastic card.

[0018] Furthermore, the movable module and the static module are respectively provided with screw rods in a direction perpendicular to the displacement direction of the movable module, and two ends of the arch plate are respectively connected to the screw rods of the movable module and the static module.

[0019] Furthermore, at least one of the elastic card and the thermal actuator is provided.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] 1. A floating sealing device of the present invention has an adaptive gap compensation structure that can change with temperature. The sealing gap is not affected by the temperature change of the air preheater and can maintain consistency in cold and hot states, thereby ensuring the sealing performance and playing an important role in energy conservation and emission reduction of the boiler air preheater.

[0022] 2. In a floating seal device of the present invention, the sealing contact material is a multi-layer palace-shaped sealing structure formed by stacking a soft packing sealing layer and a rigid sealing strip, which has a higher sealing fit and a more reliable sealing effect. The graphite-containing packing seal can also play a role in lubrication, reduce friction resistance, and extend the service life of the seal.

[0023] 3. The floating seal device of the present invention can be customized according to the different sizes of the air preheater, including the length of the floating seal, the number of elastic clips, and the number of thermal actuators; therefore, the floating seal device of the present invention can be used in various rotary air preheaters, has a wide range of adaptability, and can be promoted on a large scale.

[0024] 4. The floating seal device of the present invention has a simple sealing structure and adopts an integrated installation method, which is convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the assembly structure of a floating sealing device of the present invention;

[0026] Figure 2 For the present invention Figure 1 Cross-section view in the CC direction;

[0027] Figure 3 For the present invention Figure 1 Cross-section view along the AA direction;

[0028] Figure 4 For the present invention Figure 1 Cross-section along the BB direction;

[0029] Figure 5 A schematic structural diagram of an elastic card of a floating sealing device of the present invention;

[0030] Figure 6 It is a structural schematic diagram of a thermal actuator of a floating sealing device of the present invention;

[0031] Figure 7 It is a structural schematic diagram of a bow-shaped spring piece of a floating sealing device of the present invention;

[0032] Figure 8 A schematic diagram of the change in cold and hot state displacement of a thermal actuator during use of a floating seal device of the present invention;

[0033] Fig. 9 A schematic diagram of gap compensation driven by a thermal actuator of a floating seal device of the present invention;

[0034] Fig.10 An exploded view of a floating seal device of the present invention;

[0035] Fig.11 It is a schematic diagram of the cold and hot states of the air preheater before adopting a floating seal device of the present invention;

[0036] Fig.12 It is a schematic diagram of gap supplementation using a floating seal device of the present invention.

[0037] In the figure, 1. rear sealing plate, 2. sealing packing layer, 3. fireproof cloth, 4. pressure plate, 5. elastic card, 6. bolt, 7. thermal actuator, 8. bow spring, 9. nut, 10. screw, 11. guide plate, 12. large washer, 13. front sealing plate, 14. spacer washer, 15. main sealing plate, 16. fan plate, 17. compartment grid plate. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Example

[0041] This embodiment provides a floating seal device, which is a radial sealing device floating seal of a boiler rotary air preheater (hereinafter referred to as air preheater). Figure 1 and Fig.10 As shown, the sealing device provided in this embodiment includes a main sealing plate 15, a rear sealing plate 1, a front sealing plate 13, a sealing filler layer 2, a fireproof cloth 3, a pressure plate 4, a bolt 6, an elastic card 5, a thermal actuator 7, a bow-shaped spring clip 8, a nut 9, a screw 10, a guide plate 11, a large washer 12, and a spacer washer 14.

[0042] In the device of this embodiment, the main sealing plate 15, the rear sealing plate 1, the front sealing plate 13, the pressure plate 4, and the guide plate are all made of weather-resistant materials, that is, plates that can withstand certain high temperatures and corrosion. Commonly used ones are stainless steel and Corten steel. The sealing packing layer 2 is a refractory fiber containing graphite, including asbestos, etc. The fireproof cloth 3 can be made of silk fabrics that can withstand high temperatures above 400°C, and commonly used ones are basalt cloth, aramid, carbon fiber, glass cloth, asbestos cloth, etc.

[0043] In this embodiment, Figure 1 The main sealing plate 15, the rear sealing plate 1 and the front sealing plate 13 are all long plate-shaped parts with folded edges at a certain angle.

[0044] In this implementation, if Figure 2 and Figure 3As shown, a sealing packing 2 layer and a fireproof cloth 3 are sandwiched between the front sealing plate 13 and the rear sealing plate 1 of the floating sealing device, a certain gap is separated by a spacer washer 14 between the front sealing plate 13 and the main sealing plate 15, and the front sealing plate 13 and the main sealing plate 15 are connected to form a whole by a row of bolts 6 and nuts in sequence, and the whole forms the movable part of the floating seal. One end of the fireproof cloth 3 is sandwiched between the front sealing plate 13, the rear sealing plate 1 and the sealing packing layer 2, and the other end of the fireproof cloth 3 is sandwiched between the pressure plate 4 and the guide plate 11 after being bent to leave a certain margin length. The guide plate 11 and the pressure plate 4 are connected by a row of bolts to form the static part of the floating sealing device, and the large washer 12 plays a buffering and anti-loosening role.

[0045] Furthermore, a plurality of parallel U-shaped grooves are provided on one side of the guide plate 11 of the stationary part of the floating sealing device, the upper end of the U-shaped groove is inserted into the gap formed by the spacer washer 14 of the movable part, and the spacer washer 14 is stuck into the U-shaped groove; the movable part can only move up and down along the U-shaped groove.

[0046] Further, if Figure 3 As shown, a plurality of elastic clips 5 are arranged between the two rows of bolts of the movable part and the stationary part, that is, the two bolt holes at both ends of the elastic clip 5 connect the movable part and the stationary part respectively. The elastic clip 5 can give the movable part a certain lifting force within the elastic force range, presenting a "floating" state, and can only float along a certain range up and down.

[0047] Further, if Figure 4 , Figure 6 and Figure 7 As shown, the movable part and the stationary part are further connected by two rows of bolts respectively with a pair of thermal actuators 7 and bow-shaped springs 8 for realizing a lifting effect with temperature. The two ends of the thermal actuator 7 are respectively connected to the webs of the bow-shaped springs 8, that is, the two ends of the bow-shaped springs 8 are respectively connected to the movable part and the stationary part. This embodiment discloses that screws 10 are respectively arranged on the movable part and the stationary part. The screws 10 are used to connect the bow-shaped springs 8 so that the bow-shaped springs 8 are connected between the movable module and the stationary module. After the thermal actuator generates thrust with the increase of temperature, the bow-shaped springs 8 connected at both ends are squeezed and form a component force for lifting upward, thereby further realizing the function of the floating sealing device changing the position of the movable part of the sealing device with temperature changes; and providing help for the next step of adapting to its high temperature environment and improving the sealing effect of the floating seal.

[0048] like Fig.11As shown in the figure, these are different states of deformation of the rotor compartment grid plate of the air preheater in the cold and hot states; when the air preheater is running, the rotor rotates around the axis. The outer contour of the cold (normal temperature) air preheater rotor is a cylindrical rotating body, and there is a small dynamic and static gap between the upper end of the rotor and the static fan plate 16. In the hot state, the air preheater rotor undergoes thermal deformation, and the outer contour of the rotor changes into a "mushroom" shape, and the gap between the dynamic and static gaps becomes larger, and along the diameter direction, the gap becomes larger as it goes outward.

[0049] like Fig.12 As shown, the floating sealing device of this embodiment is formed by the floating sealing part formed by the main sealing plate 15 and the sealing filler 2 clamped by the rear sealing plate 1 and the front sealing plate 13, which is in contact and friction with the air preheater sector plate 16, playing the role of dynamic sealing, and can effectively prevent the fluid medium from flowing on both sides of the seal.

[0050] like Figure 8 , 9 As shown, when the air preheater transitions from cold state to hot state, the length of the thermal actuator 7 is extended, and the length changes from 1 to l+Δl. When the distance L between the two sets of screws fixing the two ends of the bow-shaped spring pieces remains unchanged, the bow-shaped spring pieces are squeezed, generating thrust in the up and down directions, so that the floating seal moving part is lifted up by Δh. This makes up for the air leakage gap Δh caused by the heat deformation and sinking of the air preheater compartment grid plate 17. Further, the positions of the main sealing plate 15, the rear sealing plate 1, and the front sealing plate 13 of the floating sealing device do not change with the changes in the cold and hot states, and the sealing gap between the sealing plate and the fan plate 16 will not increase, ensuring the sealing effect.

[0051] Part of the structure of the thermal actuator 7 can adopt the existing related technologies of thermal actuators, including its heat-expanding structure and displacement limiting structure.

[0052] like Figure 5 One end of the elastic card 5 is set as a long hole, and the elasticity of the elastic card 5 can be adjusted by using the installation hole position of the long hole. By adjusting the elasticity of the elastic card, the contact force between the main sealing plate 15 and the rear sealing plate 1, the front sealing plate 13 and the fan-shaped plate 16 of the floating sealing device can be adjusted.

[0053] The principles and implementation methods of the present invention are described in this article using specific embodiments. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0054] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0055] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", and "couple" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A floating seal device, characterized in that: The device comprises: An active module, the active module comprising a front sealing plate and a main sealing plate, the front sealing plate and the main sealing plate are stacked and connected, and the front sealing plate and the main sealing plate are isolated by a spacer gasket; A stationary module, the stationary module comprising a guide plate, the guide plate extending between the front sealing plate and the main sealing plate, a U-shaped groove being provided on one side of the guide plate body, a spacer washer being embedded in the U-shaped groove and movably matched with the U-shaped groove, and a pressure plate being laid on one side of the guide plate away from the front sealing plate; The device further comprises a fireproof cloth, one end of which is connected to the front sealing plate, and the other end of which is connected between the guide plate and the pressure plate; An elastic card is also connected between the movable module and the static module to provide a lifting force when the movable module is displaced; Thermal actuators are respectively arranged on both sides of the connection between the movable module and the static module. Both ends of the thermal actuators are respectively connected with arched plates, which are arranged between the movable module and the static module along the displacement direction of the movable module.

2. A floating seal device according to claim 1, characterized in that: A rear sealing plate is laid on one side of the front sealing plate away from the main sealing plate, and a sealing filler layer is filled between the front sealing plate and the rear sealing plate.

3. A floating seal device according to claim 2, characterized in that: The fireproof cloth is located at one end of the front sealing plate and is connected to the sealing filler layer.

4. A floating seal device according to claim 3, characterized in that: The fireproof cloth is bent to reserve a certain length and then connected between the guide plate and the pressing plate.

5. A floating seal device according to claim 2, characterized in that: The main sealing plate, the rear sealing plate and the front sealing plate are all long strip-shaped structures with folded edges.

6. A floating seal device according to claim 5, characterized in that: A plurality of the spacer washers are arranged in parallel in sequence along the axial direction of the long front sealing plate, and a plurality of U-shaped grooves are opened in sequence on one side of the guide plate corresponding to the plurality of spacer washers.

7. A floating seal device according to claim 2, characterized in that: The sealing filler layer is a refractory fiber layer containing graphite.

8. A floating seal device according to claim 1, characterized in that: One end of the elastic card is provided with a long hole, and the long hole is used to adjust the tightness of the elastic card so as to adjust the elastic force of the elastic card.

9. A floating seal device according to claim 1, characterized in that: The movable module and the stationary module are respectively provided with screw rods in the vertical direction along the displacement direction of the movable module, and the two ends of the arch plate are respectively connected to the screw rods of the movable module and the stationary module.

10. A floating seal device according to claim 1, characterized in that: At least one of the elastic card and the thermal actuator is provided.

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