A sealing structure for the cover of a pit furnace

Abstract

The present invention discloses a sealing structure for the cover of a pit furnace, which relates to the technical field of pit furnaces and includes: a packing groove fixedly arranged at the top of the furnace body of the pit furnace and hermetically connected to the furnace body, and packing is arranged in the packing groove; the top end of the cover of the pit furnace is fixedly connected with an annular fixing plate through a connecting cylinder; an annular pressing plate, the inner diameter of the pressing plate is larger than the diameter of the cover, the pressing plate is connected to the fixing plate, and the bottom surface of the pressing plate is in close contact with the top surface of the packing; an annular expansion joint located between the fixing plate and the pressing plate, the top end of the expansion joint abuts against the fixing plate, and the bottom end abuts against the pressing plate; a sealing cylinder located below the cover, a connecting ring is fixedly arranged at the top end of the sealing cylinder, and the connecting ring is hermetically connected to the cover through bolts; the bottom end of the sealing cylinder is inserted into fine sand in an annular groove; a closed space is formed among the pressing plate, the expansion joint, the fixing plate, the sealing cylinder, the annular groove and the furnace body. The present invention improves the sealing effect between the cover and the furnace body of the pit furnace.

Description

Technical Field

[0001] The present invention relates to the technical field of pit furnaces, and particularly to a sealing structure for the cover of a pit furnace. Background Art

[0002] The pit furnace is one of the main boiler forms in current machining production, and the processing effect of using a pit furnace in the spherical treatment of carbon compounds in steel is better. The reason is that this equipment often has a protective atmosphere during production, so that the surface accuracy of the workpiece can be ensured after completion, effectively ensuring the toughness and stiffness of the workpiece. Based on these advantages, the pit furnace is widely used in current social production, and its demand is increasing year by year.

[0003] The pit furnace has high requirements for sealing performance. Since the furnace cover needs to be opened frequently to facilitate lifting tools, the sealing performance between the furnace cover and the furnace body has a particularly important impact on the use of the pit furnace. The existing furnace covers of pit furnaces usually do not use a sealing lock ring or use a manually pressed sealing lock ring, resulting in poor sealing effect. Summary of the Invention

[0004] The purpose of the present invention is to provide a sealing structure for the cover of a pit furnace to solve the problems existing in the above-mentioned prior art and improve the sealing performance between the furnace cover and the furnace body of the pit furnace.

[0005] To achieve the above purpose, the present invention provides the following scheme:

[0006] The present invention provides a sealing structure for the cover of a pit furnace, including:

[0007] A packing groove fixedly arranged at the top of the furnace body of the pit furnace and hermetically connected to the furnace body, and packing is arranged in the packing groove; the top end of the furnace cover of the pit furnace is fixedly connected with an annular fixing plate through a connecting cylinder, the fixing plate and the furnace cover are respectively hermetically connected to the connecting cylinder, there is a gap between the bottom surface of the fixing plate and the top surface of the furnace cover, and the outer diameter of the fixing plate is larger than the diameter of the furnace cover;

[0008] An annular pressing plate, the inner diameter of the pressing plate is larger than the diameter of the furnace cover, the pressing plate is connected to the fixing plate, and the bottom surface of the pressing plate is closely attached to the top surface of the packing;

[0009] An annular expansion joint located between the fixing plate and the pressing plate, the top end of the expansion joint abuts against the fixing plate, and the bottom end abuts against the pressing plate;

[0010] A sealing cylinder located below the furnace cover, a connecting ring is fixedly arranged at the top end of the sealing cylinder, and the connecting ring is hermetically connected to the furnace cover through bolts;

[0011] An annular groove fixedly and sealingly connected to the furnace body, with fine sand disposed in the annular groove, and the bottom end of the sealing cylinder is inserted into the fine sand in the annular groove; both the sealing cylinder and the annular groove are located outside the pressing plate; a closed space is formed among the pressing plate, the expansion joint, the fixing plate, the sealing cylinder, the annular groove and the furnace body.

[0012] Preferably, the pressing plate is connected to the fixing plate through a plurality of pressing structures circumferentially distributed along the fixing plate. The pressing structure includes a mounting plate, a bolt and a spring. A placement hole is provided on the fixing plate corresponding to each mounting plate. The bottom of the mounting plate passes through the placement hole, and the mounting plate is detachably connected to the fixing plate;

[0013] The first nut, the second nut and the third nut are distributed in sequence from top to bottom and are respectively threadedly connected to the bolt. The bolt passes through the mounting plate. The mounting plate is located between the first nut and the second nut, and the first nut and the second nut are respectively in close contact with the mounting plate. The pressing plate is provided with a mounting groove corresponding to the head of the bolt, and the head of the bolt is mounted in the mounting groove. The spring is sleeved on the bolt, and the top end of the spring abuts against the third nut and the bottom end abuts against the pressing plate.

[0014] Preferably, an annular gas charging pipe is provided in the closed space. A plurality of air outlet holes are uniformly arranged along the circumference on the gas charging pipe. The gas charging pipe is communicated with a gas source through a connecting pipe. The connecting pipe passes through the furnace body and is sealingly connected to the furnace body; the gas charging pipe is used for charging a protective gas into the annular space.

[0015] Preferably, the protective gas is nitrogen.

[0016] Preferably, the inner diameter of the sealing cylinder is larger than the diameter of the furnace cover.

[0017] Preferably, the packing is graphite packing.

[0018] Preferably, it further includes a plurality of rib plates. The bottom of the rib plate is fixedly connected to the top end of the fixing plate, and the side part of the rib plate is fixedly connected to the connecting cylinder. All the rib plates are uniformly distributed along the axial direction of the fixing plate.

[0019] The present invention has achieved the following technical effects compared with the prior art:

[0020] The sealing structure of the cover of the pit furnace of the present invention improves the sealing effect between the cover of the pit furnace and the furnace body.

[0021] Specifically, a two - stage sealing structure is formed in the sealing structure of the well - type furnace cover of the present invention. The first - stage sealing structure is formed by the close fit of the pressing plate and the packing, and the second - stage sealing structure is formed by the sealing cylinder and the fine sand. Moreover, a closed space is formed between the first - stage sealing structure and the second - stage sealing medium. After filling the protective gas into the closed space, not only can the air be isolated and the sealing effect be achieved, but also using nitrogen as the protective gas can be used for fire extinguishing, improving the safety of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 FIG. is a top view of a well - type furnace provided with the sealing structure of the well - type furnace cover of the present invention;

[0024] Figure 2 FIG. is a partial structural schematic diagram of a well - type furnace provided with the sealing structure of the well - type furnace cover of the present invention;

[0025] Figure 3 is Figure 2 a partial enlarged view at B in

[0026] Figure 4 is Figure 3 a view in the direction of A in

[0027] Figure 5 FIG. is a structural schematic diagram of the pressing plate in the sealing structure of the well - type furnace cover of the present invention;

[0028] Figure 6 FIG. is a structural schematic diagram of the expansion joint in the sealing structure of the well - type furnace cover of the present invention;

[0029] Wherein, 1. furnace body; 2. furnace cover; 3. connecting cylinder; 4. rib plate; 5. fixing plate; 6. mounting plate; 7. bolt; 8. first nut; 9. second nut; 10. third nut; 11. spring; 12. expansion joint; 13. pressing plate; 14. sealing cylinder; 15. connecting ring; 16. packing; 17. packing groove; 18. annular groove; 19. fine sand; 20. gas filling pipe; 21. closed space. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] The purpose of the present invention is to provide a sealing structure for the cover of a pit furnace to solve the problems existing in the above-mentioned prior art and improve the sealing performance between the cover and the furnace body of the pit furnace.

[0032] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0033] As Figures 1 - 6 shown, this embodiment provides a sealing structure for the cover 2 of a pit furnace, including a packing groove 17, packing 16, a connecting cylinder 3, a fixing plate 5, a pressing plate 13, an expansion joint 12, a sealing cylinder 14, and an annular groove 18.

[0034] Among them, the packing groove 17 is fixedly arranged at the top of the furnace body 1 of the pit furnace and is hermetically connected to the furnace body 1, and the packing 16 is arranged in the packing groove 17; in this embodiment, the packing 16 is a flexible graphite packing 16 with a size of 30×30 and containing 316L reinforcing wires. The flexible graphite packing 16 has good heat resistance and can be used in an environment of 600°C. The packing groove 17 is made of 10mm carbon steel plates and its size is slightly smaller than that of the packing 16, so that the packing 16 is not easy to loosen in the packing groove 17. The compression amount of the packing 16 is about 5mm.

[0035] The top end of the cover 2 of the pit furnace is fixedly connected to the fixing plate 5 through the connecting cylinder 3. The fixing plate 5 is annular. The fixing plate 5 and the cover 2 are respectively hermetically connected to the connecting cylinder 3. There is a gap between the bottom surface of the fixing plate 5 and the top surface of the cover 2, and the outer diameter of the fixing plate 5 is larger than the diameter of the cover 2; this embodiment also includes a plurality of rib plates 4. The bottom of the rib plates 4 is fixedly connected to the top end of the fixing plate 5, and the side parts of the rib plates 4 are fixedly connected to the connecting cylinder 3. All the rib plates 4 are evenly distributed along the axial direction of the fixing plate 5.

[0036] The pressing plate 13 is annular, the inner diameter of the pressing plate 13 is larger than the diameter of the cover 2, the pressing plate 13 is connected to the fixing plate 5, and the bottom surface of the pressing plate 13 is in close contact with the top surface of the packing 16; in this embodiment, the pressing plate 13 is made of 35mm carbon steel plate. The function of the pressing plate 13 is to press the packing 16 to achieve the purpose of sealing. The surface of the pressing plate 13 in contact with the packing 16 is called the sealing surface. After pressing, there should be no gaps between the sealing surface and the packing 16. Therefore, the processing accuracy requirements for the sealing surface are relatively high, and it needs to reach a flatness of 1mm and a surface roughness of 6.3.

[0037] In this embodiment, the pressing plate 13 is connected to the fixing plate 5 through a plurality of pressing structures distributed circumferentially along the fixing plate 5. The pressing structure includes a mounting plate 6, a bolt 7, and a spring 11. A placement hole is provided on the fixing plate 5 corresponding to each mounting plate 6. The bottom of the mounting plate 6 passes through the placement hole, and the mounting plate 6 is detachably connected to the fixing plate 5. The first nut 8, the second nut 9, and the third nut 10 are distributed from top to bottom in sequence and are respectively threadedly connected to the bolt 7. The bolt 7 passes through the mounting plate 6. The mounting plate 6 is located between the first nut 8 and the second nut 9, and the first nut 8 and the second nut 9 are respectively in close contact with the mounting plate 6. The pressing plate 13 is provided with a mounting groove corresponding to the head of the bolt 7, and the head of the bolt 7 is mounted in the mounting groove. The spring 11 is sleeved on the bolt 7. The top end of the spring 11 abuts against the third nut 10, and the bottom end abuts against the pressing plate 13. By adjusting the third nut 10, the compression amount of the spring 11 can be adjusted, so as to adjust the pressure exerted by the spring 11 on the pressing plate 13. After all the pressing devices are installed, adjust each third nut 10 to achieve the required flatness of the pressing plate 13. After adjustment, there is a pressing amount of about 5 mm between the pressing plate 13 and the packing 16.

[0038] The expansion joint 12 is located between the fixing plate 5 and the pressing plate 13 and is annular. The top end of the expansion joint 12 abuts against the fixing plate 5, and the bottom end abuts against the pressing plate 13. In this embodiment, the expansion joint 12 is made of a 3 mm stainless steel plate and is used to connect the furnace cover 2 and the pressing plate 13. The expansion joint 12 has a certain deformation amount, which can realize the up and down movement of the pressing plate 13, so as to achieve the purpose of adjustable pressing and flatness of the pressing plate 13.

[0039] The sealing cylinder 14 is located below the furnace cover 2. A connecting ring 15 is fixedly provided at the top end of the sealing cylinder 14. The connecting ring 15 is hermetically connected to the furnace cover 2 through the bolt 7. The annular groove 18 is fixedly and hermetically connected to the furnace body 1. Fine sand 19 is provided in the annular groove 18. The bottom end of the sealing cylinder 14 is inserted into the fine sand 19 in the annular groove 18. Both the sealing cylinder 14 and the annular groove 18 are located outside the pressing plate 13. A closed space 21 is formed between the pressing plate 13, the expansion joint 12, the fixing plate 5, the sealing cylinder 14, the annular groove 18, and the furnace body 1.

[0040] An annular gas charging pipe 20 is provided in the closed space 21. A plurality of air outlet holes are uniformly arranged along the circumference on the gas charging pipe 20. The gas charging pipe 20 is communicated with a gas source through a connecting pipe. The connecting pipe passes through the furnace body 1 and is hermetically connected to the furnace body 1. The gas charging pipe 20 is used to charge a protective gas into the annular space.

[0041] In this embodiment, the protective gas is preferably nitrogen.

[0042] The sealing principle of the sealing structure of the well-type furnace cover 2 in this embodiment is as follows:

[0043] In this embodiment, a two-stage sealing structure is formed. The first-stage sealing structure is formed by the pressing plate 13 and the packing 16 being closely attached to each other. The second-stage sealing structure is formed by the bottom of the sealing cylinder 14 and the fine sand 19. And a sealed space 21 is formed between the first-stage sealing structure and the second-stage sealing medium. After the sealed space 21 is filled with a protective gas, not only can the air be isolated and the sealing effect be achieved, but also using nitrogen as the protective gas can be used for fire extinguishing, thereby improving the safety of use.

[0044] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0045] Specific examples are used in the present invention to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A sealing structure for the furnace cover of a pit furnace, characterized in that, Comprising: A packing gland fixedly arranged at the top of the furnace body of the pit furnace and hermetically connected to the furnace body, with packing arranged in the packing gland; the top end of the furnace cover of the pit furnace is fixedly connected with an annular fixing plate through a connecting cylinder, and the fixing plate and the furnace cover are respectively hermetically connected to the connecting cylinder. There is a gap between the bottom surface of the fixing plate and the top surface of the furnace cover, and the outer diameter of the fixing plate is larger than the diameter of the furnace cover; An annular pressing plate, the inner diameter of the pressing plate is larger than the diameter of the furnace cover, the pressing plate is connected to the fixing plate, and the bottom surface of the pressing plate is in close contact with the top surface of the packing; An annular expansion joint located between the fixing plate and the pressing plate, the top end of the expansion joint abuts against the fixing plate, and the bottom end abuts against the pressing plate; A sealing cylinder located below the furnace cover, a connecting ring is fixedly arranged at the top end of the sealing cylinder, and the connecting ring is hermetically connected to the furnace cover through bolts; An annular groove fixedly and hermetically connected to the furnace body, with fine sand arranged in the annular groove, and the bottom end of the sealing cylinder is inserted into the fine sand in the annular groove; both the sealing cylinder and the annular groove are located outside the pressing plate; a closed space is formed among the pressing plate, the expansion joint, the fixing plate, the sealing cylinder, the annular groove and the furnace body; The pressing plate is connected to the fixing plate through a plurality of pressing structures distributed along the circumference of the fixing plate. The pressing structure includes a mounting plate, a bolt and a spring. A placement hole is provided on the fixing plate corresponding to each mounting plate. The bottom of the mounting plate passes through the placement hole, and the mounting plate is detachably connected to the fixing plate; a first nut, a second nut and a third nut are distributed from top to bottom and are respectively threadedly connected to the bolt. The bolt passes through the mounting plate, the mounting plate is located between the first nut and the second nut, and the first nut and the second nut are respectively in close contact with the mounting plate. The pressing plate is provided with a mounting groove corresponding to the head of the bolt, and the head of the bolt is mounted in the mounting groove. The spring is sleeved on the bolt, the top end of the spring abuts against the third nut, and the bottom end abuts against the pressing plate; an annular gas charging pipe is arranged in the closed space, and a plurality of air outlet holes are uniformly arranged along the circumference on the gas charging pipe. The gas charging pipe is communicated with a gas source through a connecting pipe, and the connecting pipe passes through the furnace body and is hermetically connected to the furnace body; the gas charging pipe is used for charging a protective gas into the closed space.

2. The well-type furnace cover sealing structure according to claim 1, characterized in that: The protective gas is nitrogen.

3. The well-type furnace cover sealing structure according to claim 1, wherein: The inner diameter of the sealing cylinder is larger than the diameter of the furnace cover.

4. The well-type furnace cover sealing structure according to claim 1, characterized in that: The packing is graphite packing.

5. The well-type furnace cover sealing structure according to claim 1, characterized in that: It further includes a plurality of rib plates, the bottom of the rib plates is fixedly connected to the top end of the fixing plate, and the side parts of the rib plates are fixedly connected to the connecting cylinder. All the rib plates are uniformly distributed along the axial direction of the fixing plate.

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