Hearth sealing opening and closing mechanism

Abstract

The invention relates to the technical field of micro-positive pressure hearths in industrial devices, in particular to a hearth sealing opening and closing mechanism. The hearth sealing opening and closing mechanism comprises a valve body, a valve ball, a transverse connecting rod and a gravity lever, the valve ball is provided with a center through hole, the valve ball is fixedly connected with the gravity lever through the transverse connecting rod, the valve ball and the transverse connecting rod are both arranged in the valve body, and the valve ball is used for controlling opening and closing between a hearth and the valve body. The valve body is used for installing a connected device, the valve ball is used for limiting communication between the hearth and the valve body, the valve ball is fixedly connected with the gravity lever through the transverse connecting rod, a worker can drive the transverse connecting rod and the valve ball to rotate by operating the gravity lever so as to change the position of a center through hole of the valve ball, and opening and closing between the hearth and the valve body are achieved. The hearth sealing opening and closing mechanism is good in sealing effect, ignition operation and observation are convenient, the whole valve body is of a detachable structure, and internal quick-wear parts are convenient to replace.

Description

Technical Field

[0001] The invention relates to the technical field of micro-positive pressure furnaces in industrial devices, and in particular to a furnace sealing opening and closing mechanism. Background Art

[0002] There are some furnaces with slight positive pressure in petrochemical plants, and it may be necessary to operate through small holes in the furnaces on site. During the normal operation of these furnaces, there are often dangerous working conditions such as high temperature, flammable and explosive, toxic and harmful, which pose great safety risks. Furnaces with certain structures require an external ignition gun to be inserted into the furnace for ignition operation. After the ignition operation is completed, the ignition gun needs to be immediately withdrawn and the insertion port needs to be quickly and effectively sealed to ensure the smooth progress of normal operation.

[0003] The Chinese invention patent with the publication number CN107514489B discloses a forced sealing ball valve opening and closing drive device, which includes a sealing valve stem, a valve ball valve stem, a valve stem driving turntable and a valve stem travel block, the sealing valve stem drives the sealing driving wheel to rotate, the valve stem driving turntable drives the sealing valve stem to rotate; the valve ball valve stem drives the valve ball to rotate, and the valve stem travel block controls the rotation stroke of the valve ball valve stem; within the rotation stroke of the valve ball valve stem, the valve ball valve stem and the sealing valve stem rotate simultaneously, after the valve ball valve stem rotates to the valve ball closing position, the valve stem driving turntable drives the sealing valve stem to rotate, drives the spiral driving wheel to lift and retract the sealing cover. The above forced sealing ball valve opening and closing drive device adopts a valve stem driving turntable, cooperates with the elastic hanging ring and driving hook, disengagement hook, disengagement wedge angle and reset wedge angle installed on the valve ball valve stem, so that the valve stem driving turntable drives the operation of the valve ball and the sealing cover according to the operation process of the forced sealing ball valve, is easy to operate, and is suitable for the application of large-caliber and high-pressure valves.

[0004] However, the above-mentioned forced sealing ball valve opening and closing drive device includes a sealing valve stem, a valve ball valve stem, a valve stem driving turntable and a valve stem travel block. It adopts a valve stem driving turntable, which cooperates with an elastic hanging ring and a driving hook, a disengagement hook, a disengagement wedge angle and a reset wedge angle installed on the valve ball valve stem, so that the valve stem driving turntable drives the operation of the valve ball and the sealing cover according to the operation process of the forced sealing ball valve; the overall structure is too complicated and inconvenient to load and unload, and it is inconvenient to replace when its internal components are damaged. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a furnace sealing opening and closing mechanism, which has good sealing effect, convenient ignition operation and observation, and the valve body is a detachable structure as a whole, which is convenient for replacing the internal vulnerable parts.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A furnace sealing opening and closing mechanism comprises a valve body, a valve ball, a transverse connecting rod and a gravity lever, the valve ball is a valve ball with a central through hole, the valve ball is fixedly connected by a transverse connecting rod and a gravity lever, the valve ball and the transverse connecting rod are both arranged in the valve body, the valve ball is used to control the opening and closing between the furnace and the valve body, when the central through hole of the valve ball coincides with the center line of the valve body, the furnace and the valve body are fully opened, when the central through hole of the valve ball is perpendicular to the center line of the valve body, the furnace and the valve body are fully closed.

[0008] Furthermore, the valve body includes a valve seat, a valve seat fastener, a valve seat gland, a valve body fastener, a gland nut, a closing cylinder, a connecting rod gland, a limiting fastener and an oil filling hole, the valve seat is threadedly fixed to the outer wall of the furnace through the valve seat fastener, the valve seat gland is threadedly fixed to the valve seat through the valve body fastener and presses the closing cylinder, the closing cylinder is arranged between the valve seat and the valve seat gland, the closing cylinder and the connecting rod gland are threadedly fixed by the limiting fastener, the valve seat and the valve seat gland are threadedly fixed and form an accommodating chamber together with the closing cylinder, the valve ball is arranged in the accommodating chamber, one end of the transverse connecting rod is fixedly connected to the valve ball, the other end of the transverse connecting rod is penetrated through the closing cylinder and the connecting rod gland and is fixed to the gravity lever by a nut, an ignition inlet is arranged on the side of the valve seat gland away from the valve seat, a gland nut is threadedly fixed at the ignition inlet, an oil filling hole is arranged on the closing cylinder between the valve seat gland and the valve seat, and the oil filling hole is communicated with the accommodating chamber.

[0009] Furthermore, the closing cylinder is provided with a gasket and a stuffing box, wherein the gasket is used for sealing between the closing cylinder and the transverse connecting rod, and the stuffing box is used for sealing between the closing cylinder, the transverse connecting rod and the connecting rod gland.

[0010] Furthermore, the connecting rod gland is provided with a sliding bearing, and the sliding bearing is used for sealing between the connecting rod gland and the transverse connecting rod.

[0011] Furthermore, the valve seat gland is provided with a self-lubricating packing, and the self-lubricating packing is used for sealing between the valve ball and the valve body.

[0012] Furthermore, a sealing filler, an annular retaining ring and a ring rod are provided at the ignition inlet of the valve seat gland, the ring rod is located between the annular retaining rings, and the space between the ring rod and the annular retaining ring is filled with a sealing filler.

[0013] Furthermore, the transverse connecting rod is provided with a limit rod, and the limit rod rotates synchronously with the gravity lever, and the rotation range of the limit rod is limited by the limit fastener.

[0014] Furthermore, a groove is provided on one side of the valve seat close to the furnace, and a sealing ring is provided in the groove.

[0015] Furthermore, the gravity lever is provided with a counterweight and a fastening nut, a thread is provided in the middle of the rod body of the gravity lever, the counterweight is slidably arranged on the thread and is fixed to the gravity lever through the fastening nut thread.

[0016] Furthermore, a limit stopper is included, and the limit stopper is used to limit the gravity lever from moving further downward.

[0017] Beneficial effects of the invention: The invention discloses a furnace sealing opening and closing mechanism, comprising a valve body, a valve ball, a transverse connecting rod and a gravity lever, the valve ball is a valve ball with a central through hole, the valve ball is fixedly connected by a transverse connecting rod and a gravity lever, the valve ball and the transverse connecting rod are both arranged in the valve body, the valve ball is used to control the opening and closing between the furnace and the valve body, when the central through hole of the valve ball coincides with the center line of the valve body, the furnace and the valve body are opened, otherwise, the furnace and the valve body are closed. The valve body is used to install the connected devices. At the same time, the valve body is fixed to the furnace and connected with the furnace. The valve ball is used to limit the connection between the furnace and the valve body. The valve ball is a valve ball with a central through hole. When the central through hole of the valve ball coincides with the center line of the valve body, the furnace and the valve body are fully open. When the central through hole of the valve ball is perpendicular to the center line of the valve body, the furnace and the valve body are completely closed. The valve ball is fixedly connected by a transverse connecting rod and a gravity lever. The staff can drive the transverse connecting rod and the valve ball to rotate by operating the gravity lever to change the position of the central through hole of the valve ball to realize the opening and closing between the furnace and the valve body. The furnace sealing opening and closing mechanism of the present application has good sealing effect, convenient ignition operation and observation, and the valve body is a detachable structure as a whole, which is convenient for replacing the internal vulnerable parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the valve body of the present invention in a fully open state;

[0019] Figure 2 It is a structural schematic diagram of the valve body of the present invention in a fully closed state;

[0020] Figure 3 It is a cross-sectional view of the valve body of the present invention when it is fully closed.

[0021] Explanation of the reference numerals: valve ball 1, transverse connecting rod 2, limit rod 21, gravity lever 3, counterweight 31, fastening nut 32, valve seat 4, sealing ring 41, valve seat fastener 5, valve seat gland 6, self-lubricating packing 61, sealing packing 62, annular retaining ring 63, ring rod 64, valve body fastener 7, gland nut 8, closing cylinder 9, gasket 91, stuffing box 92, connecting rod gland 10, sliding bearing 101, limit fastener 11, oil filling hole 12, limit stopper 13. DETAILED DESCRIPTION

[0022] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0023] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0024] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0025] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, the element described as "below other elements or features" or "below other elements or features" will then be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0026] Embodiment 1:

[0027] like Figure 1-Figure 3 As shown, the present embodiment provides a furnace sealing opening and closing mechanism, which includes a valve body, a valve ball 1, a transverse connecting rod 2 and a gravity lever 3. The valve ball 1 is a valve ball 1 with a central through hole, and the valve ball 1 is fixedly connected by the transverse connecting rod 2 and the gravity lever 3. The valve ball 1 and the transverse connecting rod 2 are both arranged in the valve body. The valve ball 1 is used to control the opening and closing between the furnace and the valve body. When the central through hole of the valve ball 1 coincides with the center line of the valve body, the furnace and the valve body are fully opened. When the central through hole of the valve ball 1 is perpendicular to the center line of the valve body, the furnace and the valve body are fully closed. When in actual use, the valve body is used to install the connecting devices, and the valve body is fixed to the furnace and connected with the furnace. The valve ball 1 is used to limit the connection between the furnace and the valve body. The valve ball 1 is a valve ball 1 with a central through hole. When the central through hole of the valve ball 1 coincides with the center line of the valve body, the furnace and the valve body are fully opened. When the central through hole of the valve ball 1 is perpendicular to the center line of the valve body, the furnace and the valve body are fully closed. The valve ball 1 is fixedly connected by a transverse connecting rod 2 and a gravity lever 3. The staff can drive the transverse connecting rod 2 and the valve ball 1 to rotate by operating the gravity lever 3 to change the position of the central through hole of the valve ball 1 to realize the opening and closing between the furnace and the valve body. When it needs to be opened, the gravity lever 3 is lifted to make the central through hole coincide with the center line of the valve body. At this time, the central through hole is connected with the furnace, and the ignition gun is extended into the furnace through the central through hole to complete the ignition operation. After the operation is completed, the ignition gun is taken out, and the valve ball 1 automatically falls under the action of gravity to achieve sealing.

[0028] In this embodiment, the valve body includes a valve seat 4, a valve seat fastener 5, a valve seat gland 6, a valve body fastener 7, a gland nut 8, a closing cylinder 9, a connecting rod gland 10, a limiting fastener 11 and an oil filling hole 12. The valve seat 4 is threadedly fixed to the outer wall of the furnace through the valve seat fastener 5. The valve seat gland 6 is threadedly fixed to the valve seat 4 through the valve body fastener 7 and presses the closing cylinder 9. The closing cylinder 9 is arranged between the valve seat 4 and the valve seat gland 6. The closing cylinder 9 and the connecting rod gland 10 are threadedly fixed by the limiting fastener 11. The valve seat 4 is fixed to the outer wall of the furnace through the valve seat fastener 5. The valve seat gland 6 is threadedly fixed to the valve seat 4 through the valve body fastener 7 and presses the closing cylinder 9. The closing cylinder 9 is arranged between the valve seat 4 and the valve seat gland 6. The closing cylinder 9 and the connecting rod gland 10 are threadedly fixed by the limiting fastener 11. The seat cover 6 is fixed by threads and forms an accommodating chamber together with the closing cylinder 9, the valve ball 1 is arranged in the accommodating chamber, one end of the transverse connecting rod 2 is fixedly connected to the valve ball 1, the other end of the transverse connecting rod 2 is passed through the closing cylinder 9 and the connecting rod cover 10 and is threadedly fixed to the gravity lever 3, an ignition inlet is provided on the side of the valve seat cover 6 away from the valve seat 4, a cover nut 8 is threadedly fixed at the ignition inlet, an oil filling hole 12 is provided on the closing cylinder 9 between the valve seat cover 6 and the valve seat 4, and the oil filling hole 12 is connected to the accommodating chamber. In actual use, the valve seat 4 is fixed to the outer wall of the furnace through the valve seat fastener 5, the valve seat 4 and the valve seat gland 6 are threadedly fixed and pressed against the closing cylinder 9 through the valve body fastener 7, and a gland nut 8 is arranged at the ignition inlet of the valve seat gland 6, which can facilitate the disassembly of the valve body and the later maintenance of the valve body. The accommodating chamber formed by the valve seat 4, the valve seat gland 6 and the closing cylinder 9 is used to place the valve ball 1. The valve seat 4 and the valve seat gland 6 are provided with communicating openings on the axis and correspond to the central through hole of the valve ball 1. The opening and closing between the furnace and the valve body are controlled by the positional relationship between the central through hole of the valve ball 1 and the openings of the valve seat 4 and the valve seat gland 6. The closing cylinder 9, the connecting rod gland 10 and the limiting fastener 11 are all used for the transverse connecting rod 2 to pass through and provide sealing support. Lubricating grease is added into the accommodating chamber through the oil filling hole 12 to lubricate the valve ball 1 and the sealing material, thereby extending the service life of the valve ball 1 and the sealing material, and facilitating the staff to operate the gravity lever 3 to drive the valve ball 1 to rotate.

[0029] In this embodiment, the sealing cylinder 9 is provided with a gasket 91 and a stuffing box 92, wherein the gasket 91 is used to seal between the sealing cylinder 9 and the transverse connecting rod 2, and the stuffing box 92 is used to seal between the sealing cylinder 9, the transverse connecting rod 2 and the connecting rod gland 10. In actual use, the gasket 91 and the stuffing box 92 are used to ensure effective sealing during the movement of the transverse connecting rod 2, thereby reducing the leakage of dangerous media inside the furnace.

[0030] In this embodiment, the connecting rod gland 10 is provided with a sliding bearing 101, and the sliding bearing 101 is used to seal between the connecting rod gland 10 and the transverse connecting rod 2. In actual use, the sliding bearing 101 ensures the sealing between the connecting rod gland 10 and the transverse connecting rod 2, ensures the effective sealing during the movement of the transverse connecting rod 2, reduces the leakage of dangerous media inside the furnace, and plays a positioning and supporting role.

[0031] In this embodiment, the valve seat gland 6 is provided with a self-lubricating packing 61, which is used to seal between the valve ball 1 and the valve body. In actual use, the movement of the valve ball 1 is limited by the self-lubricating packing 61, so that the valve ball 1 can only rotate under the drive of the gravity lever 3. At the same time, the self-lubricating packing 61 plays a role in sealing between the valve body and the valve ball 1, reducing the leakage of dangerous media inside the furnace.

[0032] In this embodiment, a sealing packing 62, an annular retaining ring 63 and a ring rod 64 are provided at the ignition entrance of the valve seat gland 6. The ring rod 64 is located between the annular retaining rings 63, and the sealing packing 62 is filled between the ring rod 64 and the annular retaining ring 63. In actual use, the sealing packing 62, the annular retaining ring 63 and the ring rod 64 are used to reduce the risk of leakage of dangerous media inside the furnace during the ignition operation. The sealing packing 62 is compressed and positioned by the annular retaining ring 63 and the ring rod 64. The sealing packing 62 is a flexible material, which can not only ensure the insertion of the ignition gun, but also form a certain sealing condition between the ignition gun and the ignition gun during the ignition operation. The inner diameter of the ring rod 64 is slightly larger than the outer diameter of the ignition gun, and plays a guiding role in the process of inserting and withdrawing the ignition gun.

[0033] In this embodiment, the transverse connecting rod 2 is provided with a limit rod 21, and the limit rod 21 rotates synchronously with the gravity lever 3, and the rotation range of the limit rod 21 is limited by the limit fastener 11. In actual use, the limit rod 21 is used to limit the rotation angle of the gravity lever 3. When the limit rod 21 reaches the rotation limit position, the limit fastener 11 contacts the limit rod 21, and the rotation angle of the limit rod 21 is limited by the limit fastener 11, thereby limiting the rotation angle of the gravity lever 3.

[0034] In this embodiment, a groove is formed on one side of the valve seat 4 close to the furnace, and a sealing ring 41 is arranged in the groove. In actual use, the sealing ring 41 is arranged to ensure the sealing between the valve seat 4 and the furnace.

[0035] In this embodiment, the gravity lever 3 is provided with a counterweight 31 and a fastening nut 32. The middle part of the rod body of the gravity lever 3 is provided with a thread. The counterweight 31 is slidably arranged on the thread and is threadedly fixed to the gravity lever 3 by the fastening nut 32. In actual use, the gravity lever 3 can adjust the position of the counterweight 31 by the resistance of the valve ball 1. When the resistance of the valve ball 1 is large, the position of the counterweight 31 is adjusted away from the valve ball 1, and vice versa. After the position of the counterweight 31 and the gravity lever 3 is adjusted, they are fixed by the fastening nut 32.

[0036] In this embodiment, a limit stopper 13 is further included, and the limit stopper 13 is used to limit the gravity lever 3 from further moving downward. In actual use, the limit stopper 13 is used to limit the gravity lever 3 from further moving downward. The limit stopper 13 does not work at ordinary times. When the limit fastener 11 fails, the gravity lever 3 continues to move downward uncontrolled, and is blocked by the limit stopper 13 to prevent the gravity lever 3 from being damaged and the furnace from leaking.

[0037] All technical features in this embodiment can be freely combined according to actual needs. The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be covered by the scope of the claims of the present invention. The technology, shape, and structural parts not described in detail in the present invention are all well-known technologies.

[0038] The above embodiments are preferred implementation schemes of the present invention. In addition, other implementation schemes are also included. Any obvious replacement without departing from the concept of the present technical scheme is within the protection scope of the present invention.

Claims

1. A furnace sealing opening and closing mechanism, characterized in that: The invention comprises a valve body, a valve ball (1), a transverse connecting rod (2) and a gravity lever (3), wherein the valve ball (1) is a valve ball (1) with a central through hole, the valve ball (1) is fixedly connected by the transverse connecting rod (2) and the gravity lever (3), the valve ball (1) and the transverse connecting rod (2) are both arranged in the valve body, the valve ball (1) is used to control the opening and closing between the furnace and the valve body, when the central through hole of the valve ball (1) coincides with the center line of the valve body, the furnace and the valve body are fully opened, and when the central through hole of the valve ball (1) is perpendicular to the center line of the valve body, the furnace and the valve body are fully closed.

2. A furnace sealing opening and closing mechanism according to claim 1, characterized in that: The valve body comprises a valve seat (4), a valve seat fastener (5), a valve seat gland (6), a valve body fastener (7), a gland nut (8), a closing cylinder (9), a connecting rod gland (10), a limiting fastener (11) and an oil filling hole (12); the valve seat (4) is threadedly fixed to the outer wall of the furnace through the valve seat fastener (5); the valve seat gland (6) is threadedly fixed to the valve seat (4) through the valve body fastener (7) and presses the closing cylinder (9); the closing cylinder (9) is arranged between the valve seat (4) and the valve seat gland (6); the closing cylinder (9) and the connecting rod gland (10) are threadedly fixed to each other through the limiting fastener (11); the valve seat (4) and the connecting rod gland (10) are threadedly fixed to each other through the limiting fastener (11); The valve seat cover (6) is fixed by threads and forms a receiving chamber together with the closing cylinder (9), the valve ball (1) is arranged in the receiving chamber, one end of the transverse connecting rod (2) is fixedly connected to the valve ball (1), the other end of the transverse connecting rod (2) is passed through the closing cylinder (9) and the connecting rod cover (10) and is fixed to the gravity lever (3) by a nut, an ignition inlet is provided on the side of the valve seat cover (6) away from the valve seat (4), a cover nut (8) is threadedly fixed at the ignition inlet, an oil filling hole (12) is provided on the closing cylinder (9) between the valve seat cover (6) and the valve seat (4), and the oil filling hole (12) is connected to the receiving chamber.

3. A furnace sealing opening and closing mechanism according to claim 2, characterized in that: The sealing cylinder (9) is provided with a gasket (91) and a stuffing box (92), wherein the gasket (91) is used for sealing between the sealing cylinder (9) and the transverse connecting rod (2), and the stuffing box (92) is used for sealing between the sealing cylinder (9), the transverse connecting rod (2) and the connecting rod gland (10).

4. A furnace sealing opening and closing mechanism according to claim 2, characterized in that: The connecting rod gland (10) is provided with a sliding bearing (101), and the sliding bearing (101) is used for sealing between the connecting rod gland (10) and the transverse connecting rod (2).

5. The furnace sealing opening and closing mechanism according to claim 2, characterized in that: The valve seat gland (6) is provided with a self-lubricating filler (61), and the self-lubricating filler (61) is used for sealing between the valve ball (1) and the valve body.

6. A furnace sealing opening and closing mechanism according to claim 2, characterized in that: A sealing filler (62), an annular retaining ring (63) and a ring rod (64) are provided at the ignition entrance of the valve seat gland (6); the ring rod (64) is located between the annular retaining rings (63); and the sealing filler (62) is filled between the ring rod (64) and the annular retaining ring (63).

7. A furnace sealing opening and closing mechanism according to claim 2, characterized in that: The transverse connecting rod (2) is provided with a limiting rod (21), and the limiting rod (21) rotates synchronously with the gravity lever (3), and the rotation range of the limiting rod (21) is limited by the limiting fastener (11).

8. The furnace sealing opening and closing mechanism according to claim 2, characterized in that: A groove is formed on a side of the valve seat (4) close to the furnace, and a sealing ring (41) is arranged in the groove.

9. The furnace sealing opening and closing mechanism according to claim 1, characterized in that: The gravity lever (3) is provided with a counterweight (31) and a fastening nut (32); a thread is provided in the middle of the rod body of the gravity lever (3); the counterweight (31) is slidably arranged on the thread and is threadably fixed to the gravity lever (3) via the fastening nut (32).

10. The furnace sealing opening and closing mechanism according to claim 1, characterized in that: It also comprises a limit stopper (13), wherein the limit stopper (13) is used to limit the gravity lever (3) from further moving downward.

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