A mechanical sealing device for a top-driven kettle and its front isolation protection system

Abstract

The present invention relates to a mechanical seal device for a top-driven kettle and a front isolation protection system thereof. The protection system includes a baffle sleeve and a liquid level monitoring subsystem. The baffle sleeve is installed on the chassis of the mechanical seal for the top-driven kettle. A liquid storage tank is formed between the baffle sleeve and the mechanical seal for the top-driven kettle. The liquid level in the liquid storage tank is always higher than the medium-side O-ring at the sliding diameter. Before feeding into the kettle, an isolation liquid medium is injected into the liquid storage tank through the liquid level monitoring subsystem. The lower end of the liquid level monitoring subsystem is connected to the liquid storage tank, and the upper end is connected to the kettle. When the liquid level height is higher than the medium-side O-ring at the sliding diameter, the liquid feeding is stopped, the liquid inlet valve is closed, and the balancing valve is opened. After feeding into the kettle, the liquid level height is kept unchanged by pressure balance. The present invention, by setting a front isolation protection system, realizes effective protection of the medium-side O-ring of the mechanical seal when it is not allowed to continuously fill the kettle with isolation protection liquid in the process.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical seals, and in particular to a mechanical seal device for a top-driven kettle and a front isolation protection system thereof. Background Art

[0002] In the top stirring tank mechanical seal of petrochemical industry, the medium in the tank is often not full or full, but a small part of the top of the stirring tank is gaseous, which causes the pressure change or temperature change during the operation of the equipment, causing the gas in the tank to react chemically, causing the O-ring on the medium side of the mechanical seal to form solid or colloidal substances at the sliding diameter, which in turn causes the O-ring to fail or the compensation ring to no longer float, causing the seal to leak and lead to seal failure.

[0003] At present, the commonly used method in industry is to add a front labyrinth seal, carbon ring seal or lip seal in front of the medium side seal, and use the PLAN32 flushing system to continuously fill the isolation protection liquid between the front seal and the medium side seal, so as to effectively protect the medium side seal from being contaminated by the medium in the kettle, especially to avoid the formation of solid or gelatinous substances on the medium side O-ring at the sliding diameter, so as to prevent the failure of the entire seal due to the failure of the O-ring.

[0004] However, some production processes do not allow the continuous filling of the kettle with isolation protection liquid. In this case, the O-ring on the medium side of the mechanical seal cannot be effectively protected. Summary of the invention

[0005] The purpose of the present invention is to provide a mechanical seal device for a top-driven kettle and a front isolation protection system thereof in order to solve the above-mentioned problem. By setting up a front isolation protection system, the O-ring on the medium side of the mechanical seal can be protected to prevent the gas medium from forming a colloid on the surface of the O-ring at the sliding diameter due to changes in the operating conditions in the kettle, thereby preventing the seal from failing.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A front isolation protection system is used for a mechanical seal for a top-driven kettle. The protection system includes a baffle sleeve and a liquid level monitoring subsystem. The baffle sleeve is installed on the chassis of the mechanical seal for the top-driven kettle. A liquid storage tank is formed between the outside of the baffle sleeve and the mechanical seal for the top-driven kettle. The top of the liquid storage tank is higher than the medium-side O-ring at the sliding diameter. The liquid level monitoring subsystem is connected to the liquid storage tank. Liquid medium is injected into the liquid storage tank through the liquid level monitoring subsystem. When the liquid level height of the liquid medium is higher than the medium-side O-ring at the sliding diameter, the liquid injection is stopped and the liquid level height is maintained.

[0008] Since the baffle sleeve is provided to form a liquid storage tank, the liquid level height of the liquid storage tank is higher than the medium side O-ring at the sliding diameter, which can effectively form a liquid seal, thereby solving the problem of preventing the gas in the reactor from chemically reacting at the medium side O-ring and the sliding diameter of the mechanical seal to form solid or colloidal substances and causing mechanical seal failure under the condition that the pre-buffer fluid is not allowed to be continuously charged into the reactor.

[0009] Furthermore, the liquid level monitoring subsystem includes a pressure flushing mechanism and a liquid level gauge, the pressure flushing mechanism is connected to the upper end of the liquid level gauge through an outlet pipeline, the lower end of the liquid level gauge is connected to the liquid storage tank through a liquid inlet pipeline, and the upper end of the liquid level gauge is connected to the kettle through another balance pipeline.

[0010] Furthermore, a first stop valve is provided on the outlet pipeline of the pressure flushing mechanism, and a second stop valve is provided on the balance pipeline.

[0011] Furthermore, the pressure flushing mechanism is a PLAN53A, PLAN53B, PLAN53C or PLAN54 system.

[0012] Furthermore, the deflector sleeve is in a "dome-top hat" shape, including a vertical bushing portion and a horizontal bend portion, the upper end of the vertical bushing portion is higher than the medium-side O-ring, and the horizontal bend portion is fixed to the chassis by screws, and a ring-shaped liquid storage tank is formed between the deflector sleeve and the top-driven kettle mechanical seal.

[0013] A mechanical sealing device for a top-driven kettle is provided with the above-mentioned front isolation protection system.

[0014] Furthermore, the mechanical sealing device is a double-end mechanical sealing device or a single-end mechanical sealing device for a top-driven kettle.

[0015] When the double-end mechanical seal device for the top-driven kettle is used, it specifically includes a chassis, a cavity, a bearing assembly, a rotating shaft and a sleeve. The chassis, the cavity and the bearing assembly are connected in sequence from bottom to top, and the rotating shaft passes through the bearing assembly, the cavity and the chassis in sequence from top to bottom. The sleeve is fixedly sleeved on the rotating shaft, and the sleeve is fixedly connected to the bearing assembly to realize the rotation of the rotating shaft and the sleeve. An accommodating cavity is provided in the cavity, and a double-end sealing mechanism is provided in the accommodating cavity. The double-end sealing mechanism includes a pair of dynamic rings and static rings symmetrically arranged up and down. The dynamic ring is installed on the sleeve and rotates with the sleeve. The static ring is fixedly installed on the device. A friction sealing end face is formed between the dynamic ring and the static ring. A deflector sleeve is sleeved at the bottom of the rotating shaft in the accommodating cavity. A liquid storage tank is formed between the deflector sleeve and the double-end sealing mechanism. Liquid medium is injected into the liquid storage tank to prevent the gas in the kettle from chemically reacting at the O-ring between the dynamic ring and the sleeve, causing the O-ring to fail.

[0016] Furthermore, the shaft sleeve comprises a long shaft sleeve and a short shaft sleeve, the long shaft sleeve is fixedly sleeved on the rotating shaft through a locking disk, the short shaft sleeve is connected to the lower part of the long shaft sleeve, and the dynamic ring is connected to the short shaft sleeve.

[0017] Furthermore, the dynamic ring includes dynamic rings on the medium side and the atmosphere side, the static ring includes static rings on the medium side and the atmosphere side, a spring is provided between the dynamic ring on the medium side and the dynamic ring on the atmosphere side, the bearing assembly includes a bearing housing and a bearing provided in the bearing housing, and the sleeve is connected to the bearing.

[0018] Compared with the prior art, the present invention adds a baffle sleeve higher than the O-ring on the medium side from the bottom plate of the mechanical seal, and forms a liquid storage tank between the baffle sleeve and the sealing mechanism. Liquid medium is injected into the liquid storage tank to isolate the medium in the sealed kettle. Then, in conjunction with the external liquid level monitoring subsystem, a sealing liquid is led from the sealing liquid inlet pipeline of the external flushing system to the liquid storage tank formed by the baffle sleeve. When the sealing liquid level is higher than the O-ring at the sliding diameter of the mechanical seal, the liquid intake is stopped, and the liquid level can be observed by the external liquid level monitoring subsystem. At the same time, another pipeline is led from the external liquid level monitoring subsystem to communicate with the kettle. When the kettle is pressurized, the upper pressure of the liquid level monitoring system and the pressure in the kettle are naturally balanced. In this way, without continuously filling the kettle with isolation protection liquid, the gas can be effectively prevented from chemically reacting at the O-ring and sliding diameter of the mechanical seal to form solid or colloidal substances, thereby avoiding the resulting mechanical seal failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a mechanical sealing device for an existing top drive kettle;

[0020] Figure 2 , 3It is a schematic structural diagram of a double-end mechanical seal device for a top-driven kettle according to an embodiment of the present invention;

[0021] Figure 4 It is a schematic structural diagram of a single-end mechanical seal device for a top-driven reactor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Example

[0024] Figure 1 This is a schematic diagram of a double-end mechanical seal device for an existing top-driven kettle. When the medium in the kettle is not full or is full but a small part of the top of the stirring tank is gaseous, it is easy to cause the gas in the tank to react chemically due to changes in pressure or temperature during the operation of the equipment. The O-ring and sliding diameter of the mechanical seal ( Figure 1 Solid or colloidal substances are formed at point a in the middle, which leads to failure of the O-ring or the compensation ring no longer floating, causing the seal to leak and lead to seal failure.

[0025] To solve this problem, the present invention provides a mechanical seal front isolation protection system for a top drive kettle, referring to Figure 2 , 3 The protection system includes a baffle sleeve 8 and a liquid level monitoring subsystem 10. The baffle sleeve 8 is installed on the chassis 1 of the mechanical seal for the top drive kettle. A liquid storage tank C is formed between the outside of the baffle sleeve 8 and the mechanical seal for the top drive kettle. The liquid storage tank C can be specifically annular. The top of the liquid storage tank C is higher than the medium side O-ring 12 at the sliding diameter. The liquid level monitoring subsystem 10 is connected to the liquid storage tank C. Liquid medium is injected into the liquid storage tank C through the liquid level monitoring subsystem 10. When the liquid level height is higher than the medium side O-ring 12 at the sliding diameter, the liquid injection is stopped and the liquid level height is maintained.

[0026] Specifically, the baffle sleeve 8 is in the shape of a "dome-top hat", including a vertical bushing portion and a horizontal bending portion, the upper end of the vertical bushing portion is higher than the medium-side O-ring 12, and the horizontal bending portion is fixedly mounted on the chassis 1 by screws. The liquid level monitoring subsystem 10 includes a pressure flushing mechanism 101 and a liquid level gauge 104. The pressure flushing mechanism 101 is connected to the upper end of the liquid level gauge 104 through an outlet pipeline, the lower end of the liquid level gauge 104 is connected to the liquid storage tank C through an inlet pipeline, and the upper end of the liquid level gauge 104 is connected to the kettle through another balancing pipeline. A first stop valve 103 is provided on the outlet pipeline of the pressure flushing mechanism, and a second stop valve 102 is provided on the balancing pipeline, and the liquid inlet and liquid level monitoring are controlled by the stop valves. The pressure flushing mechanism 101 can adopt the existing PLAN53A, PLAN53B, PLAN53C or PLAN54 system in the art.

[0027] Taking the double-end mechanical seal device for top-driven kettle as an example, a detailed explanation is given below.

[0028] A double-end mechanical seal device for a top-driven kettle, such as Figure 2 As shown, the device includes a chassis 1, a cavity 2, a bearing assembly, a rotating shaft 3 and a sleeve. The chassis 1, the cavity 2 and the bearing assembly are connected in sequence from bottom to top. The rotating shaft 3 passes through the bearing assembly, the cavity 2 and the chassis 1 in sequence from top to bottom. The sleeve is fixedly sleeved on the rotating shaft 3. The sleeve is fixedly connected to the bearing assembly to realize the rotation of the rotating shaft 3 and the sleeve. An accommodating cavity is provided in the cavity 2. A double-end face sealing mechanism is provided in the accommodating cavity. The double-end face sealing mechanism includes a pair of moving rings 6 and static rings 7 symmetrically arranged up and down. The moving ring 6 includes moving rings on the atmosphere side and the medium side. The static ring 7 includes static rings on the atmosphere side and the medium side. A spring is provided between the moving rings on the atmosphere side and the medium side. The bearing assembly includes a bearing housing 9 and a bearing 11 provided in the bearing housing 9. The sleeve is connected to the bearing 11.

[0029] The shaft sleeve includes a long shaft sleeve 4 and a short shaft sleeve 5. The long shaft sleeve 4 is fixedly mounted on the rotating shaft 3 through a locking plate. The short shaft sleeve 5 is connected to the lower part of the long shaft sleeve 4. The dynamic ring 6 is connected to the short shaft sleeve 5 and rotates therewith. The static ring 7 is fixedly installed on the device, and a friction sealing end face is formed between the dynamic ring 6 and the static ring 7.

[0030] A baffle sleeve 8 is sleeved at the bottom of the rotating shaft 3 in the accommodating cavity b. In this embodiment, the baffle sleeve 8 is in the shape of a "dome high hat", including a vertical bushing portion and a horizontal bending portion. The baffle sleeve 8 is fixedly mounted on the chassis 1 by screws. A liquid reservoir C is formed between the baffle sleeve 8 and the double-end face sealing mechanism. The liquid level in the liquid reservoir C is higher than the height of the O-type sealing ring between the lower moving ring and the shaft sleeve. The liquid medium is injected into the liquid reservoir C to seal the medium in the kettle to prevent the gas in the kettle from chemically reacting at the O-type sealing ring between the moving ring and the shaft sleeve, causing the O-type sealing ring to fail.

[0031] like Figure 3 In this embodiment, the liquid storage tank C is connected to the external liquid level monitoring subsystem 10 through a pipeline. The liquid level monitoring subsystem 10 includes a pressure flushing mechanism 101 and a liquid level gauge 104. The pressure flushing mechanism 101 is connected to the liquid level gauge 104 through an outlet pipeline. The other end of the liquid level gauge 104 is connected to the liquid storage tank. The upper end of the liquid level gauge 104 is connected to the kettle through a balancing pipeline, which is used to balance the pressure at both ends of the liquid in the liquid storage tank and the liquid level gauge. A first stop valve 103 is provided on the outlet pipeline of the pressure flushing mechanism, and a second stop valve 102 is provided on the balancing pipeline. The pressure flushing mechanism is PLAN53A.

[0032] The pressure flushing mechanism 101 of this embodiment adopts PLAN53A sealing liquid. The outlet pipeline leads the sealing liquid through the stop valve 103 into the liquid level gauge 104, and then enters the liquid storage tank C from the lower end of the liquid level gauge 104 through the machine seal port A. When the liquid level is higher than the sliding diameter O-ring (the gray shadow part in the figure is the height of the liquid entering the baffle sleeve), the stop valve 103 is closed, and the stop valve 102 is connected to the machine seal port B. The port B is connected to the pressure in the kettle and is used to balance the pressure at both ends of the baffle sleeve and the liquid in the liquid level gauge. This mechanical seal with a pre-isolation protection system, even if the gas in the kettle reacts, will be isolated by the liquid, so there will be no solid accumulation or gelatinous substances at the sliding diameter, and the seal will not fail.

[0033] Figure 4 It is a structural schematic diagram of a single-end mechanical seal device for a top-driven kettle. Compared with a double-end mechanical seal device for a top-driven kettle, a single-end mechanical seal device is provided with only one dynamic ring and a static ring. Adding a front isolation protection system to the single-end mechanical seal device can prevent the mechanical seal device from solid accumulation or production of colloidal substances at the sliding diameter, and the seal will not fail.

[0034] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A front isolation protection system for a mechanical seal of a top drive kettle, characterized in that: The protection system comprises a baffle sleeve (8) and a liquid level monitoring subsystem (10). The baffle sleeve (8) is mounted on the bottom plate (1) of the top-driven kettle mechanical seal, and a liquid storage tank (C) is formed between the baffle sleeve (8) and the top-driven kettle mechanical seal, wherein the top end of the liquid storage tank (C) is higher than the medium-side O-ring (12) at the sliding diameter. The lower end of the liquid level monitoring subsystem (10) is connected to the liquid storage tank (C), and liquid medium is injected into the liquid storage tank (C) through the liquid level monitoring subsystem (10). When the liquid level is higher than the medium-side O-ring (12) at the sliding diameter, the liquid injection is stopped and the liquid level is maintained; The liquid level monitoring subsystem (10) comprises a pressure flushing mechanism (101) and a liquid level gauge (104); the pressure flushing mechanism (101) is connected to the upper end of the liquid level gauge (104) via an outlet pipeline; the lower end of the liquid level gauge (104) is connected to the liquid storage tank (C) via a liquid inlet pipeline; and the upper end of the liquid level gauge (104) is connected to the kettle via another balancing pipeline; A first stop valve (103) is provided on the outlet pipeline of the pressure flushing mechanism, and a second stop valve (102) is provided on the balance pipeline; The pressure flushing mechanism (101) is a PLAN53A, PLAN53B, PLAN53C or PLAN54 system.

2. The front isolation protection system for mechanical seal of a top drive reactor according to claim 1 is characterized in that: The deflector sleeve (8) is in the shape of a "dome-top hat", comprising a vertical bushing portion and a horizontal bent portion, the upper end of the vertical bushing portion being higher than the medium-side O-ring (12), the horizontal bent portion being fixedly mounted on the chassis (1) by means of screws, and a liquid storage tank (C) in the shape of an annular ring is formed between the deflector sleeve (8) and the top-driven kettle mechanical seal.

3. A mechanical sealing device for a top drive kettle, characterized in that: The sealing device is equipped with a front isolation protection system for a mechanical seal for a top-driven kettle as claimed in claim 1 or 2.

4. A mechanical seal device for a top-driven kettle according to claim 3, characterized in that: The mechanical seal device is a double-end mechanical seal device or a single-end mechanical seal device for a top-driven kettle.

5. A mechanical seal device for a top drive kettle according to claim 4, characterized in that: The double-end mechanical seal device for a top-driven kettle comprises a chassis (1), a cavity (2), a bearing assembly, a rotating shaft (3) and a sleeve, wherein the chassis (1), the cavity (2) and the bearing assembly are connected in sequence from bottom to top, and the rotating shaft (3) passes through the bearing assembly, the cavity (2) and the chassis (1) in sequence from top to bottom. The shaft sleeve is fixedly mounted on the rotating shaft (3), and the shaft sleeve is fixedly connected to the bearing assembly to realize the rotation of the rotating shaft (3) and the shaft sleeve. The cavity (2) is provided with a receiving cavity, and a double end face sealing mechanism is provided in the receiving cavity. The double-end face sealing mechanism comprises a pair of dynamic rings (6) and static rings (7) symmetrically arranged in an upper and lower direction, wherein the dynamic ring (6) is mounted on the shaft sleeve and rotates with the shaft sleeve, and the static ring (7) is fixedly mounted on the device, and a friction sealing end face is formed between the dynamic ring (6) and the static ring (7). A deflector sleeve (8) is sleeved at the bottom of the rotating shaft (3) in the accommodating cavity, and a liquid storage tank (C) is formed between the deflector sleeve (8) and the double-end face sealing mechanism. Liquid medium is injected into the liquid storage tank (C) to prevent the gas in the kettle from chemically reacting at the O-ring between the moving ring (6) and the shaft sleeve, causing the O-ring to fail.

6. A mechanical seal device for a top-driven kettle according to claim 5, characterized in that: The shaft sleeve comprises a long shaft sleeve (4) and a short shaft sleeve (5); the long shaft sleeve (4) is fixedly sleeved on the rotating shaft (3) via a locking disk; the short shaft sleeve (5) is connected to the lower part of the long shaft sleeve (4); and the moving ring (6) is connected to the short shaft sleeve (5).

7. A mechanical seal device for a top-driven kettle according to claim 5, characterized in that: The dynamic ring comprises an atmosphere side dynamic ring and a medium side dynamic ring, the static ring comprises an atmosphere side static ring and a medium side static ring, a spring is provided between the atmosphere side dynamic ring and the medium side dynamic ring, the bearing assembly comprises a bearing housing (9) and a bearing (11) provided in the bearing housing (9), and the shaft sleeve is connected to the bearing (11).

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