Vacuum seal assembly for a PBT polymerization reactor

Abstract

This utility model relates to the field of vacuum sealing equipment technology, and discloses a vacuum sealing assembly for a PBT polymerization reactor, comprising: a shaft sealing sleeve, which is fitted around the circumference of a rotating shaft; the outer peripheral wall of the shaft sealing sleeve extends radially outward to form a first protrusion; an auxiliary sealing sleeve, which is fitted around the inner wall of a connecting sleeve, and the two form an interference fit; a connecting sleeve is fitted onto the reactor; the inner peripheral wall of the auxiliary sealing sleeve extends radially inward to form a second protrusion; the first protrusion has a first axial extension extending along the axial direction of the rotating shaft; the second protrusion has a second axial extension extending along the axial direction of the rotating shaft; a liquid storage cavity is formed between the second protrusion and the second axial extension; an annular gap is formed between the first axial extension and the second axial extension; and a sealing liquid, which is filled into the liquid storage cavity. This utility model achieves a highly sealed state inside the reactor by using a sealing liquid between the shaft sealing sleeve and the auxiliary sealing sleeve.

Description

Technical Field

[0001] This utility model relates to the field of vacuum sealing equipment technology, and more specifically, to a vacuum sealing component for a PBT polymerization reactor. Background Technology

[0002] The polymerization of polybutylene terephthalate (PBT) is a high-vacuum reaction, with typically low absolute pressure within the reactor and long continuous operation cycles. A high-vacuum environment is crucial for driving the polymerization reaction in the forward direction. The reactor's stirring shaft, as the power input component, has a highly reliable dynamic sealing structure, which is a key aspect of the entire vacuum system. A stirring assembly is generally installed at the top of the reactor, with the stirring shaft extending outside the reactor and connected to a reducer and motor. The seal between the shaft and the reactor wall must ensure both vacuum levels and allow continuous shaft rotation.

[0003] Existing sealing devices are not designed with overlapping sealing extensions in the axial direction of rotating shafts (such as agitator shafts), making it difficult to enhance sealing performance through the synergistic effect of annular gaps and sealing fluid. In traditional sealing solutions, the fit between the seal and the rotating shaft is mostly a single radial contact, without utilizing axial extension structures to form "labyrinth-type" or "liquid-sealed" gap seals. External air can easily seep in through the sealing gaps, or PBT oligomers entrained in the gas phase inside the reactor can deposit through the gaps, not only disrupting the vacuum environment but also accelerating seal wear and shortening service life. Utility Model Content

[0004] To address at least one of the aforementioned problems, this utility model first provides a vacuum sealing assembly for a PBT polymerization reactor, comprising: a shaft sealing sleeve having at least radial elasticity; the shaft sealing sleeve being fitted around the circumference of a rotating shaft, with an interference fit between them; the outer peripheral wall of the shaft sealing sleeve extending radially outward to form a first protrusion; an auxiliary sealing sleeve coaxially disposed with the shaft sealing sleeve, the auxiliary sealing sleeve having at least radial elasticity; the auxiliary sealing sleeve being fitted around the inner wall of a connecting sleeve, with an interference fit between them; the connecting sleeve being disposed on the reactor; the inner peripheral wall of the auxiliary sealing sleeve extending radially inward... The first protrusion has a first axial extension extending along the axis of rotation; the second protrusion has a second axial extension extending along the axis of rotation; a liquid reservoir is formed between the second protrusion and the second axial extension; the first axial extension and the second axial extension at least partially overlap in the axial direction of the axis of rotation to form an annular gap between the first axial extension and the second axial extension; a sealing liquid is filled into the liquid reservoir; the level of the sealing liquid is lower than the highest position of the second axial extension to seal the annular gap.

[0005] Optionally, the rotating shaft is a motor output shaft or a stirring shaft.

[0006] Optionally, the first axial extension has an upwardly curved first hook at its end; the second axial extension has a downwardly curved second hook at its end; an assembly gap is formed between the first hook and the second hook to reduce the splashing of sealing fluid when the shaft seal sleeve rotates.

[0007] Optionally, the bottom wall of the connecting sleeve is provided with a positioning groove of an annular structure; the bottom of the auxiliary sealing sleeve is provided with a positioning protrusion of an annular structure; the positioning protrusion is fitted into the positioning groove, and a seal is formed between the two.

[0008] Optionally, the shaft seal sleeve is provided with a plurality of radial constraint members around its periphery; the radial constraint members have radial elasticity to continuously generate an axial contraction force on the shaft seal sleeve.

[0009] Optionally, the shaft seal sleeve has an annular limiting groove on its periphery; the radial constraint member is sleeved within the annular limiting groove.

[0010] Optionally, radial bosses are provided at the openings at both ends of the shaft seal sleeve to restrict the radial constraint member from dislodging from the shaft seal sleeve.

[0011] Optionally, there are two radial constraint members; the two radial constraint members are respectively located near both ends of the shaft seal sleeve.

[0012] Optionally, a bearing is fitted between the connecting sleeve and the shaft sealing sleeve to allow the rotating shaft to rotate.

[0013] Optionally, two shaft sealing sleeves are provided along the axial direction of the rotating shaft; two auxiliary sealing sleeves are also provided accordingly.

[0014] Compared with the prior art, this utility model seals the rotating shaft by setting an annular gap between the shaft sealing sleeve and the auxiliary sealing sleeve, and sealing the annular gap with a sealing liquid, thereby making the reactor highly sealed; by setting the second hook and the first hook, the splashed sealing liquid can be blocked, minimizing the entry of the sealing liquid into the reactor; by providing a radial constraint member around the shaft sealing sleeve, the sealing performance of the shaft sealing sleeve is further improved. Attached Figure Description

[0015] Figure 1 This is an overall structural diagram of the vacuum sealing assembly of the PBT polymerization reactor in this utility model;

[0016] Figure 2 for Figure 1 Top view;

[0017] Figure 3 for Figure 2 Schematic diagram of the cross section at point AA;

[0018] Figure 4 for Figure 3 A magnified view of a portion of point B in the middle;

[0019] Figure 5 for Figure 4 A magnified view of a portion of point D in the middle;

[0020] Figure 6 for Figure 3 A magnified view of a portion of point C in the middle;

[0021] Figure 7 This is a schematic diagram of the auxiliary sealing sleeve in this utility model;

[0022] Figure 8 This is a schematic diagram of the structure of the central shaft sealing sleeve of this utility model;

[0023] Figure 9 This is a schematic diagram showing the installation of the central shaft sealing sleeve, rotating shaft, and reactor of this utility model.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Shaft sealing sleeve; 2-Auxiliary sealing sleeve; 3-Sealing fluid; 4-Reactor; 5-Radial constraint; 6-Bearing; 101-Rotating shaft; 102-First protrusion; 103-First axial extension; 104-First hook; 105-Annular limiting groove; 106-Radial boss; 201-Connecting sleeve; 202-Second protrusion; 203-Second axial extension; 204-Liquid storage chamber; 205-Annular gap; 206-Second hook; 207-Positioning protrusion; 2011-Positioning groove. Detailed Implementation

[0026] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] In the description of this utility model, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship when the product is in normal use.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0029] This invention provides a vacuum sealing assembly for a PBT polymerization reactor. Please refer to [link / reference]. Figure 1-9As shown, it includes: a shaft seal sleeve 1, which is fitted around the rotating shaft 101 with an interference fit; the shaft seal sleeve 1 has at least radial elasticity, so that the shaft seal sleeve 1 and the rotating shaft 101 fit tightly together, thus isolating the reactor 4 from the outside world and keeping it in a sealed state; the rotating shaft 101 is a motor output shaft or a stirring shaft, generally the stirring shaft extends from the top of the reactor 4, and the shaft seal sleeve 1 seals the stirring shaft, thus preventing the motor output shaft from directly extending into the reactor 4; the outer peripheral wall of the shaft seal sleeve 1 extends radially outward to form a first protrusion 102; and an auxiliary part is arranged coaxially with the shaft seal sleeve 1. A sealing sleeve 2; the auxiliary sealing sleeve 2 is fitted onto the inner wall of the connecting sleeve 201, and the two form an interference fit. The auxiliary sealing sleeve 2 has at least radial elasticity, so that the auxiliary sealing sleeve 2 can be tightly assembled inside the connecting sleeve 201 for sealing. The connecting sleeve 201 is provided on the reactor 4, and flanges are connected to both ends of the connecting sleeve 201, thereby fixing the connecting sleeve 201 to the reactor 4 through the flanges. The connecting sleeve 201 can be detachably fixed to the reactor 4, or it can be directly fixed to the reactor 4 by welding or other methods, thereby further improving the sealing performance. The inner circumferential wall of the auxiliary sealing sleeve 2 radially... The first protrusion 102 extends inward to form a second protrusion 202; wherein, the first protrusion 102 has a first axial extension 103 extending axially along the shaft 101; the second protrusion 202 has a second axial extension 203 extending axially along the shaft 101; a liquid storage cavity 204 is formed between the second protrusion 202 and the second axial extension 203; the first axial extension 103 and the second axial extension 203 at least partially overlap in the axial direction of the shaft 101 to form an annular gap 205 between the first axial extension 103 and the second axial extension 203, thereby ensuring that the shaft 101 is in a position where the belt... When the rotating shaft seal sleeve 1 rotates together, there will be no direct friction between the shaft seal sleeve 1 and the auxiliary seal sleeve 2, reducing wear and improving service life; the sealing liquid 3 is filled in the storage chamber 204; the liquid level of the sealing liquid 3 is lower than the highest position of the second axial extension 203 to seal the annular gap 205, thereby ensuring that when the rotating shaft 101 drives the shaft seal sleeve 1 to rotate together, the annular gap 205 between the shaft seal sleeve 1 and the auxiliary seal sleeve 2 is sealed by the sealing liquid 3, thereby ensuring that the reactor 4 is in a highly sealed state and reducing the entry of impurities in the air into the reactor 4 and affecting the reaction.

[0030] like Figure 3-4 As shown, a bearing 6 is assembled between the connecting sleeve 201 and the shaft sealing sleeve 1 to allow the rotating shaft 101 to rotate, ensuring that the rotating shaft 101 can rotate smoothly.

[0031] In one embodiment, such as Figure 4-5As shown, the first axial extension 103 has an upwardly curved first hook 104 at its end; the second axial extension 203 has a downwardly curved second hook 206 at its end; an assembly gap is formed between the first hook 104 and the second hook 206 to reduce the splashing of sealing fluid 3 when the shaft seal sleeve 1 rotates; without the second hook 206 and the first hook 104, when the rotating shaft 101 drives the shaft seal sleeve 1 to rotate at an excessively high speed, the sealing fluid 3 may splash into the reactor 4; by providing the second hook 206 and the first hook 104, the splashed sealing fluid 3 can be blocked, and the sealing fluid 3 can be prevented from entering the reactor 4 as much as possible.

[0032] In one embodiment, such as Figure 4-5 As shown, the bottom wall of the connecting sleeve 201 has an annular positioning groove 2011; the bottom of the auxiliary sealing sleeve 2 has an annular positioning protrusion 207; the positioning protrusion 207 is assembled in the positioning groove 2011, and the two are press-fitted to form a seal, so that the auxiliary sealing sleeve 2 can be stably placed in the connecting sleeve 201 and the sealing performance is improved.

[0033] In one embodiment, such as Figure 4-5 As shown, the shaft seal sleeve 1 is provided with several radial constraint members 5 around its periphery; the radial constraint members 5 have radial elasticity to continuously generate axial contraction force on the shaft seal sleeve 1, thereby further improving the sealing performance of the shaft seal sleeve 1; the radial constraint members 5 include, but are not limited to, elastic rubber rings, O-rings, etc.

[0034] In one embodiment, such as Figure 5 As shown, the shaft seal sleeve 1 has an annular limiting groove 105 on its circumference; the radial constraint member 5 is sleeved in the annular limiting groove 105, which plays an axial limiting role for the radial constraint member 5, making it difficult for the radial constraint member 5 to loosen from the shaft seal sleeve 1.

[0035] In one embodiment, such as Figure 3 As shown, radial bosses 106 are provided at the openings at both ends of the shaft seal sleeve 1 to restrict the radial constraint member 5 from coming out of the shaft seal sleeve 1, to axially limit the radial constraint member 5, and to facilitate the assembly of the shaft seal sleeve 1.

[0036] In one embodiment, such as Figure 4 As shown, there are two radial constraint members 5; the two radial constraint members 5 are respectively close to both ends of the shaft seal sleeve 1 to improve the sealing effect.

[0037] In one embodiment, such as Figure 3As shown, there are two shaft seal sleeves 1 along the axial direction of the rotating shaft 101; there are also two auxiliary seal sleeves 2. The annular gap 205 between the shaft seal sleeve 1 and the auxiliary seal sleeve 2 is filled with sealing liquid 3 to improve the sealing effect. After two sealing with sealing liquid 3, the sealing performance of the reactor 4 is greatly improved, so that the inside of the reactor is kept as vacuum as possible.

[0038] Although the disclosure is as stated above, the scope of protection of this disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this utility model.

Claims

1. A vacuum sealing assembly for a PBT polymerization reactor, characterized in that, include: Shaft seal sleeve (1), the shaft seal sleeve (1) has at least radial elasticity; the shaft seal sleeve (1) is sleeved on the circumference of the rotating shaft (101) and an interference fit is formed between the two; the outer peripheral wall of the shaft seal sleeve (1) extends radially outward to form a first protrusion (102). An auxiliary sealing sleeve (2) is coaxially arranged with the shaft sealing sleeve (1), and the auxiliary sealing sleeve (2) has at least radial elasticity; the auxiliary sealing sleeve (2) is sleeved on the inner wall of the connecting sleeve (201), and the two form an interference fit; the connecting sleeve (201) is provided on the reactor (4); the inner peripheral wall of the auxiliary sealing sleeve (2) extends radially inward to form a second protrusion (202). The first protrusion (102) has a first axial extension (103) extending axially along the pivot (101); the second protrusion (202) has a second axial extension (203) extending axially along the pivot (101); a liquid reservoir (204) is formed between the second protrusion (202) and the second axial extension (203); the first axial extension (103) and the second axial extension (203) at least partially overlap in projection in the axial direction of the pivot (101) to form an annular gap (205) between the first axial extension (103) and the second axial extension (203). A sealing fluid (3) is filled into a reservoir (204); the level of the sealing fluid (3) is lower than the highest position of the second axial extension (203) to seal the annular gap (205).

2. The vacuum sealing assembly of a PBT polymerization reactor according to claim 1, characterized in that, The rotating shaft (101) is either the motor output shaft or the stirring shaft.

3. The vacuum sealing assembly of a PBT polymerization reactor according to claim 1, characterized in that, The first axial extension (103) has an upwardly curved first hook (104) at its end; the second axial extension (203) has a downwardly curved second hook (206) at its end; an assembly gap is formed between the first hook (104) and the second hook (206) to reduce the splashing of sealing fluid (3) when the shaft seal sleeve (1) rotates.

4. The vacuum sealing assembly of a PBT polymerization reactor according to claim 1, characterized in that, The inner bottom wall of the connecting sleeve (201) is provided with a positioning groove (2011) of an annular structure; the bottom of the auxiliary sealing sleeve (2) is provided with a positioning protrusion (207) of an annular structure; the positioning protrusion (207) is fitted into the positioning groove (2011) and a seal is formed between the two.

5. A vacuum sealing assembly for a PBT polymerization reactor according to any one of claims 1-4, characterized in that, The shaft seal sleeve (1) is provided with a plurality of radial constraint members (5) around its periphery; the radial constraint members (5) have radial elasticity so as to continuously generate an axial contraction force on the shaft seal sleeve (1).

6. The vacuum sealing assembly of a PBT polymerization reactor according to claim 5, characterized in that, The shaft seal sleeve (1) has an annular limiting groove (105) on its periphery; the radial constraint member (5) is sleeved in the annular limiting groove (105).

7. The vacuum sealing assembly of a PBT polymerization reactor according to claim 5, characterized in that, The shaft seal sleeve (1) has radial bosses (106) at both ends of the opening to restrict the radial constraint member (5) from coming out of the shaft seal sleeve (1).

8. The vacuum sealing assembly of a PBT polymerization reactor according to claim 5, characterized in that, There are two radial constraint members (5); the two radial constraint members (5) are respectively close to both ends of the shaft seal sleeve (1).

9. A vacuum sealing assembly for a PBT polymerization reactor according to any one of claims 1-4, characterized in that, A bearing (6) is fitted between the connecting sleeve (201) and the shaft sealing sleeve (1) for the rotating shaft (101) to rotate.

10. The vacuum sealing assembly of a PBT polymerization reactor according to claim 1, characterized in that, Two shaft seal sleeves (1) are provided along the axial direction of the rotating shaft (101); two auxiliary seal sleeves (2) are also provided accordingly.

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