Horizontal vacuum reaction kettle shaft seal structure and reaction kettle comprising same

Abstract

The application discloses a horizontal vacuum reaction kettle shaft sealing structure and a reaction kettle comprising the same. The shaft sealing structure is arranged outside the shaft sleeve of the horizontal vacuum reaction kettle and comprises a first sealing cavity, which is formed with an opening hole for inputting silicon oil into the sealing cavity. A first sealing member is arranged in the first sealing cavity, and the edge of the first sealing member is formed with at least one protrusion. The protrusion has a set interval with the shaft sleeve, and the set interval is suitable for forming a silicon oil film between the protrusion and the shaft sleeve. After the silicon oil enters the first sealing cavity, the first sealing member in the first sealing cavity can be expanded, and the sealing effect of the first sealing member is increased. The silicon oil film between the protrusion on the first sealing member and the shaft sleeve can reduce the friction resistance between the shaft sleeve and the first sealing member, remove the heat generated by friction, ensure that the first sealing member does not exceed the service temperature, and improve the service life of the first sealing member. Moreover, the silicon oil film can prevent external air from entering the inside of the vacuum reaction kettle, and the high vacuum state in the reaction kettle is ensured.

Description

Technical Field

[0001] This application relates to the technical field of horizontal high-temperature vacuum reaction equipment, specifically to a horizontal vacuum reactor shaft seal structure and a reactor including the same. Background Technology

[0002] Horizontal vacuum reactors mostly operate under high temperature and high vacuum conditions, and the reliability of the reactor shaft seal directly affects the purity and yield of the product. Due to the long agitator shaft, it undergoes bending deformation under its own weight, and the difference in thermal expansion displacement between the shaft and the shell during heating and cooling processes leads to excessive axial and radial runout of the agitator shaft. During production start-up and shutdown, the reactor temperature fluctuates between room temperature and 240℃. At 240℃, the thermal expansion displacement of the entire reactor is approximately 10mm, the rotor displacement is approximately 15mm, and the relative displacement between the rotor and the cylinder is approximately 5mm. The non-drive side of the reactor is fixed, and during heating, the entire reactor shell and shaft expand freely towards the drive side, causing the shaft to slide along with the bushing. Furthermore, the reactor material solidifies at low temperatures and cokes and carbonizes at high temperatures, making ordinary mechanical seals unsuitable for this condition.

[0003] Therefore, there is room for improvement in the sealing structure of existing horizontal vacuum reactors. Summary of the Invention

[0004] The technical problem to be solved by this application is that the sealing structure of existing horizontal vacuum reactors cannot meet the requirements. To this end, this application proposes a shaft seal structure for a horizontal vacuum reactor and a reactor including the same.

[0005] To address the aforementioned technical problems, this application provides the following technical solution:

[0006] In a first aspect, the technical solution of this application provides a shaft seal structure for a horizontal vacuum reactor, used to be disposed outside the shaft sleeve of the horizontal vacuum reactor, comprising:

[0007] A first sealing cavity has an opening formed thereon, the opening being used to introduce silicone oil into the sealing cavity;

[0008] A first sealing element is disposed within the first sealing cavity. The edge of the first sealing element is formed with at least one protrusion. There is a set interval between the protrusion and the bushing. The set interval is suitable for the silicone oil to form a silicone oil film between the protrusion and the bushing.

[0009] In some embodiments of the horizontal vacuum reactor shaft seal structure, the first sealing cavity includes multiple first sealing cavities, which are arranged sequentially along the extension direction of the shaft sleeve.

[0010] In some embodiments of the horizontal vacuum reactor shaft seal structure, each first sealing cavity includes two first sealing elements; the opening is located at the middle position of the two first sealing elements.

[0011] The shaft seal structure of the horizontal vacuum reactor described in some of the schemes also includes:

[0012] A circulating pump, the outlet of which is connected to the opening, is used to transport silicone oil from the oil tank through the opening to the first sealing cavity and then return it to the circulating pump after filling the first sealing cavity.

[0013] In some designs, the shaft seal structure of the horizontal vacuum reactor specifies that the pressure of the silicone oil input to the first sealing chamber by the circulating pump is controlled to be within 0.15 MPa; the reflux flow rate of the first sealing chamber is controlled to be 0.3 m³ / s. 3 / h-0.5m 3 Between / h.

[0014] In some designs, the first sealing element of the horizontal vacuum reactor shaft seal structure is a rubber seal.

[0015] The shaft seal structure of the horizontal vacuum reactor described in some of the schemes also includes:

[0016] The second sealing element is disposed at the front end of the first sealing cavity;

[0017] The second seal includes a sealing ring and a fastener for securing the sealing ring to the outside of the bushing.

[0018] In some designs, the horizontal vacuum reactor shaft seal structure uses a Glyd ring as the sealing ring, which is composed of a perfluoroether ring and a polytetrafluoroethylene ring.

[0019] The shaft seal structure of the horizontal vacuum reactor described in some of the schemes also includes:

[0020] The third seal is disposed at the front end of the second seal;

[0021] The third seal includes a sealing float ring and a flange for fixing the sealing float ring to the outside of the bushing.

[0022] Secondly, the present application provides a horizontal vacuum reactor, including a reactor body and a shaft seal structure as described in any of the solutions in the first aspect; the shaft seal structure is disposed outside the bushing of the reactor body.

[0023] The technical solution of this application has the following technical advantages over the prior art:

[0024] This application provides a horizontal vacuum reactor shaft seal structure and a reactor including the same. The shaft seal structure is disposed outside the shaft sleeve of the horizontal vacuum reactor and includes a first sealing cavity with an opening formed thereon for introducing silicone oil into the sealing cavity. A first sealing element is disposed within the first sealing cavity. At least one protrusion is formed on the edge of the first sealing element, and a predetermined interval is provided between the protrusion and the shaft sleeve. The predetermined interval is suitable for the silicone oil to form a silicone oil film between the protrusion and the shaft sleeve. After the silicone oil enters the first sealing cavity, it can expand the first sealing element within the first sealing cavity, increasing the sealing effect of the first sealing element. The silicone oil film between the protrusion on the first sealing element and the shaft sleeve can reduce the frictional resistance between the shaft sleeve and the first sealing element, carry away the heat generated by friction, ensure that the first sealing element does not exceed the operating temperature, and improve the service life of the first sealing element. Moreover, the silicone oil film can prevent external air from entering the interior of the vacuum reactor, ensuring a high vacuum state inside the reactor. Attached Figure Description

[0025] The preferred embodiments of this application will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of this application, wherein:

[0026] Figure 1 This is a schematic diagram of the shaft seal structure of a horizontal vacuum reactor according to one embodiment of this application;

[0027] Figure 2 This is a schematic diagram of the structure of the first seal in one embodiment of this application. Detailed Implementation

[0028] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0032] This embodiment provides a shaft seal structure for a horizontal vacuum reactor, used to be disposed outside a shaft sleeve 9 of the horizontal vacuum reactor. The shaft sleeve 9 is fitted onto the outside of a shaft 100 and is fixed to the outside of the shaft 100 by a pin 10. As shown in the figure, the shaft seal structure includes a first sealing cavity 11 and a first sealing element 5. An opening 12 is formed on the first sealing cavity 11, and the opening 12 is used to introduce silicone oil into the sealing cavity 11; the first sealing element 5 is disposed inside the first sealing cavity 11. Figure 2 As shown, the edge of the first sealing member 5 is formed with at least one protrusion 53, which, in combination with Figure 1 As shown, there is a set interval between the protrusion 53 of the first seal 5 and the bushing 9, the set interval being suitable for the silicone oil to form a silicone oil film between the protrusion 53 and the bushing 9.

[0033] like Figure 2 As shown, the first sealing element 5 is a lip seal, and its skeleton 51 is irregularly shaped, thus having an inner groove 52 and a protrusion 53. After the silicone oil enters the first sealing cavity 11, it can circulate in the inner groove 52 and other positions of the first sealing cavity 11, forming a silicone oil film between the protrusion 53 and the bushing 9.

[0034] In the above embodiments, the shaft seal structure is used to be disposed outside the bushing 9 of the horizontal vacuum reactor. It includes a first sealing cavity 11, on which an opening 12 for introducing silicone oil into the sealing cavity 11 is formed. A first sealing element 5 is disposed within the first sealing cavity 11. At least one protrusion 53 is formed on the edge of the first sealing element 5, and a predetermined interval is provided between the protrusion 53 and the bushing 9. This predetermined interval is suitable for the silicone oil to form a silicone oil film between the protrusion 53 and the bushing 9. After the silicone oil enters the first sealing cavity 11, it can expand the first sealing element 5 within the first sealing cavity 11, increasing the sealing effect of the first sealing element 5. The silicone oil film between the protrusion 53 on the first sealing element 5 and the bushing 9 can reduce the frictional resistance between the bushing 9 and the first sealing element 5, carrying away the heat generated by friction, ensuring that the first sealing element 5 does not exceed its operating temperature, and improving the service life of the first sealing element 5. Furthermore, the silicone oil film can prevent external air from entering the interior of the vacuum reactor, ensuring a high vacuum state inside the reactor.

[0035] Preferably, in the horizontal vacuum reactor shaft seal structure, the first sealing cavity 11 includes multiple first sealing cavities 11, which are arranged sequentially along the extending direction of the bushing 9. The multiple first sealing cavities 11 can be stabilized outside the bushing 9 by the sealing ring 7 and the fixing bolts 8. The figure illustrates two first sealing cavities 11 as an example. As shown, each first sealing cavity 11 includes two first sealing elements 5; the opening 12 is located at the middle position of the two first sealing elements 5. Dimethyl silicone oil can circulate in different first sealing cavities 11.

[0036] Furthermore, the aforementioned horizontal vacuum reactor shaft seal structure also includes a circulation pump. The outlet of the circulation pump is connected to the opening 12. The circulation pump is used to transport silicone oil in the oil tank to the first sealing cavity 11 through the opening 12. After the first sealing cavity 11 is filled, it can also be output back to the circuit where the circulation pump is located from the opening 12, thereby realizing the circulation of silicone oil in the first sealing cavity and carrying away the absorbed frictional heat from the first sealing cavity.

[0037] In the above scheme, the first sealing element 5 is a rubber sealing element. Specifically, the skeleton 51 can be made of rubber material, which can be opened by the pressure of silicone oil after silicone oil enters the first sealing cavity.

[0038] Figure 1When the shaft 100 is filled with 230℃ heat transfer oil, uneven heating or machining deviations can cause the shaft 100 to rotate eccentrically, resulting in uneven preload between the first seal 5 and the bushing 9. A portion of the first seal 5 may not follow the eccentric rotation of the shaft 100, creating a gap that leads to silicone oil leakage or uneven clamping force, thus reducing the service life of the lip seal of the first seal 5. To address this issue, the lip seal structure of the first seal 5 adopts a single-lip structure, which provides stronger load-bearing capacity. The skeleton 51 extends to the flexible area before the lip. During seal assembly, there is a 3mm interference fit between the lip of the first seal 5 and the bushing. To ensure the lip's follow-through, the mating surface between the lip and the skeleton 51 is reinforced. When the sealing fluid pressure acts on the oil seal, it further presses the lip of the first seal 5 against the bushing 9. The reinforced support of the skeleton controls the plastic deformation of the oil seal rubber material skeleton, reducing the stress on the rubber body and thus improving the oil seal's pressure-bearing capacity. Preferably, the first sealing element 5 is made of type 28 fluororubber (FKM28201) with a hardness of 80, which can operate stably for a long time under working conditions above 200°C and has good high temperature resistance, oil resistance, high vacuum resistance and corrosion resistance.

[0039] Furthermore, such as Figure 1 As shown, the horizontal vacuum reactor shaft seal structure further includes a second sealing element, which is disposed at the front end of the first sealing cavity 11. The second sealing element includes a sealing ring 3 and a fixing member 2 for fixing the sealing ring 3 to the outside of the shaft sleeve. The external fixing member 2 can be connected to a sealing element fixing ring 6, and the sealing ring 7 can be fixed to the sealing element fixing ring 6 by the fixing bolt 8. The sealing ring 3 is a Glyd ring, which is composed of a perfluoroether ring and a polytetrafluoroethylene ring. The Glyd ring serves as a secondary seal, preventing the medium and silicone oil from mixing, that is, isolating the polymer leaking from the reactor from the silicone oil. The Glyd ring is composed of a perfluoroether O-ring and a polytetrafluoroethylene ring. The polytetrafluoroethylene ring can be a square ring, located outside the O-ring, and is made of PTFE+FFKM. Due to its own deformation, it generates a high initial contact stress on the sealing surface, preventing the leakage of unpressurized liquid. When the hydraulic cylinder is working, the pressurized fluid squeezes the square polytetrafluoroethylene (PTFE) ring to the maximum extent through the elastic deformation of the perfluoroether O-ring, so that the PTFE ring is tightly attached to the inner surface of the outer fixing part 2, generating high contact stress. As the pressure of the pressurized fluid increases, the PTFE ring is squeezed even more, and the contact stress also increases, preventing the pressurized fluid from leaking.

[0040] More preferably, such as Figure 1As shown, the horizontal vacuum reactor shaft seal structure further includes a third sealing element, disposed at the front end of the second sealing element; the third sealing element includes a sealing float ring 4 and a flange 1 for fixing the sealing float ring 4 to the outside of the shaft sleeve 9. The flange 1 has threaded holes formed on it, allowing it to be fixed to the horizontal vacuum reactor with bolts. The sealing float ring 4 is made of polymer material, which minimizes the impact of process materials on the inner sealing effect. In this design, a combination seal of the sealing float ring 4, sealing ring 3, and first sealing element 5 in the form of a lip seal is used. The main function of the sealing float ring is to prevent polymer melt material from entering the first sealing cavity. The outer surface of the sealing float ring is lubricated by an oil cup, which lubricates the sealing float ring and also monitors the seal wear.

[0041] This application provides a horizontal vacuum reactor in some embodiments, including a reactor body and a shaft seal structure as described in any of the above embodiments; the shaft seal structure is disposed outside the bushing of the reactor body. The horizontal vacuum reactor of this embodiment is a polymerization reactor for the polyglycolic acid and polyester industries. For this high-temperature, high-vacuum operating condition, the shaft seal structure of this solution can meet both the characteristics of shaft thermal expansion displacement and the high-vacuum sealing requirements, achieving long-term operation of the shaft seal. The combined sealing element, consisting of a sealing float ring, a Glyd ring, and a lip seal of the first sealing element, can adapt to the harsh operating conditions of this high-temperature, high-vacuum reactor, reducing maintenance frequency, ensuring stable operation of the device, reducing enterprise maintenance costs, and improving economic efficiency.

[0042] In practical applications, the shaft seal structure can be configured with an oil tank equipped with a cooling water jacket, where silicone oil is stored. It includes two circulating pumps (one operational, one standby), a dual filter, a safety valve, a pressure regulating valve, and a rotor flow meter. The silicone oil is pumped through two separate paths via the circulating pumps, entering the two first sealing chambers 11 through openings 12. The silicone oil enters the first sealing chamber from the bottom of the opening and exits from the top after the first sealing chamber 11 is full, ensuring that the first sealing chamber 11 is completely filled with silicone oil and controlling the temperature of the first sealing chamber 11 to not exceed 70℃. An external oil cup is placed on the sealing float ring 4. If the oil level in the cup drops too quickly, it indicates significant wear on the sealing float ring 4, requiring timely replacement. For the lip seal type shaft seal of the first sealing element 5, the pressure in the first sealing chamber 11 needs to be strictly controlled to prevent excessive pre-tightening force on the lip of the first sealing element 5, which could cause abnormal wear of the lip seal. The silicone oil pressure is controlled below 0.15 MPa by using the outlet pressure regulating valve of the silicone oil circulation pump, and the return oil flow rate of the first sealing chamber 11 is controlled at 0.3 m³ / s. 3 / h-0.5m 3 Between / h, monitor the temperature of bushing 9 below 70℃. During operation, monitor the oil level in the tank in real time. If it drops, it indicates that there is external or internal leakage of the shaft seal. At this time, the silicone oil valve on the leaking side can be closed to maintain normal sealing operation.

[0043] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A shaft seal structure for a horizontal vacuum reactor, used to be installed outside the shaft sleeve of a horizontal vacuum reactor, characterized in that, include: A first sealing cavity has an opening formed thereon, the opening being used to introduce silicone oil into the sealing cavity; A first sealing element is disposed within the first sealing cavity. The edge of the first sealing element is formed with at least one protrusion. There is a set interval between the protrusion and the bushing. The set interval is suitable for the silicone oil to form a silicone oil film between the protrusion and the bushing. The first sealing element is a single-lip structure. The lip and the bushing have an interference fit of 3 mm. The skeleton of the single-lip structure extends to the flexible area in front of the lip. The joint surface between the lip and the skeleton is reinforced. The first sealing cavity includes multiple first sealing cavities, which are arranged sequentially along the extension direction of the bushing; each first sealing cavity includes two first sealing elements; the opening is located at the middle position of the two first sealing elements; The second sealing element is disposed at the front end of the first sealing cavity; the second sealing element includes a sealing ring and a fixing element for fixing the sealing ring to the outside of the bushing; the sealing ring is a Glyd ring, which is obtained by combining a perfluoroether ring and a polytetrafluoroethylene ring; A third seal is disposed at the front end of the second seal; the third seal includes a sealing float ring and a flange for fixing the sealing float ring to the outside of the bushing.

2. The horizontal vacuum reactor shaft seal structure according to claim 1, characterized in that, Also includes: A circulating pump, the outlet of which is connected to the opening, is used to transport silicone oil from the oil tank through the opening to the first sealing cavity and then return it to the circulating pump after filling the first sealing cavity.

3. The horizontal vacuum reactor shaft seal structure according to claim 2, characterized in that: The pressure of the silicone oil input to the first sealing chamber by the circulating pump is controlled to be within 0.15 MPa; the return flow rate of the first sealing chamber is controlled to be 0.3 m³ / s. 3 / h-0.5m 3 Between / h.

4. The horizontal vacuum reactor shaft seal structure according to claim 1, characterized in that: The first sealing element is a rubber sealing element.

5. A horizontal vacuum reactor, characterized in that, It includes a reactor body and a shaft seal structure as described in any one of claims 1-4; the shaft seal structure is disposed outside the bushing of the reactor body.

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