Three-end face mechanical seal for reaction kettle

Abstract

The present invention provides a three-end face mechanical seal for a reactor, which includes a shaft sleeve, a seal seat, a mounting flange and a bearing seat; a primary sealing unit is arranged between the first fixed seat at the upper end of the shaft sleeve and the upper end of the seal seat, and a first sealing cavity is formed inside the primary sealing unit; a secondary sealing unit and a tertiary sealing unit are arranged between the mounting flange and the bearing seat, a second sealing cavity communicating with the first sealing cavity is formed inside the secondary sealing unit, an isolation cavity is formed outside the secondary sealing unit and the tertiary sealing unit, the pressure of the isolation liquid in the isolation cavity is greater than the pressure in the second sealing cavity, a first liquid inlet hole communicating with the second sealing cavity, a second liquid inlet hole and a liquid outlet hole communicating with the isolation cavity are opened on the lower end face of the mounting flange. The three-end face mechanical seal for a reactor disclosed by the present invention has three sealing units, effectively improves the sealing performance, further reduces the risk of medium leakage to the atmosphere end, and improves the safety performance.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical seals, and more particularly to a triple-end face mechanical seal for a reactor. Background Art

[0002] A mechanical seal is a shaft seal device for a rotating machine, specifically referring to a device that prevents fluid leakage and is composed of at least a pair of end faces perpendicular to the axis of rotation. Under the action of fluid pressure and the elastic force of the compensation mechanism, and with the cooperation of auxiliary seals, the end faces remain in contact and relatively slide. Mechanical seals can be classified into pump seals, reactor seals, compressor seals, etc. according to the main machines they are applied to. Reactor seals are often used in conjunction with agitators.

[0003] Since the medium in a reactor is usually flammable and explosive, and generally toxic substances are present inside the reactor, it is not allowed to leak into the air. Therefore, the requirements for reactor mechanical seals are more stringent than those for pump mechanical seals. In existing reactor mechanical seal structures, double-end face seals are more common, that is, one main seal and one coolant seal. In this seal structure, once the main seal leaks, the medium will enter the isolation chamber. Although the medium will not directly enter the atmosphere end at this time, if the coolant seal leaks, then the coolant with toxic medium will enter the atmosphere end. Especially in the structure of large reactors, it is very troublesome to disassemble and assemble the mechanical seal. There is still a great risk of leakage in the above existing mechanical seal structures, and the safety performance needs to be further improved. Summary of the Invention

[0004] The problem solved by the present invention is: to overcome at least one defect in the prior art, and provide a triple-end face mechanical seal for a reactor, which has three seal units, effectively improves the sealing performance, further reduces the risk of medium leakage to the atmosphere end, and improves the safety performance.

[0005] To solve the above problems, the present invention provides a three-end face mechanical seal for a reaction kettle, which is applied to the bottom seal of the stirring shaft of the reaction kettle. It includes a shaft sleeve sleeved outside the stirring shaft. A seal seat, a mounting flange, and a bearing seat that are axially connected as a whole are sequentially sleeved outside the shaft sleeve from top to bottom. A first fixing seat is sleeved on the outer wall of the upper end of the shaft sleeve. A primary seal unit is arranged between the first fixing seat and the upper end of the seal seat. A first seal cavity is formed between the inner wall of the primary seal unit and the outer wall of the shaft sleeve. A secondary seal unit and a tertiary seal unit that are axially connected are arranged between the mounting flange and the bearing seat. A second seal cavity communicating with the first seal cavity is formed between the inner wall of the secondary seal unit and the outer wall of the shaft sleeve. The first seal cavity and the second seal cavity are filled with coolant. An isolation cavity is formed between the outer sides of the secondary seal unit and the tertiary seal unit and the inner wall of the mounting flange cavity. The isolation cavity is filled with isolation liquid, and the pressure in the isolation cavity is greater than the pressure in the second seal cavity. The secondary seal unit is used to prevent the coolant from flowing out into the isolation cavity. The tertiary seal unit is used to prevent the isolation liquid from entering the atmosphere end. A first liquid inlet hole, a second liquid inlet hole, and a liquid outlet hole are opened on the lower end face of the mounting flange. The first liquid inlet hole communicates with the second seal cavity, and the second liquid inlet hole and the liquid outlet hole respectively communicate with the isolation cavity.

[0006] Compared with the prior art, the present invention has the following advantages:

[0007] In the mechanical seal structure of the present invention, in addition to the conventional medium seal unit and coolant seal unit, an additional isolation liquid seal is added. The primary seal unit serves as the main seal to seal the medium in the kettle. The secondary seal unit serves as a safety seal. Once the primary seal fails, the medium will enter the first seal cavity and achieve temporary sealing through the secondary seal, ensuring that the equipment continues to operate until the equipment maintenance period. The tertiary seal is used to seal the isolation liquid, separating the isolation liquid from the atmosphere, preventing the isolation liquid from flowing out and damaging the bearing and polluting the environment. And after the isolation cavity is set, when the secondary seal leaks, the medium in the first seal cavity will not directly flow to the atmosphere end but be stored in the isolation cavity, ensuring safety performance. Additionally, in the present invention, the coolant only has a liquid inlet and no special liquid outlet. When the pressure of the cleaning fluid injected into the first seal cavity exceeds the set value, the end face opening force generated by the cleaning fluid at the primary seal face exceeds the corresponding closing force generated, the end face is opened, and the cleaning fluid flushes into the external kettle to realize the flushing and cleaning of the periphery of the bottom mechanical seal of the kettle. When the pressure of the cleaning fluid is lower than the set value, the seal end face closes and the mechanical seal works normally, avoiding the cumbersome and laborious problem of disassembling and cleaning large reaction kettles. Additionally, the isolation liquid in the isolation cavity can be circulated and replaced through the inlet and outlet settings, facilitating the flushing of the leaked medium in the isolation cavity.

[0008] As an improvement, the first fixing seat includes two split half rings, and the outer ends of the two half rings are connected by connecting screws; limiting protrusions are provided on the inner sides of the two half rings, and limiting grooves for inserting and fitting the limiting protrusions are provided on the outer wall of the sleeve. In the above improved structure, the first fixing seat adopts a split two-component structure, which is more convenient for processing and installation, and ensures that it can cooperate with the limiting groove on the outer wall of the sleeve after installation, realizing the stability of the connection structure.

[0009] Furthermore, the primary sealing unit includes a first moving ring assembly and a first stationary ring. A first stationary ring groove is formed at the upper end of the sealing seat, and the lower end of the first stationary ring is slidably fitted in the first stationary ring groove; a first installation groove is provided at the lower end of the first fixing seat, the upper end of the first moving ring assembly is fitted in the first installation groove, and a transmission key is fitted between the inner wall of the first moving ring assembly and the outer wall of the sleeve; the lower end of the first moving ring assembly and the upper end of the first stationary ring are in circumferentially relatively rotatable abutment. In the above improved structure, the transmission connection between the first moving ring assembly and the sleeve through the key transmission structure is more stable and reliable.

[0010] In a further improvement, a gasket is provided at the bottom of the first stationary ring. At least two pins evenly distributed in the circumferential direction are inserted through the gasket. The upper ends of the pins are fitted in the first pin grooves at the lower end of the first stationary ring, and the lower ends of the pins are correspondingly slidably inserted in the positioning pin holes at the bottom of the first stationary ring groove; a first elastic compensation member is provided between the lower end of the gasket and the bottom of the first stationary ring groove, so that the first stationary ring always has a tendency to move towards the first moving ring. In the above improved structure, the gasket makes the abutment between the first compensation member and the first stationary ring smoother; in addition, corresponding guide posts and anti-rotation parts are pre-installed on the gasket, and the guide posts and anti-rotation parts are the same pin, which simplifies the structure and can not only ensure the smooth stability of the axial movement of the first stationary ring, but also prevent the circumferential rotation of the first stationary ring.

[0011] Still further, the secondary sealing unit includes a second moving ring assembly and a second stationary ring, and the tertiary sealing unit includes a third moving ring assembly and a third stationary ring; a second fixing seat is sleeved on the outer wall of the sleeve. The upper end of the second stationary ring is fitted in the second stationary ring groove at the lower end of the mounting flange. The lower end of the second moving ring assembly is axially slidably fitted on the outside of the second fixing seat. The upper end of the second moving ring seat and the lower end of the second stationary ring are in circumferentially relatively rotatable abutment; the lower end of the third stationary ring is fitted in the third stationary ring groove at the upper end of the bearing seat. The upper end of the third moving ring seat is axially slidably fitted on the outside of the second fixing seat. The lower end of the third moving ring seat and the upper end of the third stationary ring are in circumferentially relatively rotatable abutment.

[0012] Further improved, the second moving ring assembly and the third moving ring assembly have the same structure, both including a moving ring body and a mounting base. One end of the moving ring body is fitted inside one end of the mounting base, and two symmetric lugs are convexly provided on the outer side of the other end of the mounting base. The two mounting bases are slidably fitted on the outer side of the second fixed seat along one end of the lugs, and the lugs of the two mounting bases are arranged at a 90° angle to each other. A plurality of circumferentially distributed springs are passed through the second fixed seat, and both ends of each spring respectively abut between the corresponding end faces of the two mounting bases. In the above improved structure, the second moving ring assembly and the third moving ring assembly have the same structure, which is convenient for processing. The upper and lower components can be used interchangeably during installation, reducing the installation difficulty. In addition, the axial wear of the second moving ring assembly and the third moving ring assembly is axially compensated by the same set of springs, further simplifying the mechanical seal structure and reducing costs.

[0013] Further improved, a first positioning seat is sleeved on the outer wall of the shaft sleeve near one end of the third static ring. An avoidance groove for accommodating the first positioning seat and axially communicating with the third static ring groove is further provided inside the upper end of the bearing seat. An outer baffle extending downward is provided on the outer side of the lower end of the positioning seat. A second positioning seat is further provided inside the bearing seat. An inner baffle extending upward is provided inside the upper end of the second positioning seat, and the inner baffle is vertically fitted inside the outer baffle. A liquid collecting hole communicating with the avoidance groove is provided on the outer wall of the bearing seat. An oil seal is fitted between the inner side of the lower end of the second positioning seat and the outer wall of the shaft sleeve. In the above improved structure, there is a leakage collection mechanism to collect normal isolation liquid leakage. The inverted installation mechanism can effectively block the isolation liquid leaking from the third-stage seal unit, preventing the isolation liquid from flowing down along the outer wall of the shaft sleeve to the lower bearing and damaging the bearing, and better ensuring that the leaked liquid can flow out from the liquid collecting hole and be collected.

[0014] Further improved, a base is connected to the lower end of the bearing seat and located outside the shaft sleeve. A bearing is provided between the base and the second positioning seat, and the inner ring of the bearing is fitted with the shaft sleeve, and the outer ring of the bearing is fitted with the inner hole wall of the bearing seat. In the above improved structure, the setting of the bearing makes the rotation of the shaft sleeve in the large reaction kettle more flexible, stable and not easy to shake.

[0015] Further improved, an accommodation groove is provided inside the lower end of the sealing seat, a throttling ring is installed in the accommodation groove, the lower end of the throttling ring abuts against the upper end surface inside the installation flange, and an elastic element is provided between the upper end of the throttling ring and the bottom of the accommodation groove; a guide post is further provided on the upper end surface inside the installation flange, and a guide hole for the guide post to slide and cooperate is opened on the throttling ring. In the above improved structure, after the throttling ring is installed, when the primary sealing unit leaks, it can effectively prevent the medium from quickly entering the secondary sealing unit and can achieve throttling and sealing; and the elastic force direction of the elastic element is opposite to the cleaning fluid pressure direction, playing a role similar to a check valve.

[0016] Further improved, a plurality of circumferentially evenly distributed annular grooves are concavely formed on the upper end surface of the first dynamic ring, and the inner sides of the annular grooves communicate with the inner cavity of the first dynamic ring. In the above improved structure, the setting of the annular grooves can not only improve the lubrication effect of the grinding surface but also cooperate with the first liquid inlet hole to realize the automatic cleaning of the primary sealing grinding surface. Brief Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of the triple-face mechanical seal for a reaction kettle of the present invention installed on a stirring shaft;

[0018] Figure 2 is a bottom view of the triple-face mechanical seal for a reaction kettle of the present invention;

[0019] Figure 3 is Figure 1 an enlarged structural diagram at position a in

[0020] Figure 4 is Figure 1 an enlarged structural diagram at position b in

[0021] Figure 5 is Figure 1 an enlarged structural diagram at position c in

[0022] Figure 6 is a top view of the connection structure of the second dynamic ring assembly, the third dynamic ring assembly and the second fixed seat in the present invention;

[0023] Figure 7 is Figure 6 a sectional view taken along the A-A direction in

[0024] Figure 8 is a top view of the installation base in the present invention;

[0025] Figure 9 is Figure 8 a sectional view taken along the B-B direction in

[0026] Figure 10 is Figure 5 isFigure 1 Schematic enlarged structure diagram at position d in

[0027] Figure 11 Top view of the first stationary ring in the present invention.

[0028] Explanation of reference numerals in the drawings:

[0029] 1. Sleeve; 1.1. Limiting groove; 2. Sealing seat; 2.1. First stationary ring groove; 2.2. Accommodating groove; 3. Mounting flange; 3.1. Second stationary ring groove; 3.2. Positioning pin hole; 4. Bearing housing; 4.1. Third stationary ring groove; 4.2. Avoidance groove; 4.3. Liquid collecting hole; 5. First fixing seat; 5.1. First mounting groove; 6. First sealing cavity; 7. Second sealing cavity; 8. Isolation cavity; 9. First liquid inlet hole; 10. Second liquid inlet hole; 11. Liquid outlet hole; 12. Connecting screw; 13. Limiting projection; 14. First stationary ring; 14.1. First pin groove; 14.2. Annular groove; 15. Gasket; 16. Pin shaft; 17. Second stationary ring; 18. Third stationary ring; 19. Second fixing seat; 19.1. Threaded hole; 20. Dynamic ring body; 21. Mounting base; 21.1. Lug; 21.1.1. Waist-shaped hole; 22. Spring; 23. First positioning seat; 23.1. Outer baffle; 24. Second positioning seat; 24.1. Inner baffle; 25. Oil seal; 26. Connecting base; 27. Bearing; 28. Throttle ring; 28.1. Guide hole; 29. Elastic element; 30. Guide post; 31. First small spring; 32. Positioning stud; 33. Stationary ring gland; 34. First pressing ring; 35. Second pressing ring; 36. Tightening bolt; 37. Second small spring; 38. First dynamic ring; 39. First dynamic ring seat; 40. Transmission flat key. Detailed implementation manners

[0030] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of specific embodiments of the present invention will be given with reference to the accompanying drawings.

[0031] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "external", "tail end", "outer side", "inner side wall", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. Additionally, in the description terms "first" and "second" are only for the convenience of distinction and understanding, without specific special or defined meanings. Among them, the tail end refers to the end facing away from the friction surface. For example, the tail end of the dynamic ring refers to the end of the dynamic ring facing away from the grinding surface.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood according to specific circumstances.

[0033] As Figure 1 shown, the present invention provides a three-end face mechanical seal for a reaction kettle, which is applied to the bottom of the stirring shaft of the reaction kettle to achieve dynamic sealing of the stirring shaft. It includes a shaft sleeve 1 sleeved outside the stirring shaft, and a seal seat 2, a mounting flange 3, and a bearing seat 4 are sequentially sleeved outside the shaft sleeve 1 from top to bottom. And in this structure, the seal seat 2, the mounting flange 3, and the bearing seat 4 are axially connected as a whole. Specifically, a mounting skirt is formed on the outer periphery of the lower end of the seal seat 2, and the mounting skirt is axially connected and fixed to the upper end face of the mounting flange 3 through connecting bolts. Similarly, the bearing seat 4 is axially connected to the lower end of the mounting flange 3 through a plurality of circumferentially distributed long bolts, and in this structure, a plurality of axially extending communication holes are provided on the bearing seat 4 for the long bolts to pass through, and the long bolts and the communication holes maintain a large gap, so as to adapt to the working condition of the large swing of the reaction kettle.

[0034] As Figure 1 、 3 shown, a first fixing seat 5 is sleeved on the outer wall of the upper end of the shaft sleeve 1, a primary sealing unit is provided between the upper end of the first fixing seat 5 and the seal seat 2, and a first sealing cavity 6 is formed between the inner wall of the primary sealing unit and the outer wall of the shaft sleeve 1. In this structure, the first fixing seat 5 includes two split half rings, and the outer ends of the two half rings are horizontally connected through connecting screws 12. In addition, semi-circular limiting protrusions 13 are respectively provided on the inner sides of the two half rings, and corresponding limiting grooves 1.1 are provided on the outer wall of the shaft sleeve 1. When the two half rings are relatively clamped outside the shaft sleeve 1, the limiting protrusions 13 are fitted in the limiting grooves 1.1, and the accurate and stable connection between the first fixing seat 5 and the shaft sleeve 1 is realized through the fastening of the connecting screws 12, that is, there is no axial movement after connection.

[0035] On the other hand, as Figure 1 、 4As shown in the figure, a secondary sealing unit and a tertiary sealing unit with axial connection are provided between the mounting flange 3 and the bearing housing 4. A second sealing cavity 7 communicating with the first sealing cavity 6 is formed between the inner wall of the secondary sealing unit and the outer wall of the shaft sleeve 1. The first sealing cavity 6 and the second sealing cavity 7 are filled with a coolant. An isolation cavity 8 is formed between the outer sides of the secondary sealing unit and the tertiary sealing unit and the inner wall of the mounting cavity of the mounting flange 3. The isolation cavity 8 is filled with an isolation liquid, and the pressure in the isolation cavity 8 is greater than the pressure in the second sealing cavity 7. The secondary sealing unit is used to prevent the coolant from flowing out into the isolation cavity 8. The tertiary sealing unit is used to prevent the isolation liquid from entering the atmosphere end. A first liquid inlet hole 9, a second liquid inlet hole 10 and a liquid outlet hole 11 are formed in the lower end surface of the mounting flange 3. The first liquid inlet hole 9 communicates with the second sealing cavity 7, and the second liquid inlet hole 10 and the liquid outlet hole 11 communicate with the isolation cavity 8 respectively.

[0036] In the above structure, the primary sealing unit serves as the main seal for the medium inside the sealed reactor; the secondary sealing unit serves as a safety seal. Once the primary seal fails, the medium will enter the first sealing cavity 6 and achieve temporary sealing through the secondary seal, ensuring that the equipment can continue to operate until the equipment maintenance cycle; the tertiary seal serves as a seal for the isolation liquid, separating the isolation liquid from the atmosphere, preventing the isolation liquid from flowing out and damaging the bearing 27 and polluting the environment; and after the isolation cavity 8 is provided, when the secondary seal leaks, the medium in the first sealing cavity 6 will not directly flow towards the atmosphere end but will be stored in the isolation cavity 8; the arrow with label ① indicates the flow direction of the cleaning fluid and the cooling fluid; the arrow with label ② indicates the flow direction of the isolation liquid.

[0037] As Figure 3 shown in the figure, in this embodiment, the primary sealing unit includes a first dynamic ring assembly and a first static ring 14. A first static ring groove 2.1 is formed at the upper end of the sealing seat 2. The lower end of the first static ring 14 is slidably fitted in the first static ring groove 2.1, and an O-ring is fitted between the outer wall of the first static ring 14 and the inner wall of the first static ring groove 2.1 to achieve sealing fit; in addition, a first mounting groove 5.1 is provided at the lower end of the first fixing seat 5. The upper end of the first dynamic ring assembly is fitted in the first mounting groove 5.1, and a transmission key is fitted between the inner wall of the first dynamic ring assembly and the outer wall of the shaft sleeve 1. Through the key transmission structure, the transmission connection between the first dynamic ring assembly and the shaft sleeve 1 is more stable and reliable; the lower end of the first dynamic ring assembly and the upper end of the first static ring 14 are in circumferentially relatively rotatable abutment to form a primary sealing friction surface for directly sealing the medium in the reaction kettle cavity.

[0038] As Figure 3As shown, the first moving ring assembly includes a first moving ring 38 and a first moving ring seat 39. The upper end of the first moving ring seat 39 is fitted with the first mounting groove 5.1, and a keyway is provided on the inner wall of the first moving ring seat 39. A driving flat key 40 is fitted on the outer wall of the shaft sleeve 1, and the outer side of the driving flat key 40 is fitted in the keyway. Additionally, an inwardly concave annular groove 39.1 is provided at the lower end of the first moving ring seat 39. The first moving ring 38 is fitted on the outer side of the annular groove 39.1, and a gap is left between the first moving ring 38 and the radially inner wall of the annular groove 39.1. When coolant is introduced into the first sealing cavity 6, this gap setting enables better flushing and cooling of the first moving ring 38.

[0039] More specifically, a gasket 15 is provided at the bottom of the first stationary ring 14, and at least two pins 16 evenly distributed circumferentially are passed through the gasket 15, that is, the upper and lower ends of the pins 16 protrude outward from the upper and lower end faces of the gasket 15 respectively. The upper end of the pin 16 is fitted in the first pin slot 14.1 at the lower end of the first stationary ring 14, and the lower end of the pin 16 is slidably inserted into the positioning pin hole 3.2 at the bottom of the first stationary ring groove 2.1 to achieve the anti-rotation function of the first stationary ring 14. A first elastic compensating member is provided between the lower end of the gasket 15 and the bottom of the first stationary ring groove 2.1, so that the first stationary ring 14 always has a tendency to move towards the first moving ring. And under the cooperation of the lower end of the pin 16 and the positioning pin hole 3.2, the first stationary ring 14 moves more smoothly up and down in the first stationary ring groove 2.1. Moreover, the stationary ring compensation structure can provide a more stable compensation force. Since the stationary ring and part of the structure of the mounting flange 3 are stationary, that is, the first elastic compensating member does not rotate with the rotating shaft either, the compensation force is not affected by rotation and is stable and reliable. Preferably, the first elastic compensating member in this structure includes a plurality of first small springs 31. A plurality of spring 22 holes evenly distributed circumferentially are provided at the bottom of the first stationary ring groove 2.1. Similarly, a plurality of spring 22 holes evenly distributed circumferentially are also provided on the lower end face of the gasket 15. Therefore, when installing the plurality of first small springs 31, the two ends respectively abut and fit in the corresponding spring 22 holes on the upper and lower sides to ensure that during the working process, each first small spring 31 will not turn over when compressed, ensuring the balance of the compensation force.

[0040] Furthermore, as Figure 4As shown, the secondary sealing unit includes a second dynamic ring assembly and a second static ring 17, and the tertiary sealing unit includes a third dynamic ring assembly and a third static ring 18; a second fixed seat 19 is mounted on the outer wall of the sleeve 1, and the upper end of the second static ring 17 is fitted in the second static ring groove 3.1 at the lower end of the mounting flange 3, and the lower end of the second dynamic ring assembly is axially slidably fitted on the outside of the second fixed seat 19, and the upper end of the second dynamic ring assembly and the lower end of the second static ring 17 are circumferentially rotatable relative to each other to form a secondary sealing grinding surface; the lower end of the third static ring 18 is fitted in the third static ring groove 4.1 at the upper end of the bearing seat 4, and the upper end of the third dynamic ring assembly is axially slidably fitted on the outside of the second fixed seat 19, and the lower end of the third dynamic ring assembly and the upper end of the third static ring 18 are circumferentially rotatable relative to each other to form a tertiary sealing grinding surface. More specifically, in order to ensure that the assembly structure of the second stationary ring 17 is more stable in this structure, a stationary ring pressure cover 33 is also connected to the inner cavity of the mounting flange 3, which is used to press and limit the outer side of the second stationary ring 17 away from the end of the second stationary ring groove 3.1 to ensure that the second stationary ring 17 will not detach from the second stationary ring groove 3.1. The stationary ring pressure cover 33 here is connected to the inner cavity wall of the mounting flange 3 through connecting bolts.

[0041] More specifically, Figures 6 - 9 As shown, in this embodiment, the second dynamic ring assembly and the third dynamic ring assembly have the same structure, both including a dynamic ring body 20 and a mounting base 21. One end of the dynamic ring body 20 is mounted on the inner side of one end of the mounting base 21, and the outer side of the other end of the mounting base 21 is protruding with two symmetrical lugs 21.1; the two mounting bases 21 are slidably mounted on the outer side of the second fixed seat 19 along one end of the lug 21.1, and the lugs 21.1 of the two mounting bases 21 are set at a 90° angle to each other; a plurality of springs 22 distributed along the circumferential direction are passed through the second fixed seat 19, and the two ends of each spring 22 respectively abut between the corresponding two end surfaces of the two mounting bases 21, thereby providing axial compensation force to the second dynamic ring assembly and the third dynamic ring assembly. In this structure, more specifically, in order to ensure the stability of the relative sliding between the second dynamic ring assembly and the third dynamic ring assembly and the second fixed seat 19, four threaded holes 19.1 evenly distributed along the circumference are opened on the outer wall of the second fixed seat 19, and a waist-shaped hole 21.1.1 extending in the axial direction is opened on the lug 21.1 of each mounting base 21. A positioning stud 32 is passed through each threaded hole 19.1, and the outer end of each positioning bolt is slidably fitted in the waist-shaped hole 21.1.1 of the corresponding lug 21.1, as shown in FIG. Figure 4 As shown; avoid the second dynamic ring assembly and the third dynamic ring assembly from being separated from the second fixing seat 19 under the elastic force of the spring 22, thereby realizing the pre-installation of this local structure, thereby facilitating the subsequent assembly of the overall mechanical seal.

[0042] On the other hand, Figure 5As shown in the figure, in this embodiment, a first positioning seat 23 is sleeved on the outer wall of the bushing 1 near one end of the third static seal ring 18. An avoidance groove 4.2 is also provided inside the upper end of the bearing housing 4 for accommodating the first positioning seat 23 and axially communicating with the groove 4.1 of the third static seal ring 18. An outer baffle 23.1 extending downward is provided on the outer side of the lower end of the first positioning seat 23. A second positioning seat 24 is also arranged inside the bearing housing 4. An inner baffle 24.1 extending upward is provided on the inner side of the upper end of the second positioning seat 24, and the inner baffle 24.1 is vertically fitted inside the outer baffle 23.1; a liquid collecting hole 4.3 communicating with the avoidance groove 4.2 is provided on the outer wall of the bearing housing 4. An oil seal 25 is fitted between the inner side of the lower end of the second positioning seat 24 and the outer wall of the bushing 1. The lower end of the bearing housing 4 is connected with a connecting base 26 sleeved on the outside of the bushing 1. A bearing 27 is provided between the connecting base 26 and the second positioning seat 24. The inner ring of the bearing 27 is fitted with the bushing 1, and the outer ring of the bearing 27 is fitted with the inner hole wall of the bearing housing 4. The leakage collection mechanism collects normal isolation liquid leakage. The inverted installation mechanism can effectively block the isolation liquid leaking from the third-level sealing unit, preventing the isolation liquid from flowing down along the outer wall of the bushing 1 to the lower bearing 27 and damaging the bearing 27, and better ensuring that the leaked liquid can flow out from the liquid collecting hole 4.3 and be collected.

[0043] As Figure 10 shown, more specifically, a receiving groove 2.2 is provided inside the lower end of the sealing seat 2. A throttling ring 28 is fitted in the receiving groove 2.2. The lower end of the throttling ring 28 abuts against the upper end surface of the inner side of the mounting flange 3. An elastic element 29 is provided between the upper end of the throttling ring 28 and the bottom of the receiving groove 2.2. Preferably, the elastic element 29 is a plurality of second small springs 37. A plurality of spring holes evenly distributed in the circumferential direction are provided on the upper end surface of the throttling ring 28. The lower ends of the respective second small springs 37 are abutted and fitted in the corresponding spring holes, and the upper ends of the respective springs 22 abut against the upper bottom surface of the receiving groove 2.2; a guide post 30 is also provided on the upper end surface of the inner side of the mounting flange 3. A guide hole 28.1 for slidingly fitting the guide post 30 is provided on the throttling ring 28, better ensuring the smooth up and down movement of the throttling ring 28 in the receiving groove 2.2. In this structure, the elastic force direction of the throttling device is opposite to the cleaning fluid pressure direction, playing a role similar to that of a check valve; when the lower cleaning fluid comes, it will push open the throttling ring 28 and enter the first seal for cleaning and cooling; when the first seal fails, the medium enters the first seal cavity 6, and the medium pressure is in the same direction as the force of the second small springs 37, making the throttling ring 28 more tightly pressed, strengthening the throttling effect and preventing a large amount of medium from instantaneously entering the second seal.

[0044] As Figure 11As shown, in this embodiment, the end surface of the first stationary ring 14 is specially treated. Specifically, the upper end surface of the first stationary ring 14 is concavely formed with a plurality of annular grooves 14.2 evenly distributed along the circumference. The inner side of each annular groove 14.2 communicates with the inner cavity of the first stationary ring 14. This arrangement has the following advantages: 1. A disassembly-free online cleaning device: When the pressure of the cleaning fluid injected into the first sealing chamber 6 exceeds 0.3 MPa, the end surface opening force generated by the cleaning fluid in the annular groove 14.2 exceeds the closing force generated by the second spring 22, making the end surface opening easier and allowing the cleaning fluid to quickly flow into the external reactor, flushing and cleaning the periphery of the mechanical seal at the bottom of the reactor. When the cleaning fluid pressure drops below 0.3 MPa, the sealing end surface closes, allowing the mechanical seal to operate normally, thus avoiding the tedious and laborious disassembly and cleaning of large reactors. 2. A cooling and lubricating function: The presence of the inner ring annular groove 14.2 allows the low-temperature fluid in the first sealing chamber 6 to better enter the primary seal grinding surface, cooling the seal ring and enabling the primary seal to operate normally at a medium temperature of 180°C.

[0045] In addition, in this embodiment, Figure 1 As shown, a tightening device is mounted on the outer wall of the lower end of the sleeve 1. Since a corresponding notch is provided on the side wall of the lower end of the sleeve 1 in this structure, the sleeve 1 can shrink and deform inward when subjected to radial extrusion force, which is used to drive the sleeve 1 to hold the stirring shaft tightly to achieve transmission connection. Specifically, the tightening device includes a first pressure ring 34 and a second pressure ring 35. The first pressure ring 34 is mounted on the outer wall of the sleeve 1. A notch extending vertically through the sidewall of the first pressure ring 34 allows the first pressure ring 34 to deform inward when subjected to radial extrusion. A first wedge-shaped surface, smaller at the top and larger at the bottom, is provided on the outer wall of the first pressure ring 34. Similarly, a second wedge-shaped surface, which mates with the first wedge-shaped surface, is provided on the inner wall of the second pressure ring 35. The first and second pressure rings 34, 35 are connected by axial tensioning bolts 36. Tightening the respective tensioning bolts 36 brings the first and second pressure rings 34, 35 closer together. Guided by the first and second wedge-shaped surfaces, the sidewall of the first pressure ring 34 contracts in response to the radial force, achieving a tight grip on the sleeve 1. This in turn forces the lower end of the sleeve 1 to contract radially inward and grip the agitator shaft, achieving a transmission connection. The wedge-shaped clamping device preferably has a locking angle of 10° to ensure self-locking between the components and ensure the reliability of the clamping device.

[0046] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A triple-end face mechanical seal for a reaction kettle, which is applied to the bottom seal of the stirring shaft of the reaction kettle, and is characterized in that: It includes a bushing (1) sleeved outside the stirring shaft. A sealing seat (2), a mounting flange (3), and a bearing seat (4) that are axially connected as a whole are successively sleeved outside the bushing (1) from top to bottom; a first fixing seat (5) is sleeved on the outer wall of the upper end of the bushing (1). A primary sealing unit is provided between the upper end of the first fixing seat (5) and the upper end of the sealing seat (2). A first sealing cavity (6) is formed between the inner wall of the primary sealing unit and the outer wall of the bushing (1); a secondary sealing unit and a tertiary sealing unit that are axially connected are provided between the mounting flange (3) and the bearing seat (4). A second sealing cavity (7) that communicates with the first sealing cavity (6) is formed between the inner wall of the secondary sealing unit and the outer wall of the bushing (1). The first sealing cavity (6) and the second sealing cavity (7) are filled with coolant; an isolation cavity (8) is formed between the outer sides of the secondary sealing unit and the tertiary sealing unit and the inner wall of the mounting cavity of the mounting flange (3). The isolation cavity (8) is filled with isolation liquid, and the pressure in the isolation cavity (8) is greater than the pressure in the second sealing cavity (7). The secondary sealing unit is used to prevent the coolant from flowing out into the isolation cavity (8); the tertiary sealing unit is used to prevent the isolation liquid from entering the atmosphere end; a first liquid inlet hole (9), a second liquid inlet hole (10), and a liquid outlet hole (11) are opened on the lower end face of the mounting flange (3). The first liquid inlet hole (9) communicates with the second sealing cavity (7), and the second liquid inlet hole (10) and the liquid outlet hole (11) communicate with the isolation cavity (8) respectively; The first fixing seat (5) includes two split half-rings, and the outer ends of the two half-rings are connected by connecting screws (12); limiting protrusions (13) are provided on the inner sides of the two half-rings, and limiting grooves for the limiting protrusions (13) to be inserted and fitted are provided on the outer wall of the bushing (1); the primary sealing unit includes a first dynamic ring assembly and a first static ring (14). A first static ring groove (2.1) is opened at the upper end of the sealing seat (2), and the lower end of the first static ring (14) is slidably fitted in the first static ring groove (2.1); a first mounting groove (5.1) is provided at the lower end of the first fixing seat (5). The upper end of the first dynamic ring assembly is fitted in the first mounting groove (5.1), and a transmission key is fitted between the inner wall of the first dynamic ring assembly and the outer wall of the bushing (1); the lower end of the first dynamic ring assembly and the upper end of the first static ring (14) are in circumferentially relatively rotatable abutment.

2. The triple-end mechanical seal for a reactor according to claim 1, characterized in that: A gasket (15) is provided at the bottom of the first stationary ring (14). At least two pins (16) evenly distributed in the circumferential direction are inserted through the gasket (15). The upper ends of the pins (16) are fitted into the first pin slots (14.1) at the lower end of the first stationary ring (14), and the lower ends of the pins (16) are slidably inserted into the positioning pin holes (3.2) at the bottom of the first stationary ring groove (2.1). A first elastic compensating member is provided between the lower end of the gasket (15) and the bottom of the first stationary ring groove (2.1) so that the first stationary ring (14) always has a tendency to move towards the first moving ring assembly.

3. The triple-end mechanical seal for a reactor according to claim 1, characterized in that: The secondary sealing unit includes a second moving ring assembly and a second stationary ring (17), and the tertiary sealing unit includes a third moving ring assembly and a third stationary ring (18). A second fixing seat (19) is sleeved on the outer wall of the shaft sleeve (1). The upper end of the second stationary ring (17) is fitted into the second stationary ring groove (3.1) at the lower end of the mounting flange (3). The lower end of the second moving ring assembly is axially slidably fitted on the outside of the second fixing seat (19), and the upper end of the second moving ring assembly is in circumferentially relatively rotatable abutment with the lower end of the second stationary ring (17). The lower end of the third stationary ring (18) is fitted into the third stationary ring groove (4.1) at the upper end of the bearing seat (4). The upper end of the third moving ring assembly is axially slidably fitted on the outside of the second fixing seat (19), and the lower end of the third moving ring assembly is in circumferentially relatively rotatable abutment with the upper end of the third stationary ring (18).

4. The triple-end face mechanical seal for a reactor according to claim 3, characterized in that: The second moving ring assembly and the third moving ring assembly have the same structure, and both include a moving ring body (20) and a mounting base (21). One end of the moving ring body (20) is fitted inside one end of the mounting base (21). Two symmetrically arranged lugs (21.1) protrude outward from the outside of the other end of the mounting base (21). The two mounting bases (21) are slidably fitted on the outside of the second fixing seat (19) along one end of the lugs (21.1), and the lugs (21.1) of the two mounting bases (21) are arranged at an angle of 90° to each other. A plurality of springs (22) distributed in the circumferential direction are inserted through the second fixing seat (19), and the two ends of each spring (22) respectively abut between the corresponding end faces of the two mounting bases (21).

5. The triple-end face mechanical seal for a reactor according to claim 3, characterized in that: A first positioning seat (23) is sleeved on the outer wall of the bushing (1) near one end of the third static ring (18). An avoidance groove (4.2) for accommodating the first positioning seat (23) and axially communicating with the third static ring groove (4.1) is further provided inside the upper end of the bearing seat (4). An outer baffle (23.1) extending downward is provided on the outer side of the lower end of the first positioning seat (23). A second positioning seat (24) is further arranged inside the bearing seat (4). An inner baffle (24.1) extending upward is provided inside the upper end of the second positioning seat (24), and the inner baffle (24.1) is vertically fitted inside the outer baffle (23.1). A liquid collecting hole (4.3) communicating with the avoidance groove (4.2) is provided on the outer wall of the bearing seat (4). An oil seal (25) is fitted between the inner side of the lower end of the second positioning seat (24) and the outer wall of the bushing (1).

6. The triple-end face mechanical seal for a reaction kettle according to claim 5, characterized in that: A connecting base (26) sleeved on the outside of the bushing (1) is connected to the lower end of the bearing seat (4). A bearing (27) is provided between the connecting base (26) and the second positioning seat (24). The inner ring of the bearing (27) is fitted with the bushing (1), and the outer ring of the bearing (27) is fitted with the inner hole wall of the bearing seat (4).

7. The triple-end mechanical seal for a reactor according to claim 1, characterized in that: A receiving groove (2.2) is provided inside the lower end of the sealing seat (2). A throttling ring (28) is fitted inside the receiving groove (2.2). The lower end of the throttling ring (28) abuts against the upper end surface of the inner side of the mounting flange (3). An elastic element (29) is provided between the upper end of the throttling ring (28) and the bottom of the receiving groove (2.2). A guide post (30) is further provided on the upper end surface of the inner side of the mounting flange (3). A guide hole (28.1) for the sliding fit of the guide post (30) is provided on the throttling ring (28).

8. The triple-end face mechanical seal for a reaction kettle according to claim 1, characterized in that: A plurality of circumferentially evenly distributed annular grooves (14.2) are concavely provided on the upper end surface of the first static ring (14), and the inner sides of the annular grooves (14.2) communicate with the inner cavity of the first static ring (14).

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