A bottom-entry mixer with online replacement of mechanical seal and online replacement method thereof

Abstract

The present invention relates to a bottom-entry mixer with online replacement of mechanical seals and an online replacement method thereof, wherein the bottom-entry mixer with online replacement of mechanical seals comprises: a bracket, a reducer, a coupling, a protective cover, a motor, a receiving plate, a frame, a stirring shaft, a blade, a hub, a bearing seat assembly, a double-end mechanical seal, a sealing liquid system, a flushing water system, and also comprises a rigid coupling and an auxiliary sealing system; the auxiliary sealing system comprises a mechanical seal mounting seat, a sealing ring, a sealing component, and an isolation ring; the mechanical seal mounting seat is fixedly connected to the frame; the mechanical seal mounting seat is provided with a boss, a sealing ring is provided on the boss, and the sealing component is provided with a groove with the concave surface facing downward. An isolation ring is installed under the boss seal, and the sealing component and the mechanical seal mounting seat with the isolation ring installed can be closed together and sealed. The present invention can realize the flushing, cooling, and lubrication of the double-end mechanical seal. The mechanical seal can be replaced online without emptying the material.

Description

Technical Field

[0001] The present invention relates to the technical field of bottom-entry mixers, in particular to a bottom-entry mixer with an online replacement mechanical seal and an online replacement method thereof. Background Art

[0002] The existing bottom-entry mixer is cumbersome to disassemble and replace the mechanical seal. When replacing the mechanical seal of the mixer, the slurry in the kettle needs to be emptied and the motor, reducer, frame, drive shaft or stirring shaft and other components need to be removed before replacement, which is very inconvenient. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a bottom-entry mixer with an online replacement mechanical seal and an online replacement method thereof, which allows the mechanical seal to be replaced without emptying the material, and is easy to operate.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a bottom-entry mixer with online replacement of mechanical seal, comprising: a bracket, a reducer, a coupling, a protective cover, a motor, a receiving plate, a frame, a stirring shaft, a blade, a hub, a bearing seat assembly, a double-end mechanical seal, a sealing liquid system, a flushing water system, the shaft head of the motor is fixedly connected to the shaft head of the reducer through a coupling, and also includes a rigid coupling and an auxiliary sealing system; the reducer is fixedly connected to the receiving plate and the frame; the output shaft head of the reducer is fixedly connected to the shaft head of the stirring shaft through a rigid coupling; the stirring shaft is fixedly installed with a bearing seat assembly, a double-end mechanical seal, and a sealing component; the stirring shaft is provided with a first shaft shoulder and a second shaft shoulder, the first shaft shoulder is located above the rigid coupling and is larger than The inner diameter of the rigid coupling, the second shoulder is located above the bearing seat assembly and is larger than the inner diameter of the bearing seat assembly; the sealing component is sealed and installed on the agitator shaft; the bearing seat assembly is fixedly installed on the frame; the double-end mechanical seal is sealed and connected to the machine seal mounting seat, and is fixedly connected to the agitator shaft through a locking ring; the auxiliary sealing system includes a machine seal mounting seat, a sealing ring, a sealing component, and an isolation ring; the machine seal mounting seat is fixedly connected to the frame; the machine seal mounting seat is provided with a boss, a sealing ring is provided on the boss, the sealing component is provided with a groove, and the concave surface is downward, and an isolation ring is sealed under the boss, the sealing component and the machine seal mounting seat with the isolation ring installed can be closed together, and the isolation ring fits and seals the side wall of the sealing component.

[0005] Furthermore, the sealing ring is located on the top or outside of the boss.

[0006] Furthermore, the isolation ring includes a pressure ring, a first sealing ring, a spring, a small sealing ring, and a second sealing ring. The pressure ring is fixedly connected to the first sealing ring by bolts, the second sealing ring is limited in its horizontal position and rotation by a pin, and is movably connected to the pressure ring by a spring; the isolation ring is bolted to the mechanical seal mounting seat through the pressure ring, and the isolation ring is fitted with the mechanical seal mounting seat through the small sealing ring; the second sealing ring is fitted with the sealing component; the second sealing ring is made of non-metallic sealing material.

[0007] Furthermore, the double-end mechanical seal includes a sleeve, a housing, a bearing, a skeleton oil seal, a fixed dynamic ring, a first dynamic ring, a second dynamic ring, a first static ring, and a second static ring. The housing includes a gland, a bearing seat, a connecting flange, and a housing. The sleeve is sealed with the stirring shaft, the fixed dynamic ring is sealed with the sleeve, the gland is fixedly connected with the sleeve, and a skeleton oil seal is installed between the gland and the sleeve. The gland, the bearing seat, and the connecting flange are fixedly installed on the mechanical seal mounting seat, wherein the gland and the bearing seat fix the bearing on the sleeve, wherein a skeleton oil seal is installed between the connecting flange and the sleeve; the housing is sealed with the connecting flange; the housing and the connecting flange are both provided with a collecting tank, and the second The static ring seal is installed in the collecting groove on the connecting flange, the second dynamic ring seal is installed on the shaft sleeve, the first dynamic ring seal is installed on the fixed dynamic ring, the first static ring is installed in the collecting groove on the shell through a spring and is sealed with the outer wall of the collecting groove, the first dynamic ring is in contact with the first static ring, and the second dynamic ring is in contact with the second static ring; the outer shell is provided with a sealing liquid inlet channel and a sealing liquid outlet channel, the outer shell and the first static ring, the first dynamic ring, the skeleton oil seal and the shaft sleeve are combined to form a closed space C, the sealing liquid inlet channel and the sealing liquid outlet channel are respectively connected to the closed space C; further, the shaft sleeve is sealed and connected to the stirring shaft through a locking ring and a sealing ring, and the fixed dynamic ring is sealed and connected to the stirring shaft through a locking ring and a sealing ring. The ring is sealed and connected to the sleeve by bolts and sealing rings, the pressure cover is fixedly connected to the sleeve by gaskets and bolts, and the pressure cover, bearing seat and connecting flange are fixedly installed on the machine seal mounting seat by bolts; the shell and the connecting flange are fixedly connected by bolts, and the contact surface thereof is provided with a sealing ring; the second static ring is fixedly installed in the collecting groove on the connecting flange, and the contact surface is provided with a sealing ring; the second dynamic ring is fixedly installed on the sleeve, and the contact surface is provided with a sealing ring, and the first dynamic ring is fixedly installed on the fixed dynamic ring, and the contact surface is provided with a sealing ring; the first static ring is installed in the collecting groove on the shell by a spring and a sealing ring is provided between the outer wall of the collecting groove; the sealing liquid inlet channel leads to the collecting groove on the shell The sealing liquid outlet channel is connected to the collecting tank of the connecting flange; further, the flushing water system includes a water tank, a water pump, a flushing water channel, the flushing water channel includes a first flushing water channel, a second flushing water channel, and a space A, the outer shell of the double-end mechanical seal is provided with a first flushing water channel, the mechanical seal mounting seat is provided with a second flushing water channel, and the first flushing water channel is sealed and connected to the second flushing water channel; a space A is formed between the double-end mechanical seal and the mechanical seal mounting seat, the stirring shaft and the mechanical seal mounting seat, the sealing component, and the isolation ring isolate the space B, the second flushing water channel leads to space A, and the pressure of the flushing water system is greater than the pressure of space B.

[0008] Furthermore, the reducer is fixedly connected to the receiving plate and the frame by bolts; the frame is provided with a bearing seat fixing plate, and the bearing seat assembly is fixedly connected to the bearing seat transition plate and the bearing seat fixing plate by bolts.

[0009] Furthermore, the locking ring includes an inner ring and an outer ring. The inner ring is disconnected, and its upper and lower outer walls are respectively provided with inclined surfaces. The outer ring is provided with an inner wall that matches the inclined surfaces, and the two outer rings are locked by bolts.

[0010] Furthermore, the upper half coupling portion of the rigid coupling is a detachable structure in half, and the two halves are connected by bolts.

[0011] In addition, an online replacement method is also provided, and the steps are as follows: when the double-end mechanical seal needs to be replaced, first close the sealing liquid system and the flushing water system. At this time, the second sealing ring of the isolation ring is closed with the sealing component, and then the reducer, the receiving plate, and the frame are disassembled. Then the upper and lower parts of the rigid coupling are disassembled, and then the bearing seat assembly and the bearing seat transition plate and the bearing seat fixing plate are disassembled. Then, the mounting bolts of the double-end mechanical seal and the machine seal mounting seat are removed. At this time, the double-end mechanical seal, the bearing seat assembly, the stirring shaft and the sealing component are moved down as a whole until the sealing component and the machine seal mounting seat are closed. At this time, the sealing ring is respectively fitted with the sealing component and the machine seal mounting seat. Finally, the locking ring is loosened and the double-end mechanical seal is pulled out for replacement.

[0012] Compared with the prior art, the present invention achieves the following beneficial effects: It provides a structure in which the sealing component is installed higher than the mechanical seal mounting seat, and their shapes match, with a sealing ring installed between them. A spacer ring is installed in the lower half, providing a seal with both the sealing component and the mechanical seal mounting seat. When the mechanical seal needs to be replaced, the rigid coupling is disassembled, the mounting bolts between the mechanical seal and the mechanical seal mounting seat are loosened, and the mounting bolts between the bearing assembly and the frame are loosened. The mechanical seal, bearing assembly, agitator shaft, and sealing component are then lowered as a whole. The sealing component and the mechanical seal mounting seat are now closed, forming an auxiliary seal, and the mechanical seal can then be pulled out for replacement.

[0013] A structure is also provided, which realizes external flushing of the first dynamic ring and the first static ring by setting up a flushing system, takes away impurities, flushes out the sealing state of the isolation ring, and flows into space B (inside the reactor), thereby realizing external flushing of the mechanical seal.

[0014] A structure is also provided, which realizes sealing, cleaning, cooling and lubrication of the interior of the double-end mechanical seal (space C) by setting up a sealing liquid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a bottom-entry mixer with online replacement of mechanical seals.

[0016] Figure 2 Schematic diagram of the structure of a double-end mechanical seal.

[0017] Figure 3 Schematic diagram of the structure of the sealing component and the mechanical seal mounting seat.

[0018] Figure 4 Schematic diagram of the isolation ring structure.

[0019] Figure 5 Schematic diagram of the rack structure.

[0020] Figure 6 Schematic diagram of the locking ring structure.

[0021] Explanation of reference numerals: 1 bracket, 2 reducer, 4 coupling, 3 protective cover, 5 motor, 6 receiving plate, 7 rigid coupling, 8 frame, 9 first shoulder, 10 bearing seat assembly, 11 bearing seat transition plate, 12 bearing seat fixing plate, 13 second shoulder, 14 isolation ring, 14-1 pressure ring, 14-2 first sealing ring, 14-3 small sealing ring, 14-4 second sealing ring, 15 double-end mechanical seal, 15-1 housing, 15-2 skeleton oil seal, 15-3 pressure cover, 15-4 bearing, 15-5 bearing seat, 15-6 connecting flange, 15-7 shell Body, 15-8 fixed dynamic ring, 15-9 first dynamic ring, 15-10 first static ring, 15-11 second dynamic ring, 15-12 second static ring, 15-13 sealing liquid inlet channel, 15-14 first flushing water channel, 15-15 shaft sleeve, 15-16 sealing liquid outlet channel, 15-17 collecting tank, 16 mechanical seal mounting seat, 16-1 boss, 16-2 second flushing water channel, 17 sealing ring, 18 sealing component, 18-1 groove, 19 stirring shaft, 20 blade, 21 hub, 22 locking ring, 22-1 inner ring, 22-2 outer ring. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0023] The present invention provides the following technical solutions: Figure 1As shown, a bottom-entry mixer with online replacement of mechanical seals includes: a bracket 1, a reducer 2, a coupling 4, a protective cover 3, a motor 5, a receiving plate 6, a frame 8, a stirring shaft 19, a blade 20, a hub 21, a bearing seat assembly 10, a double-end mechanical seal 15, a sealing liquid system, a flushing water system, the shaft head of the motor 5 is fixedly connected to the shaft head of the reducer 2 through the coupling 4, and also includes a rigid coupling 7 and an auxiliary sealing system; the reducer 2 is fixedly connected to the receiving plate 6 and the frame 8; the output shaft head of the reducer 2 is fixedly connected to the shaft head of the stirring shaft 19 through the rigid coupling 7; the stirring shaft 19 is fixedly installed with a bearing seat assembly 10, a double-end mechanical seal 15, and a sealing component 18; the stirring shaft is provided with a first shoulder 9 and a second shoulder 13, the first shoulder 9 is located above the rigid coupling 7 and is larger than the inner diameter of the rigid coupling 7, and the second shoulder 13 is located at the shaft Above the bearing assembly 10, and larger than the inner diameter of the bearing seat assembly 10; the sealing component 18 is sealed and installed on the stirring shaft 19; the bearing seat assembly 10 is fixedly installed on the frame 8; the double-end mechanical seal 15 is sealed and connected to the mechanical seal mounting seat 16, and is fixedly connected to the stirring shaft 19 through the locking ring 22; the auxiliary sealing system includes a mechanical seal mounting seat 16, a sealing ring 17, a sealing component 18, and an isolation ring 14; the mechanical seal mounting seat 16 is fixedly connected to the frame 8; the mechanical seal mounting seat 16 is provided with a boss 16-1, and the boss 16-1 is provided with a sealing ring 17, and the sealing component 18 is provided with a groove 18-1, and the concave surface is downward, and an isolation ring 14 is sealed and installed under the boss 16-1, and the sealing component 18 and the mechanical seal mounting seat 16 with the isolation ring 14 installed can be closed together, and the isolation ring 14 fits and seals with the side wall of the sealing component 18.

[0024] The sealing ring 17 is located on the top or outside of the boss 16 - 1 .

[0025] according to Figure 3 、 Figure 4 As shown, the isolation ring 14 includes a pressure ring 14-1, a first sealing ring 14-2, a spring, a small sealing ring 14-3, and a second sealing ring 14-4. The pressure ring 14-1 is fixedly connected to the first sealing ring 14-2 by bolts, and the second sealing ring 14-4 is limited in its horizontal position and rotation by a pin, and is movably connected to the pressure ring 14-1 by a spring; the isolation ring 14 is bolted to the mechanical seal mounting seat 16 through the pressure ring 14-1, and the isolation ring 14 is fitted with the mechanical seal mounting seat 16 through the small sealing ring 14-3; the second sealing ring 14-4 is fitted with the sealing component 18; the second sealing ring 14-4 is made of non-metallic sealing material.

[0026] according to Figure 2 、 Figure 3As shown, the double-end mechanical seal 15 includes a sleeve 15-15, a housing 15-1, a bearing 15-4, a skeleton oil seal 15-2, a fixed dynamic ring 15-8, a first dynamic ring 15-9, a second dynamic ring 15-11, a first static ring 15-10, and a second static ring 15-12. The housing 15-1 includes a gland 15-3, a bearing seat 15-5, a connecting flange 15-6, and a housing 15-7. The sleeve 15-15 is sealed to the stirring shaft 19 through a locking ring 22 and a sealing ring. The fixed dynamic ring 15-8 is sealed to the sleeve 15-15 through bolts and a sealing ring. The gland 15-3 is sealed to the shaft 19 through a gasket. The bearing 15-4 is fixedly mounted on the shaft sleeve 15-15 by the gland 15-3 and the bearing seat 15-5, and the skeleton oil seal 15-2 is installed between the shaft sleeve 15-15 and the gland 15-3, the bearing seat 15-5 and the connecting flange 15-6. The housing 15-7 is fixedly connected to the connecting flange 15-6 by bolts, and a sealing ring is provided on the contact surface of the housing 15-7 and the connecting flange 15-6. There is a collecting groove 15-17, the second static ring 15-12 is fixedly installed in the collecting groove 15-17 on the connecting flange 15-6, and a sealing ring is provided on the contact surface; the second dynamic ring 15-11 is fixedly installed on the shaft sleeve 15-15, and a sealing ring is provided on the contact surface; the first dynamic ring 15-9 is fixedly installed on the fixed dynamic ring 15-8, and a sealing ring is provided on the contact surface; the first static ring 15-10 is installed in the collecting groove 15-17 on the housing 15-7 through a spring and a sealing ring is provided between the outer wall of the collecting groove 15-17; the first dynamic ring 15-9 is in contact with the first static ring 15-10, and the second dynamic ring 15-11 is in contact with the first The two static rings 15-12 fit together; the housing 15-1 is provided with a sealing liquid inlet channel 15-13 and a sealing liquid outlet channel 15-16, the housing 15-1 and the first static ring 15-10, the first dynamic ring 15-9, the skeleton oil seal 15-2, and the shaft sleeve 15-15 are combined to form a closed space C, and the sealing liquid inlet channel 15-13 and the sealing liquid outlet channel 15-16 are respectively connected to the closed space C; the sealing liquid inlet channel 15-13 leads to the collection tank 15-17 on the housing 15-7, and the sealing liquid outlet channel 15-16 is connected to the collection tank 15-17 of the connecting flange 15-6; according to Figure 2 、 Figure 3As shown, the flushing water system includes a water tank, a water pump, a flushing water channel, and the flushing water channel includes a first flushing water channel 15-14, a second flushing water channel 16-2, and a space A. The housing 15-1 of the double-end mechanical seal 15 is provided with a first flushing water channel 15-14, and the mechanical seal mounting seat 16 is provided with a second flushing water channel 16-2. The first flushing water channel 15-14 is sealed and connected to the second flushing water channel 16-2; a space A is formed between the double-end mechanical seal 15 and the mechanical seal mounting seat 16, and the stirring shaft 19 and the mechanical seal mounting seat 16, the sealing component 18, and the isolation ring 14 isolate a space B. The second flushing water channel 16-2 leads to space A, and the pressure of the flushing water system is greater than the pressure of space B.

[0027] according to Figure 1 As shown, the reducer 2 is fixedly connected to the receiving plate 6 and the frame 8 by bolts; the frame 8 is provided with a bearing seat fixing plate 12, and the bearing seat assembly 10 is fixedly connected to the bearing seat transition plate 11 and the bearing seat fixing plate 12 by bolts.

[0028] according to Figure 6 As shown, the locking ring 22 includes an inner ring 22-1 and an outer ring 22-2. The inner ring 22-1 is disconnected, and its outer wall is provided with inclined surfaces at the upper and lower parts. The outer ring 22-2 is provided with an inner wall that matches the inclined surfaces. The two outer rings 22-2 are locked up and down by bolts.

[0029] according to Figure 1 The upper half coupling portion of the rigid coupling 7 is a detachable structure, and the two halves are connected by bolts.

[0030] Working principle: the sealing component 18 and the mechanical seal mounting seat 16 can be closed or opened. When the mixer is working, the sealing component 18 and the mechanical seal mounting seat 16 are open, and the sealing component 18 is sealed with the isolation ring 14. When the flushing water system is needed to flush the first dynamic ring 15-9 and the first static ring 15-10, the flushing water system is turned on, and the water flows through the first flushing water channel and the second flushing water channel to flow to space A, flushing the first dynamic ring 15-9 and the first static ring 15-10 and taking away the dirt. Because the water pressure of the flushing water is greater than the pressure of the reactor (space B), the second sealing ring 14-4 that was originally sealed is flushed open and flows into the reactor, that is, space B.

[0031] To replace the double mechanical seal 15, disassemble the rigid coupling 7, loosen the mounting bolts between the double mechanical seal 15 and the seal mounting base 16, and the mounting bolts between the bearing assembly 10 and the frame 8. The double mechanical seal 15, bearing assembly 10, agitator shaft 19, and seal component 18 are then lowered. The seal component 18 and seal mounting base 16 are now closed, and the sealing ring and isolation ring 14 form a secondary seal. At this point, loosen the locking ring 22 and remove the double mechanical seal 15 for replacement. There is no need to drain the material; dismantle all components.

[0032] The sealing liquid system of the double mechanical seal 15 strengthens the seal between the second dynamic ring 15-11 and the second stationary ring 15-12, as well as removing impurities, providing cooling, and lubrication. The sealing liquid enters space C (the inner cavity of the double mechanical seal) through the sealing liquid inlet channel 15-13, passes through the first dynamic ring 15-9 and the first stationary ring 15-10, then through the second dynamic ring 15-11 and the second stationary ring 15-12, before exiting through the sealing liquid outlet channel 15-16 and recirculating.

[0033] It should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0034] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is limited by the appended claims and their equivalents.

Claims

1. A bottom-entry mixer with online replacement of mechanical seal, comprising: Bracket (1), reducer (2), coupling (4), protective cover (3), motor (5), receiving plate (6), frame (8), stirring shaft (19), blade (20), wheel hub (21), bearing seat assembly (10), double end mechanical seal (15), sealing liquid system, flushing water system, the shaft head of the motor (5) is fixedly connected to the shaft head of the reducer (2) through the coupling (4), characterized in that it also includes a rigid coupling (7) and an auxiliary sealing system; The reducer (2) is fixedly connected to the receiving plate (6) and the frame (8); the output shaft head of the reducer (2) is fixedly connected to the shaft head of the stirring shaft (19) through a rigid coupling (7); the stirring shaft (19) is fixedly installed with a bearing seat assembly (10), a double-end mechanical seal (15), and a sealing component (18); the stirring shaft is provided with a first shaft shoulder (9) and a second shaft shoulder (13), the first shaft shoulder (9) is located above the rigid coupling (7) and is larger than the inner diameter of the rigid coupling (7), and the second shaft shoulder (13) is located above the bearing seat assembly (10) and is larger than the inner diameter of the bearing seat assembly (10); the sealing component (18) is sealingly installed on the stirring shaft (19); the bearing seat assembly (10) is fixedly installed on the frame (8); the double-end mechanical seal (15) is sealingly connected to the mechanical seal mounting seat (16), and is fixedly connected to the stirring shaft (19) through a locking ring (22); The auxiliary sealing system includes a mechanical seal mounting seat (16), a sealing ring (17), a sealing component (18), and an isolation ring (14); The mechanical seal mounting seat (16) is fixedly connected to the frame (8); the mechanical seal mounting seat (16) is provided with a boss (16-1), a sealing ring (17) is provided on the boss (16-1), the sealing component (18) is provided with a groove (18-1), and the concave surface is downward, an isolation ring (14) is sealingly installed under the boss (16-1), the sealing component (18) and the mechanical seal mounting seat (16) with the isolation ring (14) installed can be closed together, and the isolation ring (14) and the side wall of the sealing component (18) are in contact and sealed; The isolation ring (14) comprises a pressure ring (14-1), a first sealing ring (14-2), a spring, a small sealing ring (14-3), and a second sealing ring (14-4); the pressure ring (14-1) is fixedly connected to the first sealing ring (14-2) by bolts; the second sealing ring (14-4) is limited in horizontal position and rotation by a pin and is movably connected to the pressure ring (14-1) by a spring; the isolation ring (14) is bolted to the machine seal mounting seat (16) by the pressure ring (14-1); the isolation ring (14) is fitted to the machine seal mounting seat (16) by the small sealing ring (14-3); the second sealing ring (14-4) is fitted to the sealing component (18); The second sealing ring (14-4) is made of non-metallic sealing material.

2. The bottom-entry mixer with online replacement of mechanical seal according to claim 1, characterized in that: The sealing ring (17) is located on the top or outside of the boss (16-1).

3. The bottom-entry mixer with online replacement of mechanical seal according to claim 1, characterized in that: The double-end mechanical seal (15) includes a shaft sleeve (15-15), a housing (15-1), a bearing (15-4), a skeleton oil seal (15-2), a fixed dynamic ring (15-8), a first dynamic ring (15-9), a second dynamic ring (15-11), a first static ring (15-10), and a second static ring (15-12); the housing (15-1) includes a gland (15-3), a bearing seat (15-5), a connecting flange (15-6), and a housing (15-7); the shaft The sleeve (15-15) is sealed and connected to the stirring shaft (19), the fixed dynamic ring (15-8) is sealed and connected to the shaft sleeve (15-15), the pressure cover (15-3) is fixedly connected to the shaft sleeve (15-15), and a skeleton oil seal (15-2) is installed between the pressure cover (15-3) and the shaft sleeve (15-15), and the pressure cover (15-3), the bearing seat (15-5), and the connecting flange (15-6) are fixedly installed on the machine seal mounting seat (16), wherein the pressure cover (15-3) and the bearing seat (15 -5) The bearing (15-4) is fixedly mounted on the shaft sleeve (15-15), wherein a skeleton oil seal (15-2) is installed between the connecting flange (15-6) and the shaft sleeve (15-15); the housing (15-7) is sealedly connected to the connecting flange (15-6); a collecting groove (15-17) is provided on the housing (15-7) and the connecting flange (15-6), the second stationary ring (15-12) is sealed in the collecting groove (15-17) on the connecting flange (15-6), and the second dynamic ring (15-12) is sealed in the collecting groove (15-17) on the connecting flange (15-6). The ring (15-11) is sealingly mounted on the shaft sleeve (15-15), the first dynamic ring (15-9) is sealingly mounted on the fixed dynamic ring (15-8), the first static ring (15-10) is mounted in the collecting groove (15-17) on the housing (15-7) via a spring and is sealingly connected to the outer wall of the collecting groove (15-17), the first dynamic ring (15-9) is in contact with the first static ring (15-10), and the second dynamic ring (15-11) is in contact with the second static ring (15-12); The housing (15-1) is provided with a sealing liquid inlet channel (15-13) and a sealing liquid outlet channel (15-16); the housing (15-1) is combined with the first static ring (15-10), the first dynamic ring (15-9), the skeleton oil seal (15-2), and the shaft sleeve (15-15) to form a closed space C; the sealing liquid inlet channel (15-13) and the sealing liquid outlet channel (15-16) are respectively connected to the closed space C.

4. The bottom-entry mixer with online replacement of mechanical seal according to claim 3, characterized in that: The shaft sleeve (15-15) is sealed and connected to the stirring shaft (19) through a locking ring (22) and a sealing ring, the fixed dynamic ring (15-8) is sealed and connected to the shaft sleeve (15-15) through bolts and a sealing ring, the pressure cover (15-3) is fixedly connected to the shaft sleeve (15-15) through a gasket and bolts, and the pressure cover (15-3), the bearing seat (15-5), and the connecting flange (15-6) are fixedly mounted on the machine seal mounting seat (16) through bolts; the housing (15-7) and the connecting flange (15-6) are fixedly connected through bolts, and their contact surfaces are provided with a sealing The second static ring (15-12) is fixedly mounted in the collecting groove (15-17) on the connecting flange (15-6), and a sealing ring is provided on the contact surface; the second dynamic ring (15-11) is fixedly mounted on the shaft sleeve (15-15), and a sealing ring is provided on the contact surface; the first dynamic ring (15-9) is fixedly mounted on the fixed dynamic ring (15-8), and a sealing ring is provided on the contact surface; the first static ring (15-10) is mounted in the collecting groove (15-17) on the housing (15-7) through a spring, and a sealing ring is provided between the first static ring (15-10) and the outer wall of the collecting groove (15-17); The sealing liquid inlet channel (15-13) leads to the collecting tank (15-17) on the shell (15-7), and the sealing liquid outlet channel (15-16) is connected to the collecting tank (15-17) of the connecting flange (15-6).

5. A bottom-entry mixer with online replacement of mechanical seal according to claim 1 or 3, characterized in that: The flushing water system comprises a water tank, a water pump, and a flushing water channel. The flushing water channel comprises a first flushing water channel (15-14), a second flushing water channel (16-2), and a space A. The housing (15-1) of the double-end mechanical seal (15) is provided with the first flushing water channel (15-14), the mechanical seal mounting seat (16) is provided with the second flushing water channel (16-2), and the first flushing water channel (15-14) and the second flushing water channel (16-2) are sealed and connected. A space A is formed between the double-end mechanical seal (15) and the mechanical seal mounting seat (16). The stirring shaft (19) and the mechanical seal mounting seat (16), the sealing component (18), and the isolation ring (14) isolate a space B. The second flushing water channel (16-2) leads to the space A. The pressure of the flushing water system is greater than the pressure of the space B.

6. The bottom-entry mixer with online replacement of mechanical seal according to claim 1, characterized in that: The reducer (2) is fixedly connected to the receiving plate (6) and the frame (8) by bolts; The frame (8) is provided with a bearing seat fixing plate (12), and the bearing seat assembly (10) is fixedly connected to the bearing seat transition plate (11) and the bearing seat fixing plate (12) by bolts.

7. The bottom-entry mixer with online replacement of mechanical seal according to claim 1, characterized in that: The locking ring (22) comprises an inner ring (22-1) and an outer ring (22-2); the inner ring (22-1) is disconnected, and its upper and lower outer walls are respectively provided with inclined surfaces; the outer ring (22-2) is provided with an inner wall that matches the inclined surfaces; the two outer rings (22-2) are locked by bolts.

8. The bottom-entry mixer with online replacement of mechanical seal according to claim 1, characterized in that: The upper coupling portion of the rigid coupling (7) is a detachable structure, and the two halves are connected by bolts.

9. An online replacement method, characterized in that: Using the bottom-entry mixer with online replacement of mechanical seal according to claim 6, the steps are as follows: When the double-end mechanical seal needs to be replaced, first close the sealing liquid system and the flushing water system. At this time, the second sealing ring (14-4) of the isolation ring (14) is closed with the sealing component (18), and then the reducer (2), the receiving plate (6), and the frame (8) are disassembled. Then, the upper and lower parts of the rigid coupling (7) are disassembled. Then, the bearing seat assembly (10) and the bearing seat transition plate (11) and the bearing seat fixing plate (12) are disassembled. Then, the mounting bolts of the double-end mechanical seal (15) and the machine seal mounting seat (16) are removed. At this time, the double-end mechanical seal (15), the bearing seat assembly (10), the stirring shaft (19) and the sealing component (18) are moved downward as a whole until the sealing component (18) and the machine seal mounting seat (16) are closed. At this time, the sealing ring is respectively fitted with the sealing component (18) and the machine seal mounting seat (16). Finally, the locking ring (22) is loosened and the double-end mechanical seal (15) is pulled out for replacement.

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