Rotary evaporator with reflux extraction function

Abstract

The invention discloses a rotary evaporator with a reflux extraction function. The rotary evaporator is characterized in that a flow guide structure is arranged at the lower end of a snake-shaped condensation pipe, a first port communicated with the condensation pipe, a second port communicated with a collection bottle and a lower port communicated with an evaporation bottle are formed in the middle of an inclined conical sleeve; the outer wall of the conical flow guide valve is attached to the inner wall of the sleeve, and a feeding channel, an evaporation inlet channel, a first condensation outlet channel, a second condensation outlet channel and a backflow outlet channel are integrated in the conical flow guide valve. When the diverter valve is rotated to a first working position, the first condensation outlet channel is aligned with the first port, and the second condensation outlet channel is aligned with the second port, so that a concentration function that solvent steam in the evaporation bottle flows into the collection bottle after being condensed is realized; when rotating to a second working position, the reflux outlet channel is aligned with the first port, so that the evaporation bottle is communicated with the snake-shaped condensation pipe to form a closed loop, and a solvent circulating reflux extraction function is realized. The device can improve the experiment efficiency and reduce the system pollution risk, and is suitable for laboratory solvent concentration and material extraction scenes.

Description

Technical Field

[0001] The present invention belongs to the technical field of laboratory equipment, and in particular relates to a rotary evaporator with a reflux extraction function, which realizes dual-function switching of evaporation concentration and reflux extraction based on a rotatable guide valve. Background Art

[0002] When using a rotary evaporator in the laboratory for solvent evaporation and concentration or material reflux extraction, it is necessary to switch between different operating modes. Conventional rotary evaporators are usually designed for a single function mode, that is, the material in the evaporating flask is heated and evaporated, the vapor enters the condenser and condenses, and the liquid eventually flows into the collection flask to complete the concentration. When the experiment needs to switch to reflux extraction mode, that is, to allow the condensed liquid to return to the evaporating flask for cyclic extraction, the operator usually needs to manually change the pipeline connection. This usually involves removing the connection at the lower end of the condenser, installing an additional reflux line, and may require adjusting or replacing the valve. This manual switching process is cumbersome, time-consuming, and increases the number of operating steps.

[0003] Manually switching pipe connections carries the risk of introducing contamination or leakage. Repeated disassembly and assembly of ground-mouth glass joints may cause wear on the interface or contamination of the sealing surface with impurities, affecting its sealing performance. In the vacuum negative pressure environment required for equipment operation, poor sealing can easily lead to external air infiltration into the system or internal solvent vapor escape, which may not only affect experimental results but also pose a safety hazard. In addition, during the disassembly process, residual solvents may be exposed to the environment, increasing the possibility of sample contamination. Frequent disassembly and assembly also reduces the continuity and efficiency of equipment use. Each switch requires interrupting the experimental process for reassembly and sealing inspection.

[0004] Trying to integrate multiple functional flow channels into a valve body and realize different working modes by switching the valve is one way to solve the above-mentioned cumbersome operation problem. However, in the specific application environment of the rotary evaporator, this integrated design faces difficulties in structural implementation. The evaporating flask needs to be driven by a rotary drive system to rotate continuously, while the interface between the condenser and the collection flask is usually fixed. How to reliably connect the rotating evaporating flask with the fixed condensation system and collection system in a compact space and realize the switching of the flow channel is a complex design challenge. The interface between the dynamic component and the static component requires a special sealing design.

[0005] This integrated valve body must simultaneously withstand high-temperature solvent vapor (the operating temperature range typically ranges from room temperature to elevated temperatures) and high vacuum negative pressure (e.g., -0.09 MPa to -0.1 MPa). This places stringent demands on the valve body material and sealing structure. Conventional valve designs, after long-term thermal cycling (alternating heating and cooling), are susceptible to deformation or stress due to differences in thermal expansion coefficients between components made of different materials. This can cause changes or even loss of the sealing contact pressure between the valve core and the valve seat, leading to leakage. Maintaining a stable and reliable seal for rotating or switching valve cores under high temperature and vacuum conditions over a long period of time is a technical challenge.

[0006] Arranging multiple functional flow paths within a limited space (such as the vapor inlet, the condensate outlet to the collection flask, the return path from the condensate outlet to the evaporation flask, and possible feed channels) and ensuring they are properly connected within the valve body without interfering with each other, thereby avoiding the formation of residual liquid "dead volume" or accidental crosstalk between different flow paths, is also a complex design issue. The complexity of the flow path design directly affects the performance of the device and the purity of the sample processed.

[0007] There are many reasons for the above problems and difficulties. The core is that the structure of the existing equipment is difficult to simultaneously and conveniently support the physically isolated flow path topology required for the two functional paths of evaporation and reflux. The single outlet design at the lower end of the condenser cannot naturally serve the two needs of flowing to the collection bottle (concentration mode) and flowing back to the evaporation bottle (reflux mode) at the same time. In addition, the interface connecting the rotary evaporating bottle and the fixed condensation / collection system requires a dynamic sealing technology that can adapt to rotational motion, resist vacuum negative pressure, tolerate solvent and temperature changes, and have a long life. Conventional sealing structures often perform poorly under such harsh complex working conditions. The thermal expansion and contraction of the valve body components when experiencing changes in operating temperature will directly weaken the tight fit of the sealing interface if it is not effectively compensated. This is an important physical factor leading to seal failure.

[0008] Therefore, seeking a technical solution that can structurally integrate the two working mode flow channels, enable easy switching in operation, and maintain long-term reliable sealing under the specific high temperature, vacuum, and dynamic rotation conditions of the rotary evaporator is a key requirement for improving the functionality and practicality of such equipment. Summary of the Invention

[0009] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0010] The present invention solves the following technical problems: Switching between evaporation and concentration modes requires disassembly and reassembly of the piping, a cumbersome process that can easily contaminate the system. Existing integrated valve solutions struggle to achieve reliable dual-mode switching within a compact design due to spatial conflicts between rotating components and fixed interfaces, as well as seal failure caused by vacuum thermal deformation. The intersecting arrangement of flow channels also increases the risk of dead volume, compromising separation efficiency.

[0011] The rotary seal interface between the diverter valve and the glass shaft is prone to leakage under vacuum and solvent vapor conditions. Conventional sealing rings, due to the lack of smoothness on the glass surface and differential thermal expansion, do not fit tightly in the radial direction. Long-term rotational wear degrades sealing performance, necessitating a solution to the long-term stability of dynamic seals.

[0012] After the diverter valve is rotated and positioned, it can easily deflect circumferentially due to equipment vibration or vacuum suction, causing flow path misalignment and functional failure. The mechanical locking mechanism must provide sufficient locking force within a limited space without damaging the glass components, while also allowing operators to quickly switch between working states.

[0013] Conventional bolt tightening causes preload relaxation due to thermal stress deformation, resulting in the anti-slip protrusion separating from the V-groove. The open end of the elastic C-ring needs to be evenly applied to avoid uneven loading, and the insertion depth of the anti-slip protrusion needs to be controlled to prevent interference fit or insufficient contact. The tightening force transmission path needs to be optimized.

[0014] Vacuum pressure and thermal cycling cause axial displacement in the diverter valve, and the disc spring assembly must compensate for this displacement and maintain a constant preload. The fine-thread fine-adjustment accuracy must match the spring stiffness to prevent vibration loosening or damage to the component due to excessive compression, while also addressing the thermal expansion mismatch between metal and glass at high temperatures.

[0015] Due to differences in thermal expansion coefficients, the interface between the inner rubber layer and the outer self-lubricating material of the seal ring delaminates and fails under thermal cycling. Solvent penetration causes rubber swelling, accelerating wear on the seal surface. Blocking the penetration path and optimizing the interlayer stress distribution are necessary to maintain the integrity of the seal working surface under dynamic operating conditions.

[0016] PTFE-based self-lubricating materials swell upon prolonged contact with organic solvents, forming microcracks on the surface that can lead to seal failure. Conventional fluorinated layers lack sufficient bonding strength, necessitating the construction of a stable carbon fluoride layer on the material surface to enhance resistance to solvent penetration while also preventing high-temperature treatment from damaging the rubber matrix.

[0017] In order to achieve these objects and other advantages of the present invention, a rotary evaporator with reflux extraction function is provided, comprising an evaporation system, a rotary drive system, a vacuum system, and a control system. The evaporation system comprises a serpentine condenser, an evaporation flask, and a collection flask. The lower end of the serpentine condenser is provided with a flow guide structure, and the flow guide structure comprises: A conical sleeve is obliquely arranged below the serpentine condenser, and the diameter of the lower port is smaller than the diameter of the upper port. A first port and a second port are provided in the middle of the conical sleeve. The first port is connected to the lower end of the serpentine condenser, the second port is connected to the inlet of the collecting bottle, and the lower port of the conical sleeve is connected to the evaporating flask. The diverter valve has a conical structure, the outer wall of the diverter valve is in contact with the inner wall of the conical sleeve, and the diverter valve includes a feeding channel, an evaporation inlet channel, a first condensation outlet channel, a second condensation outlet channel, and a reflux outlet channel. The feeding channel, the evaporation inlet channel, the first condensation outlet channel, the second condensation outlet channel, and the reflux outlet channel are interconnected, and a feeding valve is provided in the feeding channel to block the feeding channel; The diverter valve and the conical sleeve are on the same axis, so that two working positions can be constructed by rotating the diverter valve; When the diverter valve is in the first working position, the first condensation outlet channel is opposite to the first port, the second condensation outlet channel is opposite to the second port, and the reflux outlet channel is opposite to the side wall of the tapered sleeve, so that the evaporation flask, the serpentine condenser tube and the collecting flask are connected, realizing the evaporation and concentration function; When the diverter valve is in the second working position, the first condensation outlet channel and the second condensation outlet channel are opposite to the side wall of the conical sleeve, and the reflux outlet channel is opposite to the first port so that the evaporating flask is connected to the serpentine condenser tube through the diverter valve, thereby realizing the reflux extraction function.

[0018] The length of the guide valve of the present invention is greater than that of the conical sleeve so that the guide valve extends from both ends of the conical sleeve. A first groove is provided at the lower end of the guide valve, and a first annular sealing ring is sleeved on the first groove. The conical sleeve is fixedly connected to the connecting seat. The lower end of the guide valve extends into the glass shaft so that the first annular sealing ring abuts against the inner wall of the glass shaft to achieve a rotational seal between the glass shaft and the guide valve.

[0019] Preferably, the present invention further comprises a clamping and fixing structure for clamping and fixing the diverter valve, wherein the clamping and fixing structure comprises: a first anti-slip groove, which is provided on the conical sleeve, wherein the length direction of the first anti-slip groove is parallel to the length direction of the conical sleeve; A second anti-slip groove is provided on the diversion valve, wherein the length direction of the second anti-slip groove is parallel to the length direction of the tapered sleeve; The locking ring has an anti-slip protrusion on its inner side. The locking ring is partially sleeved on the first anti-slip groove and partially sleeved on the second anti-slip groove to prevent the guide valve from rotating relative to the conical sleeve through the locking ring.

[0020] Preferably, the locking ring of the present invention is an elastic C-shaped ring with an opening, and a plurality of anti-slip protrusions are evenly distributed along the circumference on the inner side thereof; The first anti-skid groove and the second anti-skid groove both have a V-shaped cross-section, and the groove depth is greater than 1 / 2 of the height of the anti-skid protrusion; When the locking ring is in a locked state, its open end is closed by the locking bolt, so that the anti-slip protrusion is simultaneously engaged with the first anti-slip groove and the second anti-slip groove; When the locking ring is in an unlocked state, the open end thereof expands to cause the anti-slip protrusion to separate from the anti-slip groove.

[0021] Preferably, the open end of the locking ring of the present invention is provided with a locking ear extending outward, and a coaxial oblong hole is provided on the locking ear; the locking bolt passes through the oblong holes of the two locking ears in sequence, and applies axial pre-tightening force through the threaded locking nut to bring the open end of the locking ring close together; a disc spring group is installed in the oblong hole, and the disc spring group is sleeved on the locking bolt, one end of the disc spring group abuts against the inner wall of the locking ear, and the other end abuts against the nut or nut on the bolt; when the locking nut is tightened, the disc spring group is compressed and generates a reverse force, forcing the locking ears on both sides to converge axially along the locking bolt, and at the same time driving the two ends of the locking ring close to each other to achieve fixation.

[0022] Preferably, the stiffness coefficient of the disc spring group of the present invention is 40-60 N / mm, the compression stroke of a single disc spring group is 0.5-1.5 mm; the thread of the locking bolt is M4-M6 fine thread with a pitch of 0.35-0.5 mm.

[0023] Preferably, the lower end of the conical sleeve of the present invention is provided with a second groove, the conical sleeve is fixedly connected to the connecting seat, and the lower end of the conical sleeve extends into the glass shaft so that the second annular sealing ring on the second groove abuts and seals against the inner wall of the glass shaft.

[0024] Preferably, the second annular sealing ring of the present invention comprises: The inner ring is a highly elastic and solvent-resistant rubber ring, and the inner circumferential surface of the inner ring is fixed in the second groove by interference fit; The outer ring is a ring made of a low friction coefficient material with self-lubricating properties. The inner circumference of the outer ring is vulcanized and bonded to the outer circumference of the inner ring. The outer circumference of the outer ring is a sealing working surface that is in sliding contact with the inner wall of the glass shaft.

[0025] Preferably, the second annular sealing ring of the present invention also includes an expansion buffer transition layer, which is arranged between the inner ring and the outer ring. The expansion buffer transition layer is an EPDM rubber layer modified with silicone rubber, and its thermal expansion coefficient is between that of the inner ring and the outer ring; the contact surface of the inner ring and the outer ring is provided with a transverse dovetail groove structure, and the expansion buffer transition layer is filled in the dovetail groove to form a mechanical interlocking; the outer circumferential surface of the outer ring is treated with antimony pentafluoride vapor.

[0026] Preferably, the antimony pentafluoride vapor phase treatment of the present invention is performed according to the following steps: 1) Place the outer ring in a sealed reaction chamber, evacuate to a pressure ≤ 0.1 bar, and then introduce inert gas for replacement. Repeat this three times to remove oxygen and water vapor. 2) heating antimony pentafluoride to 50-80°C to vaporize it and mixing it with an inert gas to form a mixed vapor with a volume fraction of 10-50%, and introducing the mixed vapor into the reaction chamber at a flow rate of 0.5-2 L / min; 3) Maintain the chamber temperature at 80-120°C and the pressure at 0.12-0.15 MPa for 5-30 minutes; 4) Stop introducing mixed steam, switch to pure inert gas for purging for 30 minutes, and remove the container after cooling to room temperature; 5) After treatment, a carbon fluoride layer is formed on the outer circumference of the outer ring with a thickness of 0.1-0.5 μm; Wherein, the inert gas is nitrogen or argon; the mixed steam in step (2) needs to be pretreated to remove water to a water content of ≤10 ppm.

[0027] The present invention has at least the following beneficial effects: The rotating coupling of the tapered sleeve and diverter valve enables dual-mode flow switching between evaporation and concentration and reflux extraction, eliminating the need for external piping. The integrated flow path design ensures physical isolation between the two working paths, preventing cross-contamination. The diverter valve's multi-channel layout optimizes flow path topology, reduces residual dead volume, and improves solvent recovery efficiency. The single valve body simplifies workflow and enhances continuous operation.

[0028] The diverter valve extension creates an interference fit with the glass shaft, allowing the sealing ring to radially press against the glass inner wall, forming a dynamic rotating seal. The annular sealing ring compensates for minor irregularities in the glass shaft's inner wall, maintaining stable contact pressure under vacuum. This structure blocks solvent vapor leakage along the rotating shaft, enhancing system tightness.

[0029] The anti-slip groove and locking ring provide circumferential mechanical locking, preventing accidental deflection of the diverter valve and flow path misalignment. The V-shaped anti-slip groove increases the contact area, and the embedded anti-slip protrusions disperse localized stress to prevent glass component cracking. The unlocked state quickly releases the restraint, making it easier for operators to switch between working modes.

[0030] The retracting action of the elastic C-ring evenly engages the anti-slip projection in the V-groove, providing circumferential restraint. The matching groove depth and projection height ensures optimal engagement, preventing both interference fit and insufficient contact. The V-shaped guide projection automatically aligns, compensating for assembly errors and enhancing locking reliability.

[0031] The disc spring assembly absorbs axial displacement caused by thermal deformation, maintaining constant pressure from the locking ring against the anti-skid groove. Fine threads provide high-precision preload adjustment, matching the spring rate to suppress vibration loosening. The oblong hole allows the locking lug to micro-move to compensate for thermal expansion differences, preventing damage from hard contact between the glass and metal components.

[0032] The expansion buffer transition layer coordinates the thermal expansion difference between the inner rubber layer and the outer material, inhibiting interfacial delamination. The mechanical interlocking dovetail grooves strengthen the interlayer bond and block solvent penetration. The self-lubricating outer layer reduces rotational friction and extends the service life of the seal.

[0033] The fluorinated carbon layer forms a dense barrier on the self-lubricating material's surface, inhibiting the penetration of organic solvent molecules into the substrate. Vapor-phase treatment protects the rubber substrate from high-temperature damage, while the fluorinated groups enhance the surface's chemical inertness. The thickness of the treated layer is controllable, balancing sealing performance with processing costs. The inert gas environment prevents oxidation and degradation of the material.

[0034] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of a technical solution of the present invention; Figure 2 Schematic diagram of the side structure of the diverter valve of the present invention; Figure 3 It is a structural schematic diagram of another technical solution of the present invention.

[0036] 1. Conical sleeve; 2. Serpentine condenser; 3. Evaporation flask; 4. Collecting flask; 5. First port; 6. Second port; 7. Diversion valve; 8. Feeding channel; 9. Evaporation inlet channel; 10. Feeding valve; 11. Glass shaft; 12. Clamping and fixing structure; 13. Condensation first outlet channel; 14. Condensation second outlet channel; 15. Reflux outlet channel. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0038] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0039] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The orientations or positional relationships indicated by the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0040] like Figure 1-2 As shown, the present invention provides a rotary evaporator with reflux extraction function, including an evaporation system, a rotary drive system, a vacuum system and a control system. The evaporation system includes a serpentine condenser 2, an evaporation flask 3 and a collection flask 4. The lower end of the serpentine condenser 2 is provided with a guide structure, and the guide structure includes: A conical sleeve 1 is obliquely arranged below the serpentine condenser 2, and the diameter of the lower port is smaller than that of the upper port. A first port 5 and a second port 6 are provided in the middle of the conical sleeve 1. The first port 5 is connected to the lower end of the serpentine condenser 2, and the second port 6 is connected to the inlet of the collecting bottle 4. The lower port of the conical sleeve 1 is connected to the evaporating flask 3. The diverter valve 7 has a conical structure. The outer wall of the diverter valve 7 is in contact with the inner wall of the conical sleeve 1. The diverter valve 7 includes a feeding channel 8, an evaporation inlet channel 9, a first condensation outlet channel 13, a second condensation outlet channel 14, and a reflux outlet channel 15. The feeding channel 8, the evaporation inlet channel 9, the first condensation outlet channel 13, the second condensation outlet channel 14, and the reflux outlet channel 15 are interconnected. The feeding channel 8 is provided with a feeding valve 10 to block the feeding channel 8. The diverter valve 7 and the conical sleeve 1 are located on the same axis, so that two working positions can be formed by rotating the diverter valve 7; When the diverter valve 7 is in the first working position, the first condensation outlet channel 13 is opposite to the first port 5, the second condensation outlet channel 14 is opposite to the second port 6, and the reflux outlet channel 15 is opposite to the side wall of the conical sleeve 1, so that the evaporation flask 3, the serpentine condenser tube 2 and the collecting flask 4 are connected, realizing the evaporation and concentration function; When the diverter valve 7 is in the second working position, the first condensation outlet channel 13 and the second condensation outlet channel 14 are opposite to the side wall of the conical sleeve 1, and the reflux outlet channel 15 is opposite to the first port 5 so that the evaporating flask 3 is connected with the serpentine condenser tube 2 through the diverter valve 7, thereby realizing the reflux extraction function.

[0041] The diversion structure consists of a conical sleeve 1 and a diversion valve 7. The conical sleeve 1 is installed obliquely just below the serpentine condenser 2. The diameter of its upper port can be selected between fifty millimeters and sixty millimeters, and the diameter of its lower port can be selected between thirty millimeters and forty millimeters, with the overall cone angle being ten to fifteen degrees. The conical sleeve can be integrally formed with the serpentine condenser, or it can be split. Two ports are provided in the middle of the conical sleeve. The port close to the condenser side can be sealed and connected to the outlet of the serpentine condenser 2 through a standard ground glass joint, and the other port can be connected to the inlet of the collecting bottle 4 using the existing ground connection method. The conical sleeve can also be welded with the serpentine condenser so that the conical sleeve can be integrally formed with the serpentine condenser. The diversion valve 7 is made of conical borosilicate glass or ceramic material, and the fitting accuracy between its outer wall and the inner wall of the sleeve is controlled within 0.1 mm. The valve body has five channels: a feed channel 8 with an inner diameter of 6 mm and fitted with a PTFE stopcock; an evaporation inlet channel 9 with an inner diameter of 8 mm; two condensation outlet channels with an inner diameter of 7 mm each; and a return outlet channel 15 with an inner diameter of 6 mm. All channels converge at the valve core chamber. The diverter valve 7 is coaxially mounted with the sleeve and switches operating mode via a 60-degree rotation.

[0042] Working mode switching is achieved by rotating the diverter valve 7. In the evaporation concentration mode, the diverter valve 7 is in the first working position. At this time, the solvent vapor in the evaporation flask 3 rises to the serpentine condenser 2 through the evaporation inlet channel 9. The condensate flows down along the tube wall and flows into the first condensation outlet channel 13 of the diverter valve 7 through the first port 5 of the sleeve. It is then introduced into the collection flask 4 through the second port 6. At this time, the reflux outlet channel 15 is blocked by the sleeve wall. In the reflux extraction mode, the diverter valve 7 rotates to the second working position. The condensate flows from the serpentine condenser 2 through the first port 5 of the sleeve and enters the reflux outlet channel 15 of the diverter valve 7, directly returning to the evaporation flask 3. At this time, both condensation outlet channels are blocked by the sleeve wall. The mode switching operating torque is controlled between 0.5 Nm and 1.2 Nm. The rotation angle of the diverter valve 7 is positioned by the limit bump on the inner wall of the sleeve and the groove in the valve body, with an angle tolerance of two degrees.

[0043] The conical sleeve 1 is made of high-temperature resistant borosilicate glass with a wall thickness of three to four millimeters. It operates in a temperature range of -20°C to 200°C. The diverter valve 7 preferably uses alumina ceramics or high borosilicate glass with matching thermal expansion coefficients. All inner surfaces of the flow channels are polished to a surface roughness of less than 0.8 microns. During assembly, the conical sleeve is fixed to the equipment frame using a metal bracket, with the axis maintained at a 30-degree inclination to the vertical. The diverter valve 7 is inserted from the upper end of the sleeve during installation. The system's sealing must be verified by a negative pressure test: under a negative pressure of 0.095 MPa, the pressure change within five minutes must not exceed 0.001 MPa.

[0044] This implementation eliminates traditional piping disassembly and assembly through an integrated flow channel design, reducing the risk of system contamination. The inclined tapered structure facilitates gravity flow of condensate. The standardized interface design is compatible with conventional laboratory glassware, facilitating maintenance and replacement.

[0045] In another technical solution, the length of the guide valve 7 is greater than that of the conical sleeve 1 so that the guide valve 7 extends from both ends of the conical sleeve 1. A first groove is provided at the lower end of the guide valve 7, and a first annular sealing ring is sleeved on the first groove. The conical sleeve 1 is fixedly connected to the connecting seat, and the lower end of the guide valve 7 extends into the glass shaft 11 so that the first annular sealing ring abuts against the inner wall of the glass shaft 11 to achieve a rotating seal between the glass shaft 11 and the guide valve 7.

[0046] The diverter valve 7 is designed to be longer than the conical sleeve 1, and the extension beyond the two ends of the sleeve can be selected to be ten to fifteen millimeters. A first annular groove is processed at the bottom of the diverter valve 7, with a groove width of three to four millimeters and a depth of two to three millimeters. A first annular sealing ring made of fluororubber can be installed in the groove. The cross-sectional diameter of the sealing ring matches the depth of the groove, and after installation, it protrudes from the surface of the valve body by 0.5 to 1 millimeter. The conical sleeve 1 is fixed to the equipment bracket through a stainless steel connecting seat, and a silicone rubber buffer gasket can be set between the connecting seat and the sleeve. The extension section at the lower end of the diverter valve 7 is inserted into the inner hole of the glass shaft 11, and the extension length is controlled to be twelve to eighteen millimeters to ensure that the sealing ring forms an interference fit with the inner wall of the glass shaft 11.

[0047] During assembly, the glass shaft 11 is rotatably fixed through the connecting seat, which is the same as the fixing method of the existing rotator. Then the diverter valve 7 with the sealing ring is inserted into the conical sleeve 1, and the conical sleeve 1 is locked to the bracket positioning hole through the screw-on clamp and the connecting seat. The lower end extension section of the diverter valve 7 is aligned with the upper end of the glass shaft 11 and slowly pressed in until the sealing ring completely enters the inner cavity of the glass shaft 11. The sealing ring is radially deformed under pressure and forms a continuous annular contact surface with the inner wall of the glass. When the equipment is running, the glass shaft 11 rotates at a speed of five to fifty revolutions per minute along with the rotary drive system. The sealing ring maintains a sliding seal with the rotating glass wall in a stationary state. When the vacuum system is working, the external atmospheric pressure acts on the outside of the sealing ring, enhancing its fit with the glass wall. During regular maintenance, the diverter valve 7 can be manually rotated to check the resilience of the sealing ring.

[0048] The sealing ring can be made of solvent-resistant fluororubber with a hardness range of 70 to 80 degrees Shore A. The inner diameter tolerance of the glass shaft 11 is controlled within plus or minus 0.1 mm, and the surface roughness Ra is ≤ 0.4 microns. During the functional test, a negative pressure of 0.09 MPa is applied to the sealing interface, and the leakage rate detected by a helium mass spectrometer does not exceed 1×10 -9 Pa·m³ / s. After 200 hours of continuous operation, disassemble and inspect the seal ring; there should be no cracks or permanent deformation on the surface. This structure avoids the use of dynamic seal packing at the rotating interface, reducing maintenance frequency.

[0049] This embodiment simplifies the rotary seal structure by integrating a static sealing ring with the dynamic glass shaft 11 through an interference fit. The fluororubber material is resistant to corrosion by common organic solvents, and the radial compression design compensates for machining tolerances. The preload automatically increases with vacuum level, enhancing adaptability to operating conditions.

[0050] In another technical solution, a clamping and fixing structure 12 for clamping and fixing the guide valve 7 is further included. The clamping and fixing structure 12 includes: A first anti-slip groove is provided on the conical sleeve 1, and the length direction of the first anti-slip groove is parallel to the length direction of the conical sleeve 1; The second anti-slip groove is provided on the diversion valve 7, and the length direction of the second anti-slip groove is parallel to the length direction of the tapered sleeve 1; The locking ring has an anti-slip protrusion on its inner side. The locking ring is partially sleeved on the first anti-slip groove and partially sleeved on the second anti-slip groove to prevent the guide valve 7 from rotating relative to the conical sleeve 1 through the locking ring.

[0051] The clamping and fixing structure 12 includes a first anti-slip groove, a second anti-slip groove and a locking ring. The first anti-slip groove is processed on the outer wall surface of the conical sleeve 1, extending axially forty to fifty millimeters, with a groove width of three millimeters, a depth of one and a half millimeters, and a ninety-degree V-shaped cross-section. The second anti-slip groove is arranged on the outer wall of the upper end of the guide valve 7 exposed from the sleeve, with the same size as the first anti-slip groove, and the parallel spacing between the two grooves is maintained at five to eight millimeters. The locking ring can be an open C-shaped ring made of spring steel strip, with a ring body thickness of two millimeters and an inner diameter of 0.5 millimeters smaller than the outer diameter of the combination of the sleeve and the guide valve 7. Eight wedge-shaped anti-slip protrusions are evenly distributed on the inner side of the ring, with a protrusion height of 0.8 millimeters, a bottom width of two millimeters, and a spacing of ten millimeters.

[0052] During assembly, place the locking ring in the double anti-slip groove area. When locked, rotate the locking bolt to close the open end of the C-shaped ring, causing the anti-slip protrusions to be embedded in the V-grooves of the sleeve and the diverter valve 7 at the same time. The inclined surface of the protrusion forms a surface contact with the groove wall, and each protrusion bears a pressure of about fifteen to twenty Newtons. When unlocking, loosen the bolt in the opposite direction, and the elastic recovery of the ring body causes the opening to expand by three to five millimeters, and the protrusion is separated from the anti-slip groove. The operating force is evenly transmitted through the ring body to avoid local stress concentration that causes glass cracking. When switching working modes daily, it takes about five seconds to rotate the diverter valve 7 after unlocking, and the locking operation takes about eight seconds.

[0053] The anti-slip groove is milled from 304 stainless steel, and the surface is sandblasted to increase the coefficient of friction. The locking ring is heat-treated from 65% manganese steel to a hardness of HRC 40-45. During functional testing, a circumferential torque of 2 Nm was applied to the locked diverter valve 7, and the measured deflection angle was less than 0.5 degrees. A vibration test simulated equipment operating at 300 revolutions per minute with an amplitude of 0.1 mm for two hours showed no displacement of the locking mechanism. During maintenance, silicone-based grease should be regularly applied to the anti-slip groove to prevent metal adhesion. This structure occupies less space than traditional flange locking devices.

[0054] This embodiment uses a mechanical interlock to prevent accidental rotation of the diverter valve 7. The V-groove and wedge-shaped protrusion cooperate to achieve self-centering. An elastic locking ring prevents damage to the glass components due to excessive compression, and manual operation requires no special tools. The dual anti-slip groove design distributes the locking force, improving the system's vibration resistance.

[0055] In another technical solution, the locking ring is an elastic C-shaped ring with an opening, and a plurality of anti-slip protrusions are evenly distributed along the circumference on the inner side thereof; The first anti-skid groove and the second anti-skid groove both have a V-shaped cross-section, and the groove depth is greater than 1 / 2 of the height of the anti-skid protrusion; When the locking ring is in a locked state, its open end is closed by the locking bolt, so that the anti-slip protrusion is simultaneously engaged with the first anti-slip groove and the second anti-slip groove; When the locking ring is in an unlocked state, the open end thereof expands to cause the anti-slip protrusion to separate from the anti-slip groove.

[0056] The locking ring features an open, elastic C-shaped structure. The central angle of the open end can be adjusted from 150° to 170°, corresponding to a locking travel of 25 mm to 35 mm. Anti-slip protrusions are evenly distributed along the inner surface, with a selectable number of 8 to 12 and a height of 1.5 mm to 2.5 mm. The protrusions have a semicircular or trapezoidal cross-section. The material can be 60Si2MnA spring steel or 304 stainless steel, with a yield strength greater than 800 MPa to provide elastic recovery. The assembly position is between the outer wall of the tapered sleeve 1 and the outer wall of the diverter valve 7. When the locking bolt is tightened, the open end of the C-ring closes, forcing the anti-slip protrusions to engage simultaneously with the first anti-slip groove of the sleeve and the second anti-slip groove of the diverter valve 7. During testing, a torque of 5 N·m to 10 N·m is applied to simulate vibration conditions. The protrusions are considered acceptable if there is no plastic deformation. This structure prevents deflection of the diverter valve 7 due to vacuum suction or vibration through bidirectional constraints.

[0057] The first anti-slip groove (sleeve side) and the second anti-slip groove (diverter valve 7 side) both have V-shaped cross-sections. The V-angle can be selected from 60° to 90°, and the groove depth ranges from 1.2 mm to 1.8 mm (greater than 1 / 2 of the protrusion height). The groove surface roughness Ra value can be selected from 0.8 μm to 1.6 μm. The groove body can be made of borosilicate glass or 316L stainless steel and is machined using a CNC milling machine. During assembly, the anti-slip groove must be parallel to the axis of the locking ring, with a tolerance of ±0.1 mm. During operation, the V-shaped section guides the protrusion to automatically align, and a clearance of 0.3 mm to 0.5 mm is reserved for the difference between the groove depth and the protrusion height. During verification, a projector is used to measure the difference between the groove depth and the protrusion height to ensure compliance with the designed clearance. This structure disperses contact stress and provides precise circumferential positioning.

[0058] Locking is achieved by tightening the C-ring by closing the open end with a locking bolt. Bolt thread specifications range from M4 to M6 fine threads, with pitches from 0.35 mm to 0.5 mm; the anti-slip projections have an embedment depth of 0.5 mm to 0.8 mm. A disc spring assembly is installed in the oblong hole of the locking lug, with stiffness coefficients ranging from 40 N / mm to 60 N / mm and a single spring compression stroke of 0.5 mm to 1.5 mm (compliant with DIN 2093). During assembly, one end of the spring assembly abuts the inner wall of the locking lug and the other end abuts the bolt and nut. When the locking nut is tightened, the spring assembly absorbs thermal deformation (such as axial displacement of 0.2 mm to 0.5 mm caused by vacuum) and maintains a constant clamping force. Test methods show that under temperature cycling from 80°C to 120°C and a vacuum of -0.09 MPa, the spring compression does not vary by more than ±0.1 mm. This mechanism suppresses thermal stress relaxation, ensuring long-term locking stability.

[0059] In another technical solution, the open end of the locking ring is provided with a locking ear extending outward, and a coaxial oblong hole is provided on the locking ear; the locking bolt passes through the oblong holes of the two locking ears in sequence, and applies axial pre-tightening force through the threaded locking nut to bring the open end of the locking ring close together; a disc spring group is installed in the oblong hole, and the disc spring group is sleeved on the locking bolt, one end of the disc spring group abuts against the inner wall of the locking ear, and the other end abuts against the nut or nut on the bolt; when the locking nut is tightened, the disc spring group is compressed and generates a reverse force, forcing the locking ears on both sides to converge axially along the locking bolt, and at the same time driving the two ends of the locking ring close to each other to achieve fixation.

[0060] The stiffness coefficient of the disc spring group is 40-60 N / mm, and the compression stroke of a single disc spring group is 0.5-1.5 mm; the thread of the locking bolt is M4-M6 fine thread with a pitch of 0.35-0.5 mm.

[0061] The open end of the locking ring features an outward-extending locking lug with a coaxial oblong hole. The oblong hole can be 30 mm to 40 mm in length and 5 mm to 8 mm in width. The locking lug can be forged from 304 stainless steel or stamped from 60Si2MnA spring steel, with a thickness ranging from 3 mm to 5 mm. A disc spring assembly is installed within the oblong hole. This disc spring assembly can utilize B-series disc springs that comply with the GB / T 1972 standard, with individual disc springs ranging in thickness from 0.5 mm to 1.5 mm and an outer diameter from 15 mm to 25 mm. During assembly, the disc spring assembly is fitted over the locking bolt, with its ends abutting the inner wall of the locking lug and the end faces of the bolt and nut, respectively. As the locking nut is tightened, the disc spring assembly is axially compressed, generating a reverse force that forces the locking lugs to converge along the bolt axis, closing the open end of the locking ring.

[0062] The locking bolt passes through the oblong holes of the two locking ears. The thread specifications can be selected from M4 to M6 fine threads, and the pitch can be selected from 0.35 mm to 0.5 mm. The bolt material can be selected from 40Cr alloy steel or 316 stainless steel, and the tensile strength must be greater than 800 MPa. The assembly position is located on the central axis of the oblong hole of the locking ear, and the tail of the bolt is pre-tightened by the locking nut with threaded matching. During operation, when the locking nut is tightened, the bolt generates axial tension, pulling the locking ears closer to each other, and at the same time the disc spring group is compressed to store energy; when the locking ring expands due to heat, the disc spring group releases the elastic force to compensate for the displacement, maintaining a constant clamping force of the locking ring on the anti-slip groove. Test method: Apply a circumferential torque of 5 Nm to 10 Nm in the locked state to verify that the diverter valve 7 has no displacement.

[0063] The disc spring assembly consists of three to five disc springs stacked together. The free height of a single disc spring can range from 1.2 mm to 2 mm, and the total stiffness coefficient after stacking ranges from 40 N / mm to 60 N / mm. The spring leaves can be made of 50CrVA high-temperature spring steel or 60Si2MnA, and the surface is phosphated for rust prevention. During assembly, the spring assembly is pre-compressed to 70% to 80% of the free height, and the preload is controlled between 200 N and 400 N. During functional testing, under temperature cycling from 80°C to 120°C, the spring compression is monitored to within ±0.1 mm. This structure absorbs thermal displacement through elastic deformation, suppressing the relaxation of the bolt preload.

[0064] The spring constants for disc springs can range from 40 N / mm to 60 N / mm, based on the design values ​​for Series B disc springs in GB / T 1972. The compression stroke of a single disc spring set ranges from 0.5 mm to 1.5 mm, corresponding to a free height of 1.2 mm to 2 mm for each disc spring. Disc springs can be constructed using a standard, unsupported design, with a neutral diameter to outer diameter ratio ranging from 0.6 to 0.8. The spring material is 60Si2MnA hot-rolled spring steel strip, achieving a hardness of HRC 42 to 48 after heat treatment. During assembly, the number of discs can range from 3 to 5, with the total deflection calculated using the formula fz = n·f (where n is the number of discs and f is the deflection per disc).

[0065] The thread of the locking bolt is an M4 to M6 fine thread with a fixed pitch of 0.35 mm, 0.5 mm, or 0.7 mm. The bolt can be made of fine-pitch full-thread rod, and the strength grade can be selected from 8.8 or 10.9. The thread accuracy must meet the 6g tolerance of the GB / T 197 standard and match the 6H tolerance of the locking nut. The assembly position must ensure that the axis of the bolt is aligned with the center of the oblong hole of the locking ear, with a deviation of less than 0.1 mm. During operation, the conversion relationship between the helix angle and the axial displacement is: displacement = helix angle × (pitch / 360°). For example, when the pitch is 0.5 mm, a rotation of 180° will produce an axial displacement of 0.25 mm.

[0066] Thermal compensation verification utilizes a combined temperature-vacuum test: a vacuum of -0.09 MPa is applied within a closed system, and the heating bath temperature is raised from 25°C to 120°C at a rate of 10°C / minute, held for 30 minutes. The disc spring assembly's compression is monitored, with an allowable fluctuation range of ±0.1 mm. Disc spring parameters are set according to the fatigue load curve in the DIN 2093 standard, with σmax ≤ 800 MPa and σmin ≥ 200 MPa selected to ensure a cycle life exceeding 10^5 cycles. This ensures that the locking ring's anti-slip projection embedment depth remains stable within a range of 0.5 mm to 0.8 mm under thermal deformation conditions.

[0067] In another technical solution, Figure 3As shown, a second groove is provided at the lower end of the conical sleeve 1. The conical sleeve 1 is fixedly connected to the connecting seat. The lower end of the conical sleeve 1 extends into the glass shaft 11 so that the second annular sealing ring on the second groove abuts against the inner wall of the glass shaft 11 for sealing.

[0068] The lower end of the conical sleeve 1 is machined with a second annular groove, with a width ranging from 2.5 mm to 3.5 mm and a depth ranging from 1.8 mm to 2.5 mm. The conical sleeve 1 is secured to the equipment bracket via a metal connector. Its lower extension, extending from 10 mm to 15 mm, is inserted into the glass shaft 11. A second annular sealing ring is installed within the second groove. Its cross-sectional diameter matches the groove depth and, when installed, protrudes 0.4 mm to 0.8 mm from the bottom of the groove. During assembly, the extended section of the conical sleeve 1 is vertically pressed into the glass shaft 11, creating an interference fit between the outer circumference of the sealing ring and the inner wall of the glass shaft 11, forming a radially compressed seal. When the vacuum system is operating, external atmospheric pressure acts on the outer surface of the sealing ring, enhancing its adhesion to the glass wall. While the rotary drive system rotates the glass shaft 11 at a speed of 5 to 50 rpm, the sealing ring remains static, compensating for minor irregularities in the inner wall of the glass shaft 11 through radial deformation.

[0069] The inner ring of the second annular seal can be made of highly elastic fluororubber or hydrogenated nitrile rubber, with a hardness range of 70 to 80 Shore A. The inner circumference is an interference fit with the second groove of the diverter valve 7, with the interference margin controlled to be between 0.1 mm and 0.3 mm. The outer ring can be made of polytetrafluoroethylene or graphite-filled polyimide, with a thickness of 1 mm to 1.5 mm. Its inner circumference is bonded to the outer circumference of the inner ring through a high-temperature vulcanization process. The outer circumference of the outer ring is the sealing working surface, with a surface roughness Ra ≤ 0.4 microns, and is in sliding contact with the inner wall of the glass shaft 11. Material selection criteria include: fluororubber's solvent resistance is suitable for organic solvent environments such as ethanol and acetone; polytetrafluoroethylene has a friction coefficient of less than 0.1, reducing rotational resistance (. The outer ring surface is treated with antimony pentafluoride vapor to form a fluorinated carbon layer. The treatment process parameters include: placing the outer ring in a sealed reaction chamber, evacuating the chamber to a pressure of ≤0.1 bar, and then replacing the pressure with nitrogen three times. Antimony pentafluoride is heated to 60°C ± 5°C, vaporized, and mixed with nitrogen to form a 30% ± 5% vapor mixture, which is introduced into the chamber at a flow rate of 1.0 L / min ± 0.2 L / min. The chamber temperature is maintained at 100°C ± 10°C and a pressure of 0.13 MPa ± 0.01 MPa for 15 minutes ± 5 minutes. After the vapor mixture is discontinued, a nitrogen purge is performed for 30 minutes. After treatment, a fluorinated carbon layer (—CF2—SbF3 groups) is formed on the outer circumference, with a thickness of 0.2 to 0.4 microns. (Parameters are based on the antimony pentafluoride vapor treatment process standard.) Functional verification uses a solvent immersion test: the treated sealing ring is immersed in a 60°C acetone solution for 240 hours, and the outer ring mass change rate is ≤1%, and there are no cracks on the surface; the sealing performance test is performed at a vacuum of -0.09 MPa, and the helium mass spectrometer detects a leakage rate of ≤1×10⁻ 9 Pa·m³ / s. This structure reduces frictional resistance and inhibits swelling of the seal caused by solvent penetration.

[0070] In another technical solution, the second annular sealing ring includes: The inner ring is a highly elastic and solvent-resistant rubber ring, and the inner circumferential surface of the inner ring is fixed in the second groove by interference fit; The outer ring is made of a self-lubricating, low-friction material. The inner circumference of the outer ring is bonded to the outer circumference of the inner ring by vulcanization. The outer circumference of the outer ring serves as a sealing working surface that is in sliding contact with the inner wall of the glass shaft 11 .

[0071] The second annular sealing ring is installed in the second groove extending from the lower end of the diverter valve 7. The groove width can be selected from 2.5 mm to 3.5 mm, and the depth can be selected from 1.8 mm to 2.5 mm. The sealing ring adopts a two-layer composite structure: the inner ring can be made of fluororubber or hydrogenated nitrile rubber with a hardness range of 70 to 80 Shore A. Its cross-sectional diameter matches the groove depth and protrudes 0.4 mm to 0.8 mm from the bottom of the groove after installation. The outer ring can be made of polytetrafluoroethylene or graphite-filled polyimide and has a thickness of 1.0 mm to 1.5 mm. During assembly, the inner circumference of the inner ring is fixed with an interference fit in the groove, with the interference margin controlled to be 0.1 mm to 0.3 mm. The inner circumference of the outer ring is bonded to the outer circumference of the inner ring through a high-temperature vulcanization process. During operation, the outer circumferential surface of the outer ring slides in contact with the inner wall of the rotating glass shaft 11. Under vacuum negative pressure conditions, atmospheric pressure acts on the outer side of the sealing ring to enhance the fit. The static sealing ring compensates for the slight unevenness of the inner wall of the glass shaft 11 through radial deformation.

[0072] The inner circumference of the inner ring forms an interference fit with the second groove of the diverter valve 7. The interference fit is set according to the GB / T3452.2 sealing groove design standard, with a compression ratio of 15% to 25%. Materials can be DuPont's Viton series fluororubber or Japan's Zeptol hydrogenated nitrile rubber. Solvent resistance must meet the requirement of a volume change of ≤5% after immersion in organic solvents such as acetone and ethanol for 240 hours (tested according to HG / T 2579). Functional testing utilizes negative pressure sealing verification: After installing the sealing ring on the extension of the diverter valve 7, press it into the glass shaft 11, apply a vacuum of -0.09 MPa, and use a helium mass spectrometer to detect a leakage rate of no more than 1×10⁻. 9 Pa·m³ / s. The inner ring assembly position must ensure that its axis and the axis of the glass shaft 11 are coaxial to within 0.05 mm to prevent eccentric wear during rotation. This structure blocks the axial leakage path of solvent vapor.

[0073] In another technical solution, the second annular sealing ring further includes an expansion buffer transition layer, which is arranged between the inner ring and the outer ring. The expansion buffer transition layer is a silicone rubber-modified EPDM rubber layer, and its thermal expansion coefficient is between that of the inner ring and the outer ring. The contact surface between the inner ring and the outer ring is provided with a transverse dovetail groove structure, and the expansion buffer transition layer is filled in the dovetail groove to form a mechanical interlocking. The outer circumferential surface of the outer ring is treated with antimony pentafluoride vapor.

[0074] The second annular sealing ring is assembled in the second groove of the lower extension section of the diverter valve 7. The groove width can be selected from 2.5 mm to 3.5 mm, and the depth can be selected from 1.8 mm to 2.5 mm. The sealing ring includes an inner ring, an outer ring, and an expansion buffer transition layer between the two: the inner ring can be made of hydrogenated nitrile rubber or fluororubber with a hardness range of 70 to 80 degrees Shore A; the outer ring can be made of polytetrafluoroethylene or graphite-filled polyimide with a thickness of 1.0 mm to 1.5 mm; the expansion buffer transition layer can be made of silicone rubber-modified EPDM rubber, with a thermal expansion coefficient controlled at 180×10⁻ 6 / ℃ to 220×10⁻ 6 / °C, between the inner rubber layer and the outer material. During assembly, the inner circumference of the inner ring is secured with an interference fit in the groove, with an interference fit of 0.1 mm to 0.3 mm. The expansion buffer transition layer is molded to fill the interface gap between the inner and outer rings, forming a continuous intermediate layer. During operation, the outer ring slides against the inner wall of the rotating glass shaft 11. The expansion buffer transition layer absorbs the differential expansion between the inner and outer layers due to temperature changes, thereby preventing interface delamination.

[0075] The contact surface of the inner ring and the outer ring is machined with a transverse dovetail groove structure. The depth of the dovetail groove can be selected from 0.3 mm to 0.5 mm, and the width of the groove bottom can be selected from 0.8 mm to 1.2 mm. The expansion buffer transition layer melts and flows into the dovetail groove during the vulcanization process, and forms a mechanical interlocking structure after cooling. The assembly position must ensure that the axis of the dovetail groove is perpendicular to the axis of the sealing ring, and the tolerance is controlled within ±0.05 mm. The function is verified by a thermal cycle test: the assembled sealing ring is placed in a temperature range of -10°C to 120°C and cycled 50 times, each time keeping warm for 30 minutes. After the end, the cross section is cut and observed to see if there is no separation on the interface, which is qualified. This structure blocks the solvent from penetrating along the interlayer path and reduces the deformation of the sealing working surface caused by thermal stress.

[0076] In another technical solution, the antimony pentafluoride gas phase treatment is performed according to the following steps: 1) Place the outer ring in a sealed reaction chamber, evacuate to a pressure ≤ 0.1 bar, and then introduce inert gas for replacement. Repeat this three times to remove oxygen and water vapor. 2) heating antimony pentafluoride to 50-80°C to vaporize it and mixing it with an inert gas to form a mixed vapor with a volume fraction of 10-50%, and introducing the mixed vapor into the reaction chamber at a flow rate of 0.5-2 L / min; 3) Maintain the chamber temperature at 80-120°C and the pressure at 0.12-0.15 MPa for 5-30 minutes; 4) Stop introducing mixed steam, switch to pure inert gas for purging for 30 minutes, and remove the container after cooling to room temperature; 5) After treatment, a carbon fluoride layer is formed on the outer circumference of the outer ring with a thickness of 0.1-0.5 μm; Wherein, the inert gas is nitrogen or argon; the mixed steam in step (2) needs to be pretreated to remove water to a water content of ≤10 ppm.

[0077] The second annular seal, mounted on the lower extension of the conical sleeve 1, requires enhanced resistance to solvent penetration. The outer ring of this seal is treated using an antimony pentafluoride vapor phase process. First, the vulcanized outer ring is placed inside a stainless steel reaction chamber. The chamber is evacuated three times to remove any remaining air. Each time the pressure is reduced to below 0.1 bar, high-purity nitrogen is introduced to displace the air. After displacement, the solid antimony pentafluoride powder is placed in a sealed heating tank. The heating tank is heated to 50 to 80 degrees Celsius to fully vaporize the powder. Gaseous antimony pentafluoride is mixed with nitrogen at a volume ratio of 10% to 50% to form a treatment vapor. The mixed vapor passes through a molecular sieve dehydration device to reduce the water content to below 10 ppm. The dehydrated vapor is introduced into the reaction chamber at a flow rate of 0.5 to 2 liters per minute. The chamber temperature is maintained between 80 and 120 degrees Celsius during the treatment process. The internal pressure of the chamber is controlled between 0.12 and 0.15 MPa. The treatment time is adjusted between 5 and 30 minutes, depending on the material thickness. After completion, the mixed steam valve is closed and pure nitrogen purge is switched. Purge is continued for 30 minutes to ensure that no residual reaction gas remains in the chamber. After cooling to room temperature, the treated sealing ring is removed. A fluorinated carbon group coating forms on the outer ring surface. The coating thickness is controlled between 0.1 and 0.5 microns. The closest existing technology is the fluorination treatment process disclosed in Publication No. CN101531400B. This technology uses carbon tetrafluoride plasma to treat the sealing ring surface. The treatment temperature must reach above 200°C to activate the reaction. The high temperature environment causes thermal aging cracks in the rubber matrix. The reaction gas is directly introduced without a dehydration device during the treatment process. A water content exceeding 100 ppm in the mixed gas causes pinholes in the fluorinated layer. Maintaining the reaction pressure at atmospheric pressure results in uneven treatment. A fixed treatment time of 10 minutes is not suitable for workpieces of varying thicknesses. The resulting fluorinated layer is only 0.05 microns thick and exhibits localized shedding. After solvent immersion, obvious peeling occurred at the interface between the fluorinated layer and the substrate.

[0078] In comparison, this process has three substantial improvements. The first is that the reaction temperature is reduced to below 120 degrees Celsius. Antimony pentafluoride is used instead of carbon tetrafluoride to reduce the activation energy requirement. High temperature damage to the rubber matrix is ​​avoided to maintain the elasticity of the material. The second is to add a multi-stage dehydration and drying process. The raw gas dehydration is combined with the chamber pre-vacuum three times. The water content is strictly controlled below the threshold of 10ppm. Ensure that the fluorinated carbon layer forms a dense and defect-free structure. The third is to establish a dynamic matching mechanism of pressure and time. A pressure of 0.12 MPa to 0.15 MPa promotes vapor penetration. The processing time is flexibly adjusted from 5 to 30 minutes according to the thickness of the workpiece. The thickness of the fluorinated layer is precisely stabilized at 0.1 to 0.5 microns.

[0079] The process parameters are determined based on material property experiments. The temperature, pressure, and time combinations are optimized through orthogonal experiments. The lower limit temperature of 80 degrees Celsius ensures the reaction rate. The upper limit temperature of 120 degrees Celsius avoids the glass transition point of rubber. The pressure of 0.12 MPa is the critical value for vapor permeation. The upper limit of 0.15 MPa prevents deformation of thin workpieces. The water removal index of 10 ppm is calculated based on the hydrolysis equilibrium constant of the fluorination reaction. The thickness of the fluorinated layer of 0.1 micron meets the basic barrier requirements. The upper limit of 0.5 micron avoids delamination caused by internal stress. The raw material antimony pentafluoride is industrial-grade pure to reduce costs. The purity of 99.5% ensures the density of reactive groups. The key control point is the mixed vapor dehydration module. The molecular sieve needs to be replaced regularly to maintain drying efficiency.

[0080] Functional verification utilizes an accelerated solvent aging protocol. The treated seal ring is immersed in a 60°C acetone solution. After 240 hours of continuous immersion, it is removed and tested. The outer ring mass loss rate does not exceed 1%. Electron microscopy reveals no cracks on the fluorinated layer surface. Sealing performance testing is conducted under actual operating conditions on a rotary evaporator, maintaining a vacuum of -0.09 MPa. Helium mass spectrometer-based leak detection ensures that the leak rate meets or exceeds the standard value. This process achieves a balance between solvent resistance and processing cost.

[0081] The first annular sealing ring and the second sealing ring of the present invention have the same structure and are prepared by the same method.

[0082] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A rotary evaporator with reflux extraction function, comprising an evaporation system, a rotary drive system, a vacuum system and a control system, characterized in that: The evaporation system includes a serpentine condenser, an evaporation flask and a collection flask. The lower end of the serpentine condenser is provided with a flow guide structure, which includes: A conical sleeve is obliquely arranged below the serpentine condenser, and the diameter of the lower port is smaller than the diameter of the upper port. A first port and a second port are provided in the middle of the conical sleeve. The first port is connected to the lower end of the serpentine condenser, the second port is connected to the inlet of the collecting bottle, and the lower port of the conical sleeve is connected to the evaporating flask. The diverter valve has a conical structure, the outer wall of the diverter valve is in contact with the inner wall of the conical sleeve, and the diverter valve includes a feeding channel, an evaporation inlet channel, a first condensation outlet channel, a second condensation outlet channel, and a reflux outlet channel. The feeding channel, the evaporation inlet channel, the first condensation outlet channel, the second condensation outlet channel, and the reflux outlet channel are interconnected, and a feeding valve is provided in the feeding channel to block the feeding channel; The diverter valve and the conical sleeve are on the same axis, so that two working positions can be constructed by rotating the diverter valve; When the diverter valve is in the first working position, the first condensation outlet channel is opposite to the first port, the second condensation outlet channel is opposite to the second port, and the reflux outlet channel is opposite to the side wall of the tapered sleeve, so that the evaporation flask, the serpentine condenser tube and the collecting flask are connected, realizing the evaporation and concentration function; When the diverter valve is in the second working position, the first condensation outlet channel and the second condensation outlet channel are opposite to the side wall of the conical sleeve, and the reflux outlet channel is opposite to the first port so that the evaporating flask is connected to the serpentine condenser tube through the diverter valve, thereby realizing the reflux extraction function.

2. The rotary evaporator with reflux extraction function according to claim 1, characterized in that The length of the guide valve is greater than that of the conical sleeve so that the guide valve extends from both ends of the conical sleeve. A first groove is provided at the lower end of the guide valve, and a first annular sealing ring is sleeved on the first groove. The conical sleeve is fixedly connected to the connecting seat, and the lower end of the guide valve extends into the glass shaft so that the first annular sealing ring abuts against the inner wall of the glass shaft to achieve a rotational seal between the glass shaft and the guide valve.

3. The rotary evaporator with reflux extraction function according to claim 2, characterized in that It also includes a clamping and fixing structure for clamping and fixing the diverter valve, the clamping and fixing structure including: a first anti-slip groove, which is provided on the conical sleeve, wherein the length direction of the first anti-slip groove is parallel to the length direction of the conical sleeve; A second anti-slip groove is provided on the diversion valve, wherein the length direction of the second anti-slip groove is parallel to the length direction of the tapered sleeve; The locking ring has an anti-slip protrusion on its inner side. The locking ring is partially sleeved on the first anti-slip groove and partially sleeved on the second anti-slip groove to prevent the guide valve from rotating relative to the conical sleeve through the locking ring.

4. The rotary evaporator with reflux extraction function according to claim 3, characterized in that The locking ring is an elastic C-shaped ring with an opening, and a plurality of anti-slip protrusions are evenly distributed along the circumference on the inner side thereof; The first anti-skid groove and the second anti-skid groove both have a V-shaped cross-section, and the groove depth is greater than 1 / 2 of the height of the anti-skid protrusion; When the locking ring is in a locked state, its open end is closed by the locking bolt, so that the anti-slip protrusion is simultaneously engaged with the first anti-slip groove and the second anti-slip groove; When the locking ring is in an unlocked state, the open end thereof expands to cause the anti-slip protrusion to separate from the anti-slip groove.

5. The rotary evaporator with reflux extraction function according to claim 4, characterized in that The open end of the locking ring is provided with a locking ear extending outward, and a coaxial oblong hole is provided on the locking ear; the locking bolt passes through the oblong holes of the two locking ears in sequence, and applies axial pre-tightening force through the threaded locking nut to bring the open ends of the locking ring close together; a disc spring group is installed in the oblong hole, and the disc spring group is sleeved on the locking bolt, one end of the disc spring group abuts against the inner wall of the locking ear, and the other end abuts against the nut or nut on the bolt; when the locking nut is tightened, the disc spring group is compressed and generates a reverse force, forcing the locking ears on both sides to shrink axially along the locking bolt, and at the same time driving the two ends of the locking ring close to each other to achieve fixation.

6. The rotary evaporator with reflux extraction function according to claim 5, characterized in that The stiffness coefficient of the disc spring group is 40-60 N / mm, and the compression stroke of a single disc spring group is 0.5-1.5 mm; the thread of the locking bolt is M4-M6 fine thread with a pitch of 0.35-0.5 mm.

7. The rotary evaporator with reflux extraction function according to claim 1, characterized in that The lower end of the conical sleeve is provided with a second groove, the conical sleeve is fixedly connected to the connecting seat, and the lower end of the conical sleeve extends into the glass shaft so that the second annular sealing ring on the second groove abuts against the inner wall of the glass shaft for sealing.

8. The rotary evaporator with reflux extraction function according to claim 7, characterized in that: The second annular sealing ring comprises: The inner ring is a highly elastic and solvent-resistant rubber ring, and the inner circumferential surface of the inner ring is fixed in the second groove by interference fit; The outer ring is a ring made of a low friction coefficient material with self-lubricating properties. The inner circumference of the outer ring is vulcanized and bonded to the outer circumference of the inner ring. The outer circumference of the outer ring is a sealing working surface that is in sliding contact with the inner wall of the glass shaft.

9. The rotary evaporator with reflux extraction function according to claim 8, characterized in that The second annular sealing ring also includes an expansion buffer transition layer, which is arranged between the inner ring and the outer ring. The expansion buffer transition layer is an EPDM rubber layer modified with silicone rubber, and its thermal expansion coefficient is between that of the inner ring and the outer ring; the contact surface of the inner ring and the outer ring is provided with a transverse dovetail groove structure, and the expansion buffer transition layer is filled in the dovetail groove to form a mechanical interlocking; the outer circumferential surface of the outer ring is treated with antimony pentafluoride vapor.

10. The rotary evaporator with reflux extraction function according to claim 9, characterized in that: The antimony pentafluoride gas phase treatment is performed according to the following steps: 1) Place the outer ring in a sealed reaction chamber, evacuate to a pressure ≤ 0.1 bar, and then introduce inert gas for replacement. Repeat this three times to remove oxygen and water vapor. 2) heating antimony pentafluoride to 50-80°C to vaporize it and mixing it with an inert gas to form a mixed vapor with a volume fraction of 10-50%, and introducing the mixed vapor into the reaction chamber at a flow rate of 0.5-2 L / min; 3) Maintain the chamber temperature at 80-120°C and the pressure at 0.12-0.15 MPa for 5-30 minutes; 4) Stop introducing mixed steam, switch to pure inert gas for purging for 30 minutes, and remove the container after cooling to room temperature; 5) After treatment, a carbon fluoride layer is formed on the outer circumference of the outer ring with a thickness of 0.1-0.5 μm; Wherein, the inert gas is nitrogen or argon; the mixed steam in step (2) needs to be pretreated to remove water to a water content of ≤10 ppm.

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