Rectification kettle

Abstract

The present application relates to a kind of rectifying still, including still body, the still body is equipped with jacket and insulation layer, the still body bottom and still body side wall smooth transition, the still body bottom center has stirring mechanism, the stirring mechanism is driven to rotate by motor located in the outside of still body, stirring mechanism has the stirring blade that can be in sliding contact with the inner wall of still body, the stirring blade makes still liquid uniformly with the inner wall of still body corresponding to jacket contact.The present application is heated using heating jacket, and special stirring paddle is set, no matter how much still liquid is left, can be fully stirred, and fully contact with the inner wall of still body corresponding to heating jacket, so that product component in still liquid is fully vaporized rectification, avoid product waste.

Description

Technical Field

[0001] This invention relates to the field of distillation technology, and more specifically to a distillation kettle. Background Technology

[0002] Distillation is a separation process that separates components in a mixture based on their different volatility. Batch distillation using a distillation vessel has good separation performance, especially when distilling multiple components, as it can effectively separate the components and facilitate the treatment of residue in the vessel.

[0003] In the production of xylene musk, the intermediate product (5-tert-butyl-m-xylene) contains meta-xylene. If meta-xylene enters the nitration reactor, it will be dangerous and introduce impurities into the product. Therefore, it needs to be purified by distillation.

[0004] Existing distillation kettles use heated coils for heating. However, in batch distillation kettles, the amount of material inside decreases as distillation progresses, and in the end, only a very small amount of the residue remains. This residue cannot fully contact the heated coils for heating, resulting in a considerable amount of product remaining in the residue, leading to serious waste. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a distillation kettle, the purpose of which is to enable the kettle residue to be fully heated, so as to ensure that the product is fully distilled, the product content in the kettle residue is small, and waste is reduced. Another purpose of the present invention is to eliminate the foam generated in the distillation kettle due to the boiling of materials, promote the volatilization of each component, and improve the distillation efficiency.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A distillation vessel includes a vessel body, a jacket and an insulation layer outside the vessel body, and a stirring mechanism at the center of the bottom of the vessel body. The stirring mechanism is driven to rotate by a motor located outside the vessel body. The stirring mechanism has stirring blades, and there is a gap between the stirring blades and the inner wall of the vessel body. The stirring blades stir the liquid in the vessel body and make the liquid in the vessel body form a film that evenly covers the inner wall of the vessel body corresponding to the jacket when the liquid is low.

[0008] In the existing technology, a heating coil is used as a heat source. As the distillation process proceeds, the liquid in the distillation vessel becomes less and less, and the liquid gradually becomes difficult to contact the heating coil and cannot be effectively heated. This unheated liquid will be discharged as the vessel residue, but a large amount of product still exists in the vessel residue.

[0009] This invention employs jacket heating, with the stirring mechanism positioned at the bottom of the distillation vessel. This design avoids interfering with the equipment and instruments above the vessel, while the bottom-mounted stirring paddle ensures better contact between the liquid and the heating zone on the vessel's inner wall. This allows for better heat exchange between the residual liquid and the jacket, resulting in faster heat exchange, faster product vaporization, a lower product content in the residual liquid, more thorough product distillation, and reduced waste.

[0010] Furthermore, the stirring mechanism includes a rotating sleeve and a stirring paddle. The rotating sleeve is rotatably connected to the center of the bottom of the vessel body via a mechanical seal. The stirring paddle rotates with the rotating sleeve. The stirring paddle includes stirring blades and a stirring shaft. The stirring blades are all deflected in an arc shape, either counterclockwise or clockwise.

[0011] The stirring paddle can stir a small amount of residual liquid in the vessel. Rather than stirring, it is more like coating. When the stirring paddle rotates, the gap between the stirring blades and the inner wall of the vessel causes the liquid to cover the inner wall of the vessel corresponding to the jacket in the form of a liquid film. The excess liquid is pushed upward by the stirring paddle and circulated back and forth, replenishing the liquid film formed by the liquid and promoting the rapid vaporization of the liquid. Even if there is only a small amount of residual liquid, it can fully contact the inner wall of the vessel corresponding to the jacket.

[0012] Furthermore, the outer end of the stirring blade is close to the horizontal plane where the upper end of the jacket is located.

[0013] When the stirring blades rotate, they push the liquid in the vessel to move evenly on the inner wall of the vessel inside the jacket. Because the outer end of the stirring blades is close to the horizontal plane where the upper end of the jacket is located, the liquid in the vessel can contact the inner wall of the vessel where the jacket is located. That is, the entire vessel heated by the jacket can be pushed by the stirring blades to contact the liquid in the vessel. In other words, the present invention is not limited to how much liquid is left in the vessel. It can make the liquid in the vessel contact all the areas that the jacket can heat. The heat of the heating fluid (heat transfer oil) in the jacket is mainly used to heat the liquid in the vessel, rather than to heat the gas phase inside the vessel after the liquid in the vessel is reduced, thus avoiding the waste of heat in the jacket.

[0014] The vessel body is equipped with a defoaming net, which includes a filter screen and a support ring. The filter screen is connected to the inner side of the support ring, and the support ring is connected to the upper end of the stirring blade.

[0015] Furthermore, the filter screen inside the support ring is composed of a 20-40 mesh stainless steel filter screen and a 300g×5mm glass fiber mesh, with the glass fiber mesh located above the stainless steel filter screen.

[0016] When the stirring paddle of the present invention is stirring, it first pushes the liquid near the bottom of the vessel along the inner wall of the bottom surface of the vessel towards the side wall, and then pushes the liquid near the side wall of the vessel upward along the side wall of the vessel. When this part of the liquid reaches the uppermost liquid surface or the uppermost tip of the stirring blade, it loses its driving force and falls towards the central axis of the vessel, forming a funnel-shaped vortex at the center of the vessel. This causes the foam generated by the boiling of the liquid to flow with the liquid to the center of the vessel, and then it is destroyed by contact with the rotating defoaming net during the descent.

[0017] The mesh size of the stainless steel filter and the fiberglass mesh will not clog the liquid in the vessel and can ensure that the gas below the defoaming net rises quickly through the defoaming net. However, the foam that comes into contact with the fiberglass mesh first will lose liquid due to the capillary action of the fiberglass fibers in the warp and weft directions of the fiberglass mesh. The defoaming net is rotating, and the liquid on the fiberglass mesh is thrown off towards the vessel wall due to the centrifugal force generated by the rotation. The foam loses liquid further, and the foam that has lost liquid breaks down after passing through the stainless steel filter with smaller pore size.

[0018] In the early stage of distillation, the liquid level in the vessel is high, while the agitator is low. Even when a vortex is formed, the foam is difficult to descend to the position of the defoaming net. Therefore, the above structure is further improved. The bottom of the vessel body and the side wall of the vessel body are smoothly transitioned. The inner diameter of the lower end of the side wall of the vessel body is smaller than the inner diameter of the middle part of the side wall of the vessel body. The lower end of the rotating sleeve is connected to a pulley. The pulley is connected to the motor via a belt. The rotating sleeve and the agitator shaft are connected via a sealing ring. The agitator shaft can slide up and down along the rotating sleeve when it rotates with the rotating sleeve. When the agitator slides down to its limit, the agitator blades contact the inner wall of the vessel body.

[0019] The sliding agitator can adapt to the liquid level. In the early stage, the defoaming net is raised to defoam the liquid at a higher level. As the liquid level decreases, the net is lowered to achieve optimal stirring and heat exchange. When the agitator slides down to its limit, the agitator blades contact the inner wall of the vessel. When the agitator reverses, it can scrape and collect the residual liquid on the inner wall of the vessel, making it easier and faster to concentrate the residual liquid at the bottom of the vessel for easy discharge.

[0020] To achieve the retractable nature of the stirring paddle, a telescopic mechanism is needed to control its lifting and lowering. Furthermore, this telescopic mechanism cannot restrict the rotation of the stirring paddle during lifting and lowering. Therefore, the lower end of the stirring shaft is rotatably connected to a frame for supporting the container, and a telescopic mechanism is connected below the frame. The telescopic mechanism is used to allow the stirring shaft to slide up and down, thereby adjusting the height of the stirring blades.

[0021] When the stirring shaft can slide up and down, the distance between the stirring blade and the inner wall of the vessel can also be adjusted. At this time, the stirring paddle of the present invention is in stirring state when there is more liquid in the vessel, and mainly performs coating function when there is less liquid in the vessel. The liquid is evenly coated on the inner wall of the vessel to form a liquid film, ensuring that the liquid in the vessel and the vessel body corresponding to the jacket are in more sufficient contact.

[0022] The telescopic mechanism is preferably a hydraulic cylinder or a pneumatic cylinder, and the frame can support a container for receiving residual liquid in the vessel.

[0023] Because the stirring paddle of this invention is located at the center of the bottom of the vessel, occupying the optimal position for discharging residual liquid, this invention needs to enable the stirring mechanism to discharge residual liquid while also sealing the discharge hole so that the vessel can achieve vacuum, which is beneficial for distillation.

[0024] The stirring shaft is a cylindrical tube. The stirring blades are fixedly connected to the upper end face of the stirring shaft. The inner end of the stirring blades is located above the inner hole of the stirring shaft. A baffle is provided inside the upper end of the stirring shaft. There is a gap between the outer edge of the baffle and the inner wall of the upper end of the stirring shaft. The baffle is fixedly connected to the inner end of the stirring blades. A drain pipe is threadedly connected to the stirring shaft below the baffle. The drain pipe rotates along the thread and presses against the lower surface of the baffle.

[0025] When the upper end of the drain pipe touches the lower surface of the baffle, the drain pipe is sealed by the baffle, achieving a closure effect. This allows for vacuuming inside the vessel, which is beneficial for distillation. When the drain pipe rotates downward and disengages from the baffle, the gap between the outer edge of the baffle and the inner wall of the stirring shaft, as well as the gap between the upper end of the drain pipe and the baffle, allows the inner hole of the drain pipe to communicate with the internal space of the vessel, thus satisfying the conditions for the discharge of residual liquid from the vessel.

[0026] The upper outer wall of the drain pipe is provided with external threads, and the lower outer wall is arranged with teeth along the axis of the drain pipe. The drain pipe is driven to rotate by a worm gear rotatably connected to the stirring shaft, and the helical teeth of the worm gear mesh with the teeth of the drain pipe.

[0027] The worm gear mechanism is used to drive the drain pipe to rotate, which makes the contact between the drain pipe and the baffle plate more stable and less likely to loosen during rotation due to the threaded connection alone, thus ensuring the stable operation of the equipment.

[0028] The beneficial effects of the present invention through the above technical solution are as follows:

[0029] This invention uses a heating jacket for heating and is equipped with a special stirring paddle. Even if only a small amount of liquid remains in the vessel, it can be fully stirred and make full contact with the inner wall of the vessel corresponding to the heating jacket. This allows the product components in the residual liquid to be fully vaporized and distilled, avoiding product waste and heat source energy waste.

[0030] The stirring paddle of the present invention also has the function of collecting and discharging residual liquid in the distillation vessel, thus preventing residual liquid from adhering to and depositing on the inner wall of the distillation vessel and having a cleaning effect.

[0031] The stirring paddle of the present invention has a telescopic function and is equipped with an anti-foaming net. The stirring paddle rises and falls according to the liquid level of the liquid in the distillation vessel, so that the liquid in the vessel is fully stirred, the bubbles on the surface of the liquid in the vessel are quickly eliminated, the vaporization of the liquid in the vessel is accelerated, and the distillation efficiency is improved.

[0032] This invention has a simple structure, is easy to operate, has few internal components, is easy to clean, and is suitable for distillation of multi-component materials. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the present invention;

[0034] Figure 2 This is a cross-sectional front view of the present invention;

[0035] Figure 3 This is a schematic diagram of the stirring mechanism of the present invention;

[0036] Figure 4 This is a cross-sectional front view of the stirring mechanism of the present invention;

[0037] Figure 5 This is a diagram showing the usage state of the present invention when there is a large amount of liquid in the vessel;

[0038] Figure 6 This is a diagram showing the usage state of the present invention when the amount of liquid in the vessel is relatively small.

[0039] The following are the labels in the attached diagram: 1. Vessel body; 2. Jacket; 3. Insulation layer; 4. Motor; 5. Rotating sleeve; 6. Stirring paddle; 7. Mechanical seal; 8. Stirring blade; 9. Stirring shaft; 10. Defoaming net; 11. Filter screen; 12. Support ring; 13. Pulley; 14. Frame; 15. Telescopic mechanism; 16. Baffle plate; 17. Drain pipe; 18. Gear; 19. Worm gear; 20. Sealing ring. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0041] like Figure 1 and Figure 2As shown, a distillation vessel includes a vessel body 1. The upper end of the vessel body 1 is provided with a feeding mechanism and a connection port for connecting a vacuum pump, a distillation column, and a detection device. The vessel body 1 is provided with a jacket 2 and an insulation layer 3. The jacket 2 is located inside the insulation layer 3. The bottom of the vessel body 1 smoothly transitions to the side wall of the vessel body 1. The inner diameter of the lower end of the side wall of the vessel body 1 is smaller than the inner diameter of the middle part of the side wall of the vessel body 1. That is, the inner wall of the vessel body 1 corresponding to the jacket 2 is a conical inner wall with a slightly larger upper part and a slightly smaller lower part. However, due to the needs of use, it cannot be too obviously tilted. There is a stirring mechanism at the center of the bottom of the vessel body 1. The stirring mechanism is driven to rotate by a motor 4 located outside the vessel body 1. The stirring mechanism has stirring blades 8. There is a gap between the stirring blades 8 and the inner wall of the vessel body 1. The stirring blades 8 stir the liquid in the vessel and make the liquid in the vessel body 1 uniformly cover the inner wall of the vessel body 1 corresponding to the jacket 2 when the liquid is small.

[0042] like Figure 3 and Figure 4 As shown, the stirring mechanism includes a rotating sleeve 5 and a stirring paddle 6. The rotating sleeve 5 is rotatably connected to the bottom center of the vessel body 1 via a mechanical seal 7. The stirring paddle 6 rotates with the rotating sleeve 5. The stirring paddle 6 includes stirring blades 8 and a stirring shaft 9. The stirring blades 8 are all deflected in an arc shape, either counterclockwise or clockwise.

[0043] The outer end of the stirring blade 8 is close to the horizontal plane where the upper end of the jacket 2 is located.

[0044] The vessel body 1 is provided with a defoaming net 10, which includes a filter screen 11 and a support ring 12. The filter screen 11 is connected to the inside of the support ring 12.

[0045] The support ring 12 is a circular ring formed by bending steel strips and connecting the ends. The outer diameter of the support ring 12 is smaller than the inner diameter of the vessel body 1. The filter screen 11 inside the support ring 12 is a composite of a 20-40 mesh stainless steel filter screen and a 300g×5mm glass fiber mesh. The glass fiber mesh is located above the stainless steel filter screen. Foam preferentially contacts the glass fiber mesh and loses liquid, and then passes down through the stainless steel mesh and is destroyed. The support ring 12 is connected to the upper end of the stirring blades 8. On the one hand, the support ring 12 connecting to the upper end of each stirring blade 8 can make the stirring blades 8 more stable. On the other hand, the defoaming net 10 is relatively high, which allows it to have more opportunities to contact the foam.

[0046] The bottom of the vessel body 1 smoothly transitions to the side wall of the vessel body 1. The inner diameter of the lower end of the side wall of the vessel body 1 is smaller than the inner diameter of the middle part of the side wall of the vessel body 1. The lower end of the rotating sleeve 5 is connected to a pulley 13. The pulley 13 is connected to the motor 4 via a belt. The outer wall of the stirring shaft 9 is provided with a protrusion. The inner wall of the rotating sleeve is provided with a sliding groove that matches the protrusion. The rotating sleeve 5 and the stirring shaft 9 are connected by a sealing ring 20. The sealing ring 20 has a shape that matches the outer edge of the horizontal section of the stirring shaft. When the stirring shaft 9 rotates with the rotating sleeve 5, it can slide up and down along the rotating sleeve 5, thereby adjusting the height of the stirring blade 8. When the stirring paddle 6 slides down to the limit, the stirring blade 8 contacts the inner wall of the vessel body 1. The stirring shaft 9, which can slide up and down, is suitable for various vessel liquid heights. It is especially suitable for intermittent distillation where the vessel liquid is decreasing. Moreover, it can scrape off the residual liquid on the inner wall of the vessel at the end of the distillation.

[0047] The lower end of the stirring shaft 9 is rotatably connected to a frame 14 for supporting the container. A telescopic mechanism 15 is connected below the frame 14. In this embodiment, the telescopic mechanism 15 is a cylinder. The telescopic mechanism 15 is used to make the stirring shaft 9 slide up and down. The upper end of the frame 14 is rotatably connected to the stirring shaft 9, and the lower part is provided with a cross-shaped bracket for supporting the container.

[0048] like Figure 4 As shown, the stirring shaft 9 is a cylindrical tube, and the stirring blade 8 is fixedly connected to the upper end face of the stirring shaft 9. The inner end of the stirring blade 8 is located above the inner hole of the stirring shaft 9. A baffle 16 is provided inside the upper end of the stirring shaft 9. There is a gap between the outer edge of the baffle 16 and the inner wall of the upper end of the stirring shaft 9. The baffle 16 is fixedly connected to the inner end of the stirring blade 8. A drain pipe 17 is threadedly connected to the stirring shaft 9 below the baffle 16. The drain pipe 17 rotates along the thread and presses against the lower surface of the baffle 16.

[0049] The upper outer wall of the drain pipe 17 is provided with external threads, and the lower outer wall is provided with teeth 18 arranged along the axial direction of the drain pipe 17. The drain pipe 17 is driven to rotate by a worm gear 19 rotatably connected to the stirring shaft 9, and the helical teeth of the worm gear 19 mesh with the teeth of the drain pipe 17.

[0050] Taking the distillation of the intermediate product (5-tert-butyl-m-xylene) in the production of xylene musk as an example, the process of using this invention is as follows:

[0051] First, the material to be distilled is added to the vessel body 1 from the crude condensate tank. Then, heat transfer oil is introduced into the jacket 2 to heat the material inside the vessel body 1. During the heating process, stirring is activated, and a vortex is generated in the center of the material inside the vessel body 1. Figure 5As shown, the telescopic mechanism 15 is used to raise the stirring paddle 6 until the middle of the defoaming net 10 is higher than the bottom of the vortex. Heating continues, and when there is reflux, full reflux is started for 1 hour. After 1 hour, the discharge valve is opened to allow the initial distillation section to flow into the xylene buffer tank. When the liquid level in the xylene buffer tank reaches 80%, the discharge valve of the xylene buffer tank is opened, and the chemical pump is started to pump the xylene into the xylene metering tank for circulation. When the finished product is detected by the discharge test, the mixing section is allowed to flow into the 5-tert-butyl-m-xylene-m-xylene buffer tank. During this period, the stirring paddle 6 is lowered slightly every once in a while to ensure that the defoaming net 10 is always in contact with the material. When the liquid level in the 5-tert-butyl-m-xylene-m-xylene buffer tank reaches 80%, the discharge valve at the bottom of the 5-tert-butyl-m-xylene-m-xylene buffer tank is opened, and the chemical pump is used to pump the material back into the crude condensate tank. After that, the distillation product section is transported to the 5-tert-butyl-m-xylene refined product transfer tank until the distillation is completed. At this time, the stirring paddle 6 is lowered to the bottom (e.g., Figure 6 As shown), the remaining part at the bottom of the vessel 1 is the vessel residue liquid. Stop stirring and rotate the stirring paddle 6 in the opposite direction. The stirring paddle 6 scrapes the vessel residue liquid from the inner wall of the vessel 1 and collects it at the center of the bottom of the vessel 1. Stop stirring, place the container on the cross-shaped bracket of the frame, and use a tool to rotate the worm gear 19 to lower the drain pipe 17. The top of the drain pipe 17 is separated from the baffle plate 16, and the drain pipe 17 is connected to the inside of the vessel. The vessel residue liquid is discharged from the drain pipe 17. Slowly rotate the stirring paddle 6 in the opposite direction to accelerate the emptying of the vessel residue liquid.

[0052] The temperature control during the distillation process is as follows:

[0053] External temperature ℃ 150～170 170～180 180～220 Internal temperature℃ 100～125 125～135 125～150 Tower temperature ℃ 40～60 65～115 109～119 reflux ratio 80％ 87％ 5％

[0054] The material balance sheet for the distillation process is as follows:

[0055]

[0056]

[0057] When using existing technology for distillation, when there is usually 40kg to 50kg of liquid remaining in the distillation vessel, it is difficult for the liquid surface to come into contact with the heating coil. At this time, the heat source basically only heats the gas phase inside the distillation vessel and cannot heat the liquid. This not only results in serious energy waste, but also causes excessive products to be discharged as residual liquid in the vessel.

[0058] When using this invention for distillation, the amount of liquid remaining in the vessel is no longer limited by the heating element. The heat source can heat a small amount of liquid in the vessel, recovering an additional 30kg to 40kg of product. Even if only a small amount of liquid remains, it can still fully contact the heat source for heat exchange, avoiding energy waste.

[0059] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various modifications can be made to the technical solutions of the present invention without departing from the spirit of the present invention or the scope of disclosure.

Claims

1. A distillation vessel, comprising a vessel body (1), wherein the vessel body (1) is provided with a jacket (2) and a heat insulation layer (3), characterized in that, The bottom center of the vessel body (1) has a stirring mechanism, which is driven to rotate by a motor (4) located outside the vessel body (1). The stirring mechanism has stirring blades (8), and there is a gap between the stirring blades (8) and the inner wall of the vessel body (1). The stirring blades (8) stir the liquid in the vessel and, when the liquid is low, make the liquid form a film that evenly covers the inner wall of the vessel body (1) corresponding to the jacket (2). The stirring mechanism includes a rotating sleeve (5) and a stirring paddle (6). The rotating sleeve (5) is rotatably connected to the bottom center of the vessel body (1) via a mechanical seal (7). The stirring paddle (6) rotates with the rotating sleeve (5). The stirring paddle (6) includes stirring blades (8) and a stirring shaft (9). The stirring blades (8) all deflect in an arc shape, either counterclockwise or clockwise. The outer end of the stirring blade (8) is close to the horizontal plane where the upper end of the jacket (2) is located. The bottom of the vessel body (1) smoothly transitions to the side wall of the vessel body (1). The inner diameter of the lower end of the side wall of the vessel body (1) is smaller than the inner diameter of the middle part of the side wall of the vessel body (1). The rotating sleeve (5) is connected to the stirring shaft (9) via a sealing ring (20). The stirring shaft (9) can slide up and down along the rotating sleeve (5) when it rotates with the rotating sleeve (5), thereby adjusting the height of the stirring blade (8) and the distance between the stirring blade (8) and the inner wall of the vessel body (1). When the stirring paddle (6) slides down to its limit, the stirring blade (8) contacts the inner wall of the vessel body (1). The lower end of the rotating sleeve (5) is connected to a pulley (13), which is connected to the motor (4) via a belt. The outer wall of the stirring shaft (9) is provided with protrusions, and the inner wall of the rotating sleeve (5) is provided with a groove that matches the protrusions. The sealing ring (20) has a shape that matches the outer edge of the horizontal section of the stirring shaft (9). The stirring shaft (9) is a cylindrical tube. The stirring blade (8) is fixedly connected to the upper end face of the stirring shaft (9). The inner end of the stirring blade (8) is located above the inner hole of the stirring shaft (9). A baffle (16) is provided inside the upper end of the stirring shaft (9). There is a gap between the outer edge of the baffle (16) and the inner wall of the upper end of the stirring shaft (9). The baffle (16) is fixedly connected to the inner end of the stirring blade (8). A drain pipe (17) is threadedly connected to the stirring shaft (9) below the baffle (16). The drain pipe (17) rotates along the thread and presses against the lower surface of the baffle (16).

2. The distillation vessel according to claim 1, characterized in that, The vessel body (1) is provided with a defoaming net (10), which includes a filter screen (11) and a support ring (12). The filter screen (11) is connected to the inside of the support ring (12), and the support ring (12) is connected to the upper end of the stirring blade (8).

3. A distillation vessel according to claim 2, characterized in that, The filter screen (11) inside the support ring (12) is made of stainless steel filter screen and glass fiber mesh.

4. A distillation vessel according to claim 1, characterized in that, The lower end of the stirring shaft (9) is rotatably connected to a frame (14) for supporting the container. A telescopic mechanism (15) is connected below the frame (14) for making the stirring shaft (9) slide up and down.

5. A distillation vessel according to claim 1, characterized in that, The upper outer wall of the drain pipe (17) is provided with an external thread, and the lower outer wall is provided with teeth (18) arranged along the axial direction of the drain pipe (17). The drain pipe (17) is driven to rotate by a worm (19) rotatably connected to the stirring shaft (9). The helical teeth of the worm (19) mesh with the teeth (18) of the drain pipe (17).

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