Novel reduced pressure distillation tail connecting pipe for laboratory

Abstract

The utility model relates to a novel reduced pressure distillation tail connecting pipe for a laboratory. The novel reduced pressure distillation tail connecting pipe comprises a condensation sheet, a solvent conduit, an air exhaust branch pipe, a lower frosted opening, a pipe cavity and an upper frosted opening, the condensation sheets are distributed around the outer wall of the solvent conduit in multiple layers, so that condensation liquid volatilization can be effectively inhibited; the condensation sheet is of a sheet structure composed of a semi-oval front portion and a rectangular rear portion, the side edge of the condensation sheet is a downward arc turned edge, the condensation sheet integrally inclines downwards, and due to the integrated structural characteristic, steam condensation is facilitated, and condensate smoothly flows down along the wall; the upper frosted opening is matched and connected with the fine end grinding opening of the condenser pipe through the inner grinding opening; the exhaust branch pipe is arranged in the middle of the pipe cavity; the lower frosted opening is matched and connected with the receiving bottle; the solvent conduit is located in the center of the lumen. The simple and feasible reduced pressure distillation tail connecting pipe disclosed by the utility model not only reduces the volatilization of a solvent and protects a vacuum pump, but also improves the distillation efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical experimental instruments, and in particular relates to a vacuum distillation tail pipe for a laboratory. Background Art

[0002] In chemical synthesis experiments, reduced pressure distillation, also known as vacuum distillation, is a crucial technical method for separating and purifying compounds. That is, by distilling at a pressure lower than normal, the boiling point of the solvent contained therein is reduced, thereby achieving efficient separation of the solvent and precise purification of the product. Especially for high-boiling point substances and compounds that are susceptible to thermal decomposition, oxidation or polymerization in a normal pressure environment, reduced pressure distillation technology shows significant advantages. Reduced pressure distillation can complete the distillation process at room temperature and low temperature by precisely controlling the pressure environment, avoiding the decomposition of substances under normal pressure, and also improving the distillation efficiency. However, in chemical research, common low-boiling point solvents with good solubility and wide chemical compatibility, such as ethanol, acetone, ether, ethyl acetate, methanol, acetonitrile, etc., may be condensed in the liquid receiving bottle during the reduced pressure distillation process. Due to strong volatility, easy vaporization and high saturated vapor pressure, the solvent may change from liquid to gaseous state, so that it is sucked into the vacuum pump when the vacuum pump is working, causing pump oil pollution, reduced vacuum, equipment corrosion, air pollution, etc. The service life of the vacuum pump is seriously shortened; in addition, the rapid volatilization of the solvent obtained by reduced pressure distillation in a low-pressure environment not only seriously reduces the yield and recovery rate, but also makes it impossible to judge the volume of the solvent in the receiving bottle, resulting in missing data on the distillation efficiency and experimental results, seriously affecting the development of subsequent experiments.

[0003] The tail pipe used in conventional chemical experiments does not provide an ideal solution to the volatility of solvents, but it is more ingenious and ideal for temperature control, instrument protection and cleaning. Similar tail pipe designs such as CN213995925U install a temperature control device on the tail pipe, which can better protect the tail pipe from damage by overheated solvents. CN205261030U provides a tail pipe connection device, which effectively solves the problem that the tail pipe is not tightly matched with the condenser and the receiving bottle and is easy to fall off and break. In CN206965170U, physical principles are used to reasonably guide the clean water flow to increase the cleaning intensity, greatly reducing the difficulty of cleaning the tail pipe and the problem of solvent deposition. The above-mentioned tail pipe design generally pays more attention to the performance enhancement of the tail pipe body and ignores the impact of solvent volatilization. Different solvents have different volatilization effects during the vacuum distillation process, but they all have irreversible adverse effects on the working performance of the vacuum pump, seriously restricting the improvement of the performance of the vacuum pump itself and the ability to create a vacuum environment. Moreover, the subsequent deviation between the volume of the solvent obtained from the receiving bottle and the theoretical solvent is too serious, which is not conducive to the purification and separation of the substance, and restricts the development of subsequent experiments. Therefore, it is extremely necessary to study a new type of simple tail pipe to reduce solvent volatilization and protect the vacuum pump. In order to effectively alleviate the problems caused by solvent volatilization involved in chemical experiments, the utility model designs a laboratory vacuum distillation tail pipe, which can simply and effectively reduce the occurrence of the above problems. Summary of the invention

[0004] The utility model provides a vacuum distillation tail pipe for a laboratory, which can reduce the volatilization of solvents in the vacuum distillation process, alleviate the problem of a significant decrease in yield and recovery rate caused by the volatilization of solvents, and protect the interior of a vacuum pump from being corroded by volatile solvents.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model and the functional features embodied therein are as follows:

[0006] A laboratory vacuum distillation tail pipe comprises a condenser plate (1), a solvent conduit (2), an exhaust branch pipe (3), a lower frosted port (4), a tube cavity (5), and an upper frosted port (6);

[0007] The laboratory vacuum distillation tail pipe is made of high borosilicate glass;

[0008] The condensing sheet (1) is welded around the outer wall of the reagent conduit (2); the solvent conduit (2) is located at the center of the tube cavity (5); the exhaust branch pipe (3) is arranged in the middle of the tube cavity (5); the upper frosted port (6) is matched and connected with the thin end ground port of the condensing tube through the inner ground port; the lower frosted port (4) is matched and connected with the receiving bottle;

[0009] The condensing sheet (1) is a sheet-like structure composed of a semi-elliptical front part and a rectangular rear part. The short-axis plane of the semi-ellipse at the front end of the condensing sheet is connected to the rectangular rear part, and the side is a downward arc-shaped curl. The whole is inclined downward, and its integral structure feature helps the steam to condense and the condensate to flow smoothly along the wall;

[0010] For the condensing sheet (1), the ratio of the major axis of the front semi-ellipse to the length of the whole condensing sheet is between 1:6 and 1:20, the thickness of the condensing sheet is uniform, the ratio of the minor axis to the major axis of the ellipse is between 1:4 and 1:8; the aspect ratio of the rectangle is between 1:5 and 1:20; the curl radian is between 10-20°; the ratio of the height of the arc edge above the plane to the thickness of the condensing sheet is between 1:2 and 1:3; the condensing sheet (1) has a unique shape and design ratio, aiming to optimize the condensing effect, improve the structural stability and durability;

[0011] The condensing sheet (1) is directly welded to the outer wall of the solvent conduit (2). The forming and drawing are simpler than that on the inner wall of the lumen (5), which is convenient for the next step of processing;

[0012] For the condensing sheet (1), its semi-ellipsoidal front part has the advantages of reducing droplet splash, ensuring uniform liquid distribution, and forming stable and regular droplets of the volatile solvent on the front end, etc., so as to achieve a better effect of condensing the volatile solvent;

[0013] The condensing sheet (1) is a whole sheet-like structure. Compared with the columnar structure, the area directly in contact with the volatile solvent is increased, allowing more volatile solvent to contact and condense;

[0014] The condensing sheet (1) is directly welded to the outer wall of the solvent conduit (2), and the angle range with the plane where it is located is 15-45°, distributed in a spiral or alternating manner, and obliquely stabbing downward, increasing the impact and diffusion of the solvent gas, weakening the gas film resistance, which is beneficial to solvent condensation and the reduction of the burden on the vacuum pump;

[0015] The condensing sheet (1) is distributed in multiple layers at equal intervals around the outer wall of the solvent conduit (2), and the spacing is beneficial to the reflux of the volatile solvent after condensation;

[0016] The inner diameter of the upper ground joint (6) is the inner diameter size of laboratory standard glassware, which has universality;

[0017] The air extraction branch pipe (3) is arranged in the middle of the lumen (5), and the diameter of the air extraction branch pipe (3) conforms to the laboratory standard suction filtration port and is closely matched with the rubber tube of the common inner diameter size in the laboratory;

[0018] The obliquely stabbing condensing sheet (1) increases the impact and diffusion of the solvent gas by contacting the volatile solvent, weakens the gas film resistance, and improves the efficiency of condensing the volatile solvent;

[0019] During the described experimental operation, the downwardly arranged condenser fins (1) can better condense the steam and cause the condensate to directly drip or flow down the wall into the receiving flask. This latter process helps to increase the wetting degree of the substance, form an effective heat exchange, and achieve a better condensation effect;

[0020] The lower ground glass joint (4) is connected to the receiving flask, and the inner diameter of the lower ground glass joint (4) is the same as that of the commonly used receiving flasks in the laboratory;

[0021] The condenser fins (1) are tightly welded to the solvent conduit (2) to ensure that they are not affected by the pumping of the vacuum pump and enhance stability.

[0022] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0023] 1. When performing vacuum distillation with the present utility model, the volatile solvent can be condensed and refluxed through the condenser fins, protecting the vacuum pump from corrosion by organic solvents and ensuring the recovery of the experimental solvent;

[0024] 2. The present utility model can have multiple condenser fins at the same time, effectively improving the solvent recovery efficiency and reducing the impact caused by solvent volatilization;

[0025] 3. The condenser fins in the present utility model are of an integral glass structure, with a unique shape and design ratio, aiming to optimize the condensation effect, improve the structural stability and durability;

[0026] 4. The present utility model is applicable to the recovery and use of various commonly used volatile solvents in chemical experiments, and provides new ideas for the construction of an efficient vacuum distillation device, which is simple and fully functional;

[0027] 5. The components involved in the present utility model are easy to produce, the selected materials are firm, and it is convenient for assembly and cleaning;

[0028] 6. The upper and lower ground glass joints of the present utility model adopt the standard inner diameter in the laboratory, which is convenient for connecting and assembling with common components and constructing instruments, and has strong application performance and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of a vacuum distillation adapter for laboratory use according to the present utility model;

[0030] Figure 2 is a three-dimensional and top-left view of the condenser fins in a vacuum distillation adapter for laboratory use according to the present utility model;

[0031] Figure 3 is an installation diagram of the use of a vacuum distillation adapter for laboratory use according to the present utility model.

[0032] Figure 1In it, A is a schematic cross-sectional view of the lumen structure slightly below the air extraction branch pipe (3).

[0033] Figure 1 In it: 1 - condensation fin; 2 - solvent conduit; 3 - air extraction branch pipe; 4 - lower ground joint; 5 - lumen; 6 - upper ground joint.

[0034] Figure 2 In it: 1 - condensation fin. Specific embodiments

[0035] Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0036] According to Figures 1 to 3 Shown are schematic structural diagrams of different expressions of the present invention. A complete and detailed understanding of the present invention can be obtained based on the display of the three pictures. First, apply vacuum grease to the inner ground joint of the upper ground joint (6) and the ground joint of the thin end of the condenser tube for sealed connection. At the same time, apply vacuum grease to the lower ground joint (4) and connect it to match the mouth of the receiving bottle. After completion, tightly sleeve the rubber tube connected to the vacuum pump onto the air extraction branch pipe (3). After checking the airtightness, turn on the vacuum pump switch to extract air from the air extraction branch pipe (3) for vacuum distillation. After a period of time, the solvent for vacuum distillation flows into the receiving bottle from the solvent conduit (2). At the same time, the received solvent also begins to volatilize. Under the action of the vacuum pump extracting air, the received solvent volatilizes and rises into the lumen (5). The condensation fins (1) welded to the outer wall of the solvent conduit (2) are arranged obliquely downward, increasing the impact and diffusion of the solvent gas, weakening the gas film resistance, and enhancing the condensation effect. Therefore, the volatilized solvent condenses on the condensation fins (1). The microscopic eddies and liquid film circulation generated by the tiny undulations on the surface of the welded joint between the condensation fins (1) and the solvent conduit (2) also contribute to the further transfer and distribution of heat. The small droplets formed by condensation directly drip from the condensation fins (1) or flow through the outer wall of the solvent conduit (2), and finally flow into the receiving bottle at intervals. The solvent lost due to volatilization is recovered to complete this experimental operation.

[0037] Specific Embodiment 1: When concentrating the ethanol solution of diethyl squarate, the specific operation is as follows. Set up a vacuum distillation device. Apply vacuum grease to the inner ground joint of the upper ground joint (5) and the fine end ground joint of the condenser for sealed connection. At the same time, apply vacuum grease to the lower ground joint (4) and connect it to match the mouth of the receiving flask. After completion, tightly sleeve the rubber tube connected to the vacuum pump onto the air extraction branch pipe (3). After checking the airtightness, turn on the vacuum pump switch to extract air from the air extraction branch pipe (3) for vacuum distillation. After a period of time, the ethanol distilled under reduced pressure flows from the solvent conduit (2) into the receiving flask, and at the same time, the received ethanol starts to volatilize. Under the action of the vacuum pump extracting air, the volatilized ethanol starts to rise into the lumen (5), and when it encounters the condenser piece (1), the solvent starts to condense; the small droplets formed by condensation directly drip from the condenser piece (1) or flow to the inner wall of the solvent conduit (2) and finally flow into the receiving flask. The ethanol lost due to volatilization is recovered, and the entire concentration process of diethyl squarate is completed.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the relevant art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A new type of reduced-pressure distillation adapter for laboratory use, characterized in that: It includes a condensation sheet (1), a solvent conduit (2), an air extraction branch pipe (3), a lower ground joint (4), a lumen (5), and an upper ground joint (6); the condensation sheet (1) is an integral glass structure, and is multi-layered and welded around the outer wall of the solvent conduit (2) at equal intervals; the air extraction branch pipe (3) is arranged in the middle of the lumen (5); the lower ground joint (4) is connected to a receiving bottle; the solvent conduit (2) is located at the center of the lumen (5); the upper ground joint (6) is connected in a matching manner through an internal ground joint to the ground joint at the thin end of a condenser tube.

2. A novel vacuum distillation adapter for laboratory use according to claim 1, characterized in that The condensation sheet (1) is a sheet structure composed of a semi-elliptical front part and a rectangular rear part. The short axis plane of the semi-ellipse at the front end of the condensation sheet is connected to the rectangular rear part. The side is a downward arc-shaped curled edge. The ratio of the major axis of the front semi-ellipse to the length of the entire condensation sheet is between 1:6 and 1:

20. The thickness of the condensation sheet is uniform. The ratio of the short axis to the long axis of the ellipse is between 1:4 and 1:

8. The ratio of the length to the width of the rectangle is between 1:5 and 1:

20. The curled edge radian is between 10° and 20°. The ratio of the height of the arc edge above the plane to the thickness of the condensation sheet is between 1:2 and 1:

3.

3. A laboratory vacuum distillation tail pipe according to claim 1, characterized in that The condensation sheet (1) is made of high borosilicate glass, is directly welded to the outer wall of the solvent conduit (2), is distributed in a spiral or alternating pattern, and is obliquely stabbed downward. The angle range with the plane where it is located is 15° - 45°.

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