Lactide purification and crystallization device

Abstract

The utility model belongs to the technical field of chemical equipment, and particularly relates to a lactide purifying and crystallizing device which comprises a support, a crystallizing tank fixedly mounted on the support, a temperature control cabin fixedly mounted on the outer side of the crystallizing tank and above the support, and a collecting hopper fixedly mounted at one end, protruding out of the temperature control cabin, of the crystallizing tank and below the support. The crystallizing tank is communicated with an impurity removal cabin through a collecting hopper, a filter plate is mounted in the impurity removal cabin, the filter plate is mounted at the end, extending into the collecting hopper, of the impurity removal cabin, a blow-off pipe communicated with the collecting hopper is further fixedly mounted on the impurity removal cabin, and the side, close to the blow-off pipe, of the filter plate inclines downwards. According to the lactide purification and crystallization device, a mixed lactide-containing solution in the crystallization tank is conveyed to the impurity removal cabin through the collection hopper, so that impurities and particulate matters in the solution are filtered out by the filter plate positioned in the impurity removal cabin, and residues in the impurity removal cabin are discharged through the blow-off pipe, so that the stability of a lactide crystallization product is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to chemical equipment technical field especially relates to a propylene lactone purification crystallization device. BACKGROUND

[0002] Propylene lactone is a kind of cyclic ester, is the dimer of lactic acid. It is an important biobased degradable polymer monomer, is used to produce polylactic acid, and the most important use of propylene lactone is as the monomer of producing polylactic acid, and polylactic acid is a kind of biodegradable thermoplastic plastic.

[0003] In order to guarantee the demand of polylactic acid processing, propylene lactone needs to be sent into crystallization kettle and is treated, which will exist following problems in actual operation:

[0004] Generally, the solubility difference of propylene lactone in different solvents is utilized for purification, propylene lactone is dissolved in different solvents, and the crystallization kettle is cooled during purification, so as to precipitate propylene lactone crystallization, but due to the fact that part of propylene lactone solution contains more impurities, it is easy to make the crystallization product unstable, thereby secondary dissolution is generated in solution, and the propylene lactone purification crystallization efficiency is affected; CONTENT OF THE UTILITY MODEL

[0005] In order to overcome the defects of the prior art pointed out above, the present application has been studied in depth, and after a lot of creative labor is paid, the utility model is completed.

[0006] Specifically, the technical problem to be solved by the utility model is to provide a propylene lactone purification crystallization device, to solve the technical problem that the current device is cooled to the crystallization kettle during purification, so as to precipitate propylene lactone crystallization, but due to the fact that part of propylene lactone solution contains more impurities, it is easy to make the crystallization product unstable, thereby secondary dissolution is generated in solution, and the propylene lactone purification crystallization efficiency is affected.

[0007] To solve the above technical problems, the utility model provides the following technical scheme:

[0008] A kind of propylene lactone purification crystallization device, including support, the support is fixedly installed with crystallization tank, the outside of the crystallization tank and at the top of support is fixedly installed with temperature control cabin, the one end of the crystallization tank protruding temperature control cabin and being located below support is fixedly installed with collecting hopper, the crystallization tank is communicated with impurity removal cabin by collecting hopper;

[0009] Filter plate is installed in the impurity removal cabin, and the filter plate is installed at one end of the impurity removal cabin extending into the collecting hopper, and a blowdown pipe is further fixedly installed on the impurity removal cabin and communicated with the collecting hopper, and the side of the filter plate close to the blowdown pipe is inclined downward.

[0010] As an improved technical scheme, the impurity removal cabin is provided with a liquid conveying pipe at one end away from the collecting hopper, two ends of the liquid conveying pipe are communicated with the impurity removal cabin and the crystallization tank respectively, and a liquid pump is further arranged on the liquid conveying pipe and communicated with the crystallization tank.

[0011] As an improved technical scheme, the crystallization tank is movably connected with a first stirring rod at one end away from the support, a modulation tank and a particle cabin are fixedly arranged outside the crystallization tank respectively, the modulation tank and the particle cabin are communicated with the crystallization tank through pipes, and the modulation tank and the particle cabin are located above the first stirring rod.

[0012] As an improved technical scheme, the temperature control cabin is provided with an inlet pipe and an outlet pipe outside respectively, one end of the inlet pipe and the outlet pipe close to the crystallization tank extends into the temperature control cabin and is communicated with the temperature control cabin, and a heating rod for heating liquid in the temperature control cabin is further arranged above the temperature control cabin.

[0013] As an improved technical scheme, the support is further provided with a motor, one end of the first stirring rod protruding from the crystallization tank is in transmission connection with an output shaft of the motor, one end of the first stirring rod extending into the crystallization tank is fixedly connected with a second stirring rod, rubber scrapers are symmetrically arranged at two ends of the second stirring rod, and the rubber scrapers are attached to the inner wall of the crystallization tank at one side away from the second stirring rod.

[0014] As an improved technical scheme, one end of the first stirring rod extending into the crystallization tank is further fixedly connected with a third stirring rod, the third stirring rod is cross-shaped, and the third stirring rod is linearly arranged between the rubber scrapers.

[0015] After the above technical scheme is adopted, the beneficial effects of the present application are as follows:

[0016] 1. The crystallization tank is used for conveying the mixed solution containing lactide in the crystallization tank to the impurity removal cabin through the collecting hopper, so that the impurities and particles in the solution are filtered out by the filter plate in the impurity removal cabin, and the residues in the impurity removal cabin are discharged through the blowdown pipe, thereby ensuring the stability of the lactide crystallization product.

[0017] 2. The modulation tank is used for preparing different concentration solutions and conveying the solutions to the crystallization tank through the pipes, mixing the solutions with the lactide solution to be treated in the crystallization tank, and adding the chemical agents for promoting the precipitation of impurities in the solution and the activated carbon particles for removing impurities in the particle cabin to the crystallization tank through the pipes, thereby promoting the precipitation of impurities in the solution.

[0018] 3. The heating rod is electrically heated, so that the liquid in the temperature control cabin is heated through the inlet pipe and the outlet pipe, thereby promoting the dissolution of lactide in the solution in the crystallization tank.

[0019] 4、The utility model discloses, through the third stirring rod of cross -shaped solution containing lactide in crystallizing tank is stirred in crystallizing tank to lactide in solution in crystallizing tank is stirred, thereby promote lactide in solution, and after lactide is fully dissolved, through reducing the temperature in crystallizing tank, thereby slowly cooling solution containing lactide in crystallizing tank, make lactide crystallization precipitate, and slow cooling usually can get larger crystal. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be briefly introduced to the drawing needed in the embodiment description, obviously, the drawing in the following description only some embodiments of the utility model, for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other drawings according to these drawings. Wherein:

[0021] Figure 1 It is the three-dimensional structure schematic diagram of the utility model lactide purification crystallization device.

[0022] Figure 2 It is the section structure schematic diagram of the utility model lactide purification crystallization device.

[0023] Figure 3 It is the section structure schematic diagram of the utility model lactide purification crystallization device's impurity removal cabin.

[0024] Figure 4 It is the structure schematic diagram of the utility model lactide purification crystallization device's transfusion pipe and crystallizing tank.

[0025] Figure 5 It is the temperature control cabin structure schematic diagram of the utility model lactide purification crystallization device.

[0026] Figure 6 It is the section structure schematic diagram of the utility model lactide purification crystallization device's crystallizing tank.

[0027] Mark explanation:

[0028] 1, support, 2, crystallizing tank, 3, temperature control cabin, 4, material collecting hopper, 5, impurity removal cabin, 6, filter plate, 7, blow-off pipe, 8, transfusion pipe, 9, liquid pump, 10, first stirring rod, 11, modulating tank, 12, granular cabin, 13, water inlet pipe, 14, water outlet pipe, 15, heating rod, 16, motor, 17, second stirring rod, 18, rubber scraper, 19, third stirring rod. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0031] Meanwhile, "and / or" or "and / or" appearing in the whole text means that three schemes are included, taking "A and / or B" as an example, including A scheme, or B scheme, or A and B schemes are satisfied at the same time.

[0032] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0033] For example, Figure 1 , Figure 2 and Figure 3As shown in the drawings, the embodiment provides a propylene lactone purification crystallization device, which comprises a support 1, a crystallization tank 2 is fixedly installed on the support 1, a temperature control cabin 3 is fixedly installed on the outside of the crystallization tank 2 and above the support 1, a collecting hopper 4 is fixedly installed at one end of the crystallization tank 2 protruding from the temperature control cabin 3 and below the support 1, the crystallization tank 2 is communicated with a impurity removal cabin 5 through the collecting hopper 4, a filter plate 6 is installed in the impurity removal cabin 5, and the filter plate 6 is installed at one end of the impurity removal cabin 5 extending into the collecting hopper 4, a blowdown pipe 7 is also fixedly installed on the impurity removal cabin 5 and communicated with the collecting hopper 4, and the side of the filter plate 6 close to the blowdown pipe 7 is inclined downward, the support 1 provides support for the crystallization tank 2 and the temperature control cabin 3, and makes the temperature control cabin 3 fit with the crystallization tank 2, the temperature in the temperature control cabin 3 can promote the dissolution of propylene lactone in the solution or the crystallization of propylene lactone in the solution, the collecting hopper 4 can transport the mixed solution in the support 1 to the impurity removal cabin 5, the filter plate 6 can filter out the impurities in the solution transported through the collecting hopper 4, and the blowdown pipe 7 can discharge the impurities filtered out in the filter plate 6 and still remaining in the impurity removal cabin 5 from the impurity removal cabin 5, so as to reduce the content of impurities in the propylene lactone solution and ensure the stability of the crystallization product.

[0034] One end of the impurity removal cabin 5 away from the collecting hopper 4 is provided with a liquid inlet pipe 8, both ends of the liquid inlet pipe 8 are communicated with the impurity removal cabin 5 and the crystallization tank 2 respectively, and a liquid pump 9 communicated with the crystallization tank 2 through the liquid inlet pipe 8 is also arranged on the liquid inlet pipe 8, the solution filtered in the impurity removal cabin 5 can be discharged through the liquid inlet pipe 8, and the liquid pump 9 can pump the solution in the liquid inlet pipe 8 out of the impurity removal cabin 5 and then send it into the crystallization tank 2 again.

[0035] As shown in the drawings, Figure 4 and Figure 5 As shown in the drawings, one end of the crystallization tank 2 away from the support 1 is movably connected with a first stirring rod 10, a modulating tank 11 and a particle cabin 12 are fixedly installed on the outside of the crystallization tank 2 respectively, and the modulating tank 11 and the particle cabin 12 are communicated with the crystallization tank 2 through pipelines, and the modulating tank 11 and the particle cabin 12 are both above the first stirring rod 10, the first stirring rod 10 can rotate in the support 1 to scrape off the floating foam in the solution in the support 1, the modulating tank 11 can prepare different solutions and transport them into the crystallization tank 2 through the pipelines, so that the dissolution of propylene lactone is more sufficient, and the particle cabin 12 is filled with chemical particles promoting impurity precipitation and activated carbon particles removing color, and can be filtered out by the filter plate 6 when passing through the impurity removal cabin 5.

[0036] The temperature control cabin 3 is provided with an inlet pipe 13 and an outlet pipe 14 on the outer side, respectively, and the inlet pipe 13 and the outlet pipe 14 extend to the temperature control cabin 3 and communicate with the temperature control cabin 3 at one end close to the crystallization tank 2. The temperature control cabin 3 is further provided with a heating rod 15 for heating the liquid in the temperature control cabin 3. The inlet pipe 13 and the outlet pipe 14 adopt the inlet from bottom to outlet from top mode, so that the water temperature in the temperature control cabin 3 is uniformly distributed. The heating rod 15 can heat the water in the temperature control cabin 3 by electric heating, so as to promote the dissolution of lactide in the solution in the crystallization tank 2.

[0037] The support 1 is further provided with a motor 16, and one end of the first stirring rod 10 protruding from the crystallization tank 2 is in transmission connection with the output shaft of the motor 16. The first stirring rod 10 is fixedly connected with a second stirring rod 17 at one end extending into the crystallization tank 2. The second stirring rod 17 is symmetrically provided with rubber scrapers 18 at both ends. The rubber scrapers 18 are in contact with the inner wall of the crystallization tank 2 at a side away from the second stirring rod 17. The second stirring rod 17 is in two groups and is parallelly distributed. The second stirring rod 17 can be driven by the output shaft of the motor 16 to rotate synchronously with the first stirring rod 10 and scrape the inner wall of the crystallization tank 2 by the rubber scrapers 18, so as to reduce the probability of adhesion of substances on the inner wall of the crystallization tank 2.

[0038] The first stirring rod 10 is further fixedly connected with a third stirring rod 19 at one end extending into the crystallization tank 2. The third stirring rod 19 is in a cross shape and is linearly arranged between the rubber scrapers 18. The third stirring rod 19 can rotate synchronously with the first stirring rod 10, so as to stir the solution in the support 1, thereby promoting the dissolution of lactide in the solution when the solution in the crystallization tank 2 is heated by the temperature control cabin 3.

[0039] In use, by preparing different concentration solutions in the preparation tank 11 and delivering to the crystallization tank 2 through the pipeline, mixing with the lactide solution to be treated in the crystallization tank 2, and adding the chemical agent in the particle cabin 12 to promote the impurities in the solution to precipitate and the activated carbon particles to remove the color through the pipeline into the crystallization tank 2, the mixed solution containing lactide in the crystallization tank 2 is delivered to the impurity removal cabin 5 through the collecting hopper 4, so that the filter plate 6 in the impurity removal cabin 5 filters out the impurities and particulate matters in the solution, and the residues in the impurity removal cabin 5 are discharged through the blowdown pipe 7. In this process, the liquid pump 9 connected through the infusion tube 8 re-delivers the treated solution in the impurity removal cabin 5 into the crystallization tank 2 through the infusion tube 8, and the heating rod 15 is started to heat the liquid entering and exiting the temperature control cabin 3 through the water inlet pipe 13 and the water outlet pipe 14, so as to promote the dissolution of lactide in the solution in the crystallization tank 2, and in this process, the first stirring rod 10 is driven to rotate by the output shaft of the motor 16, the second stirring rod 17 is driven to rotate synchronously with the first stirring rod 10, the rubber scraper 18 attached to the inner wall of the crystallization tank 2 is scraped off the substances adhered to the inner wall of the crystallization tank 2, and the third stirring rod 19 in the form of a cross is used to stir the solution containing lactide in the crystallization tank 2, so as to promote the dissolution of lactide in the solution, and after the lactide is fully dissolved, the temperature in the crystallization tank 2 is lowered to slowly cool the solution containing lactide in the crystallization tank 2, so that the lactide is crystallized and precipitated, and slow cooling usually produces larger crystals.

[0040] It should be understood that the use of these embodiments is only for the purpose of illustrating the present application and is not intended to limit the scope of protection of the present application. In addition, it should also be understood that after reading the technical content of the present application, those skilled in the art can make various modifications, modifications and / or variations to the present application, and all these equivalent forms also fall within the protection scope defined by the claims attached to the present application.

Claims

1. A device for purifying and crystallizing lactide, comprising a support (1), characterized in that: The support (1) is fixedly installed with a crystallization tank (2), the outer side of the crystallization tank (2) and above the support (1) is fixedly installed with a temperature control cabin (3), one end of the crystallization tank (2) protruding from the temperature control cabin (3) and below the support (1) is fixedly installed with a collecting hopper (4), the crystallization tank (2) is communicated with a impurity removal cabin (5) through the collecting hopper (4); The impurity removal cabin (5) is installed with a filter plate (6), and the filter plate (6) is installed at one end of the impurity removal cabin (5) extending into the collecting hopper (4), and the impurity removal cabin (5) is also fixedly installed with a blowdown pipe (7) communicated with the collecting hopper (4), and the side of the filter plate (6) close to the blowdown pipe (7) is inclined downward.

2. The device for purifying and crystallizing glycolide according to claim 1, characterized in that: One end of the impurity removal cabin (5) away from the collecting hopper (4) is provided with a liquid delivery pipe (8), both ends of the liquid delivery pipe (8) are communicated with the impurity removal cabin (5) and the crystallization tank (2) respectively, and the liquid delivery pipe (8) is also provided with a liquid pump (9) communicated with the crystallization tank (2) through the liquid delivery pipe (8).

3. The device for purifying and crystallizing glycolide according to claim 2, characterized in that: One end of the crystallization tank (2) away from the support (1) is movably connected with a first stirring rod (10), and the outer side of the crystallization tank (2) is fixedly installed with a modulation tank (11) and a particle cabin (12) respectively, and the modulation tank (11) and the particle cabin (12) are communicated with the crystallization tank (2) through pipelines, and the modulation tank (11) and the particle cabin (12) are above the first stirring rod (10).

4. The device for purifying and crystallizing glycolide according to claim 1, wherein: The outer side of the temperature control cabin (3) is provided with a water inlet pipe (13) and a water outlet pipe (14) respectively, one end of the water inlet pipe (13) and the water outlet pipe (14) close to the crystallization tank (2) extends into the temperature control cabin (3) and is communicated with the temperature control cabin (3), and the upper side of the temperature control cabin (3) is also installed with a heating rod (15) for heating the liquid in the temperature control cabin (3).

5. The device for purifying and crystallizing glycolide according to claim 3, wherein: The upper side of the support (1) is also installed with a motor (16), one end of the first stirring rod (10) protruding from the crystallization tank (2) is in transmission connection with the output shaft of the motor (16), one end of the first stirring rod (10) extending into the crystallization tank (2) is fixedly connected with a second stirring rod (17), the two ends of the second stirring rod (17) are symmetrically distributed with rubber scrapers (18), and the side of the rubber scraper (18) away from the second stirring rod (17) is attached to the inner wall of the crystallization tank (2).

6. The device for purifying and crystallizing glycolide according to claim 5, wherein: One end of the first stirring rod (10) extending into the crystallization tank (2) is also fixedly connected with a third stirring rod (19), the third stirring rod (19) is cross-shaped, and the third stirring rod (19) is linearly arranged between the rubber scrapers (18).

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