Efficient dissolving device

Abstract

The utility model belongs to the technical field of chemical equipment, and particularly relates to an efficient dissolving device which comprises a dissolving kettle and a solvent kettle connected with the dissolving kettle, a dissolving kettle outlet in the bottom of the dissolving kettle is connected with a first inlet in the top of the solvent kettle through a connecting pipe, and a branch pipe and a siphon are further arranged on the connecting pipe. The branch pipe is connected with the top of the dissolving kettle, the siphon is connected with the dissolving kettle, and the branch pipe is also connected with a condenser. The solvent in the dissolving kettle can be periodically and automatically updated, so that the concentration difference in the dissolving process is improved, the large-scale continuous dissolving of materials is realized, and the dosage of the dissolving solvent is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical equipment, and in particular relates to a high-efficiency dissolving device. Background Art

[0002] Poly-L-lactic acid has good biocompatibility and degradability, high strength, good mechanical properties, and easy processing and molding. It is widely used in packaging materials, textiles, surgical sutures, drug delivery, etc. In the prior art, high molecular weight poly-L-lactic acid is usually prepared by L-lactide ring-opening polymerization. The obtained polymerization product often contains some unreacted monomers and low molecular weight products, which need to be further dissolved and purified to reduce monomer residues.

[0003] The existing poly-L-lactic acid dissolution process usually involves directly cooling the reaction after the reaction is completed, then adding a solvent and stirring and dissolving it in a polymerization kettle; or after the reaction is completed, the material is transferred from the polymerization kettle to a dissolution kettle for stirring and dissolving. Both of the above methods have the following problems: (1) As the dissolution time increases, the concentration difference decreases after the concentration increases, so the dissolution time becomes longer and the efficiency is lower; (2) In order to increase the dissolution rate, the method of increasing the amount of solvent is often adopted, so the amount of solvent used increases, which increases the production cost. Summary of the invention

[0004] In view of the above problems, the utility model provides a high-efficiency dissolving device, which has high dissolving efficiency and sufficient stirring, and can significantly shorten the material dissolving operation time.

[0005] In order to solve the above problems, the technical solution of the utility model is as follows:

[0006] A high-efficiency dissolving device comprises a dissolving kettle and a solvent kettle connected to the dissolving kettle, wherein the dissolving kettle outlet at the bottom of the dissolving kettle is connected to the first inlet at the top of the solvent kettle through a connecting pipe, and the connecting pipe is also provided with a branch pipe and a siphon pipe, wherein the branch pipe is connected to the top of the dissolving kettle, the siphon pipe is connected to the dissolving kettle, and the branch pipe is also connected to a condenser.

[0007] Further, the siphon tube includes a short tube, a long tube and an n-shaped curved tube, the short tube, the curved tube and the long tube are connected in sequence, the other end of the short tube is a siphon tube inlet, connected to the dissolving kettle, the other end of the long tube is a siphon tube outlet, connected to the connecting tube; the branch tube has a branch tube inlet and a branch tube outlet, the branch tube inlet is connected to the connecting tube, and the branch tube outlet is connected to the top of the dissolving kettle;

[0008] Wherein, on the connecting pipe, the height of the siphon pipe outlet is lower than the height of the branch pipe inlet.

[0009] Furthermore, a dissolving tank is provided in the dissolving kettle, and the dissolving tank is composed of a filter screen as a whole. A bracket is provided under the dissolving tank, and the bracket passes through the dissolving kettle and the fixing frame in sequence and is connected to the output end of the first motor. A cavity is also provided in the center of the dissolving tank.

[0010] Furthermore, a spray device is also provided in the dissolving kettle, and the spray device includes a spray disc, a spray vertical rod and a nozzle; the spray disc is located above the dissolving tank, and the top of the spray disc is connected to the branch pipe; the spray vertical rod is located in the cavity, and the upper end of the spray vertical rod is communicated with the spray disc; a plurality of nozzles are arranged at intervals on the spray disc and the spray vertical rod.

[0011] Furthermore, the volume of the dissolving kettle is 1 / 4 to 2 / 3 of the volume of the solvent kettle, and the height of the siphon tube is 1 / 3 to 2 / 3 of the height of the dissolving kettle.

[0012] Furthermore, a second inlet and a third inlet are provided on the top of the solvent kettle; valves are provided on the dissolving kettle outlet, the first inlet, the solvent kettle outlet and the long tube.

[0013] Furthermore, the dissolving kettle and the solvent kettle are both provided with jackets outside, and the solvent kettle is also provided with supporting legs.

[0014] Furthermore, the outlet of the solvent kettle is also connected to a filter.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] (1) In the present invention, the dissolving kettle and the solvent kettle are connected by a branch pipe and a siphon pipe, so that the solvent in the dissolving kettle is automatically renewed regularly, thereby increasing the concentration difference in the dissolving process and reducing the dissolving time. However, in the conventional method, there is no solvent renewal process, and as the dissolving time increases, the concentration difference decreases and the dissolving becomes slower, so the conventional dissolving time is longer;

[0017] (2) The dissolving tank of the utility model can ensure that the material is dissolved only in the dissolving tank and will not be brought into the siphon, thereby avoiding the problem of siphon clogging; the cavity reserved in the center of the dissolving tank can prevent the spraying vertical rod and the nozzle from being eroded by the material, and at the same time can make the solvent contact with the material over a large area, thereby accelerating the dissolution;

[0018] (3) The utility model realizes large-scale continuous dissolution of materials, reduces the amount of dissolving solvent, shortens the dissolution time, and can be directly pressurized and filtered after the dissolution is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0020] Figure 2This is a side sectional view of Embodiment 2 of the dissolving kettle of the utility model;

[0021] Figure 3 This is a top view of the interior of the dissolving kettle embodiment 2 of the utility model;

[0022] Description of reference numerals:

[0023] 1. Dissolving kettle; 2. Solvent kettle; 3. Branch pipe; 4. Siphon; 4a. Short pipe; 4b. Bend pipe; 4c. Long pipe; 4d. Siphon valve; 5. Connecting pipe; 6. Condenser; 7. Dissolving kettle outlet; 7a. Dissolving kettle outlet valve; 8. First inlet; 8a. First inlet valve; 9. Second inlet; 10. Third inlet; 11. Solvent kettle outlet; 11a. Solvent kettle outlet valve; 12. Support leg; 13. Dissolving tank; 14. Feeding port; 15a. Spray disc; 15b. Spray vertical rod; 15c. Nozzle; 16. Cavity; 17. Stirring rod; 18a. Bracket; 18b. Fixed bracket; 19. First motor; 25. Second motor; 31. Filter. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0025] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and 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 a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Example 1

[0028] Please refer to Figure 1A high-efficiency dissolving device comprises a dissolving kettle 1 and a solvent kettle 2 connected to the dissolving kettle 1. The dissolving kettle outlet 7 at the bottom of the dissolving kettle 1 is connected to the first inlet 8 at the top of the solvent kettle 2 through a connecting pipe 5. The connecting pipe 5 is also provided with a branch pipe 3 and a siphon pipe 4. The branch pipe 3 is connected to the top of the dissolving kettle 1, the siphon pipe 4 is connected to the dissolving kettle 1, and the branch pipe 3 is also connected to a condenser 6.

[0029] The siphon 4 includes a short tube 4a, a long tube 4c and an n-shaped elbow 4b, the short tube 4a, the elbow 4b and the long tube 4c are connected in sequence, the other end of the short tube 4a is a siphon inlet, which is connected to the dissolving kettle 1, and the other end of the long tube 4c is a siphon outlet, which is connected to the connecting pipe 5; the branch pipe 3 has a branch inlet and a branch outlet, the branch inlet is connected to the connecting pipe 5, and the branch outlet is connected to the top of the dissolving kettle 1; the long tube 4c is an L-shaped structure, the short tube 4a can be L-shaped or U-shaped. The L-shaped is adopted in this embodiment and will not be described in detail here; the elbow 4b is n-shaped and has a certain height, so that the solution can stay in the dissolving kettle 1 for a certain time to fully stir and dissolve the material. When the height in the dissolving kettle 1 is higher than the height of the elbow 4b, the solvent automatically flows back into the solvent kettle 2.

[0030] Wherein, on the connecting pipe 5, the height of the siphon pipe outlet is lower than the height of the branch pipe inlet.

[0031] The volume of the dissolving kettle 1 is 1 / 4 to 2 / 3 of the volume of the solvent kettle 2, and the height of the siphon pipe 4 (at Figure 1 H) is 1 / 3 to 2 / 3 of the height of the dissolving kettle 1.

[0032] The top of the solvent kettle 2 is provided with a second inlet 9 and a third inlet 10; valves are provided on the dissolving kettle outlet 7, the first inlet 8, the solvent kettle outlet 11 and the long tube 4c.

[0033] The dissolving kettle 1 and the solvent kettle 2 are both provided with jackets, and the solvent kettle 2 is also provided with supporting legs 12 .

[0034] Example 2

[0035] Please refer to Figure 2-3 On the basis of Example 1, a dissolving tank 13 is provided in the dissolving kettle 1, and the dissolving tank 13 is composed of a filter screen as a whole. The dissolving tank 13 can make all the materials located in the dissolving tank 13. When the solvent enters, the dissolved solution flows through the dissolving tank 13 to the dissolving kettle 1; a bracket 18a is provided under the dissolving tank 13, and the bracket 18a passes through the dissolving kettle 1 and the fixing frame 18b in sequence and is connected to the output end of the first motor 19; a cavity 16 is also provided in the center of the dissolving tank 13; a plurality of cavities 16 can be provided, and two are set in this embodiment, which will not be described in detail here.

[0036] A stirring rod 17 is provided in the dissolving tank 13, and the stirring rod 17 passes through the top of the dissolving tank 13 and the top of the dissolving tank 1 in sequence and is fixed on the dissolving tank 1; the first motor 19 can drive the bracket 18a and the dissolving tank 13 to rotate, and the dissolving tank 13 rotates relative to the stirring rod 17 to achieve the effect of stirring the material.

[0037] The dissolving kettle 1 is also provided with a spray device, which includes a spray disc 15a, a spray vertical rod 15b and a nozzle 15c; the spray disc 15a is located above the dissolving tank 13, and the top of the spray disc 15a is connected to the branch pipe 3; the spray vertical rod 15b is located in the cavity 16, and the upper end of the spray vertical rod 15b is connected to the spray disc 15a; a plurality of nozzles 15c are arranged on the spray disc 15a and the spray vertical rod 15b at intervals; the cavity 16 is cylindrical, which can avoid the problem that the spray vertical rod 15b directly enters the dissolving kettle 1 and causes the nozzle 15c to be blocked; at the same time, the spray vertical rod 15b penetrates deep into the material, and the condensed solvent is sprayed out through the nozzle 15c, which can increase the contact area between the solvent and the material. After using the dissolving kettle 1, the spray device can be used to spray the cleaning liquid on the inside and outside of the entire dissolving tank 13 and the dissolving kettle 1, so as to clean it more thoroughly.

[0038] Example 3

[0039] Please refer to Figure 1 Since the dissolved solution may contain suspended matter, tiny particles, and bacterial microorganisms, based on Example 2, the solvent kettle outlet 11 is also connected to a filter 31, and the filter element can have a good filtering effect on the above substances. After filtration, the filtrate can meet the sterilization requirements of GMP or pharmacopoeia; the internal filter element of the filter 31 adopts a folded filter element to increase the filtration area and improve the filtration speed.

[0040] The specific working process of the utility model is described by taking the dissolution of poly-L-lactic acid as an example:

[0041] When dissolution begins, the outlet valve 7a of the dissolution kettle is closed, and the first inlet valve 8a on the solvent kettle 2 is opened. The crude poly-L-lactic acid enters the dissolution tank 13 through the feeding port 14 on the dissolution tank 13, the first motor 19 and the second motor 25 are started, and an appropriate amount of solvent is added to the solvent kettle 2 through the second inlet 9, and the solvent kettle 2 is started for stirring. At the same time, the solvent kettle 2 is heated by the jacket of the solvent kettle 2 to vaporize the solvent, and the solvent vapor rises from the branch pipe 3 and passes through the condenser 6 to enter the dissolution kettle 1 after condensation; when the height of the solution in the dissolution kettle 1 exceeds the height of the bend 4b of the siphon 4, the siphon valve 4d is opened, and the solution containing the poly-L-lactic acid gradually enters the solvent kettle 2 through the siphon 4, and the siphon valve 4d can be adjusted to control the flow rate of the reflux solution; the solvent in the solvent kettle 2 continues to be vaporized and condensed in this cycle until the poly-L-lactic acid is completely dissolved, and the dissolved poly-L-lactic acid remains in the solvent kettle 2. After the dissolution is completed, during the filtering operation, the first inlet valve 8a is closed, and the third inlet 10 is connected to an external vacuum device for pressure filtering. The dissolved poly-L-lactic acid is discharged through the solvent kettle outlet 11 and enters the filter 31 for filtration; the equipment can realize large-scale continuous dissolution and filtration operations of materials.

[0042] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An efficient dissolving device, comprising a dissolving kettle (1) and a solvent kettle (2) connected to the dissolving kettle (1), characterized in that: The dissolving kettle outlet (7) at the bottom of the dissolving kettle (1) is connected to the first inlet (8) at the top of the solvent kettle (2) through a connecting pipe (5); the connecting pipe (5) is also provided with a branch pipe (3) and a siphon pipe (4); the branch pipe (3) is connected to the top of the dissolving kettle (1); the siphon pipe (4) is connected to the dissolving kettle (1); and the branch pipe (3) is also connected to a condenser (6).

2. The efficient dissolving device according to claim 1, characterized in that: The siphon pipe (4) comprises a short pipe (4a), a long pipe (4c) and an n-shaped curved pipe (4b), wherein the short pipe (4a), the curved pipe (4b) and the long pipe (4c) are connected in sequence, the other end of the short pipe (4a) is a siphon pipe inlet connected to the dissolving kettle (1), and the other end of the long pipe (4c) is a siphon pipe outlet connected to the connecting pipe (5); the branch pipe (3) has a branch pipe inlet and a branch pipe outlet, the branch pipe inlet is connected to the connecting pipe (5), and the branch pipe outlet is connected to the top of the dissolving kettle (1); Wherein, on the connecting pipe (5), the height of the siphon pipe outlet is lower than the height of the branch pipe inlet.

3. The efficient dissolution device according to claim 1, characterized in that: A dissolving tank (13) is provided in the dissolving kettle (1), the dissolving tank (13) being entirely composed of a filter screen, a bracket (18a) being provided below the dissolving tank (13), the bracket (18a) sequentially passing through the dissolving kettle (1) and a fixing bracket (18b) and being connected to an output end of a first motor (19), and a cavity (16) being provided at the center of the dissolving tank (13).

4. The efficient dissolving device according to claim 3, characterized in that: The dissolving kettle (1) is also provided with a spray device, which comprises a spray disc (15a), a spray vertical rod (15b) and a nozzle (15c); the spray disc (15a) is located above the dissolving tank (13), and the top of the spray disc (15a) is connected to the branch pipe (3); the spray vertical rod (15b) is located in the cavity (16), and the upper end of the spray vertical rod (15b) is communicated with the spray disc (15a); and a plurality of nozzles (15c) are arranged at intervals on the spray disc (15a) and the spray vertical rod (15b).

5. The efficient dissolving device according to claim 1, characterized in that: The volume of the dissolving kettle (1) is 1 / 4 to 2 / 3 of the volume of the solvent kettle (2), and the height of the siphon tube (4) is 1 / 3 to 2 / 3 of the height of the dissolving kettle (1).

6. The efficient dissolving device according to claim 1, characterized in that: The top of the solvent kettle (2) is provided with a second inlet (9) and a third inlet (10); valves are provided on the dissolving kettle outlet (7), the first inlet (8), the solvent kettle outlet (11) and the long tube (4c).

7. The efficient dissolving device according to claim 1, characterized in that: The dissolving kettle (1) and the solvent kettle (2) are both provided with jackets outside, and the solvent kettle (2) is also provided with supporting legs (12).

8. The efficient dissolving device according to claim 1, characterized in that: The solvent kettle outlet (11) is also connected to a filter (31).

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