Poly-L-lactic acid synthesis reactor

Abstract

The utility model discloses a poly-L-lactic acid synthesis reactor, and belongs to the field of poly-L-lactic acid production equipment. According to the structure, a plurality of transverse rods are arranged on a first rotating shaft, first shifting pieces are arranged at the ends of the transverse rods, extending pieces are arranged at the positions, located above the transverse rods, of the first rotating shaft, upper folding pieces are arranged at the ends of the extending pieces, a discharging door is installed at the position of a lower port of a reaction tank and driven by an electric actuator, and a primary feeding pipe is arranged on an end cover; a post-batch feeding pipe is connected between the reaction tank and the temporary storage tank, a feeding pump is mounted on the post-batch feeding pipe, a second rotating shaft is arranged in the temporary storage tank, and a plurality of second shifting pieces are arranged on the second rotating shaft. According to the utility model, the closed reaction space is constructed, and the temporary storage tank for feeding in the next batch is linked with the reaction tank, so that batch-by-batch feeding can be realized in a closed state, and the fluidity of polylactic acid monomers can be maintained before feeding. The device has positive effects on improving the production efficiency and relieving the environmental pollution.

Description

Technical Field

[0001] The utility model belongs to the technical field of poly (L-lactic acid) production equipment, in particular to a poly (L-lactic acid) synthesis reactor. Background Art

[0002] Since there is an asymmetric carbon atom in the lactic acid molecule, it is optically active, so polylactic acid is also divided into right-handed polylactic acid (PDLA), left-handed polylactic acid (PLLA), racemic polylactic acid (PDLLA), and non-optically active polylactic acid (Meso-PLA). PLLA is an important biodegradable polymer material, which is characterized by non-toxicity, non-irritation, biodegradable absorption, high strength, good plasticity, and easy processing and molding. The degradation cycle is 2 to 12 months. The degradation cycle can also be changed according to the addition of different modifiers. PLLA is enzymatically decomposed in the body and eventually forms carbon dioxide and water, which has good biocompatibility. PLLA has many uses, mainly used in surgical sutures, dentistry, ophthalmology, pharmaceutical controlled release systems, artificial skin, artificial blood vessels, bone and soft tissue defect fillers, bioabsorbable scaffolds and other medical fields.

[0003] The synthesis of poly-L-lactic acid is mainly divided into melt polycondensation and solution polymerization. Among them, the melt polycondensation method is to add L-lactic acid monomer to the catalyst at high temperature for melt polycondensation to generate PLLA poly-L-lactic acid. This method has the advantages of mild reaction conditions and high yield, but it also has problems such as increased viscosity and difficulty in control during the reaction. The solution polymerization method is to mix L-lactic acid monomer with a catalyst in an appropriate solvent and carry out a polymerization reaction by heating and stirring. This method can obtain a more uniform particle distribution, but the selection and recovery of the solvent have a certain impact on the environment. In the typical process of the solution polymerization method, a batch reaction mode is generally used, batches are spaced apart from each other, and the production continuity is poor, which restricts the production efficiency to a certain extent. Summary of the invention

[0004] The technical problem to be solved by the utility model is: how to improve the continuity of batch reaction at the process level.

[0005] The technical solution of the utility model is:

[0006] A poly-L-lactic acid synthesis reactor comprises a support frame, a reaction tank, an end cover, a motor, a first rotating shaft, a cross bar, a first paddle, an extension sheet, an upper folding sheet, a discharge door, an electric actuator, an initial feed pipe, a subsequent batch feed pipe, a temporary storage tank, a driving wheel, a conveyor belt, a passive wheel, a second rotating shaft, a second paddle, and an electric heating sleeve; the reaction tank and the temporary storage tank are respectively fixedly mounted on the support frame, an end cover is arranged at the upper port position of the reaction tank, a motor is mounted on the end cover, a first rotating shaft and a driving wheel are respectively fixed on the output shaft of the motor, the first rotating shaft and the driving wheel are respectively located inside and outside the reaction tank, and a There are multiple cross bars, a first paddle is provided at the end of the cross bar, an extension sheet is provided on the first rotating shaft and located above the cross bar, an upper folding sheet is provided at the end of the extension sheet, a discharge door is installed at the lower port of the reaction tank, the discharge door is driven by an electric actuator, a primary feed pipe is provided on the end cover, a rear batch feed pipe is connected between the reaction tank and the temporary storage tank, a feed pump is installed on the rear batch feed pipe, a second rotating shaft is provided in the temporary storage tank, a passive wheel is fixed on the second rotating shaft, the passive wheel and the driving wheel are both located within the operating range of the conveyor belt, multiple second paddles are provided on the second rotating shaft, and an electric heating sleeve is installed outside the temporary storage tank.

[0007] Preferably, the reaction tank is in an inverted cone shape, and the outer side surface of each first paddle is also in an inverted cone shape.

[0008] Preferably, a transmission box is provided on the top of the support frame, wherein the motor, the driving wheel, the conveyor belt and the driven wheel are all located in the transmission box.

[0009] Preferably, a jacket is provided on the outside of the reaction tank.

[0010] Preferably, the plane where the first paddle is located forms an angle of 30 to 40 degrees with the vertical plane.

[0011] Preferably, a pressurized pipe is installed on the end cover, and the pressurized pipe is connected to the air compressor.

[0012] Preferably, the plane where the upper folding piece is located is at an angle of 25 to 35 degrees with the horizontal plane.

[0013] In the structure of the utility model, the support frame is a basic support structure for installing other components; the reaction tank is a space for synthetic reaction; the end cover can close the reaction tank during the reaction process; the motor can be used to drive the first rotating shaft to rotate, and the cross bar installed on the first rotating shaft and the first paddle at its end can mix the reactants; the extension piece is used to set the upper folding piece, and the upper folding piece located at the top guides the reactants that are tumbling upward from the inner edge of the reaction tank due to the stirring effect, so that they are ejected toward the center of the reaction tank; the unloading door and the electric actuator that controls the opening and closing of the door are used to control the unloading; the initial feeding pipe is used to input the initial reactants, and the positive pressure gas is used to unload after the reaction of the batch is completed to complete the reaction of the batch; the rear batch feeding pipe is used for the rear batch feeding, and the temporary storage tank is used to temporarily store the monomers to be fed; the driving wheel, the conveyor belt, and the passive wheel realize the synchronous rotation of the first rotating shaft in the reaction tank and the second rotating shaft in the temporary storage tank; the second rotating shaft drives the second paddle to rotate, which has a stirring effect on the temporarily stored monomers, and combined with the temperature control effect of the electric heating sleeve, the fluidity of the polylactic acid monomer can be maintained before feeding.

[0014] The utility model discloses a poly-L-lactic acid synthesis reactor. This technical innovation constructs a closed reaction space, and links the temporary storage tank used for the subsequent batch feeding with the reaction tank as the reaction space, which can not only feed in batches in a closed state, but also maintain the fluidity of the polylactic acid monomer before feeding. Thanks to this semi-continuous feeding mode, the heating time of the subsequent batches is saved, the operation steps such as stirring and sealing are reduced to a certain extent, and the continuity between batches is improved, which has a positive effect on improving production efficiency and alleviating environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the overall diagram of the reactor;

[0016] Figure 2 is a front view of the first rotating shaft;

[0017] Figure 3 is a top view of the extended piece;

[0018] Figure 4 It is a perspective view of the temporary storage tank;

[0019] in:

[0020] 1. Support frame 2. Reactor 3. End cover 4. Motor

[0021] 5. First rotating shaft 6. Crossbar 7. First paddle 8. Extension piece

[0022] 9. Upper folding piece 10. Discharge door 11. Electric actuator 12. Initial feed pipe

[0023] 13. Rear batch feeding pipe 14. Temporary storage tank 15. Driving wheel 16. Conveyor belt

[0024] 17, passive wheel 18, second rotating shaft 19, second paddle 20, electric heating sleeve. DETAILED DESCRIPTION

[0025] The specific implementation methods of the present invention will be described in detail below. In order to avoid too many unnecessary details, the well-known structures or functions will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative expression, indicating that the quantity can be allowed to change without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meanings as those generally understood by technicians in the field to which the present invention belongs.

[0026] Example 1

[0027] A poly-L-lactic acid synthesis reactor, see Figures 1 to 4 , including a support frame 1, a reaction tank 2, an end cover 3, a motor 4, a first rotating shaft 5, a cross bar 6, a first paddle 7, an extension piece 8, an upper folding piece 9, a discharge door 10, an electric actuator 11, an initial feeding pipe 12, a rear batch feeding pipe 13, a temporary storage tank 14, a driving wheel 15, a conveyor belt 16, a passive wheel 17, a second rotating shaft 18, a second paddle 19, and an electric heating sleeve 20; the reaction tank 2 and the temporary storage tank 14 are fixedly installed on the support frame 1, an end cover 3 is provided at the upper port position of the reaction tank 2, a motor 4 is installed on the end cover 3, and the first rotating shaft 5 and the driving wheel 15 are fixed on the output shaft of the motor 4, respectively, the first rotating shaft 5 and the driving wheel 15 are respectively located inside and outside the reaction tank 2, and a plurality of cross bars are provided on the first rotating shaft 5 6, a first paddle 7 is provided at the end of the cross bar 6, an extension piece 8 is provided on the first rotating shaft 5 at a position above the cross bar 6, an upper folding piece 9 is provided at the end of the extension piece 8, a discharge door 10 is installed at the lower port of the reaction tank 2, and the discharge door 10 is driven by an electric actuator 11, a primary feed pipe 12 is provided on the end cover 3, a rear batch feed pipe 13 is connected between the reaction tank 2 and the temporary storage tank 14, a feed pump is installed on the rear batch feed pipe 13, a second rotating shaft 18 is provided in the temporary storage tank 14, a passive wheel 17 is fixed on the second rotating shaft 18, the passive wheel 17 and the driving wheel 15 are both located within the operating range of the conveyor belt 16, a plurality of second paddles 19 are provided on the second rotating shaft 18, and an electric heating sleeve 20 is installed outside the temporary storage tank 14.

[0028] Among them, the support frame 1 is a basic support structure for installing other components; the reaction tank 2 is a space for synthetic reaction; the end cover 3 can close the reaction tank 2 during the reaction process; the motor 4 can be used to drive the first rotating shaft 5 to rotate, and the cross bar 6 installed on the first rotating shaft 5 and the first paddle 7 at its end mix the reactants; the extension piece 8 is used to set the upper folding piece 9, and the upper folding piece 9 located at the top guides the reactants that are tumbling upward from the inner edge of the reaction tank 2 due to the stirring action, so that they are ejected toward the center of the reaction tank 2; the discharge door 10 and the electric actuator 11 that controls its opening and closing are used to control the unloading; the initial feed pipe 12 is used to input the initial reactants, and after the reaction of the batch is completed, the positive pressure gas is used to unload the reactants to complete the reaction of the batch; the subsequent batch feeding adopts the subsequent batch feeding pipe 13, and the temporary storage tank 14 is used to temporarily store the monomers to be fed; the driving wheel 15, the conveyor belt 16, and the passive wheel 17 realize the synchronous rotation of the first rotating shaft 5 in the reaction tank 2 and the second rotating shaft 18 in the temporary storage tank 14; the second rotating shaft 18 drives the second paddle 19 to rotate, which has a stirring effect on the temporarily stored monomers, and combined with the temperature control effect of the electric heating sleeve 20, the fluidity of the polylactic acid monomer can be maintained before feeding.

[0029] Example 2

[0030] A poly-L-lactic acid synthesis reactor, see Figures 1 to 4, including a support frame 1, a reaction tank 2, an end cover 3, a motor 4, a first rotating shaft 5, a cross bar 6, a first paddle 7, an extension piece 8, an upper folding piece 9, a discharge door 10, an electric actuator 11, an initial feeding pipe 12, a rear batch feeding pipe 13, a temporary storage tank 14, a driving wheel 15, a conveyor belt 16, a passive wheel 17, a second rotating shaft 18, a second paddle 19, and an electric heating sleeve 20; the reaction tank 2 and the temporary storage tank 14 are fixedly installed on the support frame 1, an end cover 3 is provided at the upper port position of the reaction tank 2, a motor 4 is installed on the end cover 3, and the first rotating shaft 5 and the driving wheel 15 are fixed on the output shaft of the motor 4, respectively, the first rotating shaft 5 and the driving wheel 15 are respectively located inside and outside the reaction tank 2, and a plurality of cross bars are provided on the first rotating shaft 5 6, a first paddle 7 is provided at the end of the crossbar 6, an extension piece 8 is provided on the first rotating shaft 5 at a position above the crossbar 6, an upper folding piece 9 is provided at the end of the extension piece 8, a discharge door 10 is installed at the lower port of the reaction tank 2, and the discharge door 10 is driven by an electric actuator 11, a primary feed pipe 12 is provided on the end cover 3, a rear batch feed pipe 13 is connected between the reaction tank 2 and the temporary storage tank 14, and a feed pump is installed on the rear batch feed pipe 13, a second rotating shaft 18 is provided in the temporary storage tank 14, a passive wheel 17 is fixed on the second rotating shaft 18, and the passive wheel 17 and the driving wheel 15 are both located within the operating range of the conveyor belt 16, a plurality of second paddles 19 are provided on the second rotating shaft 18, and an electric heating sleeve 20 is installed outside the temporary storage tank 14. The reaction tank 2 is in an inverted cone shape, and the outer side surface of each first paddle 7 also forms an inverted cone shape. A transmission box is provided on the top of the support frame 1, wherein the motor 4, the driving wheel 15, the conveyor belt 16, and the driven wheel 17 are all located in the transmission box. A jacket is provided on the outside of the reaction tank 2. The plane where the first paddle 7 is located is at an angle of 30 to 40 degrees to the vertical plane. A pressurized pipe is installed on the end cover 3, and the pressurized pipe is connected to the air compressor. The plane where the upper folding piece 9 is located is at an angle of 25 to 35 degrees to the horizontal plane.

[0031] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of application of the present invention shall be included in the protection scope of the present invention.

Claims

1. A poly-L-lactic acid synthesis reactor, characterized in that: The invention comprises a support frame (1), a reaction tank (2), an end cover (3), a motor (4), a first rotating shaft (5), a cross bar (6), a first paddle (7), an extension plate (8), an upper folding plate (9), a discharge door (10), an electric actuator (11), an initial feed pipe (12), a subsequent batch feed pipe (13), a temporary storage tank (14), a driving wheel (15), a conveyor belt (16), a driven wheel (17), a second rotating shaft (18), and a second paddle (19). , an electric heating sleeve (20); a reaction tank (2) and a temporary storage tank (14) are fixedly mounted on the support frame (1), an end cover (3) is arranged at the upper port of the reaction tank (2), an electric motor (4) is mounted on the end cover (3), a first rotating shaft (5) and a driving wheel (15) are fixed on the output shaft of the electric motor (4), the first rotating shaft (5) and the driving wheel (15) are respectively located inside and outside the reaction tank (2), and the first rotating shaft (5) has A plurality of cross bars (6) are provided, a first paddle (7) is provided at the end of the cross bar (6), an extension sheet (8) is provided on the first rotating shaft (5) at a position above the cross bar (6), an upper folding sheet (9) is provided at the end of the extension sheet (8), a discharge door (10) is installed at the lower end of the reaction tank (2), the discharge door (10) is driven by an electric actuator (11), a primary feed pipe (12) is provided on the end cover (3), and a discharge door (10) is provided between the reaction tank (2) and the temporary storage tank (14). ) are connected with a rear batch feed pipe (13), a feed pump is installed on the rear batch feed pipe (13), a second rotating shaft (18) is arranged in the temporary storage tank (14), a passive wheel (17) is fixed on the second rotating shaft (18), the passive wheel (17) and the driving wheel (15) are both located within the operating range of the conveyor belt (16), a plurality of second paddles (19) are arranged on the second rotating shaft (18), and an electric heating jacket (20) is installed outside the temporary storage tank (14).

2. A poly-L-lactic acid synthesis reactor according to claim 1, characterized in that: The reaction tank (2) is in an inverted cone shape, and the outer side surface of each first paddle (7) is also in an inverted cone shape.

3. A poly-L-lactic acid synthesis reactor according to claim 1, characterized in that: A transmission box is provided on the top of the support frame (1), wherein the motor (4), the driving wheel (15), the conveyor belt (16) and the driven wheel (17) are all located in the transmission box.

4. A poly-L-lactic acid synthesis reactor according to claim 1, characterized in that: A jacket is provided on the outside of the reaction tank (2).

5. A poly-L-lactic acid synthesis reactor according to claim 1, characterized in that: The plane where the first paddle (7) is located forms an angle of 30 to 40 degrees with the vertical plane.

6. A poly-L-lactic acid synthesis reactor according to claim 1, characterized in that: A pressurizing pipe is installed on the end cover (3), and the pressurizing pipe is connected to the air compressor.

7. A poly-L-lactic acid synthesis reactor according to claim 1, characterized in that: The plane where the upper folding piece (9) is located is at an angle of 25 to 35 degrees with the horizontal plane.

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