Glycolide polymerization system and control method

Abstract

The present invention discloses a glycolide polymerization system, which comprises: a mixing unit for mixing glycolide and a catalyst into a mixed material; and the reactor is arranged at the downstream of the mixing unit, is connected with the mixing unit and is used for producing the glycolide polymer through polymerization reaction. And the temperature control unit is arranged on one side of the reactor, is connected with the reactor through a pipeline, and is used for inputting the heat-conducting oil from the oil system into the reactor and also used for cooling the reaction temperature in the reactor in a partitioned manner. And the removal unit is positioned on an outlet pipeline of the reactor, is connected with the reactor and is used for removing light components in the glycolide polymer. Under the action of the catalyst, the temperature control unit controls the temperature in the reactor in different reaction zones, so that the glycolide polymer generated in the reactor can be smoothly discharged into the devolatilization device, the blockage of the reactor is reduced, the production efficiency is improved, the long-period continuous operation of the device system can be ensured, and the production cost is reduced. The invention also discloses a control method of the glycolide polymerization system.

Description

Technical Field

[0001] The present invention relates to the technical field of glycolide polymerization, and in particular to a glycolide polymerization system and a control method. Background Art

[0002] Polyglycolide is a process in which low molecular weight glycolide monomers are synthesized into high molecular weight polyglycolide (PGA) through polymerization reaction.

[0003] Glycolide, chemically known as glyceric acid, is a chemical substance with a specific molecular formula of C4H4O4. It is the basic unit of polyglycolide and forms polymers through polymerization reactions. Polymerization reaction is a chemical reaction that usually needs to be carried out under specific conditions, such as appropriate temperature, pressure and the presence of a catalyst to ensure the effective progress of the reaction. The device system for glycolide polymerization reaction includes a reactor. The reactor used in the new project is a "gate" type. After the reactor system is put into operation, the control system is difficult to control the temperature in the reactor during the actual production process. The generated glycolide polymer easily clogs the reactor, causing the entire device to be shut down for maintenance, affecting the long-term continuous operation of the device.

[0004] The existing system has difficulty in controlling the temperature of the reactor, which causes glycolide polymer to plug the reactor. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a glycolide polymerization system, which controls the reaction temperature of the improved reactor reaction zone by a temperature control unit.

[0006] In order to achieve the above object, the present invention is achieved through the following technical solutions:

[0007] A glycolide polymerization system comprising:

[0008] The mixing unit is used to mix glycolide and catalyst into a mixed material.

[0009] The reactor is arranged downstream of the mixing unit and connected to the mixing unit, and is used for producing glycolide polymer through polymerization reaction.

[0010] The temperature control unit is arranged on one side of the reactor and connected to the reactor pipeline. It is used to input the heat transfer oil from the oil system into the reactor and is also used to cool the reaction temperature in the reactor in different zones.

[0011] The removal unit is located on the outlet pipeline of the reactor and is connected to the reactor for removing light components in the glycolide polymer.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] Under the action of the catalyst, the glycolide in the mixed material undergoes a polymerization reaction in the reactor. The temperature control unit controls the temperature in the reactor in different reaction zones so that the glycolide polymer produced inside can be smoothly discharged into the devolatilizer, reducing blockage of the reactor, improving production efficiency, and ensuring long-term continuous operation of the device system.

[0014] More preferably, the reactor is a vertical reactor, and the reactor is divided into multiple reaction zones, and the multiple reaction zones are arranged from top to bottom of the reactor.

[0015] By adopting the above technical solution, the "gate" type reactor is changed into a vertical reactor, so that the glycolide polymer enters multiple reaction zones from the top of the reactor from top to bottom, forming a corresponding control relationship with the temperature control unit, and realizing temperature control of the reaction zones from top to bottom of the reactor, so that the temperature of the glycolide polymer inside it is within the index range, thereby reducing blockage of the reactor.

[0016] More preferably, the temperature control unit includes a plurality of temperature control loops, each heat transfer oil loop is connected in parallel to the reactor, and each temperature control loop uniquely corresponds to a reaction zone.

[0017] By adopting the above technical solution, each temperature control loop controls the corresponding reaction zone, and the reaction temperature in the reactor is controlled by adjusting the oil temperature.

[0018] More preferably, the temperature control circuit includes:

[0019] The first temperature control valve is arranged on the oil inlet pipeline of the reaction zone, located on one side of the reactor, and is used to control the oil inlet amount of the reaction zone by opening.

[0020] The oil pump is arranged on the oil inlet pipeline, and the outlet of the oil pump is connected to the inlet pipeline of the first temperature control valve through the oil inlet pipeline.

[0021] The third temperature control valve is located on the oil inlet pipeline. The inlet of the third temperature control valve is connected to the oil system, and the outlet is connected to the oil pump through the oil inlet pipeline. It is used to replenish the hot oil of the oil system into the reaction zone.

[0022] The air cooler is arranged on the bypass line of the oil inlet line, the inlet is connected to the outlet of the oil pump through a pipeline, the outlet is connected to the second temperature control valve, and the second temperature control valve is connected to the oil inlet line.

[0023] The oil return valve is installed on the oil return pipeline of the temperature control circuit and is connected to the oil return pipeline. It is used to control the heat transfer oil after heat exchange to the oil system.

[0024] By adopting the above technical solution, under different temperature conditions, by adjusting the openings of the first temperature control valve, the second temperature control valve and the third temperature control valve, the amount of cooling oil in the air cooler is adjusted to control the oil temperature entering the reaction zone, and then the temperature in the reaction zone is controlled. The reactor is regulated and controlled in sections, so that the glycolide polymer can be smoothly discharged to the end of the devolatilizer at the optimal temperature state, reducing blockage of the reactor.

[0025] Further optimization is that the removal unit includes:

[0026] The devolatilizer is arranged on one side of the reactor and located above the reactor. The position of the devolatilizer is higher than the top of the reactor. The inlet of the devolatilizer is connected to the bottom outlet pipeline of the reactor and is used to remove light components from the glycolide polymer by stirring under vacuum.

[0027] The vacuum pump is arranged on one side of the devolatilizer, and the inlet of the vacuum pump is connected to the devolatilizer, and is used to extract the light components out of the system in the form of vacuum.

[0028] The booster pump is connected to the outlet pipeline of the devolatilizer and is used to transport the glycolide polymer after the light components are removed to the granulation system.

[0029] By adopting the above technical solution, when the devolatilizer is stirring the glycolide polymer, the vacuum pump extracts the light components in the glycolide polymer by vacuuming, thereby preventing the light components from staying in the glycolide polymer for a long time and clogging the devolatilizer.

[0030] Further optimization is that an exhaust valve is provided on the top of the reactor, and the exhaust valve is connected to the reactor through a pipeline for discharging the gas after the reaction in the reactor.

[0031] By adopting the above technical solution, the pressure in the reactor can be controlled within the target range.

[0032] The present invention also discloses a control method for a glycolide polymerization system, comprising:

[0033] Mix glycolide with the catalyst.

[0034] The polymerization reaction is carried out in the reactor in different reaction zones to produce glycolide polymer.

[0035] During the polymerization process, the temperature control unit adjusts the cooling capacity of the air cooler to control the temperature in each reaction zone.

[0036] The vacuum pump evacuates the devolatilizer to remove light components from the glycolide polymer.

[0037] The booster pump conveys the glycolide polymer after the light components are removed to the granulation system.

[0038] By adopting the above technical solution, during the process of producing glycolide polymer, the temperature is controlled in each reaction zone and light components are removed by vacuuming, thereby preventing the glycolide polymer from clogging the reactor and the devolatilizer.

[0039] Further optimization is that during the polymerization reaction, the temperature control unit adjusts the cooling capacity of the air cooler to control the temperature in each reaction zone, including:

[0040] A temperature measuring point TIC is set on the return oil pipeline corresponding to any reaction zone of the reactor.

[0041] The control temperature index range of the preset temperature measuring point TIC is A.

[0042] Compare the value of the temperature measuring point TIC in real time with A, adjust the switch state of the valve on the temperature control loop, and adjust the oil temperature entering the reaction zone.

[0043] By adopting the above technical solution, the TIC value can be monitored in real time, and the temperature of any reaction zone can be specifically adjusted by judging whether it is within the temperature index range.

[0044] Further optimization involves comparing the real-time temperature measurement point TIC value with A, adjusting the on / off state of the valve in the temperature control loop, and adjusting the oil temperature entering the reaction zone, including:

[0045] If the TIC value is higher than A, close the first temperature control valve and open the second temperature control valve to reduce the TIC value.

[0046] If the TIC value is lower than A, open the first temperature control valve and close the second temperature control valve to increase the TIC value.

[0047] If the first temperature control valve is fully opened and the second temperature control valve is closed, and the TIC value continues to be lower than A, the third temperature control valve should be fully opened to add hot oil from the oil system to the reaction zone to increase the TIC value.

[0048] By adopting the above technical solution, the temperature of the oil return line is adjusted according to the comparison between the TIC value and A, so as to adjust the temperature inside the reactor, control the reactor within the optimal temperature range, and prevent glycolide polymer from clogging the equipment.

[0049] Further optimization is to control the temperature index range A to 215℃-240℃.

[0050] By adopting the above technical solution, the temperature range is the optimal temperature for the glycolide polymer in the reactor, and clogging is not likely to occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Schematic diagram of the system structure of this embodiment.

[0052] Figure 2 This is the process diagram of the oil guide circuit in this embodiment.

[0053] Figure numerals: 1-glycolide tank; 2-catalyst tank; 3-glycolide booster pump; 4-catalyst pump; 5-mixer; 6-reactor; 7-oil guide circuit; 70-oil pump; 71-first temperature control valve; 72-second temperature control valve; 73-third temperature control valve; 74-air cooler; 75-return oil valve; 76-connecting valve; 8-oil system; 9-devolatilizer; 10-boosting pump; 11-vacuum pump; 12-exhaust valve. DETAILED DESCRIPTION

[0054] The following is combined with Figure 1-Figure 2 The present invention is further described in detail.

[0055] Example 1

[0056] A glycolide polymerization system, such as Figure 1 Shown, including:

[0057] The mixing unit is used to mix glycolide and catalyst into a mixed material.

[0058] The reactor 6 is disposed downstream of the mixing unit and connected to the mixing unit for producing glycolide polymer through polymerization reaction.

[0059] The temperature control unit is arranged on one side of the reactor 6 and connected to the pipeline of the reactor 6. It is used to input the heat transfer oil from the oil system 8 into the reactor 6 and is also used to cool the reaction temperature in the reactor 6 in different zones.

[0060] The removal unit is located on the outlet pipeline of the reactor 6 and is connected to the reactor 6 for removing light components in the glycolide polymer.

[0061] Under the action of the catalyst, the glycolide in the mixed material undergoes a polymerization reaction in the reactor 6. The temperature control unit controls the temperature in the reactor 6 in different reaction zones so that the glycolide polymer produced inside can be smoothly discharged into the devolatilizer 9, reducing the blockage of the reactor 6, improving the production efficiency, and ensuring the long-term continuous operation of the device system.

[0062] Specifically, such as Figure 1 and Figure 2 As shown, in this embodiment, the reactor 6 is a vertical reactor 6, which is divided into multiple reaction zones, which are arranged from top to bottom from the reactor 6. By changing the "gate" type reactor 6 to a vertical reactor 6, the glycolide polymer enters the multiple reaction zones from the top of the reactor 6 from top to bottom, forming a corresponding control relationship with the temperature control unit, and achieving temperature control of the reaction zones from top to bottom of the reactor 6, so that the temperature of the glycolide polymer inside the reactor 6 is within the specified range, thereby reducing blockage of the reactor 6.

[0063] Specifically, such as Figure 1 and Figure 2 As shown, in this embodiment, the temperature control unit includes multiple temperature control circuits, each of which is connected in parallel to the reactor 6. Each temperature control circuit uniquely corresponds to a reaction zone. Each temperature control circuit controls its corresponding reaction zone, and the reaction temperature within the reactor 6 is controlled by adjusting the oil temperature.

[0064] Specifically, such as Figure 1 and Figure 2 As shown, the temperature control circuit in this embodiment includes:

[0065] The first temperature control valve 71 is provided on the oil inlet pipeline of the reaction zone, located on one side of the reactor 6 , and is used to control the oil inlet amount of the reaction zone by opening, thereby controlling the heat of the heat transfer oil entering the reactor 6 .

[0066] The oil pump 70 is provided on the oil inlet pipeline, and its outlet is connected to the inlet pipeline of the first temperature control valve 71 through the oil inlet pipeline.

[0067] The third temperature control valve 73 is located on the oil inlet pipeline, with its inlet connected to the oil system 8 and its outlet connected to the oil pump 70 through the oil inlet pipeline, for replenishing the hot oil of the oil system 8 into the reaction zone.

[0068] The air cooler 74 is provided on a bypass line of the oil inlet line, the inlet of which is connected to the outlet of the oil pump 70 via a pipeline, and the outlet of the air cooler 74 is connected to the second temperature control valve 72 , which is connected to the oil inlet line.

[0069] The oil return valve 75 is provided on the oil return pipeline of the temperature control circuit and is connected to the oil return pipeline for controlling the heat transfer oil after heat exchange to the oil system 8 .

[0070] Under different temperature conditions, by adjusting the openings of the first temperature control valve 71, the second temperature control valve 72 and the third temperature control valve 73, if the second temperature control valve 72 is opened wider, the amount of heat transfer oil entering the air cooler 74 will increase, and then the cooling capacity in the heat transfer oil will be greater, and then the cooling capacity entering the reaction zone will also increase. Therefore, by adjusting the amount of cooling oil in the air cooler 74, the oil temperature entering the reaction zone is controlled, and then the temperature in the reaction zone is controlled, and the reactor 6 is regulated and controlled in sections, so that the glycolide polymer can be smoothly discharged to the end of the devolatilizer 9 under the optimal temperature state, thereby reducing the blockage of the reactor 6.

[0071] Specifically, such as Figure 1 and Figure 2 As shown, the removal unit in this embodiment includes:

[0072] The devolatilizer 9 is arranged on one side of the reactor 6 and is located above the reactor 6. Its position is higher than the top of the reactor 6, so that a communicating vessel is formed between the devolatilizer 9 and the reactor 6. Its inlet is connected to the bottom outlet pipeline of the reactor 6, and is used to remove light components from the glycolide polymer by stirring under vacuum.

[0073] The vacuum pump 11 is provided at one side of the devolatilizer 9 , with its inlet connected to the devolatilizer 9 , and is used to extract the light components out of the system in the form of vacuum.

[0074] The booster pump 10 is connected to the outlet pipeline of the devolatilizer 9 and is used to transport the glycolide polymer after the light components are removed to the granulation system.

[0075] During the process of stirring the glycolide polymer in the devolatilizer 9 , the vacuum pump 11 extracts the light components in the glycolide polymer by vacuuming, so as to prevent the light components from staying in the glycolide polymer for a long time and clogging the devolatilizer 9 .

[0076] Specifically, such as Figure 1 and Figure 2 As shown, in this embodiment, an exhaust valve 12 is provided on the top of the reactor 6. The exhaust valve 12 is connected to the reactor 6 through a pipeline and is used to discharge the gas after the reaction in the reactor 6 to control the pressure in the reactor 6 within the index range.

[0077] Example 2

[0078] The present invention also discloses a control method for a glycolide polymerization system, comprising:

[0079] Mix glycolide with the catalyst.

[0080] In the reactor 6, polymerization reaction is carried out in the reaction zones to produce glycolide polymer.

[0081] During the polymerization reaction, the temperature control unit adjusts the cooling capacity of the air cooler 74 to control the temperature in each reaction zone.

[0082] The vacuum pump 11 evacuates the devolatilizer 9 to remove light components from the glycolide polymer.

[0083] The booster pump 10 delivers the glycolide polymer after light components are removed to the pelletizing system.

[0084] By adopting the above technical solution, during the process of producing glycolide polymer, the temperature is controlled in each reaction zone and light components are removed by vacuuming to prevent the glycolide polymer from clogging the reactor 6 and the devolatilizer 9.

[0085] Specifically, during the polymerization reaction in this embodiment, the temperature control unit adjusts the cooling amount of the air cooler 74 to control the temperature in each reaction zone, including:

[0086] A temperature measuring point TIC is set on the oil return pipeline corresponding to any reaction zone of reactor 6.

[0087] The control temperature index range of the preset temperature measuring point TIC is A.

[0088] Compare the value of the temperature measuring point TIC in real time with A, adjust the switch state of the valve on the temperature control loop, and adjust the oil temperature entering the reaction zone.

[0089] The TIC value can be monitored in real time, and the temperature of any reaction zone can be specifically adjusted by judging whether it is within the temperature index range.

[0090] Specifically, in this embodiment, the value of the temperature measuring point TIC in real time is compared with A, the switch state of the valve on the temperature control loop is adjusted, and the temperature of the oil entering the reaction zone is adjusted, including:

[0091] If the TIC value is higher than A, the first temperature control valve 71 is closed and the second temperature control valve 72 is opened to reduce the TIC value.

[0092] If the TIC value is lower than A, the first temperature control valve 71 is opened and the second temperature control valve 72 is closed to increase the TIC value.

[0093] If the first temperature control valve 71 is fully opened and the second temperature control valve 72 is closed, and the TIC value continues to be lower than A, the third temperature control valve 73 should be fully opened to add hot oil from the oil system 8 to the reaction zone to increase the TIC value.

[0094] According to the comparison between the TIC value and A, the temperature of the oil return line is adjusted to adjust the temperature inside the reactor 6, and the reactor 6 is controlled within the optimal temperature range to prevent the glycolide polymer from clogging the equipment.

[0095] Specifically, the control temperature index range A in this embodiment is 215° C.-240° C. This temperature range is the optimal temperature for the glycolide polymer in the reactor 6 and is less likely to cause clogging.

[0096] Please combine Figure 1 、 Figure 2 , Example 1 and Example 2, the implementation process of the present invention is described as follows:

[0097] The glycolide stored in the glycolide tank 1 is pressurized by the glycolide pressure pump 3 and then transported to the mixer 5. The catalyst from the catalyst tank 2 is pressurized by the catalyst pump 4 and then transported to the mixer 5 to be mixed with the glycolide to obtain a mixed material.

[0098] Under the action of the catalyst, the mixed material undergoes a polymerization reaction within reactor 6 to produce glycolide polymer. In this embodiment, reactor 6 is divided into five reaction zones, each corresponding to an oil conducting circuit 7. The five oil conducting circuits 7 constitute a temperature control unit. The temperature measurement point TIC on the oil return line reflects the oil temperature in the return line, thereby reflecting the temperature within the reaction zone. The value of this temperature measurement point TIC is controlled by an operating system that controls the openings of the first, second, and third temperature control valves 71, 72, and 73, thereby controlling the temperature within the reaction zone. The operating system is conventional and need not be described in detail.

[0099] The following uses 215°C, 240°C, and 230°C as examples to specifically describe the process of the temperature control unit regulating the temperature in the reactor 6: A control temperature index value of 215°C is set in advance at the temperature measuring point TIC. The thermal oil from the oil system 8 passes through the third temperature control valve 73, enters the oil pump 70, is pressurized, and then passes through the first temperature control valve 71 to enter the reaction zone, exchanging heat with the reaction zone. The thermal oil on the return oil line enters the oil pump 70 through the connecting valve 76. If the value of the temperature measuring point TIC is higher than 215°C in real time, it means that the temperature in the reaction zone is higher than the index value. The first temperature control valve 71 should be closed and the second temperature control valve 72 should be opened. A portion of the thermal oil enters the air cooler 74 for cooling, while the other portion passes through the first temperature control valve 71 and merges with the thermal oil from the second temperature control valve 72 before entering the reaction zone to lower the temperature in the reaction zone. If the value of the temperature measuring point TIC is lower than 215°C in real time, it means that the temperature in the reaction zone is lower than the index value. The first temperature control valve 71 should be opened. The second temperature control valve 72 is opened slightly to allow a smaller portion of the heat transfer oil to enter the air cooler 74 for cooling, while a larger portion of the heat transfer oil passes through the first temperature control valve 71 and merges with the heat transfer oil from the second temperature control valve 72 before entering the reaction zone to increase the temperature in the reaction zone. If the first temperature control valve 71 is fully opened and the second temperature control valve 72 is closed, the TIC value continues to be lower than 215°C. At this time, the third temperature control valve 73 is fully opened to directly add the hot oil from the oil system 8 to the reaction zone to quickly increase the TIC value and raise the temperature in the reaction zone to the target value.

[0100] The process of controlling the reaction zone by the oil conducting circuit 7 is as follows: the control temperature index value of the temperature measuring point TIC is set in advance to 240°C, the heat conducting oil from the oil system 8 passes through the third temperature control valve 73 and enters the oil pump 70, is pressurized, and then passes through the first temperature control valve 71 to enter the reaction zone, and exchanges heat with the reaction zone. The heat conducting oil on the return oil pipeline enters the oil pump 70 through the connecting valve 76. If the value of the temperature measuring point TIC is higher than 240°C monitored in real time, it means that the temperature in the reaction zone is higher than the index value. The first temperature control valve 71 should be closed and the second temperature control valve 72 should be opened. A part of the heat conducting oil enters the air cooler 74 for cooling, and the other part of the heat conducting oil passes through the first temperature control valve 71 and merges with the heat conducting oil from the second temperature control valve 72 before entering the reaction zone to reduce the temperature in the reaction zone. If the value of the temperature measuring point TIC is lower than 240°C monitored in real time, it means that the temperature in the reaction zone is lower than the index value. The first temperature control valve 71 should be opened. The second temperature control valve 72 is opened slightly to allow a smaller portion of the heat transfer oil to enter the air cooler 74 for cooling, while a larger portion of the heat transfer oil passes through the first temperature control valve 71 and merges with the heat transfer oil from the second temperature control valve 72 before entering the reaction zone to increase the temperature in the reaction zone. If the first temperature control valve 71 is fully opened and the second temperature control valve 72 is closed, the TIC value continues to be lower than 240°C. At this time, the third temperature control valve 73 is fully opened to directly add the hot oil from the oil system 8 to the reaction zone to quickly increase the TIC value and raise the temperature in the reaction zone to the target value.

[0101] The process of controlling the reaction zone by the oil conducting circuit 7 is as follows: the control temperature index value of the temperature measuring point TIC is set in advance to 230°C, the heat transfer oil from the oil system 8 enters the oil pump 70 after passing through the third temperature control valve 73, is pressurized, and then enters the reaction zone through the first temperature control valve 71 to exchange heat with the reaction zone. The heat transfer oil on the return oil pipeline enters the oil pump 70 through the connecting valve 76. If the value of the temperature measuring point TIC monitored in real time is higher than 230°C, it means that the temperature in the reaction zone is higher than the index value. The first temperature control valve 71 should be closed and the second temperature control valve 72 should be opened to allow a portion of the heat transfer oil to enter the air cooler 74 for cooling, and the other portion of the heat transfer oil passes through the first temperature control valve 71 and merges with the heat transfer oil from the second temperature control valve 72 before entering the reaction zone to reduce the temperature in the reaction zone; if the value of the temperature measuring point TIC monitored in real time is lower than 230°C, it means that the temperature in the reaction zone is lower than the index value. The first temperature control valve 71 should be opened to allow a smaller portion of the heat transfer oil to enter the air cooler 74 for cooling, and a larger portion of the heat transfer oil passes through the first temperature control valve 71 and merges with the heat transfer oil from the second temperature control valve 72. The heat transfer oil of valve 72 is combined and enters the reaction zone to increase the temperature in the reaction zone; if the first temperature control valve 71 is fully opened and the second temperature control valve 72 is closed, the TIC value continues to be lower than 230°C, then the third temperature control valve 73 is fully opened, and the hot oil of the oil system 8 is directly added to the reaction zone to quickly increase the TIC value and raise the temperature in the reaction zone to the index value; the same process is carried out, and the temperature of each corresponding zone is judged according to the TIC value on each oil guide circuit 7, and the temperature of each reaction zone is adjusted by adjusting the opening of the first temperature control valve 71, the second temperature control valve 72 and the third temperature control valve 73, so that the temperature of the reactor 6 is controlled by the temperature control unit to prevent or reduce the blockage of the reactor 6 by the glycolide polymer.

[0102] In the actual production process, the temperature of the TIC is controlled between 215° C. and 240° C. by the temperature control unit, and the glycolide polymer produced in the reactor 6 will rarely clog the reactor 6, ensuring long-term continuous operation of the device.

[0103] Finally, under the action of the added additives, the devolatilizer 9 stirs the glycolide polymer, and the vacuum pump 11 removes the light components in the glycolide polymer by vacuuming. At the bottom outlet of the devolatilizer 9, the booster pump 10 transports the glycolide polymer to the granulation system.

[0104] This specific embodiment is merely an explanation of the invention and is not a limitation of the invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as they are within the scope of protection of the invention, they are protected by patent law.

Claims

1. A glycolide polymerization system, characterized in that: include: A mixing unit, used for mixing glycolide and a catalyst into a mixed material; A reactor (6), disposed downstream of the mixing unit and connected to the mixing unit, for producing a glycolide polymer through a polymerization reaction; a temperature control unit, arranged on one side of the reactor (6), connected to a pipeline of the reactor (6), for inputting heat transfer oil from an oil system (8) into the reactor (6), and for cooling the reaction temperature in the reactor (6) in a zoned manner; The removal unit is located on the outlet pipeline of the reactor (6) and is connected to the reactor (6) for removing light components in the glycolide polymer.

2. The glycolide polymerization system according to claim 1, characterized in that: The reactor (6) is a vertical reactor (6), and the reactor (6) is divided into a plurality of reaction zones, and the plurality of reaction zones are arranged from top to bottom of the reactor (6).

3. The glycolide polymerization system according to claim 2, characterized in that: The temperature control unit comprises a plurality of temperature control loops (7), each of the heat transfer oil loops is connected in parallel to the reactor (6), and each of the temperature control loops (7) uniquely corresponds to the reaction zone.

4. The glycolide polymerization system according to claim 3, characterized in that: The temperature control circuit (7) comprises: a first temperature control valve (71), provided on the oil inlet pipeline of the reaction zone, located on one side of the reactor (6), and used for controlling the oil inlet amount of the reaction zone by adjusting the opening; an oil pump, arranged on the oil inlet pipeline, wherein the outlet of the oil pump is connected to the inlet pipeline of the first temperature control valve (71) via the oil inlet pipeline; a third temperature control valve (73) located on the oil inlet pipeline, wherein the inlet of the third temperature control valve (73) is connected to the oil system (8), and the outlet of the third temperature control valve (73) is connected to the oil pump via the oil inlet pipeline, and is used to replenish the hot oil of the oil system (8) into the reaction zone; An air cooler (74) is provided on a bypass line of the oil inlet line, an inlet of the air cooler is connected to an outlet of the oil pump via a pipeline, and an outlet of the air cooler is connected to a second temperature control valve (72), and the second temperature control valve (72) is connected to the oil inlet line; The oil return valve (75) is provided on the oil return pipeline of the temperature control circuit (7) and is connected to the oil return pipeline, and is used to control the heat transfer oil after heat exchange to the oil system (8).

5. The glycolide polymerization system according to claim 1, characterized in that: The removal unit comprises: a devolatilizer (9) disposed on one side of the reactor (6) and located above the reactor (6); the devolatilizer (9) is located higher than the top of the reactor (6); the inlet of the devolatilizer (9) is connected to the bottom outlet pipeline of the reactor (6), and is used to remove light components from the glycolide polymer by stirring under vacuum; a vacuum pump (11) disposed on one side of the devolatilizer (9), the inlet of the vacuum pump (11) being connected to the devolatilizer (9) for extracting the light component out of the system in a vacuum manner; A booster pump (10) is connected to the outlet pipeline of the devolatilizer (9) and is used to transport the glycolide polymer after the light components are removed to the granulation system.

6. The glycolide polymerization system according to claim 1, characterized in that: An exhaust valve (12) is provided on the top of the reactor (6), and the exhaust valve (12) is connected to the reactor (6) through a pipeline for exhausting the gas after the reaction in the reactor (6).

7. A method for controlling a glycolide polymerization system, characterized in that: include: mixing glycolide with a catalyst; A polymerization reaction is carried out in the reactor (6) in the reaction zone to produce a glycolide polymer; During the polymerization reaction, the temperature control unit adjusts the cooling capacity of the air cooler (74) to control the temperature in each reaction zone; The vacuum pump (11) evacuates the devolatilizer (9) to remove light components from the glycolide polymer; The booster pump (10) delivers the glycolide polymer after light components are removed to the granulation system.

8. The control method of the glycolide polymerization system according to claim 7, characterized in that: During the polymerization reaction, the temperature control unit adjusts the cooling amount of the air cooler (74) to control the temperature in each reaction zone, including: A temperature measuring point TIC is set on the oil return pipeline corresponding to any reaction zone of the reactor (6); The control temperature index range of the temperature measuring point TIC is preset to A; The value of the temperature measuring point TIC in real time is compared with A, and the switch state of the valve on the temperature control loop (7) is adjusted to adjust the temperature of the oil entering the reaction zone.

9. The control method of the glycolide polymerization system according to claim 8, characterized in that: The method of comparing the value of the temperature measuring point TIC in real time with A, adjusting the switch state of the valve on the temperature control loop (7), and adjusting the temperature of the oil entering the reaction zone comprises: If the TIC value is higher than A, the first temperature control valve (71) is closed and the second temperature control valve (72) is opened to reduce the TIC value; If the TIC value is lower than A, the first temperature control valve (71) is opened and the second temperature control valve (72) is closed to increase the TIC value; If the first temperature control valve (71) is fully opened and the second temperature control valve (72) is closed, and the TIC value continues to be lower than A, the third temperature control valve (73) should be fully opened to add hot oil from the oil system (8) to the reaction zone to increase the TIC value.

10. The control method of the glycolide polymerization system according to claim 7, characterized in that: The control temperature index range A is 215°C-240°C.

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