Nylon 6 polymerization device and nylon 6 production device

Abstract

The utility model provides a nylon 6 polymerization device and a nylon 6 production device, and belongs to the technical field of nylon 6 production. The nylon 6 polymerization device comprises a polymerization pipe, a first heat exchanger, a return pipeline and a circulating pump, the polymerization pipe is provided with a heat exchange pipe capable of exchanging heat with polymerization reaction; the first heat exchanger is provided with a first heat exchange channel and a second heat exchange channel, a first medium circulates in the first heat exchange channel, a second medium circulates in the second heat exchange channel, the temperature of the second medium is higher than that of the first medium, and an outlet of the first heat exchange channel is connected with the heat exchange pipe through a material conveying pipeline; the circulating pump is located on the material conveying pipeline, an inlet of the backflow pipeline is connected with the downstream part, located on the circulating pump, of the material conveying pipeline, an outlet of the backflow pipeline is connected with an inlet of the first heat exchange channel, and a backflow adjusting valve is arranged on the backflow pipeline. According to the nylon 6 polymerization device, the polymerization temperature in the polymerization pipe can be better controlled, the temperature fluctuation is effectively reduced, and the quality of a nylon 6 product is greatly improved.

Description

Technical Field

[0001] This utility model belongs to the field of nylon 6 production technology, and particularly relates to a nylon 6 polymerization device and a nylon 6 production device. Background Technology

[0002] In the production of nylon 6, precise control of the polymerization temperature in the post-polymerization tube plays a decisive role in product quality. Traditional post-polymerization tube temperature control systems generally suffer from large temperature fluctuations. This not only leads to an uneven molecular weight distribution in the nylon 6 product, severely affecting its mechanical and processing properties, but also causes excessive energy consumption and low production efficiency. For example, excessively high temperatures may promote an increase in reverse polymer reactions within the post-polymerization tube, while excessively low temperatures will result in an uneven reaction. Utility Model Content

[0003] In view of the above-mentioned problems existing in the prior art, the purpose of this utility model embodiment is to provide a nylon 6 polymerization device and a nylon 6 production device. This nylon 6 polymerization device can better control the polymerization temperature inside the polymerization tube, effectively reduce temperature fluctuations, and significantly improve the quality of nylon 6 products.

[0004] The technical solution adopted in this embodiment of the utility model is:

[0005] A nylon 6 polymerization apparatus includes a polymerization tube, a first heat exchanger, a return pipeline, and a circulation pump;

[0006] The polymerization tube is used to carry out the polymerization reaction, and the polymerization tube has a heat exchange tube.

[0007] The first heat exchanger has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is used to flow a first medium, and the second heat exchange channel is used to flow a second medium. The temperature of the second medium is greater than the temperature of the first medium.

[0008] The outlet of the first heat exchange channel is connected to the heat exchange tube via a material conveying pipeline;

[0009] The circulating pump is located on the conveying pipeline to pump the first medium in the first heat exchange channel into the heat exchange tube for heat exchange with the polymerization reaction.

[0010] The inlet of the reflux pipeline is connected to the downstream section of the conveying pipeline or the outlet of the circulating pump, the outlet of the reflux pipeline is connected to the inlet of the first heat exchange channel, and a reflux regulating valve is provided on the reflux pipeline.

[0011] In some embodiments, the nylon 6 polymerization apparatus further includes a second heat exchanger having a third heat exchange channel and a fourth heat exchange channel, wherein a caprolactam solution flows through the third heat exchange channel;

[0012] The material conveying pipeline is connected to the inlet of the heat exchange tube, the outlet of the heat exchange tube is connected to the inlet of the fourth heat exchange channel, and the outlet of the fourth heat exchange channel is connected to the inlet of the first heat exchange channel.

[0013] In some embodiments, the nylon 6 polymerization apparatus further includes an exhaust pipe connected to the fourth heat exchange channel.

[0014] In some embodiments, the nylon 6 polymerization apparatus further includes a filter located on the feed line and upstream of the circulation pump.

[0015] In some embodiments, the nylon 6 polymerization apparatus further includes a pressure gauge located on the feed line and at the inlet of the circulation pump.

[0016] In some embodiments, the nylon 6 polymerization apparatus further includes a control system and a first thermometer;

[0017] The first thermometer is installed on the pipeline connecting the outlet of the heat exchange tube and the inlet of the fourth heat exchange channel, and is used to detect the temperature of the first medium flowing out of the heat exchange tube;

[0018] The control system is electrically connected to the first thermometer and the reflux regulating valve, respectively.

[0019] In some embodiments, the nylon 6 polymerization apparatus further includes a second medium line, a medium regulating valve, and a second thermometer;

[0020] The second medium pipeline is connected to the second heat exchange channel, the medium regulating valve is located on the second medium pipeline, and the second thermometer is located on the first heat exchanger for detecting the temperature of the first medium.

[0021] The control system is also electrically connected to the medium regulating valve and the second thermometer.

[0022] A nylon 6 production apparatus, comprising a nylon 6 polymerization apparatus as described in any of the above embodiments.

[0023] Compared with the prior art, the beneficial effects of the embodiments of this utility model are as follows:

[0024] When the flow rate of the first medium output by the circulating pump of the nylon 6 polymerization device of this invention exceeds the actual demand of the polymerization tube, the reflux regulating valve on the reflux pipeline can be adjusted according to the actual demand to guide the first medium back into the first heat exchanger for circulation and heating by the second medium. In this way, not only is the temperature of the first medium stabilized and temperature changes caused by flow fluctuations avoided, but the control accuracy of the temperature of the first medium is also improved.

[0025] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit the present invention.

[0026] The overview of various implementations or examples of the technology described in this utility model is not a complete disclosure of the full scope or all features of the disclosed technology. Attached Figure Description

[0027] In drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The drawings generally illustrate various embodiments by way of example rather than limitation and, together with the description and claims, serve to explain embodiments of the utility model. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts.

[0028] Figure 1 This is a schematic diagram of the nylon 6 polymerization apparatus according to an embodiment of the present invention.

[0029] In the diagram: 1. Polymerization tube; 2. First heat exchanger; 3. Return line; 4. Circulation pump; 5. Second heat exchanger; 6. Feed line; 7. Exhaust line; 8. Caprolactam line; 9. First thermometer; 10. Return regulating valve; 11. Pressure gauge; 12. Filter; 13. Second medium line; 14. Medium regulating valve; 15. Second thermometer; 16. Melt thermometer. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0031] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar words used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. To keep the following description of the embodiments of this utility model clear and concise, detailed descriptions of known functions and known components are omitted.

[0032] like Figure 1 As shown, this utility model embodiment provides a nylon 6 polymerization device, which includes a polymerization tube 1, a first heat exchanger 2, a return pipeline 3, and a circulation pump 4.

[0033] The polymerization tube 1 is used for the polymerization reaction, and the polymerization tube 1 has a heat exchange tube 17.

[0034] The first heat exchanger 2 has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is used for the flow of a first medium, and the second heat exchange channel is used for the flow of a second medium. The temperature of the second medium is higher than that of the first medium, and the outlet of the first heat exchange channel is connected to the heat exchange tube 17 via a feed pipeline 6.

[0035] The circulating pump 4 is located on the feed line 6 to pump the first medium in the first heat exchange channel into the heat exchange tube 17, thereby absorbing the heat generated by the polymerization reaction.

[0036] The inlet of the reflux pipeline 3 is connected to the downstream part of the conveying pipeline 6 or the outlet of the circulating pump 4, the outlet of the reflux pipeline 3 is connected to the inlet of the first heat exchange channel, and a reflux regulating valve 10 is provided on the reflux pipeline 3.

[0037] When the flow rate of the first medium output by the circulating pump 4 of the nylon 6 polymerization device in this embodiment exceeds the actual demand of the polymerization tube 1, the reflux regulating valve 10 on the reflux pipeline 3 can be adjusted according to the actual demand to guide the first medium back into the first heat exchanger 2 for heating through the second medium circulation. In this way, not only is the temperature of the first medium stabilized and temperature changes caused by flow fluctuations avoided, but the control accuracy of the first medium temperature is also improved.

[0038] Through precise temperature control, the polymerization reaction of nylon 6 becomes more stable and uniform, resulting in a significantly narrower molecular weight distribution. This greatly improves the product's mechanical properties, such as strength, toughness, and wear resistance, as well as its processing performance, reducing the defect rate and enhancing the product's market competitiveness and added value.

[0039] It should be noted that the polymerization tube 1 in the polymerization apparatus can be a prepolymerization tube or a postpolymerization tube, preferably a postpolymerization tube. As the core location of the polymerization reaction, the heat exchange tube 17 can be set in the upper section of the postpolymerization tube. Through heat exchange with the first medium, a stable temperature environment required for the polymerization reaction can be maintained, ensuring the uniformity and stability of the reaction.

[0040] The first medium can be a secondary biphenyl solution, and the second medium can be a primary biphenyl solution. The secondary biphenyl solution is heated using a primary biphenyl solution. This embodiment uses a secondary biphenyl solution as the first medium and a primary biphenyl solution as the second medium for illustration.

[0041] Of course, in some other embodiments, both the first medium and the second medium can be heat transfer oil or natural gas, as long as the temperature of the second medium is greater than that of the first medium.

[0042] like Figure 1 As shown, in some embodiments, the nylon 6 polymerization apparatus further includes a second heat exchanger 5, which has a third heat exchange channel and a fourth heat exchange channel. The third heat exchange channel can be connected to the caprolactam pipeline 8, and the caprolactam solution is circulated within the third heat exchange channel.

[0043] The feed pipeline 6 connecting the first heat exchanger 2 is connected to the inlet of the heat exchange tube 17, the outlet of the heat exchange tube 17 is connected to the inlet of the fourth heat exchange channel of the second heat exchanger 5, and the outlet of the fourth heat exchange channel is connected to the inlet of the first heat exchange channel of the first heat exchanger 2.

[0044] After the first medium flowing into the heat exchange tube 17 absorbs part of the heat generated by the polymerization reaction and raises its temperature, it flows into the second heat exchanger 5 to release heat, thereby preheating the caprolactam solution and bringing it to a suitable reaction initiation temperature. This lays a good foundation for the subsequent polymerization reaction, thus realizing energy recovery, further reducing energy consumption, and improving energy utilization.

[0045] In addition, the cooled first medium can flow back into the first heat exchanger 2 to start a new round of circulating heating process, continuously providing a stable, precise and reliable temperature environment for the polymerization reaction.

[0046] It should be noted that in this embodiment, both the first heat exchanger 2 and the second heat exchanger 5 may include a tube side and a shell side. Specifically, the shell side of the first heat exchanger 2 can flow with the second medium, while the tube side flows with the first medium. The tube side of the second heat exchanger 5 can flow with the first medium, and the shell side of the second heat exchanger 5 can flow with a caprolactam solution.

[0047] In some embodiments, the nylon 6 polymerization apparatus further includes an exhaust pipe 7, which is connected to a third heat exchange channel on the second heat exchanger 5. Non-condensable gases in the system can be discharged through the exhaust pipe 7 to ensure heat exchange efficiency.

[0048] In some embodiments, the nylon 6 polymerization apparatus may further include a filter 12 and a pressure gauge 11. The pressure gauge 11 and the filter 12 are respectively disposed on the feed line 6 and located upstream of the circulating pump 4.

[0049] Filter 12 can effectively intercept impurities in the first medium, thereby preventing damage to the circulating pump 4.

[0050] Pressure gauge 11 can be located between filter 12 and circulation pump 4. Pressure gauge 11 is used to detect the pressure before circulation pump 4 to prevent damage from dry running of the equipment.

[0051] Pressure gauge 11 and circulating pump 4 are connected to the control system. When the pressure detected by pressure gauge 11 is lower than the set value, the control system can control the circulating pump 4 to stop. The set value can be determined according to the specific operating conditions.

[0052] In some embodiments, the nylon 6 polymerization apparatus further includes a control system and a first thermometer 9;

[0053] The first thermometer 9 is installed on the pipeline connecting the outlet of the heat exchange tube 17 and the inlet of the fourth heat exchange channel. It is used to detect the temperature of the first medium flowing out of the heat exchange tube 17. The control system is electrically connected to the first thermometer 9 and the reflux regulating valve 10 respectively.

[0054] The first thermometer 9 is used to transmit the detected temperature to the control system, which then controls the opening and closing of the reflux regulating valve 10 based on the first thermometer 9.

[0055] For example, when the first thermometer 9 detects that the temperature of the biphenyl or the first medium discharged from the heat exchange tube 17 is too high, the control system can control the reflux regulating valve 10 to reduce its opening degree, thereby increasing the flow rate of the first medium flowing into the heat exchange tube 17; while when the first thermometer 9 detects that the temperature of the biphenyl or the first medium discharged from the heat exchange tube 17 is too low, the control system can control the reflux regulating valve 10 to increase its opening degree, thereby reducing the flow rate of the first medium flowing into the heat exchange tube 17.

[0056] In addition, such as Figure 1As shown, in some embodiments, a melt thermometer 16 is also provided at the lower part of the polymerization tube 1. The melt thermometer 16 is used to detect the reaction temperature at the lower part of the polymerization tube 1. By controlling the opening and closing degree of the reflux regulating valve 10, the fluctuation range of the reaction temperature at the lower part of the polymerization tube 1 can be precisely controlled within ±0.4℃, and finally the goal of high-precision control of the reaction temperature can be achieved.

[0057] In some embodiments, the nylon 6 polymerization apparatus further includes a second medium line 13, a medium regulating valve 14, and a second thermometer 15;

[0058] The second medium pipeline 13 is connected to the second heat exchange channel for injecting the second medium into the second heat exchange channel.

[0059] The medium regulating valve 14 is installed on the second medium pipeline 13, and the second thermometer 15 is installed on the first heat exchanger 2 to detect the temperature of the first medium.

[0060] The control system is also electrically connected to the medium regulating valve 14 and the second thermometer 15. The control system can also control the opening and closing degree of the second medium regulating valve 14 based on the temperature feedback from the second thermometer 15. The heating efficiency of the second medium can be precisely controlled through the second medium regulating valve 14, thereby providing a stable heat source for the entire system and meeting the heat requirements of the polymerization reaction.

[0061] In some embodiments, the control system in the nylon 6 polymerization unit can be a DCS control system. The DCS control system performs centralized and intelligent control and can use advanced control algorithms to accurately control the opening of the medium regulating valve 14 and the reflux regulating valve 10 based on temperature feedback data, thereby achieving precise and dynamic control of the temperature in the nylon 6 polymerization process, ensuring that the melt temperature fluctuation in the polymerization tower is controlled within ±0.4℃, and effectively guaranteeing the high quality and stability of nylon 6 polymerization production.

[0062] This utility model embodiment also provides a nylon 6 production apparatus, which includes a nylon 6 polymerization apparatus as described in any of the above embodiments.

[0063] The above description is intended to be illustrative and not restrictive. Those skilled in the art can make variations, modifications, substitutions, and alterations to the above embodiments within the scope of this disclosure. Moreover, the above examples (or one or more of them) can be used in combination with each other, and these embodiments can be combined with each other in various combinations or arrangements.

Claims

1. A nylon 6 polymerization apparatus, characterized by, The polymeric tube, the first heat exchanger, the return pipeline and the circulating pump are included. The polymeric tube is used for polymerization reaction, and the heat exchange tube is arranged on the polymeric tube. The first heat exchanger has a first heat exchange channel and a second heat exchange channel, the first heat exchange channel is used for flowing the first medium, and the second heat exchange channel is used for flowing the second medium, and the temperature of the second medium is higher than that of the first medium. The outlet of the first heat exchange channel is connected with the heat exchange tube through the feed pipeline. The circulating pump is arranged on the feed pipeline, and is used for pumping the first medium in the first heat exchange channel into the heat exchange tube to exchange heat with the polymerization reaction. The inlet of the return pipeline is connected with the downstream part of the feed pipeline or the outlet of the circulating pump, the outlet of the return pipeline is connected with the inlet of the first heat exchange channel, and the return adjusting valve is arranged on the return pipeline.

2. A nylon 6 polymerization apparatus as defined in claim 1, wherein, The nylon 6 polymerization device further comprises a second heat exchanger, the second heat exchanger has a third heat exchange channel and a fourth heat exchange channel, and the third heat exchange channel is used for flowing the caprolactam solution. The feed pipeline is connected with the inlet of the heat exchange tube, the outlet of the heat exchange tube is connected with the inlet of the fourth heat exchange channel, and the outlet of the fourth heat exchange channel is connected with the inlet of the first heat exchange channel.

3. A nylon 6 polymerization apparatus as defined in claim 2, wherein, The nylon 6 polymerization device further comprises an exhaust pipe, and the exhaust pipe is connected with the fourth heat exchange channel.

4. A nylon 6 polymerization apparatus as defined in claim 1, wherein The nylon 6 polymerization device further comprises a filter, and the filter is arranged on the feed pipeline and is located upstream of the circulating pump.

5. A nylon 6 polymerization apparatus as defined in claim 1, wherein, The nylon 6 polymerization device further comprises a pressure gauge, and the pressure gauge is arranged on the feed pipeline and is located at the inlet of the circulating pump.

6. A nylon 6 polymerization apparatus as defined in claim 2, wherein The nylon 6 polymerization device further comprises a control system and a first temperature meter. The first temperature meter is arranged on the pipeline, which is connected between the outlet of the heat exchange tube and the inlet of the fourth heat exchange channel, and is used for detecting the temperature of the first medium flowing out of the heat exchange tube. The control system is electrically connected with the first temperature meter and the return adjusting valve.

7. A nylon 6 polymerization apparatus as defined in claim 6, wherein, The nylon 6 polymerization device further comprises a second medium pipeline, a medium adjusting valve and a second temperature meter. The second medium pipeline is connected with the second heat exchange channel, the medium adjusting valve is arranged on the second medium pipeline, and the second temperature meter is arranged on the first heat exchanger and is used for detecting the temperature of the first medium. The control system is further electrically connected with the medium adjusting valve and the second temperature meter.

8. A nylon 6 production apparatus characterized by comprising: The nylon 6 polymerization device comprises the device according to any one of claims 1-7.

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