An optimized nylon 6 extraction column device

Abstract

The utility model relates to nylon 6 production technical field, especially a kind of optimization nylon 6 extraction column device. The device includes extraction column, heating with plate heat exchanger, cooling with plate heat exchanger, cooler, cooling water pump and expansion tank;Wherein, cooler is set in the upper portion of extraction column, and heating with plate heat exchanger is communicated with the lower portion of extraction column to transport high-temperature fresh water;Cooling with plate heat exchanger and cooling water pump are connected to form closed circulating cooling system, can receive the high-temperature process water transported in the upper portion of extraction column, under the power action of cooling water pump, high-temperature process water enters cooling with plate heat exchanger to complete heat exchange, after cooling, backflow to extraction column;Expansion tank is communicated with closed circulating cooling system, for controlling system water level and discharging gas generated in circulation process. The device realizes the stable gradient of "temperature decreasing from tower bottom to tower top" of extraction column by upper and lower portion cooperation temperature control, avoids local high temperature and extraction water boiling.

Description

Technical Field

[0001] This utility model relates to the field of nylon 6 production technology, and in particular to an optimized nylon 6 extraction tower device. Background Technology

[0002] During the production of nylon 6, the polymerization reaction is a reversible equilibrium reaction. This reaction cannot completely convert the raw material monomers, resulting in a certain amount of unreacted raw material monomers adhering to the surface of the finished nylon 6 chips. If these residual monomers are not effectively removed, they will directly affect the product quality of downstream processing steps (such as spinning, injection molding, etc.), for example, causing problems such as filament breakage during spinning and a decrease in the mechanical properties of the finished product.

[0003] To reduce the monomer content in the finished chips, existing technologies generally use fresh deoxygenated water to wash and extract nylon 6 chips. Based on the principle that "the higher the extraction water temperature, the higher the extraction efficiency", existing extraction tower designs usually have a steam jacket installed on the outside of the tower. Steam is introduced into the jacket to directly heat the extraction tower and increase the temperature of the extraction water inside the tower.

[0004] However, the above-mentioned existing technical solutions have defects. The steam jacket heating method is prone to local high temperature in the extraction tower, and the water is easy to boil. After boiling, the temperature at the top of the extraction tower is easily out of control, the extracted water sprays out and causes personnel injury. At the same time, the internal temperature gradient is out of control, and the extraction effect becomes worse.

[0005] Therefore, how to avoid local high temperatures and boiling of extraction water while ensuring the required temperature for Nylon 6 slice extraction, constructing a stable temperature gradient inside the column, and controlling the temperature to keep the extraction water within a safe range has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0006] To overcome the shortcomings of the prior art, this utility model provides an optimized nylon 6 extraction tower device, including an extraction tower, a plate heat exchanger for heating, a plate heat exchanger for cooling, a cooler, a cooling water pump, and an expansion tank. The cooler is located at the top of the extraction tower, and the heating plate heat exchanger is connected to the bottom of the extraction tower to deliver high-temperature fresh water into the extraction tower. The cooling plate heat exchanger is connected to the cooling water pump to form a closed-loop cooling system. It is used to receive the high-temperature process water delivered from the top of the extraction tower. The cooling water pump provides power to drive the high-temperature process water into the cooling plate heat exchanger for heat exchange. The cooled process water is then returned to the extraction tower. The expansion tank is connected to the closed-loop cooling system and is used to control the water level of the closed-loop cooling system and to discharge the gas generated during the internal circulation process of the closed-loop cooling system.

[0007] Furthermore, the heating plate heat exchanger is connected to a fresh water supply pipeline, a heating steam pipeline, a steam condensate pipeline, and a heated fresh water pipeline. The fresh water supply pipeline is used to supply fresh deoxygenated water to the heating plate heat exchanger, the heating steam pipeline is used to supply heating steam to the heating plate heat exchanger, the steam condensate pipeline is used to discharge the condensate formed after the steam in the heating plate heat exchanger is condensed, one end of the heated fresh water pipeline is connected to the outlet of the heating plate heat exchanger, and the other end is connected to the lower part of the extraction tower.

[0008] Furthermore, the cooler is connected to the top region of the extraction tower and is used to cool the extraction water at the top of the extraction tower.

[0009] Furthermore, the closed-loop cooling system also includes a cooling water inlet pipeline, a cooling water return pipeline, a process circulation return pipeline, and a process circulation supply pipeline. One end of the cooling water inlet pipeline is connected to an external cooling water source, and the other end is connected to the cooling water inlet of the cooling plate heat exchanger. One end of the cooling water return pipeline is connected to the cooling water outlet of the cooling plate heat exchanger, and the other end is connected to the external cooling water recovery system. One end of the process circulating return water pipeline is connected to the upper part of the extraction tower, and the other end is connected to the process water inlet of the cooling plate heat exchanger. One end of the process circulating water supply pipeline is connected to the process water outlet of the cooling plate heat exchanger, and the other end is connected to the extraction tower.

[0010] Furthermore, the process circulation return water pipeline transports high-temperature process water discharged from the top of the extraction tower. After being cooled by a plate heat exchanger, the high-temperature process water flows back into the extraction tower through the process circulation water supply pipeline to maintain a stable temperature inside the extraction tower.

[0011] Furthermore, the cooling water pump is connected in series in the process circulation return water pipeline.

[0012] Furthermore, the expansion tank is connected to the process circulation return water pipeline.

[0013] Furthermore, the heating plate heat exchanger is used to heat fresh deoxygenated water to 120°C.

[0014] Furthermore, the top of the extraction tower is also connected to an overflow water pipeline, which is used to discharge the extracted water cooled by the cooler to the next process.

[0015] Furthermore, the fresh water supply pipeline, heating steam pipeline, steam condensate pipeline, heated fresh water pipeline, cooling water inlet pipeline, cooling water return pipeline, process circulation return pipeline, and process circulation supply pipeline are all made of 304L stainless steel.

[0016] Compared with existing technologies, the optimized nylon 6 extraction tower device provided by this utility model, through the reasonable configuration of the extraction tower, heating plate heat exchanger, cooling plate heat exchanger, cooler, cooling water pump and expansion tank, compared with the traditional method of directly heating the extraction tower with a steam jacket, this device delivers high-temperature fresh water to the lower part of the extraction tower through the heating plate heat exchanger. Combined with the cooler and closed-loop cooling system set in the upper part of the extraction tower, it can build a stable temperature gradient of "the highest temperature at the bottom of the tower and gradually decreasing from the bottom to the top of the tower". This avoids the situation of boiling of the extraction water due to local high temperature, and at the same time reduces the phenomenon of "bridging" of nylon 6 chips in the tower, so that the chips and extraction water can fully contact each other for material exchange, significantly improving the extraction efficiency and reducing the content of unreacted monomers in the finished chips. Secondly, the closed-loop cooling system, driven by the cooling water pump, can quickly cool down the high-temperature process water at the top of the extraction tower and then return it. Combined with the cooler, this further ensures stable tower top temperature, effectively preventing overflow accidents caused by boiling of the extraction water and improving the safety of the production process. The plate heat exchanger for heating can stably heat fresh deoxygenated water, providing a continuous and temperature-controllable high-temperature water source for the extraction tower. The closed-loop cooling system maintains stable water level and discharges gas through the expansion tank, avoiding system pressure fluctuations and ensuring stable operation of the entire extraction process. This reduces the fluctuation range of monomer content in the finished product slices and improves product quality consistency. Simultaneously, the various components of the device work collaboratively, eliminating the need for traditional steam jackets and reducing equipment problems such as jacket scaling and localized overheating damage. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the optimized nylon 6 extraction tower device provided by this utility model.

[0019] Figure label: 1-Extraction tower, 2-Expansion tank, 3-Cooling plate heat exchanger, 4-Cooling water pump, 5-Heating plate heat exchanger, 6-Cooling water inlet pipeline, 7-Cooling water return pipeline, 8-Process circulation return water pipeline, 9-Process circulation water supply pipeline, 10-Overflow water pipeline, 11-Heated fresh water pipeline, 12-Fresh water makeup pipeline, 13-Heating steam pipeline, 14-Steam condensate pipeline, 15-Cooler. Detailed Implementation

[0020] 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 embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] In the description of this utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] like Figure 1 As shown, the optimized nylon 6 extraction tower device includes an extraction tower 1, a plate heat exchanger 5 for heating, a plate heat exchanger 3 for cooling, a cooler 15, a cooling water pump 4, and an expansion tank 2. The cooler 15 is located at the top of the extraction tower 1, and the heating plate heat exchanger 5 is connected to the bottom of the extraction tower 1 to deliver high-temperature fresh water into the extraction tower 1. The cooling plate heat exchanger 3 is connected to the cooling water pump 4 to form a closed-loop cooling system. It is used to receive the high-temperature process water delivered from the top of the extraction tower 1. The cooling water pump 4 provides power to drive the high-temperature process water into the cooling plate heat exchanger 3 for heat exchange. The cooled process water flows back to the extraction tower 1. The expansion tank 2 is connected to the closed-loop cooling system and is used to control the water level of the closed-loop cooling system and to discharge the gas generated during the internal circulation process of the closed-loop cooling system.

[0023] When using, such as Figure 1As shown, the heating plate heat exchanger 5 is first started to heat the fresh deoxygenated water, which is then transported to the lower part of the extraction tower 1. The high-temperature fresh water flows from bottom to top in the extraction tower 1. At the same time, nylon 6 chips enter from the upper part of the extraction tower 1 and form a countercurrent contact with the high-temperature fresh water flowing from bottom to top. During the contact process, the high-temperature fresh water dissolves the unreacted monomers attached to the surface of the chips, thereby extracting the nylon 6 chips. As the extraction process proceeds, the water temperature gradually decreases, while the monomer concentration gradually increases and flows upward to the upper part of the extraction tower 1. When the high-temperature process water reaches the upper part of the extraction tower 1, the cooling water pump 4 is started. Under the power of the cooling water pump 4, the high-temperature process water is transported to the cooling plate heat exchanger 3. At this time, external cooling water is also introduced into the cooling plate heat exchanger 3 to exchange heat with the high-temperature process water. The temperature of the high-temperature process water decreases during the heat exchange process. The cooled process water is then transported back to the extraction tower 1 through the return pipeline to continue participating in the extraction process. During this period, the expansion tank 2, which is connected to the closed-loop cooling system, continues to play a role in controlling the water level in the closed-loop cooling system in real time, so as to avoid the water level being too high or too low and affecting the system operation. At the same time, it promptly discharges the gas generated by the system during the circulation process to prevent gas accumulation from causing system pressure fluctuations.

[0024] In addition, the cooler 15 installed at the top of the extraction tower 1 further cools the extraction water that is about to be discharged from the tower, ensuring that the water does not boil. Finally, the water that has been extracted is discharged from the overflow pipe at the top of the extraction tower 1 and enters the next process. The extracted nylon 6 chips are discharged from the bottom of the extraction tower 1 and enter the subsequent production process.

[0025] In one embodiment, such as Figure 1 As shown, the plate heat exchanger 5 for heating is connected to a fresh water supply pipeline 12, a heating steam pipeline 13, a steam condensate pipeline 14, and a heated fresh water pipeline 11. The fresh water supply line 12 is used to supply fresh deoxygenated water to the heating plate heat exchanger 5. The heating steam line 13 is used to supply heating steam to the heating plate heat exchanger 5. The steam condensate line 14 is used to discharge the condensate formed after the steam in the heating plate heat exchanger 5 is condensed. One end of the heated fresh water line 11 is connected to the outlet of the heating plate heat exchanger 5, and the other end is connected to the lower part of the extraction tower 1.

[0026] By adopting the above scheme, on the one hand, the continuous input of fresh deoxygenated water can ensure a sufficient supply of extraction water and avoid the interruption of extraction due to water shortage; on the other hand, the directional supply of heating steam and the timely discharge of condensate can ensure that the heating plate heat exchanger 5 can continuously and efficiently heat the fresh deoxygenated water, providing a stable high-temperature extraction water source for the extraction tower. At the same time, the recycling of condensate also meets the energy-saving requirements, and the directional connection of the heated fresh water pipeline 11 can ensure that the high-temperature fresh water accurately enters the lower part of the extraction tower 1.

[0027] In one embodiment, such as Figure 1 As shown, the cooler 15 is connected to the top region of the extraction tower 1 and is used to cool the extraction water at the top of the extraction tower 1.

[0028] It is understandable that connecting the cooler 15 to the top area of ​​the extraction tower 1 and targeting the top of the tower where boiling is most likely to occur can stabilize the temperature at the top of the extraction tower 1 and directly reduce the temperature of the extracted water at the top of the extraction tower 1, thus avoiding fluctuations in the extraction effect caused by abnormal temperature at the top of the tower.

[0029] In one embodiment, such as Figure 1 As shown, the closed-loop cooling system also includes a cooling water inlet pipeline 6, a cooling water return pipeline 7, a process circulation return pipeline 8, and a process circulation supply pipeline 9. One end of the cooling water inlet pipeline 6 is connected to an external cooling water source, and the other end is connected to the cooling water inlet of the cooling plate heat exchanger 3. One end of the cooling water return pipeline 7 is connected to the cooling water outlet of the cooling plate heat exchanger 3, and the other end is connected to the external cooling water recovery system. One end of the process circulating return water pipeline 8 is connected to the upper part of the extraction tower 1, and the other end is connected to the process water inlet of the cooling plate heat exchanger 3. One end of the process circulating water supply pipeline 9 is connected to the process water outlet of the cooling plate heat exchanger 3, and the other end is connected to the extraction tower 1.

[0030] In the above scheme, the closed-loop cooling system supplements the cooling water inlet pipeline 6, cooling water return pipeline 7, process circulation return pipeline 8, and process circulation supply pipeline 9, forming a complete closed loop of "cooling water source - heat exchange - process water return", which solves the problem of temperature control failure caused by incomplete piping in traditional cooling systems.

[0031] Specifically, the cooling water inlet pipeline 6 introduces external cooling water into the cooling plate heat exchanger 3 to provide continuous cooling for the high-temperature process water, while the cooling water return pipeline 7 transports the cooled water after heat exchange to the external recovery system; the process circulation return pipeline 8 directionally transports the high-temperature process water at the top of the extraction tower 1 to the cooling plate heat exchanger 3, and the process circulation supply pipeline 9 returns the cooled process water to the extraction tower 1.

[0032] In one embodiment, such as Figure 1 As shown, the process circulation return water pipeline 8 transports the high-temperature process water discharged from the top of the extraction tower 1. After being cooled by the plate heat exchanger 3, the high-temperature process water flows back into the extraction tower 1 through the process circulation water supply pipeline 9 to maintain the temperature stability inside the extraction tower 1.

[0033] In one embodiment, such as Figure 1 As shown, the cooling water pump 4 is connected in series in the process circulation return water pipeline 8, which can provide stable power for the flow of high-temperature process water in the process circulation return water pipeline 8, and solve the problem of heat exchange lag caused by insufficient process water flow power in traditional cooling systems.

[0034] In one embodiment, such as Figure 1 As shown, the expansion tank 2 is connected to the process circulation return water pipeline 8.

[0035] In one embodiment, the heating plate heat exchanger 5 is used to heat the fresh deoxygenated water to 120°C, which is the optimal temperature range for Nylon 6 slice extraction and can maximize the extraction efficiency.

[0036] In one embodiment, such as Figure 1 As shown, the top of the extraction tower 1 is also connected to an overflow water pipeline 10, which is used to discharge the extracted water cooled by the cooler 15 to the next process.

[0037] In the above scheme, the overflow water pipeline 10 can promptly transport the extracted water to the next process, avoiding the water level rise and pressure increase caused by the water stagnation in the extraction tower 1, thereby preventing the "overflow" accident.

[0038] In one embodiment, the fresh water supply pipeline 12, the heating steam pipeline 13, the steam condensate pipeline 14, the heated fresh water pipeline 11, the cooling water inlet pipeline 6, the cooling water return pipeline 7, the process circulation return water pipeline 8, and the process circulation supply water pipeline 9 are all made of 304L stainless steel, which solves the problem of frequent damage caused by the material's poor corrosion resistance and high temperature resistance in traditional pipelines.

[0039] Although this document frequently uses terms such as extraction tower, heating plate heat exchanger, cooling plate heat exchanger, cooler, cooling water pump, and expansion tank, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An optimized nylon 6 extraction tower device, characterized in that: It includes an extraction tower (1), a plate heat exchanger (5) for heating, a plate heat exchanger (3) for cooling, a cooler (15), a cooling water pump (4) and an expansion tank (2). The cooler (15) is located at the top of the extraction tower (1), and the heating plate heat exchanger (5) is connected to the bottom of the extraction tower (1) to deliver high-temperature fresh water into the extraction tower (1). The cooling plate heat exchanger (3) is connected to the cooling water pump (4) to form a closed-loop cooling system. It is used to receive the high-temperature process water delivered from the top of the extraction tower (1). The cooling water pump (4) provides power to drive the high-temperature process water into the cooling plate heat exchanger (3) for heat exchange. The cooled process water flows back to the extraction tower (1). The expansion tank (2) is connected to the closed-loop cooling system and is used to control the water level of the closed-loop cooling system and discharge the gas generated during the internal circulation process of the closed-loop cooling system.

2. The optimized nylon 6 extraction tower apparatus according to claim 1, characterized in that: The heating plate heat exchanger (5) is connected to a fresh water supply pipeline (12), a heating steam pipeline (13), a steam condensate pipeline (14), and a heated fresh water pipeline (11). The fresh water supply line (12) is used to supply fresh deoxygenated water to the heating plate heat exchanger (5), the heating steam line (13) is used to supply heating steam to the heating plate heat exchanger (5), the steam condensate line (14) is used to discharge the condensate formed after the steam in the heating plate heat exchanger (5), one end of the heated fresh water line (11) is connected to the outlet of the heating plate heat exchanger (5), and the other end is connected to the lower part of the extraction tower (1).

3. The optimized nylon 6 extraction tower apparatus according to claim 1, characterized in that: The cooler (15) is connected to the top area of ​​the extraction tower (1) and is used to cool the extraction water at the top of the extraction tower (1).

4. The optimized nylon 6 extraction tower device according to claim 1, characterized in that: The closed-loop cooling system also includes a cooling water inlet pipeline (6), a cooling water return pipeline (7), a process circulation return pipeline (8), and a process circulation supply pipeline (9). One end of the cooling water inlet pipeline (6) is connected to an external cooling water source, and the other end is connected to the cooling water inlet of the cooling plate heat exchanger (3). One end of the cooling water return pipeline (7) is connected to the cooling water outlet of the cooling plate heat exchanger (3), and the other end is connected to the external cooling water recovery system. One end of the process circulating return water pipeline (8) is connected to the upper part of the extraction tower (1), and the other end is connected to the process water inlet of the cooling plate heat exchanger (3); One end of the process circulating water supply pipeline (9) is connected to the process water outlet of the cooling plate heat exchanger (3), and the other end is connected to the extraction tower (1).

5. The optimized nylon 6 extraction tower apparatus according to claim 4, characterized in that: The process circulation return water pipeline (8) transports the high-temperature process water discharged from the top of the extraction tower (1). After being cooled by the plate heat exchanger (3), the high-temperature process water flows back to the extraction tower (1) through the process circulation water supply pipeline (9) to maintain the temperature stability inside the extraction tower (1).

6. The optimized nylon 6 extraction tower apparatus according to claim 5, characterized in that: The cooling water pump (4) is connected in series in the process circulation return water pipeline (8).

7. The optimized nylon 6 extraction tower apparatus according to claim 4, characterized in that: The expansion tank (2) is connected to the process circulating return water pipeline (8).

8. The optimized nylon 6 extraction tower apparatus according to claim 2, characterized in that: The plate heat exchanger (5) is used to heat fresh deoxygenated water to 120°C.

9. The optimized nylon 6 extraction tower apparatus according to claim 1, characterized in that: The top of the extraction tower (1) is also connected to an overflow water pipeline (10), which is used to discharge the extracted water cooled by the cooler (15) to the next process.

10. The optimized nylon 6 extraction tower apparatus according to claim 2 or 4, characterized in that: The fresh water supply pipeline (12), the heating steam pipeline (13), the steam condensate pipeline (14), the heated fresh water pipeline (11), the cooling water inlet pipeline (6), the cooling water return pipeline (7), the process circulation return water pipeline (8), and the process circulation water supply pipeline (9) are all made of 304L stainless steel.

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