Spinning solution preparation device for monitoring viscosity change trend in real time and monitoring method

Abstract

According to the spinning solution preparation device for monitoring the viscosity change trend in real time and the monitoring method, the response change principle of the viscosity change of the fluid to the pressure of the spinning solution conveying pipeline is utilized, the pressure change of the spinning solution is monitored through the pressure difference change between the pressure gauges in the production process, and the viscosity change trend of the spinning solution is monitored in real time. Therefore, the viscosity of the spinning solution can be monitored in real time in the fiber production process, the process can be adjusted in time, the product quality is maintained to be stable, the product competitiveness is improved, and the influence of other factors is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of viscosity monitoring, and particularly relates to a spinning solution preparation device and a monitoring method for real-time monitoring of the viscosity change trend. Background Art

[0002] Lyocell fiber belongs to natural plant fiber products and is favored by consumers due to its excellent fiber properties. During the production process of Lyocell fiber, the product quality is easily affected by various factors. Through continuous testing by R & D personnel, it is found that the quality of Lyocell fiber products is greatly affected by the viscosity of the spinning solution. The viscosity of the spinning solution is related to factors such as cellulose content, degree of polymerization of cellulose, and spinning solution temperature. An increase in cellulose content or the use of cellulose with a high degree of polymerization will cause a rapid increase in the viscosity of the spinning solution. The viscosity of the spinning liquid has a direct impact on fiber formation, fiber structural properties, and fiber quality. An inappropriate spinning viscosity may lead to instabilities during the spinning process, such as filament merging, filament breakage, and glue blocks.

[0003] In order to maintain the stability of product quality and enhance market competitiveness, it is required to know the viscosity value of the spinning solution in real time, so as to facilitate timely adjustment of the production process in subsequent sections to ensure product quality. However, during the production of Lyocell, the viscosity of the spinning solution is greatly affected by the degree of polymerization of the pulp and the cellulose content in the spinning solution. Although the degree of polymerization of the pulp and the cellulose content are kept stable during the production process, there are differences in the polymerization of different batches, and even the same batch of pulp, which results in fluctuations in the viscosity of the spinning solution. If the change in viscosity cannot be known in time and the process is not adjusted accordingly, it will inevitably cause fluctuations in product quality. However, there is currently no evaluation method for the viscosity of the spinning solution.

[0004] Therefore, how to overcome the above technical defects is an urgent problem for those skilled in the art to solve. Summary of the Invention

[0005] The purpose of the present invention is to provide a spinning solution preparation device and a monitoring method for real-time monitoring of the viscosity change trend, which can monitor the viscosity of the spinning solution in real time during the fiber production process.

[0006] To solve the above technical problems, the present invention provides a spinning solution preparation device for real-time monitoring of the viscosity change trend, including a first pressure gauge and a second pressure gauge respectively used to monitor the hydraulic values at both ends of the spinning solution conveying pipeline upstream of the spinning workshop.

[0007] Optionally, in the above spinning solution preparation device for real-time monitoring of the viscosity change trend, it further includes a thin-film evaporator, a spinning solution cooler, and a spinning solution buffer tank for preparing the spinning solution. The thin-film evaporator, the spinning solution cooler, and the spinning solution buffer tank are connected in series in sequence on the spinning solution conveying pipeline, and the inlet of the thin-film evaporator is used to introduce the spinning solution raw material.

[0008] Optionally, in the above-mentioned spinning solution preparation device for real-time monitoring of the viscosity change trend, a discharge pump is further included, which is arranged between the thin-film evaporator and the spinning solution cooler.

[0009] Optionally, in the above-mentioned spinning solution preparation device for real-time monitoring of the viscosity change trend, the first pressure gauge is arranged between the discharge pump and the spinning solution cooler, and the second pressure gauge is arranged between the spinning solution cooler and the spinning solution buffer tank.

[0010] Optionally, in the above-mentioned spinning solution preparation device for real-time monitoring of the viscosity change trend, the raw material of the spinning solution is a mixed solution after the pulp, solvent and stabilizer are mixed and swollen.

[0011] Optionally, in the above-mentioned spinning solution preparation device for real-time monitoring of the viscosity change trend, the solvent is NMMO solvent.

[0012] Optionally, in the above-mentioned spinning solution preparation device for real-time monitoring of the viscosity change trend, the first pressure gauge is a diaphragm pressure gauge.

[0013] Optionally, in the above-mentioned spinning solution preparation device for real-time monitoring of the viscosity change trend, the second pressure gauge is a diaphragm pressure gauge.

[0014] The present invention also provides a monitoring method for real-time monitoring of the viscosity change trend, including: by monitoring the hydraulic pressure difference in the spinning solution conveying pipeline upstream of the spinning workshop, using the principle of the response change of the pipeline pressure due to the viscosity change of the fluid, and deriving the viscosity change trend of the spinning solution from the change trend of the hydraulic pressure difference.

[0015] Optionally, in the above-mentioned monitoring method for real-time monitoring of the viscosity change trend, the spinning solution conveying pipeline is in a vacuum state.

[0016] The present invention provides a spinning solution preparation device for real-time monitoring of the viscosity change trend, and its beneficial effects are as follows:

[0017] Using the principle of the response change of the spinning solution conveying pipeline pressure due to the viscosity change of the fluid, during the production process, by monitoring the pressure change between the pressure gauges, that is, monitoring the pressure change of the spinning solution, the viscosity change of the spinning solution can be indirectly predicted, so that the viscosity of the spinning solution can be monitored in real time during the fiber production process, which is convenient for timely adjusting the process, maintaining the stability of the product quality, improving the product competitiveness, and being not affected by other factors.

[0018] The present invention also provides a monitoring method for real-time monitoring of the viscosity change trend. By monitoring the hydraulic pressure difference in the spinning solution conveying pipeline upstream of the spinning workshop, and using the principle of the response change of the pipeline pressure to the viscosity change of the fluid, the viscosity change trend of the spinning solution can be deduced from the change trend of the hydraulic pressure difference, so as to monitor the viscosity of the spinning solution in real time during the fiber production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0020] Figure 1 It is a schematic structural diagram of a spinning solution preparation device for real-time monitoring of the viscosity change trend provided by an embodiment of the present invention.

[0021] In the above figure:

[0022] 1 - thin film evaporator; 2 - discharge pump; 3 - first pressure gauge; 4 - spinning solution cooler; 5 - second pressure gauge; 6 - spinning solution buffer tank. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will describe in detail the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention, and should not be construed as a limitation of the present invention.

[0024] The core of the present invention is to provide a spinning solution preparation device and a monitoring method for real-time monitoring of the viscosity change trend, which can monitor the viscosity of the spinning solution in real time during the fiber production process.

[0025] In order to enable those skilled in the art to better understand the technical solutions provided by the present invention, the following will further elaborate on the present invention in conjunction with the drawings and specific embodiments.

[0026] Specifically, please refer to Figure 1 , a spinning solution preparation device and method for real-time monitoring of the viscosity change trend provided by the present invention include a first pressure gauge 3 and a second pressure gauge 5 respectively used to monitor the hydraulic pressure values at both ends of the spinning solution conveying pipeline upstream of the spinning workshop. The viscosity of the spinning solution is monitored in real time by using the hydraulic pressure difference monitored by the first pressure gauge 3 and the second pressure gauge 5. When the hydraulic pressure difference changes, the viscosity will also change. Subsequently, the spinning process parameters can be adjusted in a timely manner according to the pressure change to maintain the stability of the product quality.

[0027] It should be noted that the present invention utilizes the principle of the response change of the pressure in the spinning solution conveying pipeline to the change in the viscosity of the fluid, specifically as follows: Viscosity is a physical quantity that describes the internal resistance of a fluid (liquid or gas), that is, the degree of friction between adjacent layers when the fluid flows. The internal resistance of a high-viscosity fluid is large. Therefore, when the fluid flows in the pipeline, greater frictional resistance will be generated, resulting in a higher pressure required to push the fluid to flow. When the fluid flows through the pipeline, the frictional force caused by viscosity leads to a pressure drop along the way. The pressure drop of a high-viscosity fluid is usually greater than that of a low-viscosity fluid. Based on the above principle, the viscosity of the spinning solution can be deduced by monitoring the change in the pipeline pressure. The greater the viscosity, the greater the pressure.

[0028] The spinning solution preparation device provided by this solution for real-time monitoring of the viscosity change trend monitors the pressure of the spinning solution through the hydraulic difference during the production process, so as to indirectly predict the viscosity change of the spinning solution, so that the viscosity of the spinning solution can be monitored in real time during the fiber production process, which is convenient for the subsequent spinning section to timely adjust the process parameters, maintain the stability of the product quality, improve the product competitiveness, and is not affected by other factors.

[0029] In a specific embodiment, this solution further includes a thin-film evaporator 1 for preparing the spinning solution, a spinning solution cooler 4, and a spinning solution buffer tank 6. The inlet of the thin-film evaporator 1 is used to introduce the raw materials of the spinning solution, the outlet of the thin-film evaporator 1 is connected to the inlet of the spinning solution cooler 4, and the outlet of the spinning solution cooler 4 is connected to the inlet of the spinning solution buffer tank 6. Thus, the thin-film evaporator 1, the spinning solution cooler 4, and the spinning solution buffer tank 6 can be connected in series on the spinning solution conveying pipeline in sequence.

[0030] The thin-film evaporator 1 is an efficient evaporation device. Its main feature is that the fluid flows in a film shape along the heating tube wall for heat transfer and evaporation. This design makes the thin-film evaporator perform excellently in terms of heat transfer efficiency and evaporation speed, and is particularly suitable for the evaporation treatment of heat-sensitive substances.

[0031] Furthermore, this solution further includes a discharge pump 2 arranged between the thin-film evaporator 1 and the spinning solution cooler 4, which can effectively improve the fluidity of the spinning solution.

[0032] In the above setting method, the first pressure gauge 3 can be arranged between the discharge pump 2 and the spinning solution cooler 4, and the second pressure gauge 5 is arranged between the spinning solution cooler 4 and the spinning solution buffer tank 6. The change in the viscosity of the spinning solution in the pipeline between the spinning solution cooler 4 and the spinning solution buffer tank 6 can be monitored through the hydraulic difference between the first pressure gauge 3 and the second pressure gauge 5. The raw material of the spinning solution introduced into the thin-film evaporator 1 is a mixed solution after the pulp, solvent, and stabilizer are mixed and swollen. Swelling is a phenomenon in which the volume of a polymer expands in a solvent.

[0033] To improve the mixing effect, the solvent is NMMO solvent, which is an important organic cellulose solvent.

[0034] The pressure gauges for monitoring the fluid viscosity usually need to consider the high-viscosity characteristics of the fluid. Both the first pressure gauge 3 and the second pressure gauge 5 can use diaphragm pressure gauges. For the measurement of high-viscosity fluids, diaphragm pressure gauges can be used. The diaphragm pressure gauge isolates the high-viscosity fluid from the pressure sensor through a diaphragm to prevent the fluid from contaminating or clogging the sensor.

[0035] The preparation process flow of the above spinning solution is as follows: Cellulose pulp with certain viscosity characteristics and pulp with a certain cellulose content are mixed and swollen with NMMO solvent and stabilizer, and then enter the thin-film evaporator 1. Under the action of the discharge pump 2, it is transported to the spinning solution cooler 4 for heat exchange and cooling, and then enters the spinning solution buffer tank 6 in sequence. After passing through processes such as filtration, the spinning solution is transported to the spinning workshop for spinning.

[0036] In addition, this solution also provides a monitoring method for real-time monitoring of the viscosity change trend, including: By monitoring the hydraulic pressure difference in the spinning solution conveying pipeline upstream of the spinning workshop, using the principle of the response change of the pipeline pressure to the viscosity change of the fluid, the viscosity change trend of the spinning solution is deduced through the change trend of the hydraulic pressure difference, and the viscosity of the spinning solution can be monitored in real time during the fiber production process.

[0037] In a specific embodiment, to improve the accuracy of the monitoring by the first pressure gauge 3 and the second pressure gauge 5, the spinning solution conveying pipeline is in a vacuum state.

[0038] In the description of this application, unless otherwise clearly defined, words such as setting, installation, and connection should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in this application in combination with the specific content of the technical solution.

[0039] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0040] Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A spinning solution preparation device for real-time monitoring of viscosity change trends, characterized in that, It includes a first pressure gauge (3) and a second pressure gauge (5) respectively used for monitoring the hydraulic pressures at both ends of the spinning solution conveying pipeline upstream of the spinning workshop.

2. The spinning solution preparation device for real-time monitoring of the viscosity change trend according to claim 1, wherein It further includes a thin-film evaporator (1), a spinning solution cooler (4), and a spinning solution buffer tank (6) for preparing the spinning solution. The thin-film evaporator (1), the spinning solution cooler (4), and the spinning solution buffer tank (6) are connected in series in sequence on the spinning solution conveying pipeline, and the inlet of the thin-film evaporator (1) is used for introducing the raw material of the spinning solution.

3. The spinning solution preparation device for real-time monitoring of viscosity change trend according to claim 2, characterized in that It further includes a discharge pump (2) provided between the thin-film evaporator (1) and the spinning solution cooler (4).

4. The spinning solution preparation device for real-time monitoring of viscosity change trend according to claim 3, characterized in that, The first pressure gauge (3) is provided between the discharge pump (2) and the spinning solution cooler (4), and the second pressure gauge (5) is provided between the spinning solution cooler (4) and the spinning solution buffer tank (6).

5. The spinning solution preparation device for real-time monitoring of the viscosity change trend according to claim 2, characterized in that, The raw material of the spinning solution is a mixed solution after the pulp, solvent, and stabilizer are mixed and swollen.

6. The spinning solution preparation device for real-time monitoring of viscosity change trend according to claim 5, characterized in that, The solvent is NMMO solvent.

7. The spinning solution preparation device for real-time monitoring of viscosity change trend according to claim 1, characterized in that, The first pressure gauge (3) is a diaphragm pressure gauge.

8. The spinning solution preparation device for real-time monitoring of viscosity change trend according to claim 1, characterized in that, The second pressure gauge (5) is a diaphragm pressure gauge.

9. A monitoring method for real-time monitoring of the viscosity change trend, characterized in that, It includes: By monitoring the hydraulic pressure difference in the spinning solution conveying pipeline upstream of the spinning workshop, using the principle of the response change of the pipeline pressure to the viscosity change of the fluid, the viscosity change trend of the spinning solution is deduced through the change trend of the hydraulic pressure difference.

10. The monitoring method for real-time monitoring of the viscosity change trend according to claim 9, characterized in that, The spinning solution conveying pipeline is in a vacuum state.

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