High-pressure sampling system and sampling method thereof, and high-pressure flash apparatus

Abstract

The present invention relates to the technical field of fiber preparation. Disclosed are a high-pressure sampling system and a sampling method thereof, and a high-pressure flash apparatus. The high-pressure sampling system comprises a reaction kettle, a first sampling apparatus, and a second sampling apparatus. A first sampling tube is connected between the first sampling apparatus and the reaction kettle; a second sampling tube is connected between the second sampling apparatus and the reaction kettle; the first sampling tube is partially inserted into the bottom of the reaction kettle; the second sampling tube is partially inserted into the top of the reaction kettle; a first sampling valve is arranged on the first sampling tube; a second sampling valve is arranged on the second sampling tube; and the first sampling valve and the second sampling valve are both arranged outside the reaction kettle. According to the high-pressure sampling system of the present invention, by determining the composition of a high-pressure flash spinning fluid and the composition of a gas-phase medium inside a reaction kettle, the composition and the optimal formation conditions of the high-pressure flash spinning fluid can be clarified, providing a strong basis for the controllable preparation of the high-pressure flash spinning fluid and high-pressure flash nano / microfibers.

Description

A high-pressure sampling system and sampling method thereof, and a high-pressure flash spray device Technical Field

[0001] The present invention relates to the technical field of fiber preparation, in particular to a high-pressure sampling system and a sampling method thereof, and a high-pressure flash spray device. Background Art

[0002] Currently, high-pressure flash spinning is a type of solution spinning. Its basic principle is the high-speed phase separation of a polymer solution. The fiber-forming polymer forms a spinning fluid under high-temperature and high-pressure conditions within a reaction vessel and is released under normal pressure. The spinning fluid is ejected from the spinneret at high speed under high pressure and is stretched at high speed. Due to the sudden drop in pressure, the spinning fluid undergoes high-speed phase separation, and the low-boiling-point solvent and supercritical gas rapidly expand. After solidification, they form continuous nano- and micro-fibers with a cross-linked network structure.

[0003] In high-pressure flash spinning technology, the composition of the spinning fluid is a key factor affecting the final performance of the fiber. However, due to the limitations of high temperature and high pressure formation conditions, the composition of the high-pressure flash jet spinning fluid and the gaseous medium in the reaction vessel cannot be analyzed, which greatly limits the controllable preparation of high-pressure flash jet nanofibers by regulating the composition of the high-pressure flash jet spinning fluid.

[0004] Summary of the Invention

[0005] The object of the present invention is to provide a sampling system and a sampling method thereof, and a high-pressure flash spray device to measure the composition of the high-pressure flash spray spinning fluid and the gas phase medium in the reaction container.

[0006] In order to achieve the above-mentioned objectives, in a first aspect, the present invention provides a high-pressure sampling system, which includes a reactor, a first sampling device and a second sampling device, a first sampling tube is connected between the first sampling device and the reactor, a second sampling tube is connected between the second sampling device and the reactor, the first sampling tube is partially inserted into the bottom of the reactor, the second sampling tube is partially inserted into the top of the reactor, a first sampling valve is provided on the first sampling tube, and a second sampling valve is provided on the second sampling tube, and the first sampling valve and the second sampling valve are both provided outside the reactor.

[0007] Preferably, the first sampling tube is further provided with a third sampling valve, and the second sampling tube is further provided with a fourth sampling valve, and the third sampling valve and the fourth sampling valve are both provided outside the reactor.

[0008] Preferably, the reactor is provided with a temperature-pressure sensor, the first sampling device is provided with a first temperature sensor, and the second sampling device is provided with a second temperature sensor.

[0009] Preferably, the first sampling tube is provided with a first connector, the second sampling tube is provided with a second connector, the first connector is provided between the first sampling valve and the third sampling valve, and the second connector is provided between the second sampling valve and the fourth sampling valve.

[0010] Preferably, the first sampling tube is provided with a first pressure relief valve, the second sampling tube is provided with a second pressure relief valve, the first pressure relief valve is provided between the first sampling valve and the third sampling valve, and the second pressure relief valve is provided between the second sampling valve and the fourth sampling valve.

[0011] Preferably, the first sampling valve, the second sampling valve, the third sampling valve and the fourth sampling valve are all one-way valves.

[0012] Preferably, a heating device is further included, and the first sampling device and the second sampling device are respectively connected to one of the heating devices.

[0013] In order to achieve the same purpose, in a second aspect, the present invention further provides a high-pressure flash spray device, comprising the high-pressure sampling system described in the first aspect.

[0014] In the third aspect, the present invention also provides a sampling method based on the high-pressure sampling system of the first aspect, wherein a polymer and a solvent are sequentially added to the reactor, and gas is introduced into the reactor. When the temperature of the reactor reaches 120-220°C and the pressure reaches 5-20 MPa, the first sampling device and the second sampling device are heated to the same temperature as the reactor, and then liquid phase sampling of the flash spinning fluid and sampling of the gas phase medium in the reactor are performed to determine the composition of the high-pressure flash spinning fluid and the composition of the gas phase medium in the reactor.

[0015] Compared with the prior art, the sampling system for high-pressure flash spinning according to the embodiment of the present invention has the following advantages:

[0016] When the sampling system of the embodiment of the present invention is used, first, the polymer and the solvent are added to the reactor in sequence, and the gas is introduced into the reactor. The first sampling valve and the second sampling valve are closed to seal the reactor, and the reactor is stirred to prepare the flash spinning fluid. Due to the density difference, the liquid medium settles in the lower layer of the reactor, and the gas is placed in the upper layer of the reactor. The first sampling tube is partially inserted at the bottom of the reactor for sampling the liquid medium, and the second sampling tube is partially inserted at the top of the reactor for sampling the gaseous medium; then the first sampling valve and the second sampling valve are opened respectively, and the first sampling device and the second sampling device are vacuumed to form a negative pressure state. After the vacuum is drawn, the first sampling valve and the second sampling valve are closed, and then the mass of the first sampling device and the second sampling device are weighed respectively, and then the first sampling device and the second sampling device are placed on the upper layer of the reactor. The first sampling device and the second sampling device are respectively connected to the reactor, and then the reactor is heated and pressurized, and the first sampling valve and the second sampling valve are heated to the same temperature as the reactor. Then, the first sampling valve and the second sampling valve are opened to perform liquid phase sampling of the flash jet spinning fluid and the gas phase medium in the reactor through the first sampling device and the second sampling device under negative pressure. After the sampling is completed, the second sampling valve is closed. Finally, the mass of each component in the first sampling device and the second sampling device is calculated according to the mass difference, so that the composition of the high-pressure flash jet spinning fluid and the composition of the gas phase medium in the reactor can be determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a simplified structural diagram of a sampling system for high-pressure flash spinning according to an embodiment of the present invention.

[0018] In the figure, 1. reactor; 2. first sampling device; 3. second sampling device; 4. temperature-pressure sensor; 5. first sampling tube; 6. second sampling tube; 7. first sampling valve; 8. third sampling valve; 9. second sampling valve; 10. fourth sampling valve; 11. first temperature sensor; 12. second temperature sensor; 13. first pressure relief valve; 14. second pressure relief valve; 15. heating device; 16. first connector; 17. second connector. DETAILED DESCRIPTION

[0019] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0020] In describing the present invention, it should be noted that the terms "first," "second," and the like are used to describe various types of information. However, such information should not be limited to these terms; these terms are merely used to distinguish information of the same type from one another. For example, "first" information could also be referred to as "second" information, and similarly, "second" information could also be referred to as "first information" without departing from the scope of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] As shown in Figure 1, a sampling system according to a preferred embodiment of the present invention includes a reactor 1, a first sampling device 2, and a second sampling device 3. A first sampling tube 5 is connected between the first sampling device 2 and the reactor 1, and a second sampling tube 6 is connected between the second sampling device 3 and the reactor 1. The first sampling tube 5 is partially inserted into the bottom of the reactor 1, and the second sampling tube 6 is partially inserted into the top of the reactor 1. A first sampling valve 7 is provided on the first sampling tube 5, and a second sampling valve 9 is provided on the second sampling tube 6. The first sampling valve 7 and the second sampling valve 9 are both provided on the outside of the reactor 1.

[0023] Based on the above technical solution, this embodiment first adds the polymer and solvent sequentially to reactor 1, introduces gas into reactor 1, closes the first sampling valve 7 and the second sampling valve 9 to seal reactor 1, and stirs reactor 1 to prepare the flash spinning fluid. Due to the density difference, the liquid medium settles in the lower layer of reactor 1, while the gas is placed in the upper layer of reactor 1. Therefore, the first sampling tube 5 is partially inserted at the bottom of reactor 1 for sampling the liquid medium, and the second sampling tube 6 is partially inserted at the top of reactor 1 for sampling the gaseous medium.

[0024] Secondly, the first sampling device 2 and the second sampling device 3 are evacuated to form a negative pressure state. After the vacuum is drawn, the first sampling valve 7 and the second sampling valve 9 are closed, and the masses M0 and M1 of the first sampling device 2 and the second sampling device 3 are weighed respectively. Then, the first sampling device 2 and the second sampling device 3 are connected to the reactor 1 respectively, and then the reactor 1 is heated and pressurized. When the flash jet spinning fluid is in a high temperature and high pressure state, the first sampling device 2 and the second sampling device 3 are also heated to the same temperature as the reactor 1, and then the first sampling valve 7 and the second sampling valve 9 are opened, so that the first sampling device 2 and the second sampling device 3 respectively perform liquid medium sampling and gas medium sampling of flash jet spinning under the negative pressure state;

[0025] Finally, when the temperature of the first sampling device 2 and the second sampling device 3 drops to room temperature, the masses M2 and M3 of the first sampling device 2 and the second sampling device 3 are weighed respectively; if the first sampling device 2 and the second sampling device 3 are placed at -10-25°C and vacuumed, the masses M4 and M5 of the first sampling device 2 and the second sampling device 3 are weighed, the solid in the first sampling device 2 is taken out and dried, and the mass M6 of the remaining solid is weighed; the mass of each component in the first sampling device 2 and the second sampling device 3 is calculated based on the mass difference, thereby determining the composition of the spinning fluid and the composition of the gas phase medium in the reactor 1. When analyzing the components of the high-pressure flash jet spinning fluid, the following method can be used for calculation:

[0026] The polymer percentage is:

[0027] The percentage of gas is:

[0028] The percentage of solvent is:

[0029] When analyzing the gas phase components in reactor 1, the following method is used for calculation:

[0030] The percentage of gas is:

[0031] The percentage of solvent is:

[0032] In addition, this embodiment provides another calculation method for analyzing the high-pressure flash jet spinning fluid composition. After weighing the masses m2 and m3 of the first sampling device 2 and the second sampling device 3, the first sampling device 2 and the second sampling device 3 are placed at 0-25°C and filled with water. The masses m4 and m5 of the first sampling device 2 and the second sampling device 3 are weighed, and the masses of the water are m6 and m7. Then, the solid in the first sampling device 2 is removed and dried, and the mass of the remaining solid is weighed. m8. When performing high-pressure flash jet spinning fluid composition analysis, the following method is used for calculation:

[0033] The polymer percentage is:

[0034] The percentage of gas is:

[0035] The percentage of solvent is:

[0036] When analyzing the gas phase components in reactor 1, the following method is used for calculation:

[0037] The percentage of gas is:

[0038] The percentage of solvent is:

[0039] In this embodiment, the composition of the high-pressure flash spinning fluid and the composition of the gas phase medium in the high-temperature and high-pressure reactor 1 are determined by the above-mentioned calculation method.

[0040] Furthermore, in this embodiment, a third sampling valve 8 is provided on the first sampling tube 5, and a fourth sampling valve 10 is provided on the second sampling tube 6. Both the third sampling valve 8 and the fourth sampling valve 10 are located outside the reactor 1. Specifically, the first sampling valve 7 is located at one end near the first sampling device 2, the third sampling valve 8 is located at one end near the reactor 1, the second sampling valve 9 is located at one end near the second sampling device 3, and the fourth sampling valve 10 is located at one end near the reactor 1, thereby forming a pipeline structure of a primary valve and a secondary valve on the first sampling tube 5 and the second sampling tube 6, respectively. When the valves need to be closed after sampling, the third sampling valve 8 or the second sampling valve 9 on the high-temperature side is closed first, and then the first sampling valve 7 or the second sampling valve 9 on the low-temperature side is closed. This provides a safer double guarantee when sampling flash spinning under high-temperature and high-pressure conditions.

[0041] Furthermore, in this embodiment, the reactor 1 is provided with a temperature-pressure sensor 4 for real-time monitoring of the temperature and pressure inside the reactor 1; the first sampling device 2 is provided with a first temperature sensor 11 for real-time monitoring of the temperature of the first sampling device 2; and the second sampling device 3 is provided with a second temperature sensor 12 for real-time monitoring of the temperature of the second sampling device 3.

[0042] Furthermore, in this embodiment, a first connector 16 is provided on the first sampling tube 5, and a second connector 17 is provided on the second sampling tube 6. The first connector 16 is provided between the first sampling valve 7 and the third sampling valve 8, and the second connector 17 is provided between the second sampling valve 9 and the fourth sampling valve 10. The first connector 16 and the second connector 17 can be used to quickly remove the first sampling device 2 and the second sampling device 3 from the reactor 1 and weigh their masses respectively.

[0043] Furthermore, in this embodiment, a first pressure relief valve 13 is provided on the first sampling tube 5, and a second pressure relief valve 14 is provided on the second sampling tube 6. The first pressure relief valve 13 is located between the first sampling valve 7 and the third sampling valve 8, and the second pressure relief valve 14 is located between the second sampling valve 9 and the fourth sampling valve 10. After the flash jet spinning fluid sampling and component measurement are completed, the first and second pressure relief valves 13, 14 are opened to relieve pressure in the first and second sampling devices 2, 3, to facilitate the next sampling and measurement.

[0044] More specifically, in this embodiment, the first sampling valve 7, the second sampling valve 9, the third sampling valve 8 and the fourth sampling valve 10 are all one-way valves, which control the unidirectional flow of liquid medium or gaseous medium and cut off the reverse flow to avoid the backflow of the medium and affect the sampling and measurement.

[0045] Furthermore, this embodiment also includes a heating device 15, and the first sampling device 2 and the second sampling device 3 are respectively connected to the heating device 15. The first sampling device 2 and the second sampling device 3 can be heated to the same temperature as the reactor 1 through the heating device 15, and then the first sampling valve 7 and the second sampling valve 9 are opened to complete the liquid medium sampling and gas medium sampling of flash spinning under high temperature and high pressure conditions.

[0046] In order to achieve the same purpose, the present invention also provides a sampling method for high-pressure flash jet spinning, wherein a polymer and a solvent are sequentially added to the reactor 1, and gas is introduced into the reactor 1. When the temperature of the reactor 1 reaches 120-220°C and the pressure reaches 5-20 MPa, the first sampling device 2 and the second sampling device 3 are both heated to the same temperature as the reactor 1, and then the liquid phase sampling of the flash jet spinning fluid and the gas phase medium in the reactor 1 are performed to determine the composition of the high-pressure flash jet spinning fluid and the composition of the gas phase medium in the reactor 1.

[0047] More specifically, the sampling method comprises the following steps:

[0048] S1. Adding a polymer and a solvent to a reactor 1 in sequence, introducing gas into the reactor 1, closing the third sampling valve 8 and the fourth sampling valve 10, sealing the reactor 1, and then stirring the reactor 1 to prepare a flash spinning fluid;

[0049] S2, evacuate the first sampling device 2, close the first sampling valve 7 after evacuation, weigh the mass M0 of the first sampling device 2, and connect the first sampling device 2 to the reactor 1;

[0050] S3, evacuate the second sampling device 3, close the second sampling valve 9 after evacuation, weigh the mass M1 of the second sampling device 3, and connect the second sampling device 3 to the reactor 1;

[0051] S4. The reactor 1 is heated and pressurized to a temperature of 120-220° C. and a pressure of 5-20 MPa. When the flash jet spinning fluid is at a high temperature and high pressure, the first sampling device 2 and the second sampling device 3 are heated to the same temperature as the reactor 1. The first sampling valve 7 and the second sampling valve 9 are first opened, and then the third sampling valve 8 and the fourth sampling valve 10 are opened. The third sampling valve 8 and the fourth sampling valve 10 are kept open for 1-3 seconds and then closed. The first sampling valve 7 and the second sampling valve 9 are then closed. The temperatures of the first sampling device 2 and the second sampling device 3 are recorded at this time, thereby completing the liquid medium sampling and the gas medium sampling of the flash jet spinning.

[0052] S5. When the temperatures of the first sampling device 2 and the second sampling device 3 drop to room temperature, the first sampling device 2 and the second sampling device 3 are quickly removed from the reactor 1 through the first connector 16 and the second connector 17, and the masses are weighed respectively.

[0053] Then, the first sampling device 2 and the second sampling device 3 can be placed at -10-25°C and vacuumed, the mass of the first sampling device 2 and the second sampling device 3 can be weighed, the solid in the first sampling device 2 can be taken out and dried, and the mass of the remaining solid can be weighed; or the first sampling device 2 and the second sampling device 3 can be placed at 0-25°C and filled with water, the mass of the first sampling device 2 and the second sampling device 3 can be weighed, the solid in the first sampling device 2 can be taken out and dried, and the mass of the remaining solid can be weighed; finally, the mass of each component in the first sampling device 2 and the second sampling device 3 can be calculated based on the mass difference and the above analysis method, so as to determine the composition of the spinning fluid and the composition of the gaseous medium in the reactor 1.

[0054] The working process of the present invention is: a polymer and a solvent are added into the reactor 1 in sequence, and gas is introduced into the reactor 1. When the temperature of the reactor 1 reaches 120-220°C and the pressure reaches 5-20 MPa, the first sampling device 2 and the second sampling device 3 are both heated to the same temperature as the reactor 1, and then the liquid phase sampling of the flash jet spinning fluid and the gas phase medium in the reactor 1 are performed to determine the composition of the high-pressure flash jet spinning fluid and the composition of the gas phase medium in the reactor 1.

[0055] Based on the above technical solution, the present invention also provides some specific embodiments:

[0056] Example 1

[0057] The equipment and method described in the present invention are used to sample the polyethylene-dichloromethane-carbon dioxide spinning fluid system and test its composition. Polyethylene and dichloromethane are added to the reactor 1 in sequence according to a certain proportion, and carbon dioxide is introduced into the reactor 1. When the temperature in the reactor 1 reaches 180°C and the pressure reaches 8 MPa, the temperature of the first sampling device 2 and the second sampling device 3 are heated to the same temperature as the reactor 1, and then the liquid phase sampling of the spinning fluid and the gas phase medium in the reactor 1 are sampled. The method is then used to analyze the composition of the high-pressure flash jet spinning fluid and the gas phase medium in the reactor 1.

[0058] Example 2

[0059] The equipment and method described in the present invention are used to sample the polyethylene-dichloromethane-nitrogen spinning fluid system and test its composition. Polyethylene and dichloromethane are added to the reactor 1 in sequence according to a certain proportion, and nitrogen is introduced into the reactor 1. When the temperature in the reactor 1 reaches 190°C and the pressure reaches 9 MPa, the temperature of the first sampling device 2 and the second sampling device 3 are heated to the same temperature as the reactor 1, and then the liquid phase sampling of the spinning fluid and the gas phase medium in the reactor 1 are sampled. The method is then used to analyze the composition of the high-pressure flash jet spinning fluid and the gas phase medium in the reactor 1.

[0060] Example 3

[0061] The apparatus and method of the present invention are used to sample a polyester-1,2-dichloroethane-carbon dioxide spinning fluid system and test its composition. Polyester and 1,2-dichloroethane are sequentially added to a reactor 1 in a certain proportion, and carbon dioxide is introduced into the reactor. When the temperature of the reactor 1 reaches 185°C and the pressure reaches 8.5 MPa, the first sampling device 2 and the second sampling device 3 are heated to the same temperature as the reactor 1. Then, liquid phase sampling of the spinning fluid and sampling of the gaseous medium in the reactor 1 are performed. The composition of the high-pressure flash jet spinning fluid and the gaseous medium in the reactor 1 are analyzed using the method.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A high pressure sampling system, characterized in that: include: A reactor (1), a first sampling device (2) and a second sampling device (3), wherein a first sampling tube (5) is connected between the first sampling device (2) and the reactor (1), and a second sampling tube (6) is connected between the second sampling device (3) and the reactor (1), wherein a portion of the first sampling tube (5) is inserted into the bottom of the reactor (1), and a portion of the second sampling tube (6) is inserted into the top of the reactor (1), a first sampling valve (7) is provided on the first sampling tube (5), and a second sampling valve (9) is provided on the second sampling tube (6), and both the first sampling valve (7) and the second sampling valve (9) are arranged outside the reactor (1).

2. The high pressure sampling system according to claim 1, characterized in that: The first sampling tube (5) is also provided with a third sampling valve (8), and the second sampling tube (6) is also provided with a fourth sampling valve (10). The third sampling valve (8) and the fourth sampling valve (10) are both arranged outside the reaction kettle (1), and the third sampling valve (8) is located below the first sampling valve (7), and the fourth sampling valve (10) is located below the second sampling valve (9).

3. The high pressure sampling system according to claim 1, characterized in that: The reaction kettle (1) is provided with a temperature-pressure sensor (4), the first sampling device (2) is provided with a first temperature sensor (11), and the second sampling device (3) is provided with a second temperature sensor (12).

4. The high pressure sampling system according to claim 1, characterized in that: The first sampling tube (5) is provided with a first connector (16), the second sampling tube (6) is provided with a second connector (17), the first connector (16) is provided between the first sampling valve (7) and the third sampling valve (8), and the second connector (17) is provided between the second sampling valve (9) and the fourth sampling valve (10).

5. The high pressure sampling system according to claim 2, characterized in that: The first sampling tube (5) is provided with a first pressure relief valve (13), and the second sampling tube (6) is provided with a second pressure relief valve (14); the first pressure relief valve (13) is provided between the first sampling valve (7) and the third sampling valve (8), and the second pressure relief valve (14) is provided between the second sampling valve (9) and the fourth sampling valve (10).

6. The high pressure sampling system according to claim 2, characterized in that: The first sampling valve (7), the second sampling valve (9), the third sampling valve (8) and the fourth sampling valve (10) are all one-way valves.

7. The high pressure sampling system according to claim 1, characterized in that: It also comprises a heating device (15), and the first sampling device (2) and the second sampling device (3) are respectively connected to one of the heating devices (15).

8. A high pressure flash spray device, characterized in that: A high pressure sampling system comprising the high pressure sampling system according to any one of claims 1 to 7.

9. A sampling method based on the high pressure sampling system according to any one of claims 1 to 7, characterized in that: A polymer and a solvent are sequentially added into the reactor (1), and a gas is introduced into the reactor (1). When the temperature of the reactor (1) reaches 120-220°C and the pressure reaches 5-20MPa, the first sampling device (2) and the second sampling device (3) are heated to the same temperature as the reactor (1), and then the liquid phase sampling of the flash jet spinning fluid and the gas phase medium sampling in the reactor (1) are performed to determine the composition of the high-pressure flash jet spinning fluid and the composition of the gas phase medium in the reactor (1).

Images