Multifunctional modular rheological mixing method and device based on controllable flow field

Abstract

The invention discloses a multifunctional modular rheological mixing method and device based on a controllable flow field, and the method comprises the steps: fully mixing a solution through a stretching flow generated by the expansion-contraction of a convergence flow channel formed in a mixing cavity or a shear flow generated by the wall surface speed difference of a flat plate flow channel; a pressure sensor on the mixing cavity and a load sensor on the push-pull shaft respectively record the pressure intensity of a solution in the mixing cavity and the thrust on the push-pull shaft in real time, and the current viscous resistance, shear viscosity and shear rate are solved by utilizing obtained data; therefore, an optimization basis is provided for a material formula, a flow field structure and / or mixing times of next solution mixing. The device comprises an upper cavity, a lower cavity, a push-pull rod, a push-pull shaft, pressure sensors and a load sensor, the upper cavity and the lower cavity are matched to form a mixing cavity, the push-pull shaft is arranged in the mixing cavity and connected with the push-pull rod, the load sensor is arranged at one end of the push-pull rod, and the pressure sensors are distributed on one side of the mixing cavity.

Description

Technical Field

[0001] The invention relates to the technical field of co-blending and rheological property measurement, and in particular to a multifunctional modular rheological mixing method and device based on a controllable flow field. Background Art

[0002] With the development of society and the continuous progress of science and technology, rheological property measurement, material mixing and different flow field change rules usually need to rely on independent equipment to operate, which increases equipment cost, operation complexity and energy consumption. Therefore, it is of great application value to develop a controllable flow field composite device integrating a rheometer and a mixer to meet the needs of rheological property measurement and mixing integrated processing under different flow fields.

[0003] Rheological property measurement is an important means to study the rheological behavior of materials, which can provide mechanical properties and viscosity characteristics of materials. However, traditional rheometers generally need to be operated separately, and strictly require the corresponding material categories. There is production isolation from material mixing, which also makes it impossible for the rheometer to achieve real-time monitoring and improvement of solution mixing. On the other hand, material mixing is the process of dispersing and mixing different materials, which is widely used in rubber, plastics, chemical and other fields. However, traditional mixers also have strict requirements on the type of solution. Traditional mixers are difficult to mix solutions with extremely high molecular weight, poor melt fluidity, poor heat transfer and mass transfer effects, and mixers do not have the ability to measure rheological properties. It is impossible to adjust the dispersion and mixing ability of the solution in the flow field and the molecular chain disentanglement ability based on rheological properties, which ultimately leads to the inability to optimize the material formula or improve the flow field structure to solve the above problems. Therefore, it is of great application value to develop a controllable flow field composite device integrating a rheometer and a mixer to realize the demand for integrated processing of rheological property measurement and material mixing of solutions such as polymer composite solutions, polymer composite melts, and polymer hydrogels under different flow fields. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a multifunctional modular rheological mixing method based on a controllable flow field. The method can realize the integrated processing of rheological property measurement and material mixing under different flow fields, and the rheological performance parameters obtained by measurement can be used to further optimize the material formula, process structure or mixing times in the next processing process.

[0005] Another object of the present invention is to provide a multifunctional modular rheological mixing device based on a controllable flow field for implementing the above method. The device integrates the advantages of a rheometer and a mixer, and can realize integrated processing of rheological property measurement and material mixing under different flow fields.

[0006] The technical solution of the present invention is: a multifunctional modular rheological mixing method based on a controllable flow field, by arranging a push-pull shaft in a mixing chamber, under the reciprocating motion of the push-pull shaft, the solution reciprocates in the mixing chamber whose shape changes periodically, and the solution is fully mixed by utilizing the extensional flow generated by the expansion-contraction of the convergent flow channel formed in the mixing chamber or the shear flow generated by the wall velocity difference of the flat flow channel, so as to obtain the effect of continuous extensional flow or shear flow, and obtain a fully mixed solution under the action of the cyclic extensional flow or shear flow; wherein, according to the different cross-sectional shapes of the push-pull shaft, the convergent flow channel is formed between the push-pull shaft with an arc surface such as a circular cross-section and the inner wall of the mixing chamber, and the flat flow channel is formed between the push-pull shaft with a flat surface such as a rectangular cross-section and the inner wall of the mixing chamber; in the above-mentioned dispersion and mixing process, the solution undergoes a pulsating dispersion process of dispersion, reciprocation, redispersion, and reciprocation, so that the molecular chains of the solution gradually untangle, and the molecular chains and the particles are fully dispersed and mixed;

[0007] In the process of dispersing the mixed solution, the pressure sensor arranged on the mixing chamber and the load sensor arranged on the push-pull shaft respectively record the solution pressure in the mixing chamber and the thrust on the push-pull shaft in real time. The obtained data are used to solve the viscous resistance of the solution on the surface of the push-pull shaft and the shear viscosity and shear rate of the solution when the current push-pull shaft is used, thereby providing an optimization basis for the material formula, flow field structure and / or mixing times of the next solution mixing.

[0008] During this process, the data obtained are used to solve the rheological performance parameters such as the viscous resistance of the push-pull shaft surface, the shear viscosity of the solution, the shear rate, etc. in the current state. Subsequently, the influence of factors such as the number of stretching times, molecular weight, solid content, and push-pull shaft structure on the rheological properties of the solution is studied, and the critical point where the solution transforms from a heterogeneous state to complete dispersion and disentanglement of the molecular chains is clarified, thereby achieving real-time optimization of the material formulation, flow field structure, and mixing times to meet the requirements of sufficient dispersion of different solution systems and sufficient disentanglement of molecular chains.

[0009] In the above method, the specific process of using the obtained data to solve the viscous resistance of the solution on the push-pull shaft surface and the shear viscosity and shear rate of the solution when the current push-pull shaft is used is as follows:

[0010] In order to establish a simplified mathematical model inside the flow field, first, the solution in the mixing chamber is set to an isothermal, steady-state laminar flow and the weight is negligible; secondly, compared with the viscous shear force, the inertial force caused by the acceleration of the solution is also negligible; thirdly, the radius R of the push-pull axis is much larger than the minimum gap that the solution can pass through, so there is slip between the solution and the cavity wall; in addition, a follow-up rectangular coordinate system (x, y, z) is established using the cylindrical push-pull axis as an example to represent the position of each point inside the mixing chamber; in the follow-up rectangular coordinate system (x, y, z), the origin O of the rectangular coordinate system is set to the inside of the push-pull axis The center of the mixing chamber is at the center, and the entire follower coordinate system reciprocates with the push-pull shaft; the x-axis is set along the movement direction of the push-pull shaft, and the positive direction is the opposite direction of the push-pull shaft movement; the y-axis is perpendicular to the x-axis, and the positive direction directly points to the upper cavity wall of the mixing chamber; the z-axis is circled from the x-axis to the y-axis with the four fingers of the right hand in a counterclockwise direction, and the direction pointed by the thumb is the positive direction of the z-axis; but since the cross-sectional shape of the cavity is only extended but not changed in the z-axis direction, when the x and y coordinates are constant, the speed and pressure of the solution will not change much when the z-axis coordinate changes, so only the x-axis and y-axis directions are considered;

[0011] In this mathematical model, the width of the mixing chamber along the z-axis is B; the straight-line distance from x2 to x1 is L; when the horizontal coordinate is x, the distance from the position of the push-pull shaft structure surface to the axis is Y(x), the distance from the position of the test solution to the x-axis is y (y≥Y(x)), and y1=y2; the cross-sectional area with the horizontal coordinate x and perpendicular to the x-axis is A; the viscous resistance of the push-pull shaft surface is F tui ; The consistency coefficient is k; The power law exponent is n;

[0012] When the rheological mixing device is running, the pressure values ​​P1 and P2 measured by the pressure sensor and the thrust F of the push-pull shaft measured by the load sensor are recorded, and then the current solution shear viscosity η is calculated. 剪 , the calculation process is as follows:

[0013] Substituting the pressure value P1, pressure value P2 and the thrust F of the push-pull shaft into the basic equation of fluid mechanics, it is simplified to formula (1):

[0014]

[0015] Formula (1) is used to perform double integration of x and y and then multiply it by the width B of the rheological mixing chamber along the z-axis to obtain formula (2), where x is the coordinate value of the solution on the x-axis (the x-axis is the movement direction of the push-pull axis), and y is the coordinate value of the solution on the y-axis (the y-axis is the positive direction pointing directly to the upper cavity wall of the mixing chamber);

[0016]

[0017] The pressure sensor measures that the pressure value of the solution at the cross section at the x1 coordinate and perpendicular to the x-axis is P1, and the pressure value at the cross section at the x2 coordinate is P2; B is the width of the rheological mixing chamber along the z-axis; Y(x) is the distance from the position of the push-pull shaft structure surface to the axis when the horizontal coordinate is x; y(x) is the distance from the position of the solution to be tested to the x-axis when the horizontal coordinate is x (y(x)≥Y(x)), and y(x1)=y(x2); L is the straight-line distance from x2 to x1; F is the thrust of the push-pull shaft; F tui is the viscous resistance on the push-pull shaft surface; τ yx is the shear stress of the solution along the x-axis at the corresponding coordinate (x, y).

[0018] Then, the power law equation and formula (2) are used to form an equation group to establish the functional relationship between the shear rate and each sensor parameter. Since the shear rate is equal to the velocity gradient, the velocity gradient du / dy of the solution at the (x, y) coordinate is solved:

[0019]

[0020] Where γ is the shear rate, k is the consistency coefficient, and n is the power law exponent;

[0021] According to the force balance equation of the solution in the x-axis direction, the σ of the solution at the (x, y) coordinate is solved. x :

[0022] The velocity u(x) of the solution at the (x,y) coordinate can be further solved by taking the definite integral of y from formula (3):

[0023]

[0024] in Then, the viscous resistance F on the push-pull shaft surface is solved by the same flow rate at different cross sections, i.e. A1u(x1) = A3u(x3). tui Numerical solution of ;

[0025] Finally, the shear viscosity η of the solution at the (x, y) coordinate is solved by formula (3) and the power law equation: 剪 :

[0026]

[0027] Finally, the shear viscosity η is obtained 剪 , shear rate γ, viscous resistance F on the push-pull shaft surface tui The numerical value of .

[0028] The solution is a dilute solution, a semi-dilute solution, a concentrated solution, a melt, a polyelectrolyte or a gel.

[0029] The present invention provides a multifunctional modular rheological mixing device based on a controllable flow field for the above-mentioned rheological mixing method, comprising an upper cavity, a lower cavity, a push-pull rod, a push-pull shaft, a pressure sensor and a load sensor, wherein the upper cavity cooperates with the lower cavity to form a mixing cavity, the push-pull shaft is arranged in the mixing cavity, and a gap for solution to pass through is left between the surface of the push-pull shaft and the inner wall of the mixing cavity, push-pull rods are connected to both sides of the push-pull shaft, and both ends of the push-pull rod are installed between the upper cavity and the lower cavity, one end of the push-pull rod is externally connected to a load device, and a load sensor is provided at the connection between the push-pull rod and the load device, and a plurality of pressure sensors are distributed on one side of the mixing cavity. Among them, the pressure sensor is used to detect the pressure in the mixing cavity in real time during the mixing process, and the load sensor is coaxially arranged with the push-pull shaft to detect the thrust of the push-pull shaft in real time during the mixing process.

[0030] The push-pull shaft reciprocates in the mixing chamber, and a circulating flow field area is formed between the push-pull shaft and the mixing chamber, and the flow field area serves as a sealed working area. The push-pull shaft cooperates with the mixing chamber, and when the push-pull shaft reciprocates back and forth, the mixing chamber forms a front chamber and a rear chamber on the front and rear sides of the push-pull shaft, and the volumes of the front and rear chambers change periodically.

[0031] The flow field region is a shear flow field region or a stretching flow field region.

[0032] The cross section of the push-pull shaft is circular, rectangular, trapezoidal or pentagonal.

[0033] The push-pull rod includes a front support push-pull rod and a rear support push-pull rod, which are respectively detachably connected to the two sides of the push-pull shaft. By disassembling and assembling the front and rear support push-pull rods, push-pull shafts of different cross-sectional shapes or sizes can be replaced according to actual needs, and the specific connection method can adopt the conventional installation method of existing similar push-pull shafts.

[0034] The connection surface between the upper cavity and the lower cavity is also provided with a gasket and a packing, which are respectively distributed on the outer periphery of the mixing cavity. The packing is used as a sealing device to prevent the solution from leaking out due to internal pressure; the gasket has a buffering and sealing function, and can also be used to adjust the gap between the upper and lower cavities.

[0035] The top of the upper cavity is also provided with a gland and a visualization window, which are respectively distributed above the mixing cavity. The gland is used to press and install the upper cavity and the lower cavity; the visualization window can be made of quartz glass and is arranged at a non-middle position on the upper cavity. When the solution is added, the tightening and fixing of the gland can be observed through the visualization window, so that a completely closed mixing chamber is formed between the upper and lower cavities. In the process of dispersing the mixed solution, the mixing process of the solution can be observed in real time through the visualization window.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] In this multifunctional modular rheological mixing method and device based on controllable flow field, periodic reciprocating motion is used to provide a controllable flow field for the solution, which is conducive to obtaining a solution with sufficient dispersion, mixing and molecular chain disentanglement under different flow fields. At the same time, the data of the solution mixing is recorded in real time by sensors (including various pressure sensors and load sensors). After analysis, the material formula, flow field type, mixing times and other parameters required for different solutions to meet the conditions of sufficient dispersion and sufficient disentanglement can be determined, thereby optimizing and improving the mixing effect of various solutions. Secondly, the reciprocating flow field design is used to uniformly improve the fluidity of the solution in the mixing chamber, avoiding local overheating or uneven mass transfer. With the help of real-time feedback from sensors, performance issues such as molecular chain degradation can be addressed by controlling parameters such as mixing times, push-pull rod speed, and heating temperature.

[0038] This multifunctional modular rheological mixing device based on controllable flow field integrates the characteristics of rheometer and mixer, forming a replaceable design and multifunctional modular design of the equipment structure, realizing the rheological property measurement and material mixing processing of polymer composite solutions, polymer composite melts, polymer hydrogels and other solutions under different flow field conditions. It closely combines the rheological property measurement under different flow fields with the material mixing process, realizes the integrated operation of measurement and processing, and does not need to perform mixing and rheological tests separately, saving time, experimental steps and material costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1( a ) is a schematic diagram showing the principle of the stretching flow field during the dispersion mixing process inside the mixing chamber of the multifunctional modular rheological mixing device.

[0040] FIG1( b ) is a schematic diagram showing the principle of the shear flow field during the dispersion mixing process inside the mixing chamber of the multifunctional modular rheological mixing device.

[0041] Figure 2 This is a schematic diagram of the principle of this multifunctional modular rheological mixing device.

[0042] Figure 3 for Figure 2 AA direction cross-section view.

[0043] Figure 4 for Figure 2 BB direction cross-sectional view.

[0044] Figure 5 Schematic diagram of the structure of the mixing chamber.

[0045] Figure 6 for Figure 5 Top view of the .

[0046] Figure 7 for Figure 6 Partial cross-sectional view of the middle pressure cover.

[0047] Figure 8 It is a structural schematic diagram when the cross section of the push-pull shaft is rectangular.

[0048] Fig. 9 It is a structural schematic diagram when the cross section of the push-pull shaft is trapezoidal.

[0049] Fig.10 It is a schematic diagram of the structure when the cross section of the push-pull shaft is a pentagon.

[0050] Fig.11 It is a structural schematic diagram when the cross section of the push-pull shaft is circular.

[0051] In the above figures, the components indicated by the reference numerals are as follows:

[0052] 1 is the surface of the push-pull shaft, 2 is the position of the composite material to be tested in the solution, V is the running speed of the push-pull shaft, and F is the thrust of the push-pull shaft;

[0053] 3 is packing, 4 is upper cavity, 5 is solution, 6 is visualization window, 7 is push-pull rod, 8 is lower cavity, 9 is push-pull shaft, 10 is pressure sensor, 11 is load sensor, 12 is gland, and 13 is gasket. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0055] Example 1

[0056] This embodiment provides a multifunctional modular rheological mixing device based on a controllable flow field, such as Figures 2 to 7As shown, it includes an upper cavity 4, a lower cavity 8, a push-pull rod 7, a push-pull shaft 9, a pressure sensor 10 and a load sensor 11. The upper cavity and the lower cavity cooperate to form a mixing cavity. The push-pull shaft is arranged in the mixing cavity, and a gap for the solution to pass through is left between the surface of the push-pull shaft and the inner wall of the mixing cavity. Push-pull rods are connected to both sides of the push-pull shaft. The two ends of the push-pull rod are installed between the upper cavity and the lower cavity. One end of the push-pull rod is externally connected to a load device, and a load sensor is provided at the connection between the push-pull rod and the load device. Several pressure sensors are distributed on one side of the mixing cavity. Among them, the pressure sensor is used to detect the pressure in the mixing cavity in real time during the mixing process. The load sensor is coaxially arranged with the push-pull shaft and is used to detect the thrust of the push-pull shaft in real time during the mixing process. The connection surface between the upper cavity and the lower cavity is also provided with a gasket 13 and a packing 3, and the gasket and the packing are respectively distributed on the periphery of the mixing cavity. Among them, the packing is used as a sealing device to prevent the solution from leaking out due to internal pressure; the gasket has a buffering and sealing function, and can also be used to adjust the gap between the upper and lower cavities. A pressure cover 12 and a visualization window 6 are also provided on the top of the upper cavity, and the pressure cover and the visualization window are respectively distributed above the mixing chamber. Among them, the pressure cover is used to press and install the upper cavity and the lower cavity; the visualization window can be made of quartz glass and is set in a non-middle position on the upper cavity. When the solution is added, the tightening and fixing of the pressure cover can be observed through the visualization window, so that a completely enclosed mixing chamber is formed between the upper and lower cavities. In the process of dispersing the mixed solution, the mixing process of the solution can be observed in real time through the visualization window.

[0057] The push-pull shaft reciprocates in the mixing chamber, and a circulating flow field area is formed between the push-pull shaft and the mixing chamber, which serves as a sealed working area. The push-pull shaft cooperates with the mixing chamber, and when the push-pull shaft reciprocates back and forth, the mixing chamber forms a front chamber and a rear chamber on the front and rear sides of the push-pull shaft, and the volume of the front and rear chambers changes periodically. The flow field area is a shear flow field area or a stretching flow field area.

[0058] The push-pull rod includes a front support push-pull rod and a rear support push-pull rod, which are detachably connected to both sides of the push-pull shaft. By disassembling and assembling the front and rear support push-pull rods, push-pull shafts of different cross-sectional shapes or sizes can be replaced according to actual needs. The specific connection method can adopt the conventional installation method of existing similar push-pull shafts. Figures 8 to 11 As shown, a push-pull shaft with a circular, rectangular, trapezoidal or pentagonal cross section can be used.

[0059] Example 2

[0060] This embodiment provides a multifunctional modular rheological mixing method based on a controllable flow field, which is implemented by the multifunctional modular rheological mixing device described in Example 1.

[0061] The method comprises arranging a push-pull shaft in a mixing chamber. Under the reciprocating motion of the push-pull shaft, the solution reciprocates in the mixing chamber whose shape changes periodically. The solution is fully mixed by utilizing the extensional flow generated by the expansion-contraction of the convergent flow channel formed in the mixing chamber or the shear flow generated by the wall velocity difference of the flat flow channel, thereby obtaining a continuous extensional flow or shear flow effect, and obtaining a fully mixed solution under the action of the cyclic extensional flow or shear flow. According to the different cross-sectional shapes of the push-pull shaft, the convergent flow channel is formed between the push-pull shaft with an arc surface such as a circular cross section and the inner wall of the mixing chamber (the extensional flow field formed by it is shown in FIG. 1(a)), and the flat flow channel is formed between the push-pull shaft with a flat surface such as a rectangular cross section and the inner wall of the mixing chamber (the shear flow field formed by it is shown in FIG. 1(b)). In the above-mentioned dispersion and mixing process, the solution undergoes a pulsating dispersion process of dispersion, reciprocation, redispersion, and reciprocation, so that the molecular chains of the solution gradually untangle, and the molecular chains and the particles are fully dispersed and mixed. In the process of dispersing and mixing the solution, the pressure sensor set on the mixing chamber and the load sensor set on the push-pull shaft respectively record the solution pressure in the mixing chamber and the thrust on the push-pull shaft in real time, and use the obtained data to solve the viscous resistance of the solution on the push-pull shaft surface and the shear viscosity and shear rate of the solution when the current push-pull shaft is used, thereby providing an optimization basis for the material formula, flow field structure and / or mixing times of the next solution mixing. In this process, the obtained data are used to solve the rheological performance parameters such as the viscous resistance on the push-pull shaft surface, the shear viscosity and shear rate of the solution in the current state. Subsequently, the influence of factors such as the number of stretching times, molecular weight, solid content, and push-pull shaft structure on the rheological properties of the solution is studied, and the critical point of the solution from the heterogeneous state to complete dispersion and molecular chain disentanglement is clarified, thereby realizing real-time optimization of the material formula, flow field structure and mixing times to meet the requirements of sufficient dispersion of different solution systems and sufficient disentanglement of molecular chains.

[0062] Among them, the specific process of using the obtained data to solve the viscous resistance of the solution on the push-pull shaft surface and the shear viscosity and shear rate of the solution when using the current push-pull shaft is as follows (the principle is shown in Figure 1):

[0063] In order to establish a simplified mathematical model inside the flow field, first, the solution in the mixing chamber is set to an isothermal, steady-state laminar flow and the weight is negligible; secondly, compared with the viscous shear force, the inertial force caused by the acceleration of the solution is also negligible; thirdly, the radius R of the push-pull axis is much larger than the minimum gap that the solution can pass through, so there is slip between the solution and the cavity wall; in addition, a follow-up rectangular coordinate system (x, y, z) is established using the cylindrical push-pull axis as an example to represent the position of each point inside the mixing chamber; in the follow-up rectangular coordinate system (x, y, z), the origin O of the rectangular coordinate system is set to the inside of the push-pull axis The center of the mixing chamber is at the center, and the entire follower coordinate system reciprocates with the push-pull shaft; the x-axis is set along the movement direction of the push-pull shaft, and the positive direction is the opposite direction of the push-pull shaft movement; the y-axis is perpendicular to the x-axis, and the positive direction directly points to the upper cavity wall of the mixing chamber; the z-axis is circled from the x-axis to the y-axis with the four fingers of the right hand in a counterclockwise direction, and the direction pointed by the thumb is the positive direction of the z-axis; but since the cross-sectional shape of the cavity is only extended but not changed in the z-axis direction, when the x and y coordinates are constant, the speed and pressure of the solution will not change much when the z-axis coordinate changes, so only the x-axis and y-axis directions are considered;

[0064] In this mathematical model, the width of the mixing chamber along the z-axis is B; the straight-line distance from x2 to x1 is L; when the horizontal coordinate is x, the distance from the position of the push-pull shaft structure surface to the axis is Y(x), the distance from the position of the test solution to the x-axis is y (y≥Y(x)), and y1=y2; the cross-sectional area with the horizontal coordinate x and perpendicular to the x-axis is A; the viscous resistance of the push-pull shaft surface is F tui ; The consistency coefficient is k; The power law exponent is n;

[0065] When the rheological mixing device is running, the pressure values ​​P1 and P2 measured by the pressure sensor and the thrust F of the push-pull shaft measured by the load sensor are recorded, and then the current solution shear viscosity η is calculated. 剪 , the calculation process is as follows:

[0066] Substituting the pressure value P1, pressure value P2 and the thrust F of the push-pull shaft into the basic equation of fluid mechanics, it is simplified to formula (1):

[0067]

[0068] Formula (1) is used to perform double integration of x and y and then multiply it by the width B of the rheological mixing chamber along the z-axis to obtain formula (2), where x is the coordinate value of the solution on the x-axis (the x-axis is the movement direction of the push-pull axis), and y is the coordinate value of the solution on the y-axis (the y-axis is the positive direction pointing directly to the upper cavity wall of the mixing chamber);

[0069]

[0070] The pressure sensor measures that the pressure value of the solution at the cross section at the x1 coordinate and perpendicular to the x-axis is P1, and the pressure value at the cross section at the x2 coordinate is P2; B is the width of the rheological mixing chamber along the z-axis; Y(x) is the distance from the position of the push-pull shaft structure surface to the axis when the horizontal coordinate is x; y(x) is the distance from the position of the solution to be tested to the x-axis when the horizontal coordinate is x (y(x)≥Y(x)), and y(x1)=y(x2); L is the straight-line distance from x2 to x1; F is the thrust of the push-pull shaft; F tui is the viscous resistance on the push-pull shaft surface; τ yx is the shear stress of the solution along the x-axis at the corresponding coordinate (x, y).

[0071] Then, the power law equation and formula (2) are used to form an equation group to establish the functional relationship between the shear rate and each sensor parameter. Since the shear rate is equal to the velocity gradient, the velocity gradient du / dy of the solution at the (x, y) coordinate is solved:

[0072]

[0073] Where γ is the shear rate, k is the consistency coefficient, and n is the power law exponent;

[0074] According to the force balance equation of the solution in the x-axis direction, the σ of the solution at the (x, y) coordinate is solved. x :

[0075] The velocity u(x) of the solution at the (x,y) coordinate can be further solved by taking the definite integral of y from formula (3):

[0076]

[0077]

[0078] Then, the viscous resistance F on the push-pull shaft surface is solved by the same flow rate at different cross sections, i.e. A1u(x1) = A3u(x3). tui Numerical solution of ;

[0079] Finally, the shear viscosity η of the solution at the (x, y) coordinate is solved by formula (3) and the power law equation: 剪 :

[0080]

[0081] Finally, the shear viscosity η is obtained 剪 , shear rate γ, viscous resistance F on the push-pull shaft surface tui The numerical value of .

[0082] The solution is a dilute solution, a semi-dilute solution, a concentrated solution, a melt, a polyelectrolyte or a gel.

[0083] As described above, the present invention can be better implemented. The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made according to the content of the present invention are covered by the scope of protection required by the claims of the present invention.

Claims

1. A multifunctional modular rheological mixing method based on a controllable flow field, characterized in that: By arranging a push-pull shaft in the mixing chamber, the solution reciprocates in the mixing chamber whose shape changes periodically under the reciprocating motion of the push-pull shaft, and the solution is fully mixed by utilizing the extension flow generated by the expansion-contraction of the convergent flow channel formed in the mixing chamber or the shear flow generated by the wall velocity difference of the flat flow channel, thereby obtaining the effect of continuous extension flow or shear flow, and obtaining a fully mixed solution under the action of the cyclic extension flow or shear flow; In the process of dispersing the mixed solution, the pressure sensor arranged on the mixing chamber and the load sensor arranged on the push-pull shaft respectively record the solution pressure in the mixing chamber and the thrust on the push-pull shaft in real time. The obtained data are used to solve the viscous resistance of the solution on the surface of the push-pull shaft and the shear viscosity and shear rate of the solution when the current push-pull shaft is used, thereby providing an optimization basis for the material formula, flow field structure and / or mixing times of the next solution mixing.

2. The multifunctional modular rheological mixing method based on controllable flow field according to claim 1, characterized in that: The specific process of using the obtained data to solve the viscous resistance of the solution on the push-pull shaft surface and the shear viscosity and shear rate of the solution when using the current push-pull shaft is as follows: Record the pressure values ​​P1 and P2 measured by the pressure sensor and the thrust F of the push-pull shaft measured by the load sensor, and then calculate the current solution shear viscosity η 剪 , the calculation process is as follows: Substituting the pressure value P1, pressure value P2 and the thrust F of the push-pull shaft into the basic equation of fluid mechanics, it is simplified to formula (1): Formula (1) is used to perform double integration of x and y and then multiply it by the width B of the rheological mixing chamber along the z-axis to obtain formula (2), where x is the coordinate value of the solution on the x-axis (the x-axis is the movement direction of the push-pull axis), and y is the coordinate value of the solution on the y-axis (the y-axis is the positive direction pointing directly to the upper cavity wall of the mixing chamber); The pressure sensor measures that the pressure value of the solution at the cross section at the x1 coordinate and perpendicular to the x-axis is P1, and the pressure value at the cross section at the x2 coordinate is P2; B is the width of the rheological mixing chamber along the z-axis; Y(x) is the distance from the position of the push-pull shaft structure surface to the axis when the horizontal coordinate is x; y(x) is the distance from the position of the solution to be tested to the x-axis when the horizontal coordinate is x (y(x)≥Y(x)), and y(x1)=y(x2); L is the straight-line distance from x2 to x1; F is the thrust of the push-pull shaft; F tui is the viscous resistance on the push-pull shaft surface; τ yx is the shear stress of the solution along the x-axis at the corresponding coordinate (x, y). Then, the power law equation and formula (2) are used to form an equation group to establish the functional relationship between the shear rate and each sensor parameter. Since the shear rate is equal to the velocity gradient, the velocity gradient du / dy of the solution at the (x, y) coordinate is solved: Where γ is the shear rate, k is the consistency coefficient, and n is the power law exponent; According to the force balance equation of the solution in the x-axis direction, the σ of the solution at the (x, y) coordinate is solved. x : The velocity u(x) of the solution at the (x,y) coordinate can be further solved by taking the definite integral of y from formula (3): in Then, the viscous resistance F on the push-pull shaft surface is solved by the same flow rate at different cross sections, i.e. A1u(x1) = A3u(x3). tui Numerical solution of ; Finally, the shear viscosity η of the solution at the (x, y) coordinate is solved by formula (3) and the power law equation: 剪 : Finally, the shear viscosity η is obtained 剪 , shear rate γ, viscous resistance F on the push-pull shaft surface tui The numerical value of .

3. The multifunctional modular rheological mixing method based on controllable flow field according to claim 1, characterized in that: The solution is a dilute solution, a semi-dilute solution, a concentrated solution, a melt, a polyelectrolyte or a gel.

4. A multifunctional modular rheological mixing device based on a controllable flow field for implementing the rheological mixing method according to any one of claims 1 to 3, characterized in that: It includes an upper cavity, a lower cavity, a push-pull rod, a push-pull shaft, a pressure sensor and a load sensor. The upper cavity and the lower cavity cooperate to form a mixing cavity. The push-pull shaft is arranged in the mixing cavity, and a gap for the solution to pass through is left between the surface of the push-pull shaft and the inner wall of the mixing cavity. Push-pull rods are connected to both sides of the push-pull shaft, and both ends of the push-pull rods are installed between the upper cavity and the lower cavity. One end of the push-pull rod is externally connected to a load device, and a load sensor is provided at the connection between the push-pull rod and the load device. A plurality of pressure sensors are distributed on one side of the mixing cavity.

5. The multifunctional modular rheological mixing device based on controllable flow field according to claim 4, characterized in that: The push-pull shaft reciprocates in the mixing chamber, and a circulating flow field area is formed between the push-pull shaft and the mixing chamber.

6. The multifunctional modular rheological mixing device based on controllable flow field according to claim 5, characterized in that: The flow field region is a shear flow field region or a stretching flow field region.

7. The multifunctional modular rheological mixing device based on controllable flow field according to claim 4, characterized in that: The cross section of the push-pull shaft is circular, rectangular, trapezoidal or pentagonal.

8. The multifunctional modular rheological mixing device based on controllable flow field according to claim 4, characterized in that: The push-pull rod comprises a front support push-pull rod and a rear support push-pull rod, and the front support push-pull rod and the rear support push-pull rod are detachably connected to both sides of the push-pull shaft respectively.

9. The multifunctional modular rheological mixing device based on controllable flow field according to claim 4, characterized in that: The connection surface between the upper cavity and the lower cavity is also provided with a gasket and a packing, and the gasket and the packing are respectively distributed on the periphery of the mixing cavity.

10. The multifunctional modular rheological mixing device based on controllable flow field according to claim 4, characterized in that: A pressure cover and a visualization window are also provided on the top of the upper cavity, and the pressure cover and the visualization window are respectively distributed above the mixing cavity.

Images