Integrally invertible rheometer

Abstract

The utility model provides an integrally invertible rheometer, which aims at solving the problems that the existing rheometer is single in measurement mode, cannot perform high shear rate test and the like, relates to the technical field of flow measurement, and comprises a base, a rack, a rheology test system and a stop mechanism, and rotating shafts are arranged on the left side and the right side of the middle part of a frame of the base; the rotating shaft is fixedly connected with a rack, stop mechanisms corresponding in position are arranged on the two sides of the base and the two sides of the rack, and a rheology testing system is fixed to the rack. The integrally invertible rheometer can be used for measuring high-viscosity and low-viscosity samples at the same time, so that more measurement modes are provided, and the measurement can be carried out at a high shear rate.

Description

Technical Field

[0001] The utility model belongs to the technical field of fluid rheology measurement, and more specifically, relates to a rheometer which can be inverted as a whole. Background Art

[0002] Currently, there are two main types of rheometers used for rheological measurements: capillary rheometers and rotational rheometers. Capillary rheometers can achieve high shear rates, but their measurement mode is relatively simple, and they can only obtain viscosity, a material function. Furthermore, because low-viscosity materials easily leak through the capillary, capillary rheometers cannot be used to measure low-viscosity liquids. Rotational rheometers can measure a variety of material functions, including viscosity, storage modulus, loss modulus, and loss angle. However, due to factors such as torque, boundary damage, and the rod climbing effect, high shear rate tests are often not possible.

[0003] Patents with prior art application numbers CN201110391282.9 and CN201120490781.9 disclose a linear vibration annular gap extrusion rheometer, comprising: a barrel with a central through-hole, an extrusion plunger rod sliding in the barrel, a center rod coaxially mounted within the barrel, a pressure sensor and a temperature sensor extending into the barrel, and a heating and cooling device mounted around the barrel. The invention is characterized in that: the annular gap between the center rod and the barrel forms a test chamber; the sample to be tested, which can flow within the barrel, flows out through the test chamber under the extrusion action of the extrusion plunger rod; and as the sample to be tested flows within the test chamber, the center rod vibrates linearly along the centerline. The rheometer disclosed in this patent is unable to perform rheological testing of fluids under the superposition of a pressure flow field and a drag flow field, and the fluid in the rheometer is prone to leakage. Utility Model Content

[0004] The main problem solved by the present invention is that capillary rheometers in the prior art can only measure the viscosity of fluids but cannot measure low-viscosity fluids, and rotational rheometers cannot measure fluids with high shear rates in most cases, and provide a rheometer that can be inverted as a whole.

[0005] In view of the above technical problems, the present invention adopts the following specific technical solutions:

[0006] A rheometer that can be inverted as a whole includes a base and a frame, as well as a rheological testing system and a stopping mechanism. The base frame is provided with rotating shafts on the left and right sides, and the rotating shafts are fixedly connected to the frame; the base and the left and right sides of the frame are both provided with stopping mechanisms with corresponding positions; the rheological testing system is arranged on the frame.

[0007] Preferably, the stopping mechanism includes a stopping mechanism 1 and a stopping mechanism 2, and the stopping mechanism 1 is provided with two pairs, and the stopping mechanism 1 is respectively arranged on the left and right sides of the base, and the pair of stopping mechanism 1 on the same side of the base is symmetrical about the rotation axis; a pair of stopping mechanism 2 is symmetrically arranged on the frame, so that the stopping mechanism 2 is aligned with the stopping mechanism 1 when the frame rotates around the rotation axis.

[0008] Preferably, the rheological testing system includes a drive system 1, a drive system 2, a barrel and a pressure and temperature sensor, the drive system 1 is connected to the plunger, the plunger head is fixed on the top of the plunger, and the drive system 1 drives the plunger to move linearly up and down; the drive system 2 is connected to the rotor through a connecting rod, the rotor and the plunger head are arranged opposite to each other, and the drive system 2 drives the rotor to rotate.

[0009] Preferably, a leak-proof device is provided on the plunger head.

[0010] Preferably, a heating device is provided in the barrel, and the pressure and temperature sensor is provided on the barrel.

[0011] Preferably, the rheological testing system includes stress-controlled, strain-controlled and mixed-controlled rheological testing systems.

[0012] Preferably, the first driving system of the stress-controlled rheological testing system is a pressure-controlled system, and the second driving system is a torque-controlled system. The position of the piston movement is measured by a grating ruler, and an optical encoder is provided on the connecting rod.

[0013] Preferably, the first drive system and the second drive system of the strain-controlled rheological testing system are both speed-controlled systems, and a torque measurement system is provided on the plunger.

[0014] Preferably, the first driving system of the hybrid controlled rheological testing system is a speed controlled system, the second driving system is a torque controlled system, the pressure and temperature sensors are arranged on the barrel, and the optical encoder is arranged on the connecting rod.

[0015] Preferably, the first driving system of the hybrid controlled rheological testing system is a pressure controlled system, the second driving system is a speed controlled system, the position of the piston movement is measured by a grating ruler, and a torque measurement system is provided on the connecting rod.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] The rheometer of the present application includes a base and a frame, as well as a rheological test system and a stop mechanism. The base frame is provided with a rotating shaft on both sides, and the rotating shaft is fixedly connected to the frame. The base and the frame are provided with corresponding stop mechanisms on both sides. The rheological test system is arranged on the frame, and the frame can rotate around the rotating shaft, thereby driving the entire rheological test system to rotate. When the second stop mechanism is aligned with the first stop mechanism above the rotating shaft, the rheometer is upright; when the second stop mechanism is aligned with the first stop mechanism below the rotating shaft, the rheometer is inverted. When the rheometer is upright, the plunger can move up and down linearly, pushing the material in the barrel to be squeezed out from the annular gap between the rotor and the barrel, forming a pressure flow. The rotor can remain stationary or rotate to form a drag flow. The rheological measurement of the pressure flow field is achieved by measuring and analyzing the flow field in the annular gap between the rotor and the barrel. In this case, high-viscosity materials can be measured, a higher shear rate can be achieved, and rheological measurement under the orthogonal superposition of the pressure flow field and the drag flow field can be achieved. When the rheometer is inverted, the plunger and the anti-leakage device on the plunger (such as a rubber ring) can hold the material. At this time, low-viscosity materials can be measured. The drag flow is formed by the rotation of the rotor, and the plunger can be stationary or oscillate up and down to form a pressure flow. Rheological measurements can be achieved under the condition of orthogonal superposition of the pressure flow field and the drag flow field. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the stress-controlled rheological testing system of the utility model;

[0019] Figure 2 This is a schematic diagram of the structure of the strain-controlled rheological testing system of the utility model;

[0020] Figure 3 This is an enlarged schematic diagram of the size structure of the rotor and barrel of the utility model;

[0021] Figure 4 Schematic diagram of the structure of the hybrid controlled rheological testing system (I) of the present utility model;

[0022] Figure 5 This is a schematic diagram of the structure (II) of the hybrid controlled rheological testing system of the present utility model.

[0023] In the schematic diagram, 1. Drive system 1; 2. Frame; 3. Base; 4. Plunger; 5. Barrel (including heating device); 6. Plunger head (copper); 7. Rotating shaft; 8. Drive system 2; 9. Stop mechanism 2; 10. Stop mechanism 1; 11. Grating scale; 12. Rotor; 13. Optical encoder; 14. Pressure and temperature sensor; 15. Torque measurement system. DETAILED DESCRIPTION

[0024] To clearly illustrate the technical features of the present invention, the present invention is described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein, and therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below. Furthermore, in the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," and the like, indicating positions or locations, are based on the positions or locations shown in the accompanying drawings and are intended solely for ease of description and simplification of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and are therefore not intended to limit the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not intended to indicate or imply relative importance or to implicitly specify the number of the technical features indicated. Thus, features designated "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this application, "plurality" means two or more, unless otherwise specified or defined. In this application, unless otherwise specified or defined, terms such as "mounted," "connected," "connected," and "fixed" should be interpreted broadly. For example, they can refer to fixed, removable, or integrated connections; mechanical, electrical, or communication connections; direct or indirect connections through an intermediary; internal communication between two components; or interaction between two components. A person skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances. In this application, unless otherwise specified or defined, a first feature being "above" or "below" a second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. In this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of this application. In this specification, illustrative expressions of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0025] Example 1

[0026] like Figure 1As shown, a rheometer that can be inverted as a whole includes a base 3 and a frame 2, as well as a rheological testing system and a stopping mechanism. Rotating shafts 7 are provided on the left and right sides of the frame of the base 3, and the rotating shafts 7 are fixedly connected to the frame 2; the base 3 and the left and right sides of the frame 2 are both provided with stopping mechanisms with corresponding positions; the rheological testing system is arranged on the frame 2.

[0027] The stopping mechanism includes a stopping mechanism 10 and a stopping mechanism 2 9. There are two pairs of stopping mechanisms 10, which are respectively arranged on the left and right sides of the base 3, and the stopping mechanisms 10 on the same side of the base 3 are symmetrical about the rotation axis 7 on the same side; there is a pair of stopping mechanisms 2 9, which are arranged on the frame 2, so that when the frame 2 rotates around the rotation axis 7, the stopping mechanism 2 9 is aligned with the stopping mechanism 10. After alignment, the frame 2 and the base 3 can be relatively fixed to ensure that the stopping mechanism 10 is aligned with the stopping mechanism 2 9. The rheological test system includes a drive system 1, a drive system 2 8, a barrel 5 and a pressure and temperature sensor 14. Under the drive of the drive system 1, the plunger 4 can make a linear motion up and down, pushing the material in the barrel 5 out from the annular gap between the rotor 12 and the barrel 5, forming a pressure flow. The rheological measurement of the pressure flow field is achieved by measuring and analyzing the flow field; the drive system 2 8 is connected to the rotor 12 through a connecting rod. The rotor 12 is arranged opposite to the plunger head 6. The rotor 12 can make a rotational motion under the drive of the drive system 2 8, driving the rotor 12 A drag flow field is formed between the barrel 5 and the material, and the rheological measurement of the drag flow field is achieved by measuring and analyzing the flow field; the barrel 5 includes a heating device, which can be heated by a ceramic electric heating tile, and a pressure and temperature sensor 14 is placed on the barrel 5. The drive system 1 is connected to the plunger 4, and the plunger head 6 is fixed on the top of the plunger 4. The drive system 2 8 is connected to the rotor 12 through a connecting rod. The plunger head 6 is arranged opposite to the rotor 12. The plunger head 6 can be equipped with a leak-proof device, such as a rubber ring, to prevent the sample from leaking during rotation when the rheometer is inverted.

[0028] The stop mechanism 10 is arranged on both the upper and lower sides of the rotating shaft 7. When the stop mechanism 2 9 is aligned with the stop mechanism 10 above the rotating shaft 7, the rheometer is upright; when the stop mechanism 2 9 is aligned with the stop mechanism 10 below the rotating shaft 7, the rheometer is inverted.

[0029] When the rheometer is in the upright position, with stopper mechanism 2 (9) aligned with stopper mechanism 1 (10) above the rotating shaft 7, it is primarily used to measure high-viscosity samples. The flow field formed by the sample between the rotor 12 and the barrel 5 is the test flow field. This flow field is formed by the compressive force of the plunger 4 and the drag force of the rotor 12. The sample to be tested is placed above the rotor 12. The plunger 4 drives the plunger head 6, forcing the sample into the gap between the rotor 12 and the barrel 5. Drive system 1 (10) of the rheological testing system controls the vertical motion of the plunger 4 at a constant speed (or constant pressure). Drive system 2 (8) controls the rotation of the rotor 12 via a connecting rod. The rotational motion can be constant speed, sinusoidal oscillation, or other forms of rotation. The movement of drive system 1 (1) and drive system 2 (8) is computer-controlled, and can be performed simultaneously or independently.

[0030] When the rheometer is inverted, stopper mechanism 2 (9) is aligned with stopper mechanism 1 (10) below the rotating shaft (7). This is primarily used for measuring low-viscosity samples. A leak-proof device, such as a rubber ring, is added to the plunger tip (6). The plunger tip (6) is adjusted to the appropriate position to form a cup-shaped structure with the barrel (4). The sample is placed in the cup-shaped structure, completely submerging the rotor (12). Since the sample does not flow out due to gravity, low-viscosity samples can be measured. The flow field formed by the sample between the rotor (12) and the barrel (5) is the measurement flow field. This flow field is formed by the movement of the material under the compressive force of the plunger (4) and the drag force of the rotor (12). For rheological testing, drive system 1 (1) is stationary or performs sinusoidal up-and-down motion. Drive system 2 (8) controls the rotational motion of the rotor (12). This rotational motion can be constant speed, sinusoidal, or other forms of rotation. The movement of drive systems 1 (1) and 2 (8) is computer-controlled and can be performed simultaneously or independently.

[0031] Rheological testing systems are divided into three types: stress-controlled, strain-controlled and mixed-controlled rheological testing systems. Figure 1 As shown, in this embodiment, the stress-controlled rheological testing system includes a drive mechanism 1, a drive mechanism 2 8, a barrel 5, and a pressure and temperature sensor 14. Drive mechanism 1 is connected to a plunger 4, to which a plunger head 6 is fixed. The displacement and velocity of the plunger head 6 are measured by a grating scale 11, one end of which is fixed relative to the frame 2 and the other end is positioned opposite the plunger 4. Drive mechanism 2 8 is connected to a rotor 12 via a connecting rod, on which an optical encoder 13 is mounted. The plunger head 6 is positioned opposite the rotor 12. The stress-controlled rheological testing system includes a barrel 5 for holding material, which forms a measurement flow field with the rotor 12. The stress-controlled rheological testing system is advantageous in scenarios requiring precise stress control, such as creep measurements. It can also serve as an alternative to the strain-controlled type in measurement modes, such as constant shear rate measurements, where stress and strain (or strain rate) can be adjusted to stable values ​​through feedback.

[0032] like Figure 3 As shown, the rotor and barrel size structure around the flow field are measured. In this embodiment, the height of the rotor when the rheometer is inverted is , the diameter of the rotor 12 is , barrel 5 inner diameter , rotor speed (or ;Speed ​​resolution is higher than , the maximum speed is higher than ), the rotor can provide a torque greater than , the torque resolution is greater than , the angular displacement resolution is greater than The motor response time (the time it takes for the actual speed to reach the control speed) is less than In the oscillation motion mode, the rotor oscillation frequency is , the amplitude is The pressure sensor range is , the maximum pressure that the plunger can provide is , the temperature sensor range is ℃, the temperature range of the heating device in the barrel is room temperature to ℃, the speed of the plunger, That is approximately , motion speed control accuracy .

[0033] Example 2

[0034] like Figure 2 As shown, in this embodiment, both drive systems 1 and 2 of the strain-controlled rheological testing system are speed-controlled systems. Drive system 1 is connected to a plunger 4, a plunger head 6 being fixed to the top of the plunger 4. Drive system 2 8 is connected to a rotor 12 via a connecting rod. The plunger head 6 and rotor 12 are positioned opposite each other. A torque measurement system 15 is provided on the plunger 4, which measures torque using a torque sensor or current feedback from a rotating motor. Strain-controlled rheological testing systems are advantageous in scenarios requiring precise strain control, such as relaxation measurements. They can also serve as an alternative to strain-controlled systems in measurement modes such as constant shear rate measurements, where stress, strain (or strain rate) can be adjusted to a stable value through feedback.

[0035] When the rheometer is upright, that is, the stop mechanism 2 9 is aligned with the stop mechanism 10 above the rotating shaft 7, it is mainly used to measure high-viscosity samples; when the rheometer is inverted, that is, the stop mechanism 2 9 is aligned with the stop mechanism 10 below the rotating shaft 7, it is mainly used to measure low-viscosity samples, and a leak-proof device, such as a rubber ring, is installed in the gap between the plunger head 6 and the barrel 5.

[0036] Example 3

[0037] like Figure 4 As shown, in this embodiment, the hybrid-controlled rheological testing system comprises a first drive system that is speed-controlled, and a second drive system that is torque-controlled. The pressure and temperature sensor 14 is mounted on the barrel 5, and the optical encoder 13 is mounted on the connecting rod. In this configuration, the pressure flow generated by the plunger 4 pushing the material through the slit between the rotor 12 and the barrel 5 when in an upright position serves as the primary measurement flow field, enabling measurement of high-viscosity materials and high shear rates. The primary flow field is controlled at a constant velocity. This system can be substituted for the stress-controlled system in measurement modes such as constant shear rate measurement, where stress, strain (or strain rate) can be adjusted to a stable value through feedback. The rotor 12 can be stationary or rotating, generating orthogonal superposition flow fields during rotation. This configuration is advantageous when precise control of drag flow stress is required, such as when testing creep properties of a material in the direction of rotation. This system can be substituted for the stress-controlled system in measurement modes such as constant shear rate measurement, where stress, strain (or strain rate) can be adjusted to a stable value through feedback. When inverted, plunger 4 is at the bottom. Combined with leak-proof devices such as rubber rings, it forms a material-holding space with barrel 5, effectively preventing leakage of low-viscosity samples and enabling measurement. At this point, the drag flow field generated by the rotation of rotor 12 becomes the primary flow field. Rotor 12 can rotate at a constant speed, oscillate, or rotate in steps, while plunger 4 can be stationary or oscillate. When plunger 4 oscillates, a superimposed flow field of pressure flow and drag flow is generated. This configuration is advantageous when precise control of the drag flow stress is required, such as when testing the creep properties of a material in the direction of rotation. In measurement modes such as constant shear rate measurements, where stress and strain (or strain rate) can be adjusted to stable values ​​through feedback, this configuration can be used in place of a strain-controlled type.

[0038] like Figure 5As shown, the hybrid-controlled rheological testing system features a pressure-controlled drive system (first system) and a velocity-controlled drive system (second system). The position of the plunger 4 is measured by a linear scale 11, and a torque measurement system is installed on the connecting rod, measuring torque via a torque sensor or current feedback from the rotating motor. In this configuration, the pressure flow generated by the plunger 4 pushing the material through the narrow gap between the rotor 12 and the barrel 5 when in an upright position serves as the primary measurement flow field, enabling measurements of high-viscosity materials and high shear rates. The primary flow field is controlled by constant pressure, making this configuration advantageous when measuring rheological behaviors where stress is a key factor, such as the critical shear stress of wall slip. In measurement modes such as constant shear rate measurements, where stress and strain (or strain rate) can be adjusted to stable values ​​through feedback, this configuration can be substituted for the strain-controlled type. The rotor 12 can be stationary or rotating, generating orthogonal superposition flow fields during rotation. In this case, the superimposed flow field is advantageous when precise strain control is required. For example, when the superimposed flow field exhibits large oscillations (with amplitudes reaching the nonlinear viscoelastic region), it can be substituted for the stress-controlled type in measurement modes such as constant shear rate measurements, where stress, strain, or strain rate can be adjusted to stable values ​​through feedback. When inverted, low-viscosity materials can be measured, and the drag flow field generated by the rotation of rotor 12 becomes the mainstream field. Rotor 12 can rotate at a constant speed, oscillate, or rotate in steps, while plunger 4 can be stationary or oscillate. When plunger 4 oscillates, a superimposed flow field of pressure flow and drag flow can be obtained. In this case, the mainstream field is advantageous when precise strain control is required. For example, when the mainstream field exhibits large oscillations (with amplitudes reaching the nonlinear viscoelastic region), it can be substituted for the stress-controlled type in measurement modes such as constant shear rate measurements, where stress, strain, or strain rate can be adjusted to stable values ​​through feedback.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to fall within the scope of protection of the present invention.

Claims

1. An integrally invertible rheometer, comprising a base and a frame, characterized in that: It also includes a rheological testing system and a stopping mechanism. The left and right sides of the frame of the base are provided with rotating shafts, and the rotating shafts are fixedly connected to the frame; the left and right sides of the base and the frame are provided with stopping mechanisms with corresponding positions; the rheological testing system is arranged on the frame.

2. The integrally invertible rheometer according to claim 1, characterized in that: The stopping mechanism includes a stopping mechanism 1 and a stopping mechanism 2. The stopping mechanism 1 is provided with two pairs. The stopping mechanism 1 is respectively arranged on the left and right sides of the base. The pair of stopping mechanisms 1 on the same side of the base are symmetrical about the rotation axis; a pair of stopping mechanisms 2 are symmetrically arranged on the frame so that the stopping mechanism 2 is aligned with the stopping mechanism 1 when the frame rotates around the rotation axis.

3. The integrally invertible rheometer according to claim 1, characterized in that: The rheological testing system includes a driving system 1, a driving system 2, a barrel and a pressure and temperature sensor. The driving system 1 is connected to the plunger, and the plunger head is fixed on the top of the plunger. The driving system 1 drives the plunger to move linearly up and down; the driving system 2 is connected to the rotor through a connecting rod, and the rotor and the plunger head are arranged opposite to each other. The driving system 2 drives the rotor to rotate.

4. The integrally invertible rheometer according to claim 3, characterized in that: The plunger head is provided with a leak-proof device.

5. The integrally invertible rheometer according to claim 3, characterized in that: A heating device is provided in the barrel, and the pressure and temperature sensor is arranged on the barrel.

6. The integrally invertible rheometer according to claim 3, characterized in that: The rheological testing system includes stress-controlled, strain-controlled and mixed-controlled rheological testing systems.

7. The integrally invertible rheometer according to claim 6, characterized in that: The first driving system of the stress-controlled rheological testing system is a pressure-controlled system, and the second driving system is a torque-controlled system. The position of the piston movement is measured by a grating ruler, and an optical encoder is provided on the connecting rod.

8. The integrally invertible rheometer according to claim 6, characterized in that: The first and second drive systems of the strain-controlled rheological testing system are both speed-controlled systems. The pressure and temperature sensors are arranged on the barrel, and the torque measurement system is arranged on the connecting rod.

9. The integrally invertible rheometer according to claim 6, characterized in that: The first driving system of the hybrid controlled rheological testing system is a speed controlled system, the second driving system is a torque controlled system, the pressure and temperature sensors are arranged on the barrel, and the connecting rod is provided with an optical encoder.

10. The integrally invertible rheometer according to claim 6, characterized in that: The first driving system of the hybrid controlled rheological testing system is a pressure controlled system, and the second driving system is a speed controlled system. The position of the piston movement is measured by a grating ruler, and a torque measurement system is provided on the connecting rod.

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