Suspended rotary viscometer and use method thereof

Abstract

The invention belongs to the field of liquid viscosity measurement, and provides a suspended rotational viscometer and a use method thereof. An outer cylinder upper / lower magnet is mounted at the upper / lower end of an outer cylinder of the viscometer; two fixing rings are installed in the middle of the outer cylinder, an outer multi-pole magnet is sleeved between the two fixing rings, and a constant-speed rotation driving system is arranged on the outer side of the outer multi-pole magnet. Inner cylinder upper / lower magnets are mounted at the upper end / lower end of the inner cylinder; the outer cylinder upper / lower magnet and the inner cylinder upper / lower magnet repel each other in magnetic force, and the inner cylinder suspends in the outer cylinder; the upper portion of the inner cylinder is provided with a sensing element, and the lower portion of the inner cylinder is provided with a counterweight ring. According to the using method, a relation curve between the liquid viscosity and the rotating speed of the inner cylinder is obtained through the liquid with the known viscosity, the actually measured rotating speed is compared with the relation curve in the using process, and the accurate liquid viscosity is obtained. The problem that an existing product cannot perform sealed measurement is solved, external interference is reduced, and the measurement result is more reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid viscosity measuring instruments, and in particular relates to a suspended rotational viscometer and a use method thereof. Background Art

[0002] Rotational viscometers are widely used in many industries such as chemical, pharmaceutical and food to evaluate the viscosity of various liquids such as oils, fats, foods, drugs and polymers.

[0003] Traditional viscometers such as capillary viscometers and falling ball viscometers have relatively low measurement accuracy and complex operation, requiring a long time for sample preparation and measurement, and poor repeatability and stability of measurement results. Rotational viscometers have become the most widely used type of viscometers due to their good measurement accuracy and repeatability and convenient operation.

[0004] The principle of the rotational viscometer is based on the characteristics of Newtonian fluids, that is, when an object rotates in a liquid, due to the viscosity of the liquid, the object will encounter a certain amount of resistance. By measuring the resistance of the rotating object, the viscosity of the liquid can be calculated. The current rotational viscometer structure usually includes a rotatable cylindrical rotor, which is connected to a motor through a rotating shaft, and the motor drives the rotor to rotate. During measurement, the liquid to be tested is filled in a beaker, the rotor is vertically immersed in the liquid, and the rotor is suspended in the liquid and rotates. When the speed is stable, the torque is measured by the torque sensor on the rotating shaft to calculate the viscosity of the liquid. This structure has the following problems: First, the beaker is an open container, which causes the liquid surface to directly contact the outside air. Many liquids that cannot be exposed to air cannot be measured, such as toxic, volatile or easily oxidized and denatured drugs; Second, because the upper liquid surface of the liquid is a free liquid surface, when the speed is fast, the liquid will present a vortex-shaped inverted cone liquid surface due to centrifugal force, and even turbulence will occur. This change in flow state will cause serious distortion of viscosity measurement values; third, because the rotor is connected to the shaft, when the rotor is completely immersed in the liquid, part of the shaft will also be immersed in the liquid. The rotation of the shaft provides additional driving force for the liquid, which introduces interference factors into the measurement value and reduces the accuracy of the result. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a suspended rotational viscometer, comprising an outer cylinder fixedly arranged and an inner cylinder movably arranged inside the outer cylinder, wherein the outer cylinder is a hollow cylindrical container, the upper end of the outer cylinder is a detachable upper cover, an outer cylinder upper magnet is fixedly installed at the upper end of the outer side of the outer cylinder, an outer cylinder lower magnet is fixedly installed at the lower end of the outer side of the outer cylinder, and a rotation speed measuring instrument is fixedly installed at the upper part of the outer side of the outer cylinder; two fixing rings are fixedly installed at the middle part of the outer side of the outer cylinder, and the spacing between the two fixing rings is the same as the height of the outer multi-pole magnet; the outer multi-pole magnet is rotatably sleeved between the two fixing rings in the middle part of the outer cylinder, and a constant speed rotation driving system is arranged on the outer side of the outer multi-pole magnet; The inner cylinder is a hollow cylindrical cylinder, an inner cylinder upper magnet is fixedly installed on the upper end of the outer side of the inner cylinder, and an inner cylinder lower magnet is fixedly installed on the lower end of the outer side of the inner cylinder; the outer cylinder upper magnet and the inner cylinder upper magnet magnetically repel each other, and the outer cylinder lower magnet and the inner cylinder lower magnet magnetically repel each other, the inner cylinder is suspended inside the outer cylinder, and a gap is left between the inner cylinder and the outer cylinder; an inner multi-pole magnet is fixedly installed on the middle part of the inner side of the inner cylinder, and the inner multi-pole magnet and the outer multi-pole magnet are at the same height; an induction element is arranged on the upper part of the outer side of the inner cylinder, and the induction element is at the same height as the speed measuring instrument; a counterweight ring is fixedly installed on the lower part of the outer side of the inner cylinder.

[0006] Preferably, the constant speed rotation drive system includes an outer sleeve gear, which is fixedly mounted on the outer periphery of the outer multi-pole magnet; the constant speed rotation drive system also includes a motor fixedly mounted on one side of the outer cylinder, a drive gear is mounted on the motor shaft, and the drive gear is meshed with the outer sleeve gear.

[0007] Preferably, an upper opening is provided on the upper cover of the outer cylinder, a liquid outlet hose is fixedly arranged on the outer side of the upper cover of the outer cylinder, and one end of the liquid outlet hose is sealed and connected to the upper opening; a lower opening is provided on the bottom end of the outer cylinder, a liquid inlet hose is fixedly arranged on the outer side of the bottom end of the outer cylinder, and one end of the liquid inlet hose is sealed and connected to the lower opening; the other end of the liquid inlet hose is connected to micro liquid metering pump one, and the other end of the liquid outlet hose is connected to micro liquid metering pump two.

[0008] Preferably, the rotation speed measuring instrument is a Hall sensor, and the sensing element is a magnetic block.

[0009] Preferably, the speed measuring instrument is a laser speed meter, and the sensing element is a reflective patch.

[0010] The method for using the aforementioned suspended rotational viscometer comprises the following steps: The liquid to be tested is injected into the outer cylinder until the liquid to be tested fills the space between the inner cylinder and the outer cylinder, and the inner cylinder is suspended in the outer cylinder by magnetic force; Start the motor, the motor drives the driving gear and the outer gear to rotate, the outer gear drives the outer multi-pole magnet to rotate to form a rotating magnetic field, the rotating magnetic field drives the inner multi-pole magnet and drives the inner cylinder to rotate, and the counterweight ring can keep the position of the inner cylinder stable when it rotates; The rotation speed measuring instrument cooperates with the sensing element to measure the rotation speed of the inner cylinder, and the liquid viscosity is obtained according to the previously calibrated corresponding relationship between the rotation speed of the inner cylinder and the liquid viscosity.

[0011] Preferably, before the first use, a liquid of known viscosity is injected into the suspension rotational viscometer, the motor is started, and the speed reading is recorded after the speed of the inner drum is stabilized; thereafter, after the liquid is drained and the suspension rotational viscometer is cleaned, another liquid of different viscosity is injected into the suspension rotational viscometer, and the above steps are repeated until enough data points are measured, and the data points are fitted to obtain a relationship curve between the liquid viscosity and the speed of the inner drum.

[0012] The beneficial effects of the present invention are: The viscometer adopts a suspended inner cylinder with a magnetic levitation structure and a contactless speed measuring instrument. The inner cylinder of the viscometer has no contact with the outer cylinder and the external structure. Therefore, the outer cylinder container can be fully enclosed. During the measurement process, the liquid does not contact the outside world, which solves the problem that existing products cannot be measured in a sealed manner.

[0013] Since the outer cylinder is a closed container, the liquid can be completely filled so that the upper liquid level of the liquid to be measured is limited by the upper cover of the outer cylinder. Even if the rotation speed is high, no inverted cone vortex will be generated. The liquid flow state is more stable and the measurement result is more reliable.

[0014] The inner cylinder realizes contactless transmission through magnetic field coupling of two multi-stage magnets, avoiding the introduction of additional interference factors, and also avoiding problems such as failure and leakage that may be caused by wear of rotating parts.

[0015] The preferred solution of the present invention adds a micro liquid metering pump and liquid inlet and discharge hoses, which can realize automatic liquid addition and liquid discharge more conveniently, accurately and quantitatively. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an overall structural diagram of a suspended rotational viscometer according to an embodiment of the present invention; Figure 2 It is a partial enlarged view of the suspended rotational viscometer according to an embodiment of the present invention; Figure 3 for Figure 2 AA direction section view; Figure 4 A structural breakdown diagram of a suspended rotational viscometer according to an embodiment of the present invention; Figure 5 Schematic diagram of radial magnetization of the upper magnet and the lower magnet according to an embodiment of the present invention; Figure 6 A schematic diagram of magnetic pole distribution of a multi-pole magnet according to an embodiment of the present invention; In the figure: 1-inner cylinder, 2-inner multi-pole magnet, 3a-speed measuring instrument, 3b-sensing element, 4a-magnet on outer cylinder, 4b-magnet under outer cylinder, 4c-magnet on inner cylinder, 4d-magnet under inner cylinder, 5-outer cylinder, 6-weight ring, 7-outer multi-pole magnet, 8-jacket gear, 9-fixed ring, 10-liquid outlet hose, 11-driving gear, 12-micro liquid metering pump one, 13-motor, 14-liquid inlet hose, 15-micro liquid metering pump two. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with specific embodiments, wherein the accompanying drawings are only used for illustrative descriptions and represent only schematic diagrams rather than actual drawings, and should not be understood as limiting the present invention. In order to better illustrate the specific embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted. Based on the specific embodiments of the present invention, all other specific embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] like Figure 1 , Figure 2 As shown, the high-precision suspension type rotational viscometer provided by the present invention comprises an inner cylinder 1 and an outer cylinder 5, wherein the outer cylinder 5 is a hollow cylindrical container, and the upper end of the outer cylinder 5 is a detachable outer cylinder cover, wherein the outer cylinder cover is provided with an outer cylinder upper opening, and the outer cylinder upper opening is connected with one end of the liquid outlet hose 10; the outer cylinder 5 is provided with an outer cylinder lower opening at the bottom, and the outer cylinder lower opening is connected with one end of the liquid inlet hose 14. A pair of fixed rings 9 with a certain distance are fixedly installed in the middle of the outer side of the outer cylinder 5. The outer multi-pole magnet 7 is rotatably sleeved in the middle of the outer side of the outer cylinder 5, and the outer multi-pole magnet 7 is sandwiched between the two fixed rings 9. An outer sleeve gear 8 is fixedly installed on the outer periphery of the outer multi-pole magnet 7. An outer cylinder upper magnet 4a is fixedly installed on the upper end of the outer side of the outer cylinder 5, and an outer cylinder lower magnet 4b is fixedly installed on the lower end of the outer side of the outer cylinder 5. A speed measuring instrument 3a is provided on the upper part of the outer side of the outer cylinder 5, and the speed measuring instrument 3a is located below the outer cylinder upper magnet 4a, and the height of the speed measuring instrument 3a is the same as that of the sensing element 3b on the outer side of the inner cylinder 1. When in use, the outer cylinder 5 can be fixed on the laboratory table by a clamp device or the like as required.

[0019] like Figure 3 , Figure 4 As shown, the inner cylinder 1 is a closed cylindrical hollow sleeve, the upper end of the outer side of the inner cylinder 1 is fixedly provided with an inner cylinder upper magnet 4c, the lower end of the outer side of the inner cylinder 1 is fixedly provided with an inner cylinder lower magnet 4d, the upper and lower ends of the inner cylinder 1 are sealed, and the inner multi-pole magnet 2 is fixedly installed in the middle of the inner side of the inner cylinder 1. A counterweight ring 6 is installed at the lower part of the outer side of the inner cylinder 1, and a sensing element 3b at the same height as the speed measuring instrument 3a is installed at the upper part of the outer side of the inner cylinder 1. The inner cylinder 1 is suspended in the outer cylinder 5 by magnetic force, and a certain distance is left between the outer wall of the inner cylinder 1 and the inner wall of the outer cylinder 5. When in use, the liquid to be tested is injected until the liquid to be tested fills the space between the inner cylinder 1 and the outer cylinder 5.

[0020] like Figure 5As shown, the outer cylinder upper magnet 4a, the outer cylinder lower magnet 4b, the inner cylinder upper magnet 4c and the inner cylinder lower magnet 4d are all radially magnetized, that is, one of the inner and outer half circles of the ring is N pole, and the other is S pole. Among them, the magnetic poles of the outer cylinder upper magnet 4a and the inner cylinder upper magnet 4c are set in opposite directions, and the magnetic forces repel each other. The magnetic poles of the outer cylinder lower magnet 4b and the inner cylinder lower magnet 4d are set in opposite directions, and the magnetic forces repel each other. After the inner cylinder 1 is placed in the outer cylinder 5, the upper and lower ends of the inner cylinder 1 are both subject to repulsive forces, thereby realizing the magnetic suspension of the inner cylinder 1. The setting of the counterweight ring 6 lowers the center of gravity of the inner cylinder 1, increases the overall mass and inertia, and can maintain a stable position during high-speed rotation.

[0021] like Figure 6 As shown, the inner multi-pole magnet 2 and the outer multi-pole magnet 7 are both multi-pole magnetized, that is, N poles and S poles are alternately formed at equal angular intervals along the circumferential direction. The use of multi-pole magnetization can ensure that when the outer multi-pole magnet 7 rotates at high speed, the inner multi-pole magnet 2 is stably stressed. During measurement, the outer multi-pole magnet 7 rotates at a constant speed under the drive of the motor 13 to form a rotating magnetic field. The inner multi-pole magnet 2 drives the inner cylinder 1 to rotate under the drive of the rotating magnetic field. The higher the speed of the inner cylinder 1, the greater the viscous resistance it encounters, until the viscous resistance is balanced with the driving force of the external magnetic field, and the inner cylinder 1 reaches a balanced speed, which is slower than the speed of the outer multi-pole magnet 7. The greater the speed difference between the two, the greater the viscosity of the liquid. At this time, the induction element 3b periodically passes near the speed measuring instrument 3a due to rotation, and the speed measuring instrument 3a thus measures the speed of the inner cylinder 1, and the liquid viscosity can be obtained according to the previously calibrated correspondence between the speed of the inner cylinder 1 and the liquid viscosity.

[0022] The motor 13 is a fixed speed motor, fixedly arranged on one side of the outer cylinder 5. A driving gear 11 is fixedly mounted on the rotating shaft of the motor 13, and the driving gear 11 is meshed and connected with the outer gear 8, and the outer multi-pole magnet 7 is driven to rotate through the driving gear 11 and the outer gear 8.

[0023] The other end of the liquid inlet hose 14 is connected to the micro liquid metering pump 12. When in use, the micro liquid metering pump 12 is connected to the liquid container to be tested, and the liquid to be tested can be accurately and quantitatively pumped into the outer cylinder 5. The other end of the liquid outlet hose 10 is connected to the micro liquid metering pump 2 15. After the measurement is completed, the micro liquid metering pump 2 15 extracts the test liquid and discharges it into the collection container.

[0024] The rotation speed measuring instrument 3a can be a Hall sensor. Correspondingly, the sensing element 3b can be a magnetic block. When the magnetic block approaches the detection range of the Hall sensor, the Hall sensor sends an electrical signal, and the rotation speed of the inner drum 1 can be obtained by simple calculation based on the signal frequency.

[0025] The speed measuring instrument 3a can also be a laser speed meter. Accordingly, the sensing element 3b is a reflective patch. The probe of the laser speed meter faces the inner cylinder 1. When the reflective patch is rotated to the position closest to the laser speed meter probe, the probe receives the reflected light signal, and the speed of the inner cylinder 1 can be obtained by simple calculation based on the signal frequency.

[0026] Before the first use, calibration is required in the laboratory: inject a liquid of known viscosity into the suspension rotational viscometer, start the motor 13, and record the speed reading after the speed of the inner cylinder 1 stabilizes; then drain the liquid, clean the suspension rotational viscometer, and inject another liquid of different viscosity into the suspension rotational viscometer, repeat the above steps until enough data points are measured, fit the data points, and obtain the relationship curve between the liquid viscosity and the speed of the inner cylinder 1. In subsequent use, the actual measured speed is compared with the calibrated relationship curve to obtain the accurate liquid viscosity.

[0027] In the embodiments of the present invention, technical features that are not described in detail are all existing technologies or conventional technical means and will not be described in detail here.

[0028] Finally, it should be noted that the above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them, and the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any technician familiar with the technical field can modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be covered within the protection scope of the present invention.

Claims

1. A suspended rotational viscometer, comprising an outer cylinder (5) which is fixedly arranged and an inner cylinder (1) which is movably arranged inside the outer cylinder (5), characterized in that: The outer cylinder (5) is a hollow cylindrical container, the upper end of the outer cylinder (5) is a detachable upper cover, an outer cylinder upper magnet (4a) is fixedly mounted on the outer upper end of the outer cylinder (5), an outer cylinder lower magnet (4b) is fixedly mounted on the outer lower end of the outer cylinder (5), and a rotation speed measuring instrument (3a) is fixedly mounted on the outer upper part of the outer cylinder (5); two fixing rings (9) are fixedly mounted on the middle part of the outer side of the outer cylinder (5), and the spacing between the two fixing rings (9) is the same as the height of the outer multi-pole magnet (7); the outer multi-pole magnet (7) is rotatably sleeved between the two fixing rings (9) in the middle part of the outer cylinder (5), and a constant speed rotation drive system is arranged on the outer side of the outer multi-pole magnet (7); The inner cylinder (1) is a hollow cylindrical cylinder. An inner cylinder upper magnet (4c) is fixedly mounted on the outer upper end of the inner cylinder (1), and an inner cylinder lower magnet (4d) is fixedly mounted on the outer lower end of the inner cylinder (1). The outer cylinder upper magnet (4a) and the inner cylinder upper magnet (4c) are magnetically repelled from each other, and the outer cylinder lower magnet (4b) and the inner cylinder lower magnet (4d) are magnetically repelled from each other. The inner cylinder (1) is suspended inside the outer cylinder (5), and a gap is left between the inner cylinder (1) and the outer cylinder (5). An inner multi-pole magnet (2) is fixedly mounted on the middle part of the inner side of the inner cylinder (1), and the inner multi-pole magnet (2) and the outer multi-pole magnet (7) are at the same height. A sensing element (3b) is arranged on the outer upper part of the inner cylinder (1), and the sensing element (3b) and the rotation speed measuring instrument (3a) are at the same height. A counterweight ring (6) is fixedly mounted on the outer lower part of the inner cylinder (1).

2. A suspended rotational viscometer according to claim 1, characterized in that: The constant speed rotation drive system comprises an outer sleeve gear (8) which is fixedly mounted on the outer periphery of the outer multi-pole magnet (7); the constant speed rotation drive system also comprises a motor (13) which is fixedly mounted on one side of the outer cylinder (5), a driving gear (11) being mounted on the rotating shaft of the motor (13), and the driving gear (11) being meshed with the outer sleeve gear (8).

3. A suspended rotational viscometer according to claim 1 or 2, characterized in that: The upper cover of the outer cylinder (5) is provided with an upper opening, and a liquid outlet hose (10) is fixedly arranged outside the upper cover of the outer cylinder (5), and one end of the liquid outlet hose (10) is sealed and connected to the upper opening; the bottom end of the outer cylinder (5) is provided with a lower opening, and a liquid inlet hose (14) is fixedly arranged outside the bottom end of the outer cylinder (5), and one end of the liquid inlet hose (14) is sealed and connected to the lower opening; the other end of the liquid inlet hose (14) is connected to a first micro liquid metering pump (12), and the other end of the liquid outlet hose (10) is connected to a second micro liquid metering pump (15).

4. A suspended rotational viscometer according to claim 3, characterized in that: The rotation speed measuring instrument (3a) is a Hall sensor, and the sensing element (3b) is a magnetic block.

5. A suspended rotational viscometer according to claim 3, characterized in that: The speed measuring instrument (3a) is a laser speed meter, and the sensing element (3b) is a reflective patch.

6. The method for using a suspended rotational viscometer as claimed in claim 2, characterized in that: The following steps are involved: The liquid to be tested is injected into the outer cylinder (5) until the liquid to be tested fills the space between the inner cylinder (1) and the outer cylinder (5), and the inner cylinder (1) is suspended in the outer cylinder (5) by magnetic force; The motor (13) is started, the motor (13) drives the driving gear (11) and the outer gear (8) to rotate, the outer gear (8) drives the outer multi-pole magnet (7) to rotate to form a rotating magnetic field, the rotating magnetic field drives the inner multi-pole magnet (2) and drives the inner cylinder (1) to rotate, and the counterweight ring (6) can keep the position of the inner cylinder (1) stable when it rotates; The rotation speed measuring instrument (3a) cooperates with the sensing element (3b) to measure the rotation speed of the inner cylinder (1), and the viscosity of the liquid is obtained according to the previously calibrated corresponding relationship between the rotation speed of the inner cylinder (1) and the viscosity of the liquid.

7. The method for using a suspended rotational viscometer according to claim 6, characterized in that: Before the first use, a liquid of known viscosity is injected into the suspension rotational viscometer, and the motor (13) is started. After the rotation speed of the inner cylinder (1) is stabilized, the rotation speed reading is recorded. After the liquid is drained and the suspension rotational viscometer is cleaned, another liquid of different viscosity is injected into the suspension rotational viscometer. The above steps are repeated until enough data points are measured, and the data points are fitted to obtain a relationship curve between the liquid viscosity and the rotation speed of the inner cylinder (1).

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