A device for measuring kinematic viscosity and a method for using the same

Abstract

The invention relates to a device for measuring kinematic viscosity, comprising a double-bulb capillary viscometer, a sealed thermostatic box, a fixed jacket, a positioning platform, an automatic timing system and a suction cleaning system; the sealed thermostatic box is rotatably mounted on the positioning platform, and the double-bulb capillary viscometer is fixed in the sealed thermostatic box through the fixed jacket; the upper end openings of the main pipe and the branch pipe of the double-bulb capillary viscometer are respectively connected to the suction cleaning system by pipelines, and liquid level sensors are respectively arranged on the upper and lower sides of the upper and lower bulbs of the double-bulb capillary viscometer, and the liquid level sensors are respectively connected to the automatic timing system for data transmission; thereby solving the problem that the device for measuring kinematic viscosity in the prior art cannot realize automatic measurement of a wide viscosity range; the invention also provides a method for using the device, which is used to accurately measure the viscosity-temperature characteristics of non-transparent liquids or liquids of various colors.

Description

Technical Field

[0001] The invention relates to a device for measuring kinematic viscosity and a use method thereof. Background Art

[0002] Viscosity measurement is an important means to control production processes, ensure production safety, evaluate product quality, and conduct medical testing and scientific research in the fields of petroleum, chemical, pharmaceutical, food, textile, and national defense. Capillary viscometer is one of the important methods for measuring kinematic viscosity. It is recognized as the most accurate method in viscosity measurement and is indispensable in the petroleum, chemical, pharmaceutical and other industries.

[0003] Capillary viscometers are based on the principle of relative measurement, that is, measuring the time required for a certain volume of liquid to flow through a capillary under the action of gravity. Common capillary viscometers are divided into positive flow capillary viscometers such as Pinnacle, Ubbelohde, and Finkelstein, as well as countercurrent capillary viscometers. There are also various types of automated or optimized capillary viscometers, most of which are optimized and deformed based on these methods to improve accuracy or efficiency or for use under certain conditions.

[0004] Since the measuring range of capillary viscometers of various specifications is limited, in actual work, dozens of capillary viscometers of different specifications need to be purchased to form a capillary viscometer group, which increases the equipment cost.

[0005] During the working process of the capillary viscometer, the method of taking the average value by repeated measurements is adopted. The positive flow capillary viscometer can measure repeatedly with high accuracy after one cleaning. The countercurrent capillary viscometer needs to be cleaned after each measurement and has slightly lower accuracy. In particular, the countercurrent capillary viscometer is generally used for viscosity measurement of non-transparent liquids such as petroleum products or liquids of various colors. The positive flow capillary viscometer will be blocked from sight and light by the color. The cleaning process of the capillary viscometer is cumbersome and requires repeated flushing with a large amount of hazardous chemicals such as gasoline, petroleum ether, and alcohol, which increases the cost of consumables and is not conducive to laboratory safety.

[0006] Most of the existing automated capillary viscometers are based on positive flow capillary viscometers with automatic timing systems and automatic suction and cleaning systems. Most of the automatic timing systems are photothermal, photoelectric, and fiber optic sensor methods. The light source transmitting end is fixed on one side of the capillary viscometer, and the receiving end sensor element is fixed on the other side. The refraction characteristics of light are used to achieve the timing purpose. Some equipment that can automatically measure the viscosity of non-transparent liquids or liquids of various colors needs to be cleaned after each measurement, and cannot automatically measure repeatedly at one time.

[0007] In addition, the viscosity of the fluid is closely related to temperature, and the study of the viscosity-temperature characteristics of the sample is of great significance. When studying the viscosity-temperature characteristics of liquid samples, the viscosity of the liquid decreases significantly as the temperature increases. Due to the limitation of the measurement range of a single-specification capillary viscometer, it is often necessary to use multiple capillary viscometers, and the test is discontinuous, which inevitably leads to measurement errors.

[0008] In summary, the devices for measuring kinematic viscosity in the prior art cannot realize automatic measurement over a wide viscosity range, especially accurate, automatic, and wide viscosity range measurement of the viscosity of non-transparent liquids or liquids of various colors. Summary of the invention

[0009] The present invention provides a device for measuring kinematic viscosity, which is used to solve the problem that the existing device for measuring kinematic viscosity cannot realize automatic measurement over a wide viscosity range. The present invention also provides a method for using the device for measuring kinematic viscosity, which is used to improve the measurement accuracy of the device. In order to achieve the above-mentioned purpose:

[0010] The technical solution adopted by the device for measuring kinematic viscosity of the present invention is specifically as follows:

[0011] A device for measuring kinematic viscosity comprises a double-bulb capillary viscometer, a sealed thermostatic box, a fixed jacket, a positioning platform, an automatic timing system and a suction cleaning system; the sealed thermostatic box is rotatably mounted on the positioning platform, and the double-bulb capillary viscometer is fixed in the sealed thermostatic box through the fixed jacket; the upper end openings of the main pipe and the branch pipe of the double-bulb capillary viscometer are respectively connected to the suction cleaning system by pipelines, and liquid level sensors are respectively arranged on the upper and lower sides of the upper and lower bulbs of the double-bulb capillary viscometer, and the liquid level sensors are respectively connected to the automatic timing system for data transmission.

[0012] The beneficial effects of the device for measuring kinematic viscosity of the present invention are as follows: by reasonably setting the structures and corresponding connection relationships of the double-ball capillary viscometer, the sealed constant temperature box, the automatic timing system and the suction and cleaning system; the double-ball capillary viscometer structure is adopted to truly realize the kinematic viscosity measurement in a wide viscosity range, replacing the traditional method of using a capillary viscometer group, saving instrument costs; the double-ball capillary viscometer retains the basic characteristics of the positive flow capillary viscometer, guarantees the effectiveness and accuracy in principle, and can achieve good results; thereby solving the problem that the device for measuring kinematic viscosity in the prior art cannot realize automatic measurement in a wide viscosity range.

[0013] Furthermore, the double-bulb capillary viscometer comprises a main pipe, a first branch pipe, a second branch pipe, a third branch pipe, an upper bulb, a lower bulb, a capillary, a hanging ball and a liquid storage ball. The inner surfaces of the connections between the components of the double-bulb capillary viscometer all adopt smooth arc transitions. The center lines of the main pipe, the first branch pipe and the second branch pipe are in the same plane, which is the first plane. The center lines of the first branch pipe and the third branch pipe are parallel to each other. The plane is the second plane. The first plane and the second plane are perpendicular to each other. An overflow port is provided in the middle of the spherical surface of the liquid storage ball. The end of the third branch pipe is in a hook shape and is connected to the overflow port of the liquid storage ball. The upper bulb and the lower bulb are arranged on the main pipe. The liquid level sensors respectively arranged on the lower side of the upper bulb and the upper side of the lower bulb can be the same liquid level sensor.

[0014] Beneficial effects: the double-bulb capillary viscometer comprises a main pipe, a first branch pipe, a second branch pipe, a third branch pipe, an upper bulb, a lower bulb, a capillary, a hanging ball and a liquid storage ball. The inner surfaces of the joints between the components adopt smooth arc transitions, which is conducive to the movement of liquid in the double-bulb capillary viscometer; the first plane and the second plane are set as vertical planes, and the sealed constant temperature box is tilted parallel to the first plane from the main pipe to the first branch pipe. During the tilting process, the overflow port of the third branch pipe is always in the middle position of the liquid storage ball, so that the sample will not flow into the overflow port as the instrument tilts; the structural layout of the double-bulb capillary viscometer is more reasonable, the volume of the double-bulb capillary viscometer is reduced, and it is conducive to ensuring that the sample volume in the liquid storage ball is always constant when the sealed constant temperature box is tilted parallel to the first plane, thereby improving the measurement accuracy.

[0015] Furthermore, the shapes of the upper and lower bulbs are both ellipsoidal, and the volume of the lower bulb is set to 3 to 6 times the volume of the upper bulb; the shapes of the suspension ball and the liquid storage ball are both spherical, and the volumes of the suspension ball and the lower bulb are equal, which is 6 times the volume of the lower bulb; the angle β between the line connecting the centers of the suspension ball and the liquid storage ball and the horizontal plane is 15° to 75°.

[0016] Beneficial effect: The shape of the upper bulb and the lower bulb are both ellipsoidal. When the double-bulb capillary viscometer is tilted, the liquid in the upper bulb and the lower bulb flows out completely to avoid remaining at the bottom of the upper bulb or the lower bulb. When the double-bulb capillary viscometer is tilted, the center of the liquid storage ball is higher than the center of the hanging ball relative to the vertical state. The center of the liquid storage ball cannot be higher than the center of the hanging ball, otherwise the liquid cannot flow into the liquid storage ball. The angle between the line connecting the centers of the hanging ball and the liquid storage ball and the horizontal plane is not less than the set maximum rotation angle of the sealed constant temperature box. The rotation angle of the incubator can be designed to be 15° to 60°, and the angle β between the center line of the hanging ball and the liquid storage ball and the horizontal plane can be designed to be 15° to 75°, so as to ensure that the double-bulb capillary viscometer works normally under any tilt state; optimally, the maximum rotation angle of the sealed constant temperature box is set to 60°, so that the viscosity measurement range of the double-bulb capillary viscometer is the widest, and correspondingly, the angle between the center line of the hanging ball and the liquid storage ball and the horizontal is equal to the set maximum rotation angle of the sealed constant temperature box, that is, the angle β is 60°, which is conducive to the shortest size of the double-bulb capillary viscometer. By reasonably setting the volume relationship of the upper bulb, the lower bulb, the hanging ball and the liquid storage ball, it is ensured that after "injection"-"adjustment of sample volume", the sample volume meets the "minimum volume" requirement of the test; that is, the sample usage is reduced, and the volume of the liquid storage ball is not too large; while realizing the movement and storage of the liquid in the double-bulb capillary viscometer, the structure of the double-bulb capillary viscometer is made more reasonable.

[0017] Furthermore, the automatic measurement timing system includes an electric bridge, a level conversion circuit, a single-chip microcomputer and a digital display; the liquid level sensors respectively arranged on the upper and lower sides of the upper and lower bulbs of the double-bulb capillary viscometer are platinum wire electrodes, one end of the platinum wire electrode is sintered in the glass tube wall of the main tube, and the other end of the platinum wire electrode is provided with a terminal, and the terminal is conductively connected to the bridge arm of the electric bridge.

[0018] Beneficial effects: By reasonably setting the structure of the automatic measurement timing system, the automatic measurement timing system can accurately display the signal detected by the liquid level sensor, so that the liquid level detection on the upper and lower sides of the upper and lower bulbs can be accurate; further improving the measurement accuracy of the double-bulb capillary viscometer.

[0019] Furthermore, the fixed jacket is fixed on the double-bulb capillary viscometer, and is installed and disassembled together with the double-bulb capillary viscometer on a sealed constant temperature box. The electrode wiring of the automatic timing system is embedded in the fixed jacket, and the fixed jacket is made of temperature-resistant and heat-conductive materials.

[0020] Beneficial effects: The fixed jacket fixes the double-bulb capillary viscometer, and the electrode circuit of the automatic timing system is embedded in the fixed jacket to form a whole, which is conducive to free installation and disassembly on the sealed constant temperature box, ensuring that the double-bulb capillary viscometer is in the target position; the fixed jacket is made of temperature-resistant and heat-conductive material, which is conducive to uniform fluid temperature in the double-bulb capillary viscometer.

[0021] Furthermore, the sealed constant temperature box includes a box body, the material of the box body is heat-resistant glass; an insulation sleeve is arranged in the box body, the lower part of the box body is provided with a pipe inlet, the upper part is provided with a pipe outlet, the bottom is provided with a thermocouple, and the upper end is provided with a sealing cover threadedly connected to the box body; the sealed constant temperature box also includes a fixed cover arranged at the upper end of the box body.

[0022] Beneficial effects: The sealed constant temperature box provides a constant temperature environment and better ensures the stability of the temperature field; the box body is made of heat-resistant glass to visualize the test process; different temperature controls are achieved through an external temperature-controlled constant temperature bath, which is conducive to the accurate measurement of the liquid viscosity-temperature characteristic relationship.

[0023] Furthermore, the positioning platform includes two A-type brackets and a base fixedly connected to the A-type brackets, the upper end of the A-type bracket is provided with a coaxial shaft for rotationally assembled with the sealed constant temperature box, the base is provided with a level bubble for measuring the horizontality and a freely adjustable height foot for adjusting the height and horizontality of the A-type bracket, and a positioning pin rod for forming a rotation stop with the sealed constant temperature box is provided on an oblique support of the A-type bracket.

[0024] Beneficial effects: The positioning platform structure is reasonably set so that the height and levelness of the positioning platform can be freely adjusted, and a horizontal bubble is set on the base to detect the levelness of the positioning platform; a positioning pin rod is set on an oblique support of the A-type bracket to form a rotation stop with the sealed constant temperature box; by adjusting the position of the positioning pin rod, the sealed constant temperature box can be fixed at different inclination angles.

[0025] Furthermore, the suction and cleaning system includes a vacuum pump, a liquid pump, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, a sample bottle, a cleaning liquid bottle and a reagent bottle; wherein the second solenoid valve and the third solenoid valve are three-way solenoid valves and the sixth solenoid valve is a multi-way solenoid valve, and when the power is off, each solenoid valve is closed and the pipeline is closed.

[0026] Beneficial effect: The suction cleaning system with this structure can achieve thorough cleaning of the double-bulb capillary viscometer, avoid the influence of residual liquid from the previous measurement on the current experiment, and further improve the detection accuracy of the device for measuring kinematic viscosity.

[0027] Furthermore, the device for measuring kinematic viscosity also includes a control unit for realizing automatic control, and the control unit includes a control panel, a controller, a logic control circuit, etc. The control unit receives signals and issues instructions to realize the start and stop of the vacuum pump and the liquid pump, the opening and closing of each electromagnetic valve, and the transmission of the liquid level sensor detection signal.

[0028] Beneficial effects: By reasonably setting the control unit structure, the automatic control of the kinematic viscosity measuring device can be realized, the labor intensity of the experimenters can be reduced, the efficiency can be improved, and the influence of human factors can be avoided.

[0029] The technical solution adopted by the method for using the kinematic viscosity measuring device of the present invention is specifically as follows:

[0030] (1) Preparation before measurement: Check the position of the double-bulb capillary viscometer in the sealed constant temperature box, ensure that all interfaces are installed and sealed well, the sealed constant temperature box can rotate flexibly, and adjust the positioning pin rod at the rear of the positioning platform to make the constant temperature box vertical. Adjust the free height adjustment foot at the bottom of the positioning platform to make the bubble on the top of the base level.

[0031] (2) Injection process: the sample to be tested and the cleaning solution are placed in the corresponding sample bottle, cleaning solution bottle, and reagent bottle. The third solenoid valve is energized to connect the a pipe, the fifth solenoid valve is energized to open, the sixth solenoid valve is energized to connect the e pipe, the seventh solenoid valve is energized to open, and the vacuum pump is turned on. The sample to be tested enters the liquid storage ball from the first branch pipe. After working for a certain period of time, the vacuum pump is turned off and the solenoid valve is disconnected. The injection is completed, and the excess sample will flow from the overflow port of the liquid storage ball into the hook at the end of the fourth branch pipe.

[0032] (3) Adjust the sample volume: The second solenoid valve is energized to connect pipe d, and the third solenoid valve is energized to connect pipe b to the atmosphere. The liquid pump is turned on to extract the excess sample. After working for a certain period of time, the liquid pump is turned off and the solenoid valve is disconnected, and the sample adjustment is completed.

[0033] (4) Sample constant temperature: Set the temperature to be tested, and use an external constant temperature control tank to maintain a constant temperature in the sealed constant temperature box.

[0034] (5) Adjust the inclination of the double-bulb capillary viscometer: According to the measurement requirements, adjust the positioning pin rod at the rear of the positioning platform to make the capillary tilt at a certain angle or keep it vertical.

[0035] (6) Viscosity measurement: The third solenoid valve is energized to connect the b pipe to the atmosphere, the fourth solenoid valve is energized to open, the seventh solenoid valve is energized to open, and the vacuum pump is turned on. When the sample liquid level rises to the position of the first liquid level sensor, the controller receives a signal, the fifth solenoid valve is energized to open, and the vacuum pump is turned off, so that the main pipe, the first branch pipe, and the second branch pipe are connected to the atmosphere, and the sample liquid level automatically falls. The time difference between the sample flowing through the second liquid level sensor and the third liquid level sensor, and the third liquid level sensor and the fourth liquid level sensor is automatically recorded, and the sample kinematic viscosity is automatically calculated. Repeat the measurement multiple times and take the average value of the measurement results.

[0036] (7) Cleaning: The fifth solenoid valve is energized to open, the second solenoid valve is energized to connect the c pipeline, the sixth solenoid valve is energized to connect the f pipeline, and the vacuum pump is turned on. After a period of time, the fourth solenoid valve is energized to open, and the third solenoid valve is energized to connect the a pipeline.

[0037] (8) Drying: After cleaning is completed, switch the sixth solenoid valve to the g pipeline to connect to the atmosphere to dry the equipment.

[0038] The beneficial effects of the method for using the device for measuring kinematic viscosity of the present invention are as follows: when the method is used for measurement, it is not limited by the color of the liquid and the transparency of the liquid, and can meet the requirements of accurate, automatic, and wide viscosity range measurement of the kinematic viscosity of non-transparent liquids or liquids of various colors. When the method is used for measurement, it can meet the requirements of viscosity detection at different temperatures, and one-time sample addition can realize the study of the viscosity-temperature characteristics of the sample, and the detection process is continuous; after measurement using the method, the cleaning is thorough, and at the same time, the use of a large amount of hazardous chemicals in the cleaning process is reduced, thereby reducing the cost of consumables, improving the laboratory environment, and improving the safety level of the laboratory. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of an embodiment of a device for measuring kinematic viscosity of the present invention;

[0040] Figure 2 A schematic diagram of the structure of a sealed thermostatic box of an embodiment of the device for measuring kinematic viscosity of the present invention;

[0041] Figure 3 A front view of a double-bulb capillary viscometer which is an embodiment of a device for measuring kinematic viscosity of the present invention;

[0042] Figure 4 A partial left view of a double-bulb capillary viscometer of an embodiment of the device for measuring kinematic viscosity of the present invention;

[0043] Figure 5 A schematic diagram of a suction cleaning system of an embodiment of a device for measuring kinematic viscosity of the present invention;

[0044] Figure 6Schematic diagram of the angle β between the line connecting the centers of the suspension ball and the liquid storage ball and the horizontal plane.

[0045] In the figure: 01-double bulb capillary viscometer, 02-sealed thermostat, 03-fixed jacket, 04-positioning platform, 1-main pipe, 2-first branch pipe, 3-second branch pipe, 4-third branch pipe, 5-upper bulb, 6-lower bulb, 7-capillary, 8-hanging ball, 9-liquid storage ball, 10-overflow port, 11-first liquid level sensor, 12-second liquid level sensor, 13-third liquid level sensor, 14-fourth liquid level sensor, 15-inlet, 16-outlet, 17-insulation sleeve, 18-box, 19-fixed cover, 20-sealed cover, 21-thermocouple, 22-reagent bottle, 23-type A Bracket, 24-concentric axis, 25-fixed disc, 26-horizontal bubble, 27-free height adjustment foot, 28-positioning pin rod, 29-inlet pipe, 30-outlet pipe, 31-suction cleaning system pipeline, 32-vacuum pump, 33-liquid pump, 34-first solenoid valve, 35-second solenoid valve, 36-third solenoid valve, 37-fourth solenoid valve, 38-fifth solenoid valve, 39-sixth solenoid valve, 40-seventh solenoid valve, 41-main pipe outlet, 42-first branch pipe outlet, 43-second branch pipe outlet, 44-third branch pipe outlet, 45-sample bottle, 46-cleaning liquid bottle. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0047] like Figure 1 and Figure 2As shown, a device for measuring kinematic viscosity includes a double-bulb capillary viscometer 01, a sealed constant temperature box 02, a fixed jacket 03, a positioning platform 04, an automatic timing system and a suction cleaning system; the sealed constant temperature box 02 is rotatably assembled on the positioning platform 04; the double-bulb capillary viscometer 01 is fixed in the sealed constant temperature box 02 through the fixed jacket 03, and the upper end openings of the main pipe 1 and the branch pipe of the double-bulb capillary viscometer 01 are respectively connected to the suction cleaning system through pipelines. The double-bulb capillary viscometer 01 adopts a double-bulb timing structure different from the conventional one, and the double bulbs are respectively an upper bulb 5 and a lower bulb 6, and the upper and lower sides of the upper bulb 5 and the lower bulb 6 are respectively provided with There are liquid level sensors, the liquid level sensors arranged on the upper side of the upper bulb 5 are the first liquid level sensor 11 and the second liquid level sensor 12, and the liquid level sensor arranged on the lower side of the lower bulb 6 is the fourth liquid level sensor 14; in this embodiment, the liquid level sensors arranged on the lower side of the upper bulb 5 and the upper side of the lower bulb 6 are the same liquid level sensor, which is the third liquid level sensor 13; in other embodiments, the liquid level sensors arranged on the lower side of the upper bulb 5 and the upper side of the lower bulb 6 may not be the same liquid level sensor, that is, two liquid level sensors are used to approach the upper bulb 5 and the lower bulb 6 respectively, to measure the liquid level on the lower side of the upper bulb 5 and the upper side of the lower bulb 6. The first liquid level sensor 11, the second liquid level sensor 12, the third liquid level sensor 13 and the fourth liquid level sensor 14 are respectively connected to the automatic timing system for data transmission. In this embodiment, the fixed jacket 03 is fixed to the double-bulb capillary viscometer 01, and is installed and disassembled on the sealed constant temperature box 02 together with the double-bulb capillary viscometer 01. The electrode wiring of the automatic timing system is embedded in the fixed jacket 03 to form a whole, which is modularly arranged. The fixed jacket 03 is made of temperature-resistant and heat-conductive materials. In other embodiments, the fixed jacket 03 also adopts a modular arrangement, and the fixed jacket 03 is made of metal materials or heat-resistant and heat-conductive organic materials.

[0048] like Figure 3 and Figure 4 As shown, the double-bulb capillary viscometer 01 includes a main pipe 1, a first branch pipe 2, a second branch pipe 3, a third branch pipe 4, an upper bulb 5, a lower bulb 6, a capillary 7, a hanging ball 8 and a liquid storage ball 9. The components of the double-bulb capillary viscometer 01 are a complete and indivisible whole, and the inner surfaces of the joints between the components are all smooth arc transitions. The center lines of the main pipe 1, the first branch pipe 2 and the second branch pipe 3 are all in the same plane, which is the first plane. The center lines of the first branch pipe 2 and the third branch pipe 4 are parallel to each other, and the plane is the second plane. The first plane and the second plane are perpendicular to each other. An overflow port 10 is opened in the middle of the spherical surface of the liquid storage ball 9. The end of the third branch pipe 4 is in a hook shape and is connected to the overflow port 10 of the liquid storage ball 9. The upper bulb 5 and the lower bulb 6 are arranged on the main pipe 1.

[0049] The double-bulb capillary viscometer 01 retains the basic features of the positive flow capillary 7 viscometer, which guarantees the effectiveness and measurement accuracy in principle and follows Poiseuille's law.

[0050] According to Poiseuille's law, the kinematic viscosity of the capillary viscometer after kinetic energy correction and terminal correction is calculated as follows:

[0051]

[0052] When the outflow time t is greater than a certain value, generally, t ≥ 200s, the calculation formula is simplified to:

[0053]

[0054] Obviously, the measuring range of the capillary 7 viscometer is proportional to the effective height h in the vertical direction and inversely proportional to the volume V of the capillary 7 viscometer bulb.

[0055] In order to achieve the purpose of the double-bulb capillary viscometer 01 to meet the measurement of a wide viscosity range, a double-bulb timing structure with different volumes is adopted. The capillary 7 of the double-bulb capillary viscometer 01 is 2.0mm thick, the upper bulb 5 is designed to have a volume of 1ml, the lower bulb 6 is designed to have a volume of 5ml, and the distance between the lower end of the upper bulb 5 and the upper end of the lower bulb 6 is 2cm.

[0056] In order to achieve the purpose of the double-bulb capillary viscometer 01 to meet the measurement of a wide viscosity range, the capillary 7 has an adjustable inclination angle to achieve the purpose of changing the effective height h in the vertical direction. The sealed constant temperature box is designed to be freely tilted, driving the double-bulb capillary viscometer to rotate in the range of 0° to 60°.

[0057] The volume of the suspension ball 8 is designed to be 5 ml, and the volume of the liquid storage ball 9 is designed to be 30 ml. The upper bulb 5 and the lower bulb 6 are ellipsoidal, and the suspension ball 8 and the liquid storage ball 9 are spherical. The angle between the center line of the suspension ball 8 and the liquid storage ball 9 and the capillary 7 is designed to be 30°, that is, the angle β between the center line of the suspension ball 8 and the liquid storage ball 9 and the horizontal plane is 60°.

[0058] When the upper bulb 5 and double bulb capillary viscometer 01 are vertical, the capillary constant C = 1.0 mm 2 / s 2 Since the liquid outflow time t is generally (200~600)s, the measurement range is: v1=C·t=(200~600)mm 2 / s;

[0059] When the upper bulb 5 and double bulb capillary viscometer 01 are tilted at α = 60°, the measuring range is: ν2 = ν1·cosα = (100-300) mm 2 / s;

[0060] When using the lower bulb 6 and double bulb capillary viscometer 01 vertically, the measuring range is:

[0061] When using the lower bulb 6 and double bulb capillary viscometer 01 with an inclination of α = 60°, the measuring range is: ν4 = ν3·cosα = (20~60) mm 2 / s;

[0062] The double bulb capillary viscometer 01 can achieve (20~600)mm 2 / s viscosity range measurement.

[0063] In other embodiments, the thickness of the capillary 7 can be selected to be 1.0mm, 2.0mm, 3.0mm or 4.0mm; the volume of the upper bulb 5 is designed to be 1ml, and the volume of the lower bulb 6 is designed to be 3ml, 4ml, 5ml or 6ml; the distance between the lower end of the upper bulb 5 and the upper end of the lower bulb 6 is 2cm; the maximum tilt angle α of the sealed constant temperature box should not be greater than 60°, and can be set to 15°, 45° or 60°, and the angle β between the line connecting the centers of the suspension ball 8 and the liquid storage ball 9 and the horizontal plane is not less than the corresponding maximum tilt angle α, and can be set to 15°, 30°, 45°, 60° or 75°. That is, α is 15°, β is not less than 15°, and optimally, β is 15°; α is 30°, β is not less than 30°, and optimally, β is 30°; α is 45°, β is not less than 45°, and optimally, β is 45°; all of them can meet the design requirements. The angle β between the center line of the suspension ball 8 and the liquid storage ball 9 and the horizontal plane is specifically shown in Figure 6 .

[0064] The four liquid level sensors located on the upper and lower sides of the upper bulb 5 and the lower bulb 6 on the main tube 1 of the double-bulb capillary viscometer 01 are all platinum wire electrodes; the four platinum wire electrodes are platinum wire electrodes a, b, c and d respectively; one end of the four platinum wire electrodes are sintered in the glass tube wall of the main tube 1, and the other end is provided with terminal posts, which are a*, b*, c* and d* respectively; the first liquid level sensor 11 is 1.5 cm above the upper end of the upper bulb 5, the second liquid level sensor 12 is 1 cm above the upper end of the upper bulb 5, the third liquid level sensor 13 is located between the lower end of the upper bulb 5 and the upper end of the lower bulb 6, and the fourth liquid level sensor 14 is 1 cm below the lower end of the lower bulb 6.

[0065] The automatic measurement timing system includes a bridge, a level conversion circuit, a single chip microcomputer and a digital display; the terminals a*, b*, c*, d* are respectively conductively connected to the bridge arms of the bridge; when the liquid surface flows through a, b, c, d, the bridge resistance changes, and the voltage output signal of the bridge is amplified by an amplifier and then connected to the level conversion circuit, and automatic timing is realized through the single chip microcomputer and the digital display.

[0066] The fixed jacket 03 is connected to the sealed thermostatic box 02, and the fixed jacket 03 and the sealed thermostatic box 02 are connected by threads; the sealed thermostatic box 02 includes a box body 18, and the material of the box body 18 is heat-resistant glass; an insulation sleeve 17 is arranged in the box body 18, and the lower part of the box body 18 is provided with a pipe inlet 15, the upper part is provided with a pipe outlet 16, and the bottom is provided with a thermocouple 21, and the thermocouple is immersed in the constant temperature bath, which is conducive to real-time temperature monitoring and minimizes measurement errors; the upper end is provided with a sealing cover 20 threadedly connected to the box body 18; the sealed thermostatic box 02 also includes a fixed cover 19 arranged at the upper end of the box body 18. The box body 18 of the sealed thermostatic box 02 is provided with two symmetrical fixed discs 25, and the sealed thermostatic box 02 needs to be connected to an external temperature-controlled thermostatic tank, and the temperature-controlled thermostatic tank is separated from the sealed thermostatic box 02 to minimize the impact of vibration; the box body 18 is filled with methyl silicone oil to keep the box body 18 at a constant temperature. In other embodiments, the sealed thermostatic box 02 may adopt other cylindrical or tubular structures with a sealing cover 20 .

[0067] like Figure 1 As shown, the positioning platform 04 includes two A-type brackets 23 and a base fixedly connected to the A-type bracket 23, the upper end of the A-type bracket 23 is provided with a coaxial shaft for rotationally assembled with the sealed constant temperature box 02, and two symmetrical fixed disks 25 are fixedly connected to the upper outer side surface of the box body 18 of the sealed constant temperature box 02, and concentric holes are opened on the fixed disks 25, and the concentric shafts are rotationally assembled in the concentric holes; in other embodiments, the rotational assembly between the sealed constant temperature box 02 body and the positioning platform 04 can be achieved by setting pins on the same straight line on both sides of the sealed constant temperature box 02 body, and setting pin holes on the positioning platform 04 for rotationally cooperating with the pins, and the rotational assembly between the sealed constant temperature box 02 body and the positioning platform 04 is achieved by the rotational cooperation between the pin holes and the pins. The base is provided with a level bubble 26 for measuring the horizontality and a freely adjustable height foot 27 for adjusting the height and horizontality of the A-type bracket 23. A positioning pin rod 28 for forming a rotation stop with the sealed constant temperature box 02 is provided on an oblique support of the A-type bracket 23; by adjusting the position of the positioning pin rod 28, the sealed constant temperature box 02 can be fixed at different inclination angles.

[0068] like Figure 5As shown, the suction and cleaning system includes a vacuum pump 32, a liquid pump 33, a first solenoid valve 34, a second solenoid valve 35, a third solenoid valve 36, a fourth solenoid valve 37, a fifth solenoid valve 38, a sixth solenoid valve 39, a seventh solenoid valve 40, a sample bottle 45, a cleaning liquid bottle 46 and a reagent bottle 22; wherein the second solenoid valve 35, the third solenoid valve 36 are three-way solenoid valves and the sixth solenoid valve 39 is a multi-way solenoid valve, and each solenoid valve is closed in the power-off state, and the pipeline is closed; the fourth solenoid valve 37 controls the main pipe outlet 41, the third solenoid valve 36 controls the first branch pipe outlet 42, the fifth solenoid valve 38 controls the second branch pipe outlet, and the second solenoid valve 35 controls the third branch pipe outlet 44. The inlet pipe 29 and the outlet pipe 30 of the sealed thermostatic box 02, as well as the suction and cleaning system pipeline 31 are respectively connected to the inlet and outlet fixed transfer interfaces and the suction and cleaning fixed transfer interfaces provided on the fixed disc 25.

[0069] The kinematic viscosity measuring device also includes a control unit for realizing automatic control, and the control unit includes a control panel, a controller, a logic control circuit, etc. The control unit receives signals and issues instructions to realize the start and stop of the vacuum pump 32 and the liquid pump 33, the opening and closing of each electromagnetic valve, and the transmission of the liquid level sensor detection signal. In other embodiments, the control unit may not be provided, and manual control may be adopted instead of the control unit control.

[0070] The technical solution adopted by the method for using the kinematic viscosity measuring device of the present invention is specifically as follows:

[0071] (1) Preparation before measurement: Check the position of the double-bulb capillary viscometer 01 in the sealed constant temperature box 02, ensure that all interfaces are installed and sealed well, and that the sealed constant temperature box 02 can rotate flexibly. Adjust the positioning pin 28 at the rear of the positioning platform 04 to make the constant temperature box vertical. Adjust the free height adjustment foot 27 at the bottom of the positioning platform 04 to make the bubble on the top of the base level.

[0072] (2) Sampling process: the sample to be tested and the cleaning solution are placed in the corresponding sample bottle 45, the cleaning bottle 46 and the reagent bottle 22, the third solenoid valve 36 is energized to connect the a pipeline, the fifth solenoid valve 38 is energized to open, the sixth solenoid valve 39 is energized to connect the e pipeline, the seventh solenoid valve 40 is energized to open, the vacuum pump 32 is turned on, and the sample to be tested enters the liquid storage ball 9 from the first branch pipe 2. After working for a certain period of time, the vacuum pump 32 is turned off and the solenoid valve is disconnected, and the sampling is completed. The excess sample will flow into the hook at the end of the fourth branch pipe from the overflow port 10 of the liquid storage ball 9.

[0073] (3) Adjusting the sample quantity: The second solenoid valve 35 is energized to connect the d pipe, and the third solenoid valve 36 is energized to connect the b pipe to the atmosphere. The liquid pump 33 is turned on to extract the excess sample. After working for a certain period of time, the liquid pump 33 is turned off and the solenoid valve is disconnected, and the sample adjustment is completed.

[0074] (4) Sample constant temperature: Set the temperature to be tested, and use an external constant temperature control tank to maintain the temperature of the sealed constant temperature box 02.

[0075] (5) Adjust the inclination of the double-bulb capillary viscometer 01: According to the measurement requirements, adjust the positioning pin 28 at the rear of the positioning platform 04 to make the capillary 7 tilt at a certain angle or keep it vertical.

[0076] (6) Viscosity measurement: The third solenoid valve 36 is energized to connect the b pipe to the atmosphere, the fourth solenoid valve 37 is energized to open, the seventh solenoid valve 40 is energized to open, and the vacuum pump 32 is turned on. When the sample liquid level rises to the position of the first liquid level sensor 11, the controller receives a signal, the fifth solenoid valve 38 is energized to open, and the vacuum pump 32 is closed, so that the main pipe 1, the first branch pipe 2, and the second branch pipe 3 are connected to the atmosphere, and the sample liquid level automatically falls. The time difference between the sample flowing through the second liquid level sensor 12 and the third liquid level sensor 13, and the third liquid level sensor 13 and the fourth liquid level sensor 14 is automatically recorded, and the sample kinematic viscosity is automatically calculated. Repeat the measurement multiple times and take the average value of the measurement results.

[0077] In particular, when measuring the viscosity-temperature characteristic relationship of a liquid sample, the viscosity of the liquid decreases as the temperature increases. Using a temperature rise measurement, select the "upper bulb 5 + vertical" - "upper bulb 5 + inclined" - "lower bulb 6 + vertical" - "lower bulb 6 + inclined" method and repeat steps four to six without changing the liquid sample.

[0078] (7) Cleaning: The fifth solenoid valve 38 is energized to open, the second solenoid valve 35 is energized to connect the c pipe, the sixth solenoid valve 39 is energized to connect the f pipe, and the vacuum pump 32 is turned on. After a period of time, the fourth solenoid valve 37 is energized to open, and the third solenoid valve 36 is energized to connect the a pipe.

[0079] (8) Drying: After cleaning is completed, the sixth solenoid valve 39 is switched to connect the g pipeline to the atmosphere to dry the equipment.

[0080] In the present invention, in order to achieve accurate measurement of the kinematic viscosity of the liquid sample, the kinematic viscosity measuring device needs to be calibrated with a capillary constant as in a general capillary viscometer. According to work requirements, when the instrument is calibrated with a standard viscosity liquid under various working conditions, different values ​​of the bulb, temperature and tilt angle are set within the protection scope of the present invention.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A device for measuring kinematic viscosity, characterized in that: It comprises a double-bulb capillary viscometer, a sealed thermostatic box, a fixed jacket, a positioning platform, an automatic timing system and a suction cleaning system; the sealed thermostatic box is rotatably mounted on the positioning platform, and the double-bulb capillary viscometer is fixed in the sealed thermostatic box through the fixed jacket; wherein the sealed thermostatic box is designed to be freely tiltable, driving the double-bulb capillary viscometer to rotate within the range of 0° to 60°; The upper end openings of the main pipe and the branch pipe of the double-bulb capillary viscometer are connected to the suction and cleaning system by pipelines, and liquid level sensors are arranged on the upper and lower sides of the upper bulb and the lower and upper and lower sides of the lower bulb of the double-bulb capillary viscometer, and the liquid level sensors are connected to the automatic timing system for data transmission; The double-bulb capillary viscometer comprises a main pipe, a first branch pipe, a second branch pipe, a third branch pipe, an upper bulb, a lower bulb, a capillary, a hanging ball and a liquid storage ball. The inner surfaces of the joints between the components of the double-bulb capillary viscometer are all smooth arc transitions. The center lines of the main pipe, the first branch pipe and the second branch pipe are in the same plane as the first plane. The center lines of the first branch pipe and the third branch pipe are parallel to each other. The plane where the center lines of the first branch pipe and the third branch pipe are located is the second plane. The first plane is perpendicular to the second plane. An overflow port is provided in the middle of the spherical surface of the liquid storage ball. The end of the third branch pipe is in a hook shape and is connected to the overflow port of the liquid storage ball. The upper bulb and the lower bulb are arranged on the main pipe. The liquid level sensors respectively arranged on the lower side of the upper bulb and the upper side of the lower bulb are the same liquid level sensor. The upper and lower spherical bulbs are both ellipsoidal in shape, and the volume of the lower spherical bulb is set to be 3 to 6 times the volume of the upper spherical bulb; the shapes of the suspension ball and the liquid storage ball are both spherical, and the volume of the suspension ball is equal to that of the lower spherical bulb, which is 6 times the volume of the lower spherical bulb; the angle β between the line connecting the centers of the suspension ball and the liquid storage ball and the horizontal plane is 15° to 75°.

2. The device for measuring kinematic viscosity according to claim 1, characterized in that: The automatic timing system includes an electric bridge, a level conversion circuit, a single-chip microcomputer and a digital display; the liquid level sensors respectively arranged on the upper and lower sides of the upper bulb and the upper and lower sides of the lower bulb of the double-bulb capillary viscometer are platinum wire electrodes, one end of the platinum wire electrode is sintered in the glass tube wall of the main tube, and the other end of the platinum wire electrode is provided with a terminal, and the terminal is conductively connected to the bridge arm of the electric bridge.

3. The device for measuring kinematic viscosity according to claim 1, characterized in that: The fixed jacket is fixed on the double-bulb capillary viscometer, and is installed and disassembled on a sealed constant temperature box together with the double-bulb capillary viscometer. The electrode wiring of the automatic timing system is embedded in the fixed jacket, and the fixed jacket is made of temperature-resistant and heat-conductive material.

4. The device for measuring kinematic viscosity according to claim 1, characterized in that: The sealed constant temperature box includes a box body, the material of the box body is heat-resistant glass; an insulation sleeve is arranged in the box body, a pipe inlet is arranged at the lower part of the box body, a pipe outlet is arranged at the upper part, a thermocouple is arranged at the bottom, and a sealing cover threadedly connected to the box body is arranged at the upper end; the sealed constant temperature box also includes a fixed cover arranged at the upper end of the box body.

5. The device for measuring kinematic viscosity according to claim 1, characterized in that: The positioning platform includes two A-type brackets and a base fixedly connected to the A-type brackets. The upper end of the A-type bracket is provided with a coaxial shaft for rotationally assembled with the sealed constant temperature box. The base is provided with a level bubble for measuring the horizontality and a freely adjustable height foot for adjusting the height and horizontality of the A-type bracket. A positioning pin rod for forming a rotation stop with the sealed constant temperature box is provided on an oblique support of the A-type bracket.

6. The device for measuring kinematic viscosity according to claim 1, characterized in that: The suction and cleaning system includes a vacuum pump, a liquid pump, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, a sample bottle, a cleaning liquid bottle and a reagent bottle; wherein the second solenoid valve and the third solenoid valve are three-way solenoid valves and the sixth solenoid valve is a multi-way solenoid valve, and in the power-off state, each solenoid valve is closed and the pipeline is closed.

7. The device for measuring kinematic viscosity according to claim 1, characterized in that: The device for measuring kinematic viscosity also includes a control unit for realizing automatic control, and the control unit includes a control panel, a controller, and a logic control circuit. The control unit receives signals and issues instructions to realize the start and stop of the vacuum pump and the liquid pump, the opening and closing of each electromagnetic valve, and the transmission of the liquid level sensor detection signal.

8. A method for using the device for measuring kinematic viscosity according to claim 1, characterized in that: (1) Preparation before measurement: Check the position of the double-bulb capillary viscometer in the sealed constant temperature box, ensure that all interfaces are installed and sealed well, the sealed constant temperature box can rotate flexibly, and adjust the positioning pin rod at the rear of the positioning platform to make the constant temperature box vertical, and adjust the free height adjustment foot at the bottom of the positioning platform to make the bubble on the top of the base level; (2) Sampling process: the sample to be tested and the cleaning solution are placed in the corresponding sample bottle and cleaning solution bottle, the third solenoid valve is energized to connect the a pipe, the fifth solenoid valve is energized to open, the sixth solenoid valve is energized to connect the e pipe, the seventh solenoid valve is energized to open, the vacuum pump is turned on, and the sample to be tested enters the liquid storage ball from the first branch pipe. After working for a certain period of time, the vacuum pump is turned off and the solenoid valve is disconnected, and the sampling is completed. The excess sample will flow from the overflow port of the liquid storage ball into the hook at the end of the fourth branch pipe; (3) Adjusting the sample volume: The second solenoid valve is energized to connect the d pipe, and the third solenoid valve is energized to connect the b pipe to the atmosphere. The liquid pump is turned on to extract the excess sample. After working for a certain period of time, the liquid pump is turned off and the solenoid valve is disconnected, and the sample adjustment is completed. (4) Sample constant temperature: Set the temperature to be tested, and use an external constant temperature control tank to maintain a constant temperature in the sealed constant temperature box; (5) Adjust the inclination of the double-bulb capillary viscometer: According to the measurement requirements, adjust the positioning pin rod at the rear of the positioning platform to make the capillary tilt at a certain angle or keep it vertical; (6) Viscosity measurement: The third solenoid valve is energized to connect the b pipe to the atmosphere, the fourth solenoid valve is energized to open, the seventh solenoid valve is energized to open, and the vacuum pump is turned on. When the sample liquid level rises to the position of the first liquid level sensor, the controller receives a signal, the fifth solenoid valve is energized to open, and the vacuum pump is turned off, so that the main pipe, the first branch pipe, and the second branch pipe are connected to the atmosphere, and the sample liquid level automatically falls. The time difference between the sample flowing through the second liquid level sensor and the third liquid level sensor, and the third liquid level sensor and the fourth liquid level sensor is automatically recorded, and the sample kinematic viscosity is automatically calculated; the measurement is repeated multiple times, and the measurement results are averaged; (7) Cleaning: The fifth solenoid valve is energized to open, the second solenoid valve is energized to connect the c pipe, the sixth solenoid valve is energized to connect the f pipe, and the vacuum pump is turned on. After a period of time, the fourth solenoid valve is energized to open, and the third solenoid valve is energized to connect the a pipe; (8) Drying: After cleaning is completed, switch the sixth solenoid valve to the g pipeline to connect to the atmosphere to dry the equipment.

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