Dynamic pressure variable temperature liquid surface tension testing device

Abstract

The utility model belongs to the field of surface tension testing, and particularly discloses a dynamic pressure variable temperature liquid surface tension testing device which comprises a vacuum box, a temperature adjusting module and a testing platform module, the vacuum box is divided into a vacuum box upper part and a vacuum box lower part; the temperature adjusting module comprises a condenser, a compressor, a fan, a heating resistance wire, a filter, a cold-heat exchanger, a capillary tube and an evaporator. The temperature adjusting module is arranged on the upper portion of the vacuum box and can exchange heat with the lower portion of the vacuum box. The device and the method can be used for measuring the surface tension of the liquid under different pressure and different temperature conditions, so that the physical and chemical properties of the liquid can be understood by measuring the surface tension under different temperature and pressure, the optimization of related industrial processes, the improvement of the performance of a fire extinguishing material, the prediction and understanding of the thermodynamic behavior of the liquid and the like can be facilitated; and the method has far-reaching influence on scientific research and industrial application.

Description

Technical Field

[0001] This utility model relates to the field of dynamic pressure variable temperature liquid surface tension testing technology, and specifically to a dynamic pressure variable temperature liquid surface tension testing device. Background Technology

[0002] There are many types of fire extinguishing agents with varying properties. Among them, the core component of foam fire extinguishing agents, surfactants, reduces the surface tension of aqueous solutions, forming a cohesive foam layer on the surface of flammable liquids. This foam layer isolates the air and lowers the temperature of the combustion zone, making it a primary fire extinguishing material for extinguishing fuel oil fires. It is widely used in petrochemical enterprises, solvent plants, oil fields, oil depots, garages, airports, and other fields. However, my country has a vast territory and complex geographical environment, with significant pressure differences between high-altitude plateaus and plains, and substantial temperature differences between winter and summer in the north and south. This inevitably affects the surface tension properties of surfactants, and consequently, the fire extinguishing performance of foam fire extinguishing agents. Therefore, testing the surface tension of different foam fire extinguishing agents under different pressures and temperatures is of great significance for assessing their fire extinguishing effectiveness.

[0003] Surface tension is a force acting on the surface of a liquid that reduces the liquid's surface area. Because a thin layer called the surface layer exists between the liquid and the gas, the molecules in the surface layer are less dense than those in the liquid interior, and the distance between the molecules is greater. The intermolecular interactions manifest as attraction, which is surface tension. Common methods for testing surface tension include the platinum plate method, platinum ring method, pendant drop method, bubble pressure method, drop weight method, capillary rise method, and maximum bubble pressure method. In the platinum ring method, a platinum ring is first immersed 2-3 mm below the liquid surface (or the interface between two immiscible substances), and then the platinum ring is slowly lifted upwards. A film forms between the ring and the liquid surface. The maximum force exerted by the film on the ring during the entire lifting process is measured and then converted into the true surface (interfacial) tension value.

[0004] In the prior art, Chinese utility model patent CN202320634193 discloses a variable-temperature liquid surface tension coefficient measuring instrument, which designs an experimental device for measuring the variable-temperature liquid surface tension coefficient, providing a measuring device with a clear principle, simple structure, and convenient use. This device adjusts the liquid temperature by heating a water bath and uses the pull-out method to measure the surface tension coefficient at different temperatures. Simultaneously, it utilizes a photoelectric gate assembly and a single-chip microcomputer control system to accurately detect changes in liquid film height and tension, achieving high-precision measurement. This device can obtain the liquid surface tension coefficient at different temperatures and conveniently and smoothly adjust the rise and fall of the liquid level, improving the accuracy and repeatability of the measurement. Chinese utility model patent CN215004844U discloses a vacuum high-temperature surface tension meter, which designs a vacuum high-temperature surface tension meter that solves the problem of graphite sheet oxidation, making the test data accurate and effective, and providing feasibility for surface tension testing of easily oxidized samples. This device evacuates air from a vacuum chamber, and inert gas is introduced into the chamber to further purge the air, allowing the test substrate to be tested under the protection of both oxidizing and inert gases. This solves the oxidation problem of surface tension test substrates. Water cooling lowers the temperature of the outer side of the heating furnace, preventing accelerated aging or damage to the equipment and protecting operators from burns. The photographing window features replaceable transparent quartz glass for easy maintenance and replacement.

[0005] However, the CN215004844U device can only test surface tension under vacuum conditions and lacks the ability to measure surface tension under different pressure conditions. Furthermore, this device is used to determine the surface tension of materials under high-temperature (above 1000℃) conditions under vacuum, which is not applicable to most research. The CN215004844U device is only suitable for temperature variations within a certain range. This testing device is placed in air and temperature-controlled by a water bath, making it unsuitable for measuring low-temperature liquids and also unsuitable for measuring surface tension under variable pressure environments. Moreover, there are currently no reports in China regarding dynamic pressure variable temperature liquid surface tension testing devices and methods. Utility Model Content

[0006] To address the shortcomings of existing devices, such as their inability to measure liquid surface tension under different pressures and low temperatures, and their failure to isolate the measuring device from the external environment, this invention provides a dynamic pressure-temperature variable-temperature liquid surface tension testing device. This device is placed in a vacuum chamber, and the pressure inside the chamber can be adjusted by a vacuum pump, achieving isolation from the external environment. The vacuum chamber contains a heating resistance wire, and there is also an electric heating device on the lifting platform. A small compressor is also installed on the vacuum chamber to adjust the temperature from low to high. Furthermore, the device can be connected to a computer to monitor its various statuses in real time, thus solving the problems mentioned in the background section.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a dynamic pressure variable temperature liquid surface tension testing device, characterized in that the device includes a vacuum chamber, a temperature control module, and a testing platform module;

[0008] The vacuum chamber is divided into two parts: the upper part of the vacuum chamber and the lower part of the vacuum chamber; the temperature regulation module includes: a condenser, a compressor, a fan, a heating resistance wire, a filter, a heat exchanger, a capillary tube, and an evaporator; the condenser, compressor, fan, filter, heat exchanger, capillary tube, and evaporator are housed in a metal protective shell and located in the upper part of the vacuum chamber, and can exchange heat with the lower part of the vacuum chamber.

[0009] Preferably, the compressor is connected to a fan to dissipate heat from the compressor; the compressor is connected to a condenser and an evaporator respectively; the evaporator is connected to a heat exchanger; the heat exchanger is connected to a capillary tube; the capillary tube is connected to a dryer filter; and the dryer filter is connected to the condenser.

[0010] Preferably, a heating resistance wire is provided on the lower inner wall of the vacuum chamber, and a vacuum pump is provided on the outside of the vacuum chamber. The vacuum pump is connected to the evacuation port. By controlling the vacuum valve and venting port located on the outer wall of the vacuum chamber, the vacuum chamber can be evacuated.

[0011] Preferably, the outer wall of the vacuum chamber is also equipped with a vacuum gauge that can read the pressure inside the chamber at any time.

[0012] Preferably, the test platform module includes: an electromagnetic force balance sensor, a hook, a balancer, a platinum ring, a temperature sensor, a watch glass, a lifting platform, a level, and a motor.

[0013] Preferably, the electromagnetic force balance sensor is connected to the hook via a balancer; the platinum ring is placed on the hook, and a temperature sensor is installed behind the hook; the surface dish is placed on an electrically heated lifting platform, and a level is installed below the electrically heated lifting platform near the outside; the lifting platform is connected to a motor.

[0014] The beneficial effects of this utility model are:

[0015] 1) The testing environment of this invention is placed in a vacuum chamber, achieving isolation from the external environment. This design effectively avoids interference from airflow and other environmental factors on the measurement results, improving the accuracy and stability of the measurement. The vacuum chamber contains a heating resistance wire and a small, temperature-adjustable compressor, enabling a wide range of temperature adjustments from low to high temperatures. This allows it to adapt to the testing needs of liquids under more environmental conditions, especially for surface tension testing at low temperatures. This device can measure the surface tension of liquids under different pressure conditions, which is particularly important for scientific research and industrial applications requiring testing of liquid surface tension under specific pressure environments.

[0016] 2) This device can be connected to a computer to monitor its various statuses in real time, including parameters such as temperature, pressure, and surface tension. This not only improves the real-time nature of the data but also facilitates data recording and analysis. The operation process of this device has been optimized, with simple and clear steps, making it easy for operators to follow the steps to conduct experiments, reducing operational errors and improving experimental efficiency. Because the device's design considers environmental control and precise temperature and pressure regulation, the repeatability and accuracy of experiments are significantly improved, which is crucial for the reliability requirements of scientific research. This device can reduce experimental failures and repetitive experiments caused by environmental factors, thereby saving experimental costs, improving experimental efficiency, and demonstrating good economic benefits.

[0017] 3) This utility model device can provide more accurate data support for the study of the physicochemical properties of liquids, which helps to optimize related industrial processes, improve material properties, predict and understand the thermodynamic behavior of liquids, and has important scientific research and industrial application value. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a dynamic pressure variable temperature liquid surface tension testing device;

[0019] In the diagram, 1-condenser, 2-compressor, 3-fan, 4-heating resistance wire, 5-electromagnetic force balance sensor, 6-vacuum port, 7-vacuum pump, 8-dryer filter, 9-heat exchanger, 10-capillary tube, 11-evaporator, 12-vent, 13-pressure gauge, 14-door, 15-lifting platform, 16-level, 17-motor, 18-vacuum valve, 19-computer, 20-hook, 21-balancer, 22-temperature sensor, 23-platinum ring, 24-watch glass. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other. It should also be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] Please see Figure 1 This utility model provides a technical solution: a dynamic pressure variable temperature liquid surface tension testing device, the device including a vacuum chamber, a temperature adjustment module, and a testing platform module;

[0025] The vacuum chamber is divided into two parts: the upper part of the vacuum chamber and the lower part of the vacuum chamber; the temperature regulation module includes: condenser 1, compressor 2, fan 3, heating resistance wire 4, filter 8, heat exchanger 9, capillary tube 10 and evaporator 11; the condenser 1, compressor 2, fan 3, filter 8, heat exchanger 9, capillary tube 10 and evaporator 11 are placed in a metal protective shell and set in the upper part of the vacuum chamber, and can exchange heat with the lower part of the vacuum chamber.

[0026] In the device structure, the vacuum chamber isolates the external environment, ensuring the stability of the testing environment. Inside the vacuum chamber are heating resistance wires and a temperature regulation device to achieve high-temperature control. A lifting platform is used to hold the petri dish containing the liquid to be tested; accurate surface tension data is obtained by the slow rise and fall of the platform during testing. A platinum ring, used to measure the liquid surface tension, is mounted on a hook and comes into contact with the liquid surface via the movement of the lifting platform. It works in conjunction with the heating resistance wire to quickly adjust the temperature of the solution inside the petri dish. A small compressor regulates the temperature inside the chamber, achieving low-temperature control. A vacuum pump regulates the pressure inside the vacuum chamber, enabling surface tension testing under different pressure conditions. A computer interface connects to a computer to monitor and record parameters such as temperature, pressure, and surface tension in real time during the testing process.

[0027] Furthermore, the compressor 2 is connected to the fan 3, which dissipates heat from the compressor 2; the compressor 2 is connected to the condenser 1 and the evaporator 11 respectively; the evaporator 11 is connected to the heat exchanger 9; the heat exchanger 9 is connected to the capillary tube 10; the capillary tube 10 is connected to the dryer filter 8; and the dryer filter 8 is connected to the condenser.

[0028] Furthermore, a heating resistance wire 4 is provided on the lower inner wall of the vacuum chamber, and a vacuum pump 7 is provided on the outside of the vacuum chamber. The vacuum pump 7 is connected to the evacuation port 6. By controlling the vacuum valve 18 and the venting port 12 located on the outer wall of the vacuum chamber, the vacuum chamber can be evacuated.

[0029] The outer wall of the vacuum chamber is also equipped with a vacuum gauge 13 that can read the pressure inside the chamber at any time.

[0030] Furthermore, the test platform module includes: an electromagnetic force balance sensor 5, a hook 20, a balancer 21, a platinum ring 23, a temperature sensor 22, a surface dish 24, a lifting platform 15, a level 16, and a motor 17.

[0031] The electromagnetic force balance sensor 5 is connected to the hook 20 via a balancer 21; the platinum ring 23 is placed on the hook 20, and a temperature sensor 22 is installed behind the hook 20; the surface dish 24 is placed on the electrically heated lifting platform 15, and a level 16 is installed below the electrically heated lifting platform 15 near the outside; the lifting platform 15 is connected to the motor 17.

[0032] The entire device is connected to computer 19, and can be controlled via software.

[0033] When using the above-mentioned dynamic pressure variable temperature liquid surface tension testing device, the following steps are included:

[0034] Step 1: Open the chamber door 14, adjust the equipment to a horizontal plane, check the level 16 to see if the instrument is level, remove the platinum ring 23, clean it three times with deionized water, then heat the platinum ring 23 with an alcohol lamp until it is red-hot, cool it and install it on the hook 20; take out the watch glass 24, clean it three times with deionized water, wipe it clean and place the test solution (pure water) into the watch glass 24, the volume of the solution should be about 1 / 2 to 2 / 3 of the volume of the watch glass 24, then place the watch glass 24 on the lifting platform 15, turn on the equipment power, open the surface tension testing system software in the computer 19, and check the working status of each component of the equipment through the computer 19 to see if it is normal;

[0035] Step 2: Close the vent 12, open the vacuum valve 18, start the vacuum pump 7, and adjust the ambient pressure inside the chamber, such as adjusting the ambient pressure inside the chamber to 100 kPa; at the same time, control the heating resistance wire 4 or the compressor to enter the working state through the computer 19, and adjust the temperature inside the chamber; such as setting the temperature to 30℃.

[0036] Once the temperature from temperature sensor 22 and the pressure from pressure gauge 13 reach the test conditions, close vacuum valve 18 and vacuum pump 7, and start the testing device via computer 19; simultaneously, check that the temperature on computer 19 has reached the set temperature. Finally, click the test button in the surface tension testing system, and the testing platform will automatically rise and fall to complete the test. The test result, 71.31 mN / m, will be displayed on the software interface.

[0037] Step 3: After the test is completed, control the heating resistance wire 4 or the compressor to exit the working state via computer 19, open the vent 12, and wait for the temperature and pressure to return to the external environment state. Then, remove the platinum ring 23 and the watch glass 24 for cleaning in order to conduct the next test.

[0038] The device of this invention places the test environment within a vacuum chamber, achieving isolation from the external environment. This design effectively avoids interference from airflow and other environmental factors on the measurement results, improving the accuracy and stability of the measurement. The vacuum chamber contains a heating resistance wire and a small, temperature-adjustable compressor, enabling a wide range of temperature adjustments from low to high temperatures. This allows it to adapt to the testing needs of liquids under more environmental conditions, especially for surface tension testing at low temperatures. This device can measure the surface tension of liquids under different pressure conditions, which is particularly important for scientific research and industrial applications requiring testing of liquid surface tension under specific pressure environments.

[0039] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dynamic pressure variable temperature liquid surface tension testing device, characterized in that, The device includes a vacuum chamber, a temperature control module, and a testing platform module; The vacuum chamber is divided into two parts: the upper part of the vacuum chamber and the lower part of the vacuum chamber; the temperature regulation module includes: condenser (1), compressor (2), fan (3), heating resistance wire (4), filter (8), heat exchanger (9), capillary tube (10) and evaporator (11); the condenser (1), compressor (2), fan (3), filter (8), heat exchanger (9), capillary tube (10) and evaporator (11) are placed in a metal protective shell and set in the upper part of the vacuum chamber, and can exchange heat with the lower part of the vacuum chamber.

2. The dynamic pressure variable temperature liquid surface tension testing device according to claim 1, characterized in that: The compressor (2) is connected to the fan (3), and the fan (3) dissipates heat from the compressor (2). The compressor (2) is connected to the condenser (1) and the evaporator (11) respectively. The evaporator (11) is connected to the heat exchanger (9). The heat exchanger (9) is connected to the capillary tube (10). The capillary tube (10) is connected to the dryer filter (8). The dryer filter (8) is connected to the condenser.

3. The dynamic pressure variable temperature liquid surface tension testing device according to claim 1, characterized in that: A heating resistance wire (4) is provided on the lower inner wall of the vacuum chamber, and a vacuum pump (7) is provided on the outside of the vacuum chamber. The vacuum pump (7) is connected to the air extraction port (6). By controlling the vacuum valve (18) and the air release port (12) located on the outer wall of the vacuum chamber, the vacuum chamber can be evacuated.

4. The dynamic pressure variable temperature liquid surface tension testing device according to claim 1, characterized in that: The outer wall of the vacuum chamber is also equipped with a vacuum gauge (13) that can read the pressure inside the chamber at any time.

5. The dynamic pressure variable temperature liquid surface tension testing device according to claim 1, characterized in that: The test platform module includes: an electromagnetic force balance sensor (5), a hook (20), a balancer (21), a platinum ring (23), a temperature sensor (22), a surface dish (24), a lifting platform (15), a level (16), and a motor (17).

6. The dynamic pressure variable temperature liquid surface tension testing device according to claim 5, characterized in that: The electromagnetic force balance sensor (5) is connected to the hook (20) through the balancer (21); the platinum ring (23) is placed on the hook (20), and a temperature sensor (22) is installed behind the hook (20); the surface dish (24) is placed on the electrically heated lifting platform (15), and a level (16) is installed on the outside of the electrically heated lifting platform (15), and the lifting platform (15) is connected to the motor (17).

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