A method for evaluating the performance of foaming agents based on force sensors

Abstract

The present invention relates to a method for evaluating the performance of a foaming agent based on a force sensor, belonging to the technical field of flotation reagent evaluation methods, and solves the problems of inaccurate foam state evaluation method and large workload in the prior art. The steps of the present invention include: Step 1: Make a standard curve; Step 2: Inject the foaming agent solution; Step 3: Inflate; Step 4: Record the force signal during the foam growth process; Step 5: Stop inflating; Step 6: Record the force signal during the foam decay process; Step 7: Place the force sensor (32) in the tested foaming agent solution; Step 8: Make a standard curve; Step 9: Inflate at a fixed gas velocity; Step 10: Record the force signal of the gas holdup. The present invention provides more accurate guidance for evaluating the performance of the foaming agent.

Description

Technical Field

[0001] The invention relates to the technical field of flotation agent evaluation methods, and in particular to a method for evaluating foaming agent performance based on a force sensor. Background Art

[0002] Coal is one of the main energy sources in my country and is of great significance to the development of the national economy. Its position in my country's energy structure will not change for a long time in the future. With the improvement of coal mining mechanization and the maturity of lump coal heavy medium separation technology, coal separation has shown characteristics such as micronization and high ash content, resulting in technical problems such as weak coal slime recovery capacity and substandard quality. The difficulty in separating coal slime has become one of the problems that the industry is concerned about and urgently needs to solve. In recent years, the flotation process has increasingly highlighted its strong advantages in separating (micro) fine coal, and it has played a considerable role in solving the problem of difficult separation of coal slime.

[0003] Froth flotation is a selective separation of target minerals and gangue based on the differences in physical and chemical properties of mineral surfaces. During the flotation process, as the hydration film between bubble particles thins and breaks, particles collide with bubbles, and hydrophobic particles tend to adhere to the bubbles to form mineralized bubbles, and float to the foam phase to be discharged as concentrate, while hydrophilic particles continue to stay in the slurry and eventually sink to the bottom to be discharged as tailings. The mineralization of particles and bubbles is the core step of flotation, so the formation and stability of foam directly affects the flotation effect.

[0004] Foamability and stability are two important indicators for evaluating foam, which can predict and judge the flotation results to a certain extent. Foamability refers to the speed of foam growth and the amount of foam generated; foam stability refers to the ability of foam to maintain its original state, that is, the difficulty of bubble merger and rupture. When the foam layer is unstable, bubbles are prone to merger and rupture, resulting in a decrease in flotation yield; but if the foam layer is too stable, it will bring difficulties to the concentrate dehydration operation, so an unstable or overly stable foam layer is not conducive to flotation. In recent years, domestic and foreign scholars have conducted a lot of research on the properties of foam.

[0005] In the past studies, the main test method for the stability of the macroscopic foam layer was the airflow method. The stability of the foam is usually measured by a combination of dynamic and static methods, and the evaluation indicators are the maximum height of the foam layer and the foam (half) life. The records are mainly based on the naked eye observation of the test personnel. This traditional method increases the workload of the test and has large errors. Therefore, it is extremely necessary to develop a real-time recording and high-precision test method and system. Summary of the invention

[0006] In view of the above analysis, the embodiments of the present invention aim to provide a method for evaluating the performance of a foaming agent based on a force sensor, so as to solve the problems of inaccurate existing foam state evaluation methods and large workload, thereby providing more accurate guidance for evaluating the performance of the foaming agent.

[0007] The present invention provides a method for evaluating the performance of a foaming agent based on a force sensor, and the steps include:

[0008] Step 1: Make a standard curve;

[0009] Step 2: Inject the foaming agent solution;

[0010] Step 3: Inflate;

[0011] Step 4: Record the force signal during the foam growth process;

[0012] Step 5: Stop inflating;

[0013] Step 6: Record the force signal during the foam decay process;

[0014] Step 7: Place the force sensor in the tested foaming agent solution;

[0015] Step 8: Make a standard curve;

[0016] Step 9: Inflate at a fixed gas velocity;

[0017] Step 10: Record the force signal of the gas holdup.

[0018] Further, in the above Step 1, weights of different masses are placed on the force sensor, the changes in the voltage signals generated by the test are recorded, and the corresponding linear relationship is determined based on the measured voltage signals and the weights of the weights, and the corresponding standard curve is made.

[0019] Further, in the above Step 3, the air pump and the gas flowmeter are turned on to generate bubbles in the column body of the pneumatic flotation column; in the above Step 9, the air pump and the gas flowmeter are turned on to inflate at a fixed gas velocity.

[0020] Further, in the above Step 4, during the generation of bubbles, the bubbles continuously rise in the liquid and form a foam layer at the top, and the force sensor inside the column body of the pneumatic flotation column will receive an upward force, and among them, the electrical signal is recorded by the data acquisition device.

[0021] Further, in the above Step 6, during the decay process, due to the bubble coalescence, the foam layer gradually decreases, and the force sensor inside the column body of the pneumatic flotation column will receive a downward force, and among them, the electrical signal is recorded by the data acquisition device.

[0022] Further, in step 8, weights of different masses are placed on the force sensor, the changes in the voltage signals generated by the experiment are recorded, and the corresponding linear relationship is determined based on the measured voltage signals and the weights of the weights, and the corresponding standard curve is made.

[0023] Further, in step 10, during the inflation process, bubbles are generated inside the liquid, which will generate electrical signals on the force sensor placed in the liquid, and the electrical signals are saved and recorded by the data acquisition device.

[0024] Further, a porous sand core and an air chamber are provided inside the pneumatic flotation column, the air chamber is located below the porous sand core, and the air pump is communicated with the air chamber.

[0025] Further, the porous sand core is provided at the lower part of the pneumatic flotation column, and the upper part of the porous sand core is used for injecting a foaming agent.

[0026] Further, the force sensor moves up and down inside the pneumatic flotation column through a displacement moving device.

[0027] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects:

[0028] (1) The present invention can record experimental data through a force sensor, obtain a force curve through signal transformation processing, and the change trends of foam growth rate, growth ability, water-carrying ability, decay ability, drainage ability, and gas holdup can be qualitatively analyzed from the force curve, that is, the multi-functional and multi-index fusion of foam evaluation indexes is realized by using the idea of micro-nano mechanics.

[0029] (2) The present invention can relatively reduce the workload of the test personnel and avoid the failure to observe and record the tiny differences generated during the test process. The data monitored and recorded by this method can well correspond to the test process, realize the real-time and accurate recording of test data, and facilitate subsequent analysis and qualitative evaluation of the performance of the foaming agent.

[0030] (3) The present invention solves the problems of inaccurate evaluation of the foam state by test personnel and long time consumption, thereby providing more accurate guidance for evaluating the performance of the foaming agent.

[0031] (4) The present invention improves the test efficiency by setting a displacement moving component inside the pneumatic flotation column, enabling the force sensor to move up and down flexibly inside the column body, and meeting the changes of different test conditions and requirements.

[0032] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent specification. Moreover, some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the specification and the drawings. Brief Description of the Drawings

[0033] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs denote the same components.

[0034] Figure 1 It is a schematic structural diagram of the system for evaluating the performance of a foaming agent according to the present invention;

[0035] Figure 2 It is a schematic diagram of the structure of the force sensor according to the present invention;

[0036] Figure 3 It is a schematic structural diagram of the force sensor testing device according to the present invention;

[0037] Figure 4 It is a schematic diagram of the connection structure between the force sensor and the slider according to the present invention.

[0038] Reference Signs:

[0039] 1 - Feeding Device; 11 - Predispersion Device; 12 - Diversion Pipe; 13 - Valve; 14 - Peristaltic Pump; 15 - Feed Pipe; 2 - Inflation Device; 21 - Air Pump; 22 - Gas Flowmeter; 23 - Inflation Pipe; 3 - Force Sensor Testing Device; 31 - Inflatable Flotation Column; 311 - Feed Inlet; 312 - Air Inlet; 313 - Discharge Outlet; 314 - Porous Sand Core; 315 - Air Chamber; 32 - Force Sensor; 33 - Displacement Activity Device; 331 - Sliding Groove; 332 - Slider; 333 - Displacement Control Bolt; 4 - Data Acquisition Device; 41 - Signal Amplifier; 42 - Data Acquisition Card; 43 - Computer. Detailed Embodiments

[0040] The preferred embodiments of the present invention will be specifically described below with reference to the drawings. The drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0041] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly defined and limited, the term "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood according to specific circumstances.

[0042] The terms "top", "bottom", "above", "under", and "on" used throughout the description are relative positions with respect to the components of the device, such as the relative positions of the top and bottom substrates inside the device. It is understood that the device is multifunctional and independent of its orientation in space.

[0043] Embodiment 1

[0044] A specific embodiment of the present invention, as Figure 1 - Figure 2 shown, discloses a system for evaluating the performance of a foaming agent based on a force sensor, including a feeding device 1, an air inflating device 2, a force sensor testing device 3, and a data acquisition device 4; the feeding device 1 is connected to the force sensor testing device 3, the air inflating device 2 is connected to the force sensor testing device 3, and the force sensor testing device 3 is electrically connected to the data acquisition device 4. The feeding device 1 is used to convey the agent to be tested to the force sensor testing device 3, the air inflating device 2 is used to convey gas to the force sensor testing device 3, and the data acquisition device 4 is used to collect and record the data generated by the force sensor testing device 3.

[0045] Compared with the traditional testing device, the system for evaluating the performance of the foaming agent in this embodiment adopts the idea of micro-nano mechanics and applies the force sensor to the system for evaluating the performance of the foaming agent, which can relatively reduce the workload of the test personnel and avoid the failure to observe and record the tiny differences generated during the test. The data monitored and recorded by this device can well correspond to the test process, realizing real-time and accurate recording of the test data, facilitating subsequent analysis and making a qualitative evaluation of the performance of the foaming agent.

[0046] The force sensor testing device 3 includes an air inflating flotation column 31. A porous sand core 314 and an air chamber 315 are provided inside the air inflating flotation column 31, and the air chamber 315 is located below the porous sand core 314. Specifically, the porous sand core 314 is provided at the lower part of the air inflating flotation column 31, and the space between the porous sand core 314 and the bottom of the air inflating flotation column 31 is the air chamber 315, and the air chamber 315 is used to generate bubbles.

[0047] The pneumatic flotation column 31 is further provided with a feed inlet 311, an air inlet 312 and a discharge outlet 313. The feed inlet 311 is arranged at the upper-middle position of the wall surface of the pneumatic flotation column 31 and is communicated with the feed pipe 15. The air inlet 312 is arranged at the lower position of the wall surface of the pneumatic flotation column 31 and is communicated with the air chamber 315. The discharge outlet 313 is arranged in the area where the porous sand core 314 is located and is communicated with the discharge pipe.

[0048] The force sensor test device 3 further includes a force sensor 32 and a displacement moving device 33. The force sensor 32 is arranged inside the pneumatic flotation column 31. Specifically, the displacement moving device 33 is arranged on the inner wall of the pneumatic flotation column 31. The force sensor 32 is connected to the displacement moving device 33 as a moving member and can move up and down on the displacement moving device 33.

[0049] In order to reduce the test error and ensure the accuracy of the test results, preferably, 2 force sensors 32 that are symmetric left and right and have the same horizontal height are arranged in the flotation column, and finally their average value is taken as the result of one test.

[0050] The 2 force sensors 32 are used to detect the dynamic changes of foam properties such as the liquid content, gas holdup, and drainage rate in the foam during the foam growth and decay processes. As a sensing device, they can convert the detected information into electrical signals and output them according to certain rules.

[0051] It should be noted that in this embodiment, in order to evaluate the performance of the foaming agent, during the foam growth process, decay process, and gas holdup test, the growth rate of the foam, the amount of foam generated, the coalescence and rupture of bubbles, the drainage volume during the foam decay process, and the internal pressure of the foaming agent solution during the gas injection process all change with time. The signals detected by the force sensor 32 are to record the above series of changes generated during the entire test process.

[0052] Such as Figure 3 - Figure 4As shown in the figure, in order to enable the two force sensors 32 to adapt to different test conditions and move up and down in the pneumatic flotation column 31, two displacement devices 33 are provided on the inner wall of the pneumatic flotation column 31. The displacement device 33 includes a sliding groove 331, a slider 332, and a displacement control bolt 333. Specifically, the sliding groove 331 is fixed to the inner wall of the pneumatic flotation column 31 by bolts and serves as a guide rail. The slider 332 is embedded in the sliding groove 331, and the force sensor 32 is fixed to the slider 332. The displacement control bolt 333 is arranged at the top of the sliding groove 331, and the lower part of the displacement control bolt 333 is connected to the slider 332 for controlling the height position of the force sensor 32 fixed on the slider 332 in the pneumatic flotation column 31. Specifically, by turning the displacement control bolt 333, the slider 332 fixing the force sensor 32 moves downward along the sliding groove 331 under the drive of the displacement control bolt 333, and the force sensor 32 is placed at other heights. It can be understood that turning the displacement control bolt 333 in the reverse direction can cause the slider 332 to move upward along the sliding groove 331.

[0053] As a possible technical solution of this embodiment, a strip-shaped groove is provided on the inner wall of the pneumatic flotation column 31. The strip-shaped groove is arranged along the axial direction of the pneumatic flotation column 31. Preferably, there are two strip-shaped grooves, and the two strip-shaped grooves are symmetrically arranged.

[0054] Further, one end of the force sensor 32 is a cantilever end, and a slider is provided at the other end. The slider is connected in cooperation with the strip-shaped groove, and the slider can slide upward along the strip-shaped groove.

[0055] Further, in order to be able to control the height of the slider in the pneumatic flotation column 31, a limiting rod is provided at the upper end of the strip-shaped groove, and a spring is provided at the lower end of the strip-shaped groove. The limiting rod is connected to the upper end of the pneumatic flotation column 31 through a connecting block. The limiting rod and the connecting block are in threaded connection. The lower part of the limiting rod abuts against the upper end of the slider, and the upper end of the spring abuts against the lower end of the slider.

[0056] When it is necessary to move the force sensor 32 downward, rotate the limiting rod to drive the slider to move downward along the strip-shaped groove. At this time, the spring is compressed. When it is necessary to move the force sensor 32 upward, only need to rotate the limiting rod in the reverse direction, and the spring resumes and pushes the slider up.

[0057] In order to facilitate the feeding of the reagent to be tested into the force sensor test device 3, the test system is also provided with a feeding device 1. The feeding device 1 includes a foaming agent pre-dispersion device 11, a diversion pipe 12, a valve 13, a peristaltic pump 14, and a feeding pipe 15. Specifically, the pre-dispersion device 11, the diversion pipe 12, the valve 13, the peristaltic pump 14, and the feeding pipe 15 are connected in sequence, and one end of the feeding pipe 15 is connected to the feeding port 311 on the wall of the pneumatic flotation column 31.

[0058] In this embodiment, the test system is provided with an inflation device 2, and the inflation device 2 includes an air pump 21, a gas flow meter 22, and an inflation pipe 23; specifically, the air pump 21 and the gas flow meter 22 are connected by a conduit, the air pump 21, the gas flow meter 22, and the inflation pipe 23 are connected in sequence, and one end of the inflation pipe 23 is connected to the air inlet 312 on the wall of the inflation flotation column 31. During the test, the air velocity can be freely adjusted according to different test conditions.

[0059] In order to convert the test changes detected by the force sensor 32 into the required data, the test system is further provided with a data acquisition device 4, including a wire, a signal amplifier 41, a data acquisition card 42, and a computer 43; specifically, the signal amplifier 41 is connected to the 2 force sensors 32 through a wire for amplifying the output signal, the data acquisition card 42 is connected to the signal amplifier 41 through a wire for collecting and storing data, and the computer 43 is connected to the data acquisition card 42 for recording and observing the real-time changes of the output data.

[0060] In this embodiment, the feeding device 1 is communicated with the feeding port 311 on the force sensor test device 3 through the feeding pipe 15, the inflation device 2 is communicated with the air inlet 312 on the force sensor test device 3 through the inflation pipe 23, and the force sensor test device 3 is connected to the signal amplifier 41 of the data acquisition device 4 through a wire.

[0061] Embodiment 2

[0062] Another specific embodiment of the present invention discloses a method for evaluating the performance of a foaming agent based on a force sensor, using the system for evaluating the performance of a foaming agent based on a force sensor in Embodiment 1, and the steps include:

[0063] Step 1: Make a standard curve.

[0064] Place weights of different masses on the force sensor 32, record the changes in the voltage signals generated by the test, and determine the corresponding linear relationship according to the measured voltage signals and the weights of the weights, and make the corresponding standard curve;

[0065] Specifically, the force sensor 32 in this embodiment uses a bimorph as a cantilever beam to measure the acting force. The bimorph is a piezoelectric device, which exhibits a reversible piezoelectric effect. The material deforms under the action of an external force or an opposite external force, and charges are generated inside. When a force F is applied to the end of the bimorph cantilever beam, compressive strain is generated on the lower surface and expansion is generated on the upper surface, and vice versa. The charge Q accumulated on the surface of the bimorph can be calculated by Equation (1):

[0066]

[0067] In the formula, F - the applied force; the dimensions of the device: L - length, t - thickness; d 31- Piezoelectric material charge constant.

[0068] The force F at the end of the wafer cantilever beam can be calculated by Equation (2):

[0069]

[0070] Where E and I are the Young's modulus and moment of inertia of the cantilever beam, respectively.

[0071] The deformation y of the bimorph end along the central axis is linearly related to the applied force, resulting in a proportional change in surface charge. Therefore, there is a linear relationship between the output electrical signal and the applied gravity, and the force of the bimorph can be described by Hooke's law (F = K·y).

[0072] Step 2: Inject the foaming agent solution.

[0073] Open valve 13 and start the pump head of peristaltic pump 14 to inject the pre-stirred and configured homogeneous foaming agent solution into the column body of the pneumatic flotation column 31 through the feed pipe 15 from the feed port 311 on the side wall of the pneumatic flotation column 31; in this embodiment, one of the typical non-ionic foaming agents such as sec-octanol, MIBC, and n-pentanol, and the cationic foaming agent DTAB and the anionic foaming agent SDS is selected. The type and quantity of the foaming agent can be selected according to the test requirements and purposes.

[0074] Step 3: Inflate.

[0075] Open the air pump 21 and the gas flowmeter 22. The gas is inhaled into the air chamber 315 of the pneumatic flotation column 31 through the air inlet pipe 23 from the air inlet 312 and passes through the porous sand core 314 to generate bubbles in the column body of the pneumatic flotation column 31. The different gas velocities can be adjusted according to the test scheme.

[0076] Step 4: Record the force signal during the foam growth process.

[0077] During the generation of bubbles, the bubbles continuously converge towards the upper part of the column body of the pneumatic flotation column 31 to form a foam layer. At this time, the force sensor 32 inside the column body receives an upward acting force, and the signal response is displayed and recorded on the computer 43 through the signal amplifier 41 and the data acquisition card 42. The corresponding force can be calculated according to the standard curve measured in Step 1. Different foaming agents have different bubble generation speeds and capabilities, and the forces exerted on the force sensor are also different. The foaming ability and water-carrying ability of the foaming agent can be analyzed according to the test results.

[0078] Step 5: Stop inflating.

[0079] Wait until the height of the foam layer is stable, then close the air pump 21 and the gas flowmeter 22. The inflation ends, the bubbles start to merge and break, and the foam decay begins. The height of the foam layer gradually decreases.

[0080] Step 6: Recording of force signals during the foam decay process.

[0081] During the decay process of the foam layer, a downward force is exerted on the force sensor 32 inside the column. The signal response is displayed and recorded on the computer 43 through the signal amplifier 41 and the data acquisition card 42. The corresponding force can be calculated based on the standard curve measured in Step 1. Different foaming agents have different foaming abilities and different bubble coalescence and rupture speeds, so the forces received by the force sensor 32 are different. In the initial stage of decay, the liquid drainage process of the foam layer is mainly gravity drainage. Due to different liquid contents in the foam, a higher liquid content will result in a greater drainage rate. The foam stabilizing ability and liquid drainage ability of the foaming agent can be analyzed based on the test results.

[0082] Step 7: Changing the position of the force sensor.

[0083] Change the position of the force sensor 32. Twist the displacement control bolt 333 to move the slider 332 fixing the force sensor 32 downward along the sliding groove 331, and place the force sensor 32 in the foaming agent solution to be tested.

[0084] Step 8: Making a standard curve.

[0085] Place different mass weights on the force sensor 32 placed in the foaming agent solution, record the change in the voltage signal generated by the test, and determine the corresponding linear relationship based on the measured voltage signal and the gravity of the weights to make the corresponding standard curve. It is confirmed that there is a good linear relationship between the electrical signal and the applied gravity.

[0086] Step 9: Inflation.

[0087] Turn on the air pump 21 and the gas flowmeter 22, and fix the gas velocity.

[0088] Step 10: Recording of force signals of gas holdup.

[0089] During the inflation process, bubbles are generated inside the liquid, and the internal pressure will also change. This change causes the force sensor 32 placed in the liquid to generate an electrical signal. The signal response is displayed and recorded on the computer 43 through the signal amplifier 41 and the data acquisition card 42. The corresponding force can be calculated based on the standard curve measured in Step 8. When the inflation volume is constant, the rising speed and size distribution of the bubbles in the liquid phase determine the size of the gas holdup in the solution. The gas holdup is different in different foaming agent solutions.

[0090] It should be noted that when testing the performance of other foaming agents, repeat Steps 1 to 10.

[0091] Compared with the traditional test method for evaluating the performance of foaming agents, the method of using a force sensor to evaluate the performance of foaming agents can relatively reduce the workload of testers and avoid the situation that the tiny differences generated during the test cannot be observed and recorded. The data monitored and recorded by this method can well correspond to the test process, realizing the real-time and accurate recording of test data, facilitating subsequent analysis and making a qualitative evaluation of the performance of foaming agents. The present invention solves the problems of inaccurate evaluation of foam state by testers and long time consumption, thus providing more accurate guidance for evaluating the performance of foaming agents.

[0092] Compared with the traditional foam stability test device and method, the present invention can record experimental data through a force sensor, obtain a force curve after signal transformation processing, and qualitatively analyze the changing trends of foam growth rate, growth ability, water-carrying ability, decay ability, drainage ability, gas holdup, etc. from this force curve, that is, realizing the integration of multiple functions and multiple indicators for foam evaluation indicators by using the idea of micro-nano mechanics.

[0093] As mentioned above, the above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for evaluating the performance of a foaming agent based on a force sensor, characterized in that, The steps include: Step 1: Make a standard curve; Place weights of different masses on the force sensor (32), record the change in the voltage signal generated by the test, and determine the corresponding linear relationship based on the measured voltage signal and the gravity of the weights, and make the corresponding standard curve; Step 2: Inject the frother solution; Step 3: Inflate; Step 4: Record the force signal during the foam growth process; During the process of generating bubbles, the bubbles continuously converge towards the upper part of the column body of the pneumatic flotation column (31) to form a foam layer. At this time, the force sensor (32) inside the column body is subjected to an upward acting force; In the said Step 4, during the process of generating bubbles, the bubbles continuously float upward in the liquid and form a foam layer at the top. The force sensor (32) inside the column body of the pneumatic flotation column (31) will be subjected to an upward force. Among them, the electrical signal is recorded by the data acquisition device (4); The force sensor (32) moves up and down inside the pneumatic flotation column (31) through the displacement moving device (33); The displacement moving device (33) is arranged on the inner wall of the pneumatic flotation column (31). The displacement moving device (33) includes a sliding groove (331), a slider (332), and a displacement control bolt (333). The sliding groove (331) is fixed on the inner wall of the pneumatic flotation column (31), the slider (332) is embedded in the sliding groove (331), the force sensor (32) is fixed on the slider (332), the displacement control bolt (333) is arranged at the top of the sliding groove (331), and the lower part of the displacement control bolt (333) is connected to the slider (332); Step 5: Stop inflating; Step 6: Record the force signal during the foam decay process. During the decay process of the foam layer, a downward force will be exerted on the force sensor (32) inside the column body; Step 7: Place the force sensor (32) in the tested frother solution; Step 8: Make a standard curve; Place weights of different masses on the force sensor (32) placed in the frother solution, record the change in the voltage signal generated by the test, and determine the corresponding linear relationship between the measured voltage signal and the gravity of the weights, and make the corresponding standard curve; Step 9: Inflate with a fixed gas velocity; Step 10: Record the force signal of the gas holdup.

2. The method for evaluating the performance of a foaming agent based on a force sensor according to claim 1, characterized in that, In the said Step 3, turn on the air pump (21) and the gas flowmeter (22) to generate bubbles inside the column body of the pneumatic flotation column (31); In the said Step 9, turn on the air pump (21) and the gas flowmeter (22) to inflate with a fixed gas velocity.

3. The method for evaluating the performance of a foaming agent based on a force sensor according to claim 1, characterized in that, In the said Step 6, during the decay process, due to the coalescence of bubbles, the foam layer gradually decreases, and the force sensor (32) inside the column body of the pneumatic flotation column (31) will be subjected to a downward force. Among them, the electrical signal is recorded by the data acquisition device (4).

4. The method for evaluating the performance of a foaming agent based on a force sensor according to claim 1, characterized in that, In the said Step 10, during the inflation process, bubbles are generated inside the liquid, which will generate an electrical signal for the force sensor (32) placed in the liquid, and the electrical signal is saved and recorded by the data acquisition device (4).

5. The method for evaluating the performance of a foaming agent based on a force sensor according to claim 2, characterized in that, Inside the pneumatic flotation column (31), there is a porous sand core (314) and an air chamber (315). The air chamber (315) is located below the porous sand core (314), and the air pump (21) is communicated with the air chamber (315).

6. The method for evaluating the performance of a foaming agent based on a force sensor according to claim 5, characterized in that, The porous sand core (314) is arranged at the lower part of the pneumatic flotation column (31), and the upper part of the porous sand core (314) is used for injecting a foaming agent.

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