Fuel oil nondestructive inspection agent and preparation method thereof

Abstract

The invention belongs to the technical field of non-destructive inspection, and discloses a fuel oil non-destructive inspection agent and a preparation method thereof, the fuel oil non-destructive inspection agent material comprises an activation adsorbent, a dispersant, a surfactant and a propellant; the ratio of the activated adsorbent to the dispersing agent to the surfactant to the propellant is 58: 240: 2: 200. The activation adsorbent is talcum powder; the surfactant is DuPont FSN-100 (Fractional Sensitive Number) The dispersing agent is a mixed solution of mineral oil, trichloroethane, nitromethane and acetonitrile according to a mixing ratio of 30: 60: 5: 5; the propellant is tetrafluoroethane, and the addition amount is 200g. The fuel oil nondestructive flaw detection agent provided by the invention is simple in use process, only the surface needs to be wiped dry with cloth, the flaw detection agent is directly applied, and leakage detection is completed in one step by only using the flaw detection agent; the flaw detection agent is simple and convenient to operate, is directly shown, is non-flammable, has excellent comprehensive performance, can quickly and sensitively detect tiny leakage, does not cause any damage to a unit by using the flaw detection agent, and does not need equipment such as a power supply and a black light lamp.

Description

Technical Field

[0001] The present application relates to the technical field of non-destructive flaw detection, and more specifically, to a fuel non-destructive flaw detection agent and a preparation method thereof. Background Art

[0002] Nondestructive testing (NDT) can detect internal defects in test pieces that are invisible to the naked eye. When inspecting the surface quality of test pieces, NDT can detect many tiny defects that are difficult to see with the naked eye. Another advantage of NDT is its 100% inspection capability. As is well known, destructive testing destroys the test piece upon completion, making it suitable only for sampling. Unlike destructive testing, NDT can be completed without damaging the test piece. Therefore, NDT allows for 100% or piece-by-piece inspection of products. Many critical materials, structures, or products must be foolproof, and only NDT can effectively ensure quality. A fuel flow regulator is assembled from multiple housings and covers, creating complex internal oil circuits. After assembly, pressure testing requires inspection of the joints for oil and gas leaks. Rapidly and accurately detecting engine leaks has long been a pressing industry challenge. Numerous methods exist for inspecting fuel system components for leaks, including staining, fluorescence, and magnetic penetration.

[0003] Prior art publication CN108169411A provides a nondestructive testing agent. The agent comprises a colorant and a developer. The colorant's raw materials, calculated by mass fraction, include: 20-25% by weight of a nonionic surfactant, 20-30% by weight of a black wolfberry-red yeast rice mixed extract, and the balance being a propellant. The developer's raw materials, calculated by mass fraction, include: 6-10% by weight of cellulose nanofibers, 2-3% by weight of a plasticizer, 1-2% by weight of a surfactant, 7-10% by weight of an adsorbent, and 30-40% by weight of ethanol, with the balance being a propellant. The nondestructive testing agent of this invention is not only environmentally friendly but also has the advantage of high detection sensitivity. Furthermore, the nondestructive testing agent utilizes a propellant to spray the colorant and developer onto the surface of the workpiece to be inspected, making it simple and convenient to operate.

[0004] Although the above-mentioned prior art solutions can achieve relevant beneficial effects through the structure of the prior art, they still have the following defects: there are many methods for checking leakage in the prior art, such as coloring, fluorescence, magnetic penetration, etc. These methods are cumbersome to operate, time-consuming, labor-intensive, inconvenient to use, and have unsatisfactory sensitivity, especially for complex structured complete products such as regulators.

[0005] In view of this, we propose a fuel non-destructive detection agent and a preparation method. Summary of the Invention

[0006] 1. Technical problems to be solved

[0007] The purpose of this application is to provide a fuel non-destructive flaw detection agent and a preparation method, which solves the technical problems raised in the above-mentioned background technology and realizes the technical effect of providing a non-destructive flaw detection material that is simple to operate, directly displays images, is non-flammable, has excellent comprehensive properties, and can quickly and sensitively detect tiny leaks. The use of this flaw detection agent does not cause any damage to the unit and does not require power supply, black light lamps and other equipment.

[0008] 2. Technical solution

[0009] The technical solution of this application provides a fuel non-destructive testing agent: the material components include: an activated adsorbent, a dispersant, a surfactant and a propellant;

[0010] The proportions of each material component are:

[0011] Activated adsorbent: dispersant: surfactant: propellant = 58:240:2:200;

[0012] The activated adsorbent is talc; the surfactant is DuPont FSN-100;

[0013] The dispersant was a mixture of mineral oil, trichloroethane, nitromethane, and acetonitrile in a ratio of 30:60:5:5;

[0014] The propellant is tetrafluoroethane, and the added amount is 200 grams.

[0015] In this technical solution, the fuel nondestructive testing agent of this application works by utilizing the capillary action of the adsorbent, the main component of the agent, to adsorb the oil (or oil vapor) in the test piece onto the surface, creating a wetting effect and forming a colored mark. The application process is simple: simply wipe the surface dry with a cloth before applying the agent. Leak detection is completed in one step using only the agent. This nondestructive testing material can quickly and sensitively detect even small leaks. Using this agent does not cause any damage to the unit, does not require a power source or blacklight, and is harmless to humans and animals.

[0016] The present invention provides a method for preparing a fuel nondestructive testing agent, comprising the following steps:

[0017] S1. Drying: Place the talc powder in a vacuum drying oven at 120±5℃ for 24 hours to remove moisture to a moisture content of ≤0.1%. Immediately seal and store in a desiccator after drying to prevent moisture absorption.

[0018] S2. Ultrafine grinding: Use a jet mill for ultrafine grinding, set the pressure to 0.8-1.0 MPa, and grind for 150 minutes. After grinding, pass the material through a 3000 mesh sieve to ensure uniform particle size.

[0019] S3. Classification: Use airflow classifier to perform particle size classification, collect particles between 2-10 μm (detected by laser particle size analyzer) as qualified activated adsorbents, and return those that do not meet the particle size requirements to the crushing process.

[0020] S4. Dispersant Preparation: In a reactor equipped with a stirrer, add mineral oil (30 parts), trichloroethane (60 parts), nitromethane (5 parts), and acetonitrile (5 parts) in sequence. Stir at 300-500 rpm and mix at room temperature for 30 minutes to ensure complete miscibility of the components. After mixing, perform a stability test and observe for 24 hours without stratification.

[0021] S5. Compounding and dispersion: including main agent mixing and homogenization;

[0022] Mixing of the main agent: Add the pretreated activated adsorbent - talc (58 parts) into a high shear mixer, slowly add the dispersant (240 parts) while stirring at 500-800 rpm, and continue stirring for 60 minutes.

[0023] A surfactant, DuPont FSN-100 (2 parts), was added to improve the wettability and permeability of the system, and stirring was continued for 30 minutes.

[0024] Homogenization: Use a high-pressure homogenizer to homogenize the mixed liquid, set the pressure to 30-50 MPa, and cycle homogenization 3 times to ensure that the material particle size is uniform and there is no agglomeration. Test the viscosity (50-100 mPa·s at 25°C, using a rotational viscometer) and density (0.85-0.95 g / cm 3 ).

[0025] S6. Canning and propellant addition:

[0026] S61. Pressurize and seal: inject the compounded main agent of the flaw detection agent into the pressure-resistant container through the filtering device, and immediately pressurize and seal to ensure airtightness.

[0027] S62. Propellant filling: Use a quantitative filling machine to inject tetrafluoroethane (200 grams) into the container. The filling pressure is controlled at 0.6-0.8 MPa at 25°C.

[0028] After filling, leak detection and pressure testing are carried out.

[0029] S7. Finished product inspection: 5% of the products in each batch will be randomly sampled for sensitivity test, flammability test and corrosion test.

[0030] As an optional solution of the present invention, in step S2, an airflow mill equipped with an artificial intelligence optimization algorithm is used to perform ultrafine grinding (preferably a PLC intelligent controlled airflow mill produced by Qingdao Shina Machinery Equipment Co., Ltd.). Specifically, the following steps are included:

[0031] 1. Raw material preparation: Confirm that the talc powder to be crushed has completed drying pretreatment, is stored in a nitrogen-filled and sealed desiccator, and has a moisture content of ≤0.1% as measured by a Karl Fischer titrator.

[0032] 2. Parameter Settings: Open the AI optimization algorithm control system interface of the airflow mill and enter the target particle size parameters. Set the target particle size range to 2-10μm and the D90 value to ≤10μm. Set the initial crushing pressure parameter to 0.8-1.0MPa and the grinding time to 150 minutes.

[0033] 3. Crushing operation:

[0034] 3.1. First open the high-pressure gas supply system and adjust the gas pressure to a stable state to ensure that the gas pressure entering the crusher meets the equipment requirements.

[0035] 3.2. Start the air flow mill. After the equipment runs stably, open the feeding device and feed the talcum powder slowly and evenly into the mill feed port. The feeding speed should be controlled within the rated range of the equipment.

[0036] 3.3. Start the ultrasonic vibrating screen and set the appropriate vibration frequency and amplitude to ensure that the material can be evenly distributed on the screen and effectively screened.

[0037] 3.4. Start the dynamic image analyzer, put it into real-time monitoring state, and begin to collect particle images of the material at the crusher outlet.

[0038] 4. Real-time monitoring and automatic adjustment:

[0039] 4.1. The particle size sensor installed inside the pulverizer monitors the material particle size data in real time and compares and analyzes it with the preset particle size target parameters. If the particle size is detected to deviate from the target range, the system automatically adjusts the pressure parameters of the airflow pulverizer to optimize the pulverization effect by controlling the flow and pressure of the high-pressure gas, gradually bringing the material particle size closer to the target value.

[0040] 4.2. The ultrasonic vibrating screen will screen the crushed materials in real time. The materials that fail to pass the 3000 mesh screen will automatically return to the feed port of the crusher for re-crushing to ensure that the particle size of the discharged materials is uniform.

[0041] 4.3. The dynamic image analyzer continuously collects images of material particle morphology and uses image recognition algorithms to analyze information such as particle shape and size distribution. If abnormal particle morphology (such as agglomeration, abnormal ratio of oversized or undersized particles) or particle size distribution deviation is detected, the data is immediately fed back to the artificial intelligence optimization algorithm control system.

[0042] 4.4. The control system automatically adjusts the crushing parameters (such as pressure, feed speed, etc.) based on the feedback information from the dynamic image analyzer and the data from the particle size sensor after comprehensive judgment, or starts the fault alarm program to prompt the operator to perform manual intervention.

[0043] 5. End of operation: When the grinding time reaches 150 minutes, or the material particle size has been tested to be stable and within the target range, stop the feeding device and stop feeding talc powder into the grinder. Continue to run the airflow mill for 3-5 minutes to discharge all the residual material in the grinding chamber, and then turn off the airflow mill and the high-pressure gas supply system.

[0044] 6. Data recording: During the entire crushing process, the artificial intelligence optimization algorithm control system automatically records key parameters and operating data, including real-time crushing pressure, feed speed, grinding time, material particle size detection data, dynamic image analysis results, etc.

[0045] As an optional solution of the present invention, in step S3, an air flow classifier with an adaptive adjustment function is used to classify the crushed talc powder into particle sizes. The process comprises the following steps:

[0046] 1. Transport the crushed talcum powder to the feed port of the classifier to ensure that the material enters the classifier evenly and continuously. Turn on the air classifier, start the classifying impeller and air supply system, and make the classifier enter a stable operating state.

[0047] 2. The built-in laser particle size analyzer of the classifier continuously detects the particle size of the passing materials and provides real-time feedback on the particle size data.

[0048] 3. Adaptive adjustment: Based on the detection results of the laser particle size analyzer, the control system automatically adjusts the air flow velocity and the speed of the classifier impeller. If the particle size is detected to be too large, the air flow velocity or the speed of the classifier impeller is increased to enhance the classification effect. If the particle size is detected to be too small, the air flow velocity or the speed of the classifier impeller is reduced to avoid over-classification.

[0049] 4. Target particle collection: The classifier accurately collects particles between 2-10μm as qualified activated adsorbents and collects them into a designated container. An electrostatic adsorption device is installed inside the classifier. The electrostatic adsorption device utilizes the surface charge differences of particles of different particle sizes to enhance the collection effect of target particle size (2-10μm).

[0050] 5. Intelligent sorting and return: For materials that do not meet the particle size requirements, the intelligent sorting system automatically identifies and sorts them out. The sorted unqualified materials are returned to the crushing process through the conveyor device for further crushing.

[0051] The intelligent sorting system combines an air-jet sorting device and a robotic arm sorting device. The air-jet sorting device uses high-pressure airflow to blow unqualified particles away from the main conveyor line. The Sorter air-jet sorter is preferred. The robotic arm sorting device uses visual recognition and robotic gripping to accurately separate large particles (>10μm). The high-performance, six-axis, lightweight robotic arm from Songling PiPER is preferred.

[0052] 6. Particle size distribution test: After each batch of products is graded, the collected qualified products are subjected to detailed particle size distribution test to ensure that the D90 value is ≤10μm.

[0053] 7. End of operation: When the classification of a batch of products is completed, stop feeding, continue to run the classifier for 3-5 minutes, discharge the residual material, and turn off the air classifier and related equipment.

[0054] As an optional solution of the present invention, step S4 includes the following steps:

[0055] 1. Raw material preparation: prepare mineral oil (30 parts), trichloroethane (60 parts), nitromethane (5 parts), and acetonitrile (5 parts), and check the raw material purity report (≥99%).

[0056] Prepare antioxidants (such as BHT, added in an amount of 0.01%-0.05%) and stabilizers (such as organic phosphonates, added in an amount of 0.02%-0.1%) to ensure their compatibility.

[0057] 2. Dispersant preparation:

[0058] 2.1. Add materials in sequence: Start cooling the reactor jacket with water (20°C) and start the variable frequency agitator at 300 rpm. Add the following via metering pumps: mineral oil (30 parts) and trichloroethane (60 parts), stirring for 10 minutes; then add nitromethane (5 parts), stirring for 5 minutes; then add acetonitrile (5 parts), stirring for 5 minutes. After each addition, collect characteristic peak data using an online infrared spectrometer to confirm that no undissolved material remains.

[0059] 2.2. Mixing Process Control: Increase the stirring speed to 500 rpm and continue mixing for 30 minutes. The online infrared spectrometer automatically collects spectra of the mixed solution every 5 minutes and compares them with the pre-set spectrum of a completely miscible standard. If the characteristic peak deviation exceeds ±5%, extend the stirring time by 10 minutes and retest.

[0060] 2.3 Additives: After mixing for 15 minutes, add the antioxidant (BHT) via a microsyringe while stirring. After mixing for 25 minutes, add the stabilizer (organic phosphonate) and continue stirring for 10 minutes. Maintain a slight positive pressure (0.02 MPa) in the reactor during this addition process to prevent air from entering.

[0061] 3. Stability test:

[0062] 3.1 Transfer and Storage: Transfer the mixed solution to a stability test tank via a pipe. Filter the mixture using a 0.22μm filter cartridge during transfer. Seal the test tank and place it in a constant temperature and light environment. Mark the time.

[0063] 3.2 Centrifugation test: Immediately after the transfer is completed, take a 50ml sample and place it in a centrifuge. Centrifuge at 3000rpm for 30 minutes. Observe whether there is precipitation or stratification at the bottom of the centrifuge tube. If there is:

[0064] Sediment thickness > 0.5mm: judged as unqualified, returned to the reactor for re-mixing

[0065] Slightly turbid but no obvious stratification: Extend the test time to 48 hours and verify again;

[0066] 3.3 Long-term stability observation: Observe the liquid state in the test tank every 6 hours and record any phase separation, discoloration, or turbidity. After 24 hours, take another sample for infrared spectroscopy analysis and density testing.

[0067] 4. Quality confirmation records: The qualification criteria are: the matching degree between the infrared spectrum characteristic peak and the standard spectrum is ≥98%; no precipitation or stratification in the centrifugal test; no visible change in the 24-hour stability test; density deviation ≤±0.01g / cm 3 ;

[0068] Record each infrared spectrum test result, centrifugal test phenomenon, and temperature / light data. Save parameters such as stirring speed, time, and additive amount during the mixing process. Regularly check the oxygen concentration in the reactor and maintain it below 2%.

[0069] As an optional solution of the present invention, step S5 includes the following steps:

[0070] 1. Mix talcum powder and dispersant:

[0071] 1.1. Establish a vacuum environment, turn on the vacuum degassing function of the high shear mixer, and increase the vacuum degree in the tank to 0.08MPa to prevent material oxidation and bubble mixing.

[0072] 1.2. Start the planetary agitator and set the speed to 500 rpm. Slowly add talcum powder (58 parts) through the screw conveyor. The feeding time is controlled within 10-15 minutes to avoid caking.

[0073] 1.3. After the talc powder is completely added, increase the speed to 800 rpm and add the dispersant (240 parts) at a uniform speed through a metering pump. The addition process lasts for 20 minutes.

[0074] 1.4. Torque monitoring and dispersion judgment: real-time monitoring of torque sensor data;

[0075] 2. Surfactant addition and ultrasonic-assisted dispersion:

[0076] 2.1. Addition of surfactant: Turn off the vacuum system, reduce the speed to 300 rpm, and add DuPont FSN-100 (2 parts) through the feeding port. The feeding time is ≤ 5 minutes.

[0077] 2.2. Ultrasonic dispersion start: Turn on the ultrasonic device, set the power to 400W, the frequency to 25kHz, and the action time to 30 minutes. Insert the ultrasonic probe 10-15cm below the liquid surface to ensure that the cavitation effect covers the entire mixing system.

[0078] 2.3. Adjustment of stirring parameters: During the ultrasonic action, the stirring speed was maintained at 400 rpm to promote the diffusion of surfactants through the synergistic effect of mechanical vibration and cavitation effect.

[0079] 3. Homogenization:

[0080] 3.1. High pressure homogenizer parameter setting:

[0081] 3.1.1, Pressure and circulation control:

[0082] First cycle: The pressure is set to 30 MPa, the flow rate is controlled at 50 L / h, and the material forms a high-speed jet (flow rate ≥ 100 m / s) when passing through the homogenizing valve.

[0083] Secondary circulation: The pressure is increased to 40 MPa to further break up the agglomerates and detect the particle size distribution (D50≤5μm).

[0084] Three cycles: The pressure is set at 50 MPa to ensure uniform particle size of the material, D90 ≤ 10 μm.

[0085] 3.1.2. Dynamic pressure compensation: When the system pressure fluctuation exceeds ±2%, the dynamic compensation system automatically adjusts the homogenizing valve opening.

[0086] 3.2. Homogenization process monitoring: record homogenization pressure and flow data every 5 minutes. The pressure fluctuation is required to be ≤±1MPa and the flow rate is stable at 45-55L / h.

[0087] Carry out particle size and viscosity testing, and after three cycles, stop the machine and take samples.

[0088] 4. Exception handling:

[0089] 4.1. Insufficient dispersion: This can be caused by torque consistently below 200 N·m or by talc precipitation observed during sampling. The solution is to add 5-10 parts of dispersant to improve system wettability, extend the stirring time by 20 minutes, and increase the speed to 900 rpm.

[0090] 4.2 Agglomeration after homogenization: This occurs when particle size testing reveals D90 > 10 μm, or when agglomerates are observed under a microscope. The solution is to check the homogenization valve for wear, replace it with a new one, and then re-homogenize; reduce the feed flow rate to 30 L / h, and increase the shear time.

[0091] 5. End of operation: Turn off the high-pressure homogenizer, drain the remaining material, and clean the pipeline with an ethanol-water mixture three times. Then rinse with purified water until the pH is neutral. Turn on the self-cleaning mode of the high-shear mixer and wipe the stirring blade and tank wall with a soft brush and detergent to avoid scratching the inner wall.

[0092] As an optional solution of the present invention, in step S6, the prepared flaw detection agent base is filtered through a 0.5μm filter cartridge equipped with an automatic backwash function to remove any impurities and large particles, ensuring product purity. A servo-driven, high-precision filling machine is used to inject the base agent into the pressure-resistant container. During the filling process, the filling volume and liquid level are monitored in real time to ensure filling accuracy.

[0093] A quantitative filler equipped with mass flow control and pressure compensation is used to inject 200 grams of tetrafluoroethane into the container. The filling process is carried out at a low temperature (5-10°C) to reduce the volatilization loss of tetrafluoroethane. The filling pressure is controlled at 0.6-0.8MPa (25°C). During the filling process, the pressure and temperature changes in the container are monitored in real time. The pressure compensation system automatically adjusts the filling speed to ensure a stable filling process.

[0094] 3. Beneficial effects

[0095] One or more technical solutions provided in the technical solution of this application have at least the following technical effects or advantages:

[0096] 1. The fuel nondestructive testing agent of the present invention is non-flammable and has excellent comprehensive performance;

[0097] 2. Non-destructive testing materials that can quickly and sensitively detect tiny leaks;

[0098] 3. The use of this flaw detection agent will not cause any damage to the unit, and does not require power supply, black light and other equipment.

[0099] 4. The application process is simple. You only need to wipe the surface dry with a cloth first and then apply the flaw detection agent directly. The leak detection is completed in one step using the flaw detection agent. After the detection is completed, the flaw detection agent can be easily removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 Schematic diagram comparing the particle size distribution of the sample of the present application and the British sample adsorbent (1000 times) disclosed in a preferred embodiment of the present application; 1a is the particle size distribution diagram of the British sample adsorbent; 1b is the particle size distribution diagram of the sample adsorbent of the present application;

[0101] Figure 2 Schematic diagram of the morphology comparison (5000 times) of the adsorbent of the sample of the present application and the British sample disclosed in a preferred embodiment of the present application; 2a is the adsorption morphology of the British sample; 2b is the morphology of the sample adsorbent of the present application;

[0102] Figure 3 This is a schematic diagram of the process flow of using the fuel non-destructive flaw detection agent disclosed in a preferred embodiment of the present application;

[0103] Figure 4 This is a schematic diagram of the process flow for using common leak detection agents. DETAILED DESCRIPTION

[0104] The present application is further described in detail below with reference to the accompanying drawings.

[0105] Reference Figure 1 and Figure 2 , the embodiment of the present application provides a fuel non-destructive flaw detection agent: the material components include: an activated adsorbent, a dispersant, a surfactant and a propellant;

[0106] The proportions of each material component are:

[0107] Activated adsorbent: dispersant: surfactant: propellant = 58:240:2:200;

[0108] The activated adsorbent is talcum powder; the surfactant is DuPont FSN-100; talcum powder (mainly composed of hydrated magnesium silicate) has a flaky crystal structure and a large specific surface area (about 10-20m 2 / g), with numerous microscopic pores on its surface. During the flaw detection process, fuel molecules adhere to the pores on the talc powder's surface through physical adsorption, forming distinct adsorption traces that indicate the location of leaks. Its chemical stability and neutral pH (7±0.5) prevent chemical reactions with fuel or metal engine components, ensuring a safe and reliable flaw detection process. Ultrafine talc powder with a particle size of 2-10μm is selected; this particle size ensures good dispersion, preventing agglomeration and clogging of the nozzle, while also providing sufficient adsorption surface.

[0109] The dispersant was a mixture of mineral oil, trichloroethane, nitromethane, and acetonitrile in a ratio of 30:60:5:5;

[0110] Mineral oil, the main component of the dispersant, has low volatility and good lubricity, reducing system viscosity (approximately 10-20 mPa·s at 25°C), evenly dispersing talc and preventing sedimentation. It is also chemically inert and has no adverse reactions with fuels or metals.

[0111] Trichloroethane: A strong solvent that quickly dissolves additives and impurities in fuel, enhancing the affinity of the flaw detection agent for fuel. It has a low boiling point (approximately 74°C) and evaporates quickly after injection, leaving behind clear adsorption traces.

[0112] Nitromethane: It has high polarity and can adjust the surface tension of the dispersant (about 25-30mN / m), allowing the flaw detection agent to quickly spread into a film on the metal surface, thereby improving the detection coverage.

[0113] Acetonitrile: It has good miscibility with other components and can accelerate the mixing of the system. At the same time, it lowers the freezing point of the dispersant (below -45°C), ensuring the normal use of the flaw detection agent in low temperature environments.

[0114] DuPont FSN-100 is a fluorocarbon surfactant whose molecular structure consists of fluorocarbon segments and hydrophilic groups. The fluorocarbon segments impart extremely low surface tension (up to 15-18 mN / m), resulting in a contact angle of less than 10° on metal surfaces, enabling superwetting and spreading. The hydrophilic groups ensure good solubility in the dispersant, enhancing system stability. Due to their high surface activity, even a small amount of fluorocarbon surfactant can significantly reduce the surface tension of a system.

[0115] The propellant is tetrafluoroethane, added in an amount of 200 grams. Tetrafluoroethane is a colorless gas at room temperature, with a boiling point of 26.1°C, a critical temperature of 101.1°C, and a critical pressure of 4.06 MPa. As a propellant, its low boiling point allows it to vaporize rapidly after pressurized canning, providing stable spray power (spray pressure of approximately 0.6-0.8 MPa at 25°C). Its non-flammability (no explosive limit) and chemical stability (no reaction with metals or fuel) meet the safety requirements of flaw detection agents.

[0116] The fuel nondestructive flaw detection agent described in this application is a specialized product designed for use in the specific working environments of leak detection within nondestructive testing. The ultimate goal of leak detection is to magnify minute cracks and display them as visible color marks for easy observation and troubleshooting. The working principle of the fuel nondestructive flaw detection agent is to utilize the capillary action of the adsorbent, the main component of the flaw detection agent, to absorb the oil (or oil vapor) in the test piece onto the surface of the object, creating a wetting effect and forming a colored color mark.

[0117] Ordinary leak detection agents are complete sets of products consisting of cleaning agents, penetrants, and developers, and defect inspection is completed in accordance with strict operating procedures.

[0118] The fuel non-destructive testing agent only has the developer to complete the leakage inspection of the fuel hydraulic system.

[0119] Reference Figure 3 and Figure 4 The working principle of the fuel non-destructive flaw detection agent of the present application is to utilize the main component of the flaw detection agent, the adsorbent, to form a capillary phenomenon to adsorb the oil (or oil gas) in the test piece to the surface of the object, generating a wetting effect and forming a colored mark. Compared with ordinary leak detection agents, the fuel leak detection agent of the present application has a simpler application process. It only needs to wipe the surface dry with a cloth and then directly apply the flaw detection agent. The leak detection is completed in one step using only the flaw detection agent. The non-destructive flaw detection material can quickly and sensitively detect tiny leaks. The use of this flaw detection agent does not cause any damage to the unit, does not require power supply and black light equipment, and is harmless to humans and animals.

[0120] Conventional leak detection agents are complete sets of products consisting of a cleaning agent, penetrant, and developer, and are used to detect defects according to strict operating procedures. Conventional leak detection agents artificially add brightly colored dyes to the leaking liquid, which are then absorbed by the developer to amplify and reveal defects. Adjusting the matching between the penetrant and developer improves detection sensitivity. However, fuel nondestructive detection agents use fuel as a hypothetical leaking liquid, relying solely on the agent's performance to ensure ultra-high sensitivity, without the need for bright colors to amplify the display.

[0121] The present invention provides a method for preparing a fuel nondestructive testing agent, comprising the following steps:

[0122] A method for preparing a fuel nondestructive flaw detection agent comprises the following steps:

[0123] S1. Drying: Place the talc powder in a vacuum drying oven at 120±5°C for 24 hours to remove moisture to a moisture content of ≤0.1% (measured using a Karl Fischer titrator). Immediately after drying, seal and store in a desiccator to prevent moisture absorption. Excessive moisture content in the talc powder will lead to uneven dispersion and decreased product stability. After drying, the moisture content should be ≤0.1%. Samples should be taken every 4 hours during the drying process to ensure moisture content is met.

[0124] S2. Ultrafine grinding: Use a jet mill for ultrafine grinding, set the pressure to 0.8-1.0 MPa, and grind for 150 minutes. After grinding, pass the material through a 3000 mesh sieve (sieve size is about 5 μm) to ensure uniform particle size.

[0125] S3. Classification: Use airflow classifier to perform particle size classification, collect particles between 2-10 μm (detected by laser particle size analyzer) as qualified activated adsorbents, and return those that do not meet the particle size requirements to the crushing process.

[0126] S4. Dispersant Preparation: In a reactor equipped with a stirrer, add mineral oil (30 parts), trichloroethane (60 parts), nitromethane (5 parts), and acetonitrile (5 parts) in sequence. Stir at 300-500 rpm and mix at room temperature for 30 minutes to ensure complete miscibility of the components. After mixing, perform a stability test and observe for 24 hours without stratification.

[0127] S5. Compounding and dispersion: including main agent mixing and homogenization;

[0128] Main agent mixing: Add the pretreated activated adsorbent - talc (58 parts) into a high shear mixer, slowly add the dispersant (240 parts) while stirring at 500-800 rpm, and continue stirring for 60 minutes to ensure that the talc is completely dispersed.

[0129] A surfactant, DuPont FSN-100 (2 parts), was added to improve the wettability and permeability of the system, and stirring was continued for 30 minutes.

[0130] Homogenization: Use a high-pressure homogenizer to homogenize the mixed liquid, set the pressure to 30-50 MPa, and cycle homogenization 3 times to ensure that the material particle size is uniform and there is no agglomeration. Test the viscosity (50-100 mPa·s at 25°C, using a rotational viscometer) and density (0.85-0.95 g / cm 3 ).

[0131] S6. Canning and propellant addition:

[0132] S61. Gland sealing: inject the compounded flaw detection agent main agent into the pressure-resistant container through the filter device (0.5μm filter element), and immediately seal it with the gland to ensure airtightness.

[0133] S62. Propellant filling: Use a quantitative filling machine to inject tetrafluoroethane (200 grams) into the container. The filling pressure is controlled at 0.6-0.8 MPa at 25°C.

[0134] After filling, conduct leakage detection (no bubbles when immersed in water) and pressure test (maintain 0.5MPa pressure at 25℃ for 24 hours without change).

[0135] S7. Finished product inspection: 5% of the products in each batch are randomly sampled for sensitivity testing (simulating fuel leakage, detection limit ≤ 0.1μL / min), flammability testing (closed cup flash point ≥ 60°C) and corrosion testing (no obvious corrosion after immersing aluminum alloy specimens for 72 hours).

[0136] Furthermore, in step S3, the particle size of talc directly affects the adsorption and penetration properties of the flaw detection agent and must be strictly controlled within the range of 2-10 μm. Each batch of products is tested for particle size distribution, and the D90 value must be ≤10 μm.

[0137] Furthermore, in step S4, the mixing ratio of the dispersant and the homogenization process determine the stability of the product, and a centrifugation test (3000 rpm, 30 minutes) is required to verify that there is no precipitation or stratification.

[0138] Furthermore, in step S2, an air flow mill equipped with an artificial intelligence optimization algorithm is used to perform ultrafine grinding operations. The particle size target parameters are input into the system in advance, and the grinder automatically adjusts the pressure to 0.8-1.0 MPa based on the real-time monitoring of the material particle size feedback, and the grinding time is set to 150 minutes. During the grinding process, an ultrasonic vibrating screen is used to screen the material in real time to ensure that the material can pass through a 3000 mesh sieve (sieve size is about 5 μm) after grinding. At the same time, a dynamic image analyzer and a high-definition camera are installed at the outlet of the grinder to monitor the material particle morphology in real time. Once abnormal particle morphology or particle size distribution deviation is found, the grinding parameters are automatically adjusted or a fault alarm is activated to ensure uniform material particle size. Specifically comprising the following steps:

[0139] 1. Raw Material Preparation: Confirm that the talc powder to be crushed has been pre-dried and stored in a nitrogen-filled, sealed desiccator. The moisture content should be ≤ 0.1% as determined by Karl Fischer titrator. Remove the talc powder from the desiccator and transfer it to a dedicated feed container. Keep the container clean and dry to prevent secondary contamination.

[0140] 2. Parameter Settings: Open the AI optimization algorithm control system interface of the airflow mill and enter the target particle size parameters. Set the target particle size range to 2-10μm and the D90 value to ≤10μm. Set the initial crushing pressure parameter to 0.8-1.0MPa and the grinding time to 150 minutes.

[0141] 3. Crushing operation:

[0142] 3.1. First open the high-pressure gas supply system and adjust the gas pressure to a stable state to ensure that the gas pressure entering the crusher meets the equipment requirements.

[0143] 3.2. Start the air flow mill. After the equipment runs stably, open the feeding device and feed the talcum powder slowly and evenly into the feed port of the mill. The feeding speed should be controlled within the rated range of the equipment to avoid clogging the crushing chamber due to excessive feeding.

[0144] 3.3. Start the ultrasonic vibrating screen and set the appropriate vibration frequency and amplitude to ensure that the material can be evenly distributed on the screen and effectively screened.

[0145] 3.4. Start the dynamic image analyzer, put it into real-time monitoring state, and begin to collect particle images of the material at the crusher outlet.

[0146] 4. Real-time monitoring and automatic adjustment:

[0147] 4.1. The AI-powered optimization algorithm control system monitors material particle size data in real time via a particle size sensor installed inside the pulverizer, comparing and analyzing it against preset target particle size parameters. If the particle size deviates from the target range, the system automatically adjusts the pressure parameters of the airflow pulverizer. By controlling the flow and pressure of the high-pressure gas, the system optimizes the pulverization effect, gradually bringing the material particle size closer to the target value.

[0148] 4.2. The ultrasonic vibrating screen will screen the crushed materials in real time. The materials that fail to pass through the 3000 mesh sieve (sieve size is about 5μm) will automatically return to the feed port of the crusher for re-crushing to ensure that the particle size of the discharged materials is uniform.

[0149] 4.3. The dynamic image analyzer continuously collects images of material particle morphology and uses image recognition algorithms to analyze information such as particle shape and size distribution. If abnormal particle morphology (such as agglomeration, abnormal ratio of oversized or undersized particles) or particle size distribution deviation is detected, the data is immediately fed back to the artificial intelligence optimization algorithm control system.

[0150] 4.4. The control system automatically adjusts the crushing parameters (such as pressure, feed speed, etc.) based on the feedback information from the dynamic image analyzer and the data from the particle size sensor after comprehensive judgment, or starts the fault alarm program to prompt the operator to intervene manually. Particle size feedback control is performed according to the following formula:

[0151] P 调整 =P 当前 +k p e(t)+k i ∫[e(t)dt]+k d [de(t) / (dt)]; e(t) = D 实际 -D 目标 Where, P 调整 Is the adjusted crusher pressure (the pressure value at the next moment), the new pressure value calculated by the PID control algorithm is used to optimize the crushing effect. 当前 is the current crusher pressure (the pressure value at the previous moment). e(t) is the particle size deviation (the difference between the actual particle size at the current moment and the target particle size). It reflects the degree of deviation between the current crushing effect and the target value and is the core input of PID control. p It is a proportional control parameter, which directly adjusts the pressure according to the current deviation e(t). The larger the deviation, the larger the adjustment amount. i k is the integral control parameter, which adjusts the historical integral of the deviation e(t) to eliminate the steady-state error. d is the differential control parameter, which adjusts the rate of change of the deviation e(t) to suppress overshoot and oscillation. t is the time variable; D 实际It is the actual particle size, which means the material particle size monitored in real time by the particle size sensor or dynamic image analyzer. 目标 The target particle size represents the pre-set target value of the material particle size. During the parameter setting stage, the operator enters the target particle size range into the system.

[0152] 5. End of operation: When the grinding time reaches 150 minutes, or the material particle size has been tested to have stabilized and reached the target range, stop the feed device and stop feeding talc into the grinder. Continue to run the airflow mill for 3-5 minutes to discharge all the remaining material in the grinding chamber, then turn off the airflow mill and the high-pressure gas supply system. Turn off the ultrasonic vibrating screen and dynamic image analyzer in sequence, and save the monitoring data and analysis results. Clean the airflow mill, remove detachable parts (such as the feed port, grinding chamber lining, etc.), and use special tools to remove residual material inside to prevent residual material from affecting the next grinding effect.

[0153] 6. Data recording: During the entire crushing process, the artificial intelligence optimization algorithm control system automatically records key parameters and operating data, including real-time crushing pressure, feed speed, grinding time, material particle size detection data, dynamic image analysis results, etc.

[0154] Furthermore, in step S3, an airflow classifier with adaptive adjustment function is used to classify the crushed talc powder into particle size. The classifier is equipped with a built-in laser particle size analyzer to continuously detect the particle size of the passing material. The airflow velocity and the speed of the classifier impeller are adjusted in real time according to the test results, and particles between 2-10μm are accurately collected as qualified activated adsorbents. Materials that do not meet the particle size requirements are automatically identified by the intelligent sorting system and returned to the crushing process. Each batch of products undergoes detailed particle size distribution testing, requiring a D90 value of ≤10μm. The test data is stored in conjunction with the production batch information.

[0155] The following steps are involved:

[0156] 1. Transport the crushed talcum powder to the feed port of the classifier to ensure that the material enters the classifier evenly and continuously. Turn on the air classifier, start the classifying impeller and air supply system, and make the classifier enter a stable operating state.

[0157] 2. The built-in laser particle size analyzer of the classifier continuously detects the particle size of the passing materials and provides real-time feedback on the particle size data.

[0158] 3. Adaptive adjustment: Based on the detection results of the laser particle size analyzer, the control system automatically adjusts the air flow velocity and the speed of the classifier impeller. If the particle size is detected to be too large, the air flow velocity or the speed of the classifier impeller is increased to enhance the classification effect. If the particle size is detected to be too small, the air flow velocity or the speed of the classifier impeller is reduced to avoid over-classification.

[0159] 4. Target Particle Collection: The classifier precisely collects particles between 2 and 10 μm as qualified activated adsorbents and collects them into designated containers. An electrostatic adsorption device is installed within the classifier. This device utilizes the surface charge differences of particles of different sizes to enhance the collection of target particles (2-10 μm). The device automatically adjusts the adsorption intensity based on the particle surface charge to ensure classification accuracy.

[0160] 5. Intelligent sorting and return: For materials that do not meet the particle size requirements (such as particle size >10μm or <2μm), the intelligent sorting system automatically identifies and sorts them out. The sorted unqualified materials are returned to the crushing process through the conveyor device for re-crushing.

[0161] The intelligent sorting system combines an air-jet sorting device and a robotic arm sorting device. The air-jet sorting device uses high-pressure airflow to blow unqualified particles away from the main conveyor line. The Sorter air-jet sorter is preferred. The robotic arm sorting device uses visual recognition and robotic gripping to accurately separate large particles (>10μm). The high-performance, six-axis, lightweight robotic arm from Songling PiPER is preferred.

[0162] 6. Particle size distribution testing: After each batch of products is graded, a detailed particle size distribution test is performed on the collected qualified products to ensure that the D90 value is ≤10μm. The test data is bound to the production batch information and stored in the database for subsequent traceability and quality analysis.

[0163] 7. End of operation: When the classification of a batch of products is completed, stop feeding and continue to run the classifier for 3-5 minutes to discharge the residual material. Turn off the air classifier and related equipment, and clean the inside of the classifier to prevent material residue from affecting the next batch of production.

[0164] Furthermore, in step S4, the reactor is a reactor with a stirring device and has magnetic sealing and explosion-proof functions; the reactor is equipped with a variable frequency speed regulating stirrer. During the mixing process, the mixing state of each component is monitored in real time by an online infrared spectrometer to ensure complete mutual solubility. After the mixing is completed, the dispersant is transferred to a stability test tank and observed for 24 hours under constant temperature and light conditions. At the same time, a centrifugal test (3000rpm, 30 minutes) is used to verify that there is no precipitation or stratification. In order to enhance the stability of the dispersant, a trace amount of antioxidant and stabilizer is added during the mixing process. The antioxidant can effectively inhibit the deterioration of the easily oxidized components in the dispersant, and the stabilizer improves the stability of the system by forming intermolecular forces with each component. Comprising the following steps:

[0165] 1. Raw material preparation: prepare mineral oil (30 parts), trichloroethane (60 parts), nitromethane (5 parts), and acetonitrile (5 parts), and check the raw material purity report (≥99%).

[0166] Prepare antioxidants (such as BHT, added in an amount of 0.01%-0.05%) and stabilizers (such as organic phosphonates, added in an amount of 0.02%-0.1%) to ensure their compatibility.

[0167] 2. Dispersant preparation:

[0168] 2.1. Add materials in order: Start the cooling water (20℃) in the jacket of the reactor and turn on the variable frequency agitator to 300rpm.

[0169] Add mineral oil (30 parts) and trichloroethane (60 parts) in sequence through a metering pump, stirring for 10 minutes after addition; then add nitromethane (5 parts) and stir for 5 minutes after addition; then add acetonitrile (5 parts) and stir for 5 minutes after addition;

[0170] Each time a component was added, characteristic peak data were collected by an online infrared spectrometer to confirm that no undissolved matter remained.

[0171] 2.2. Mixing Process Control: Increase the stirring speed to 500 rpm and continue mixing for 30 minutes. The online infrared spectrometer automatically collects spectra of the mixed solution every 5 minutes and compares them with the pre-set spectrum of a completely miscible standard. If the characteristic peak deviation exceeds ±5%, extend the stirring time by 10 minutes and retest.

[0172] 2.3 Additives: After mixing for 15 minutes, add the antioxidant (BHT) via a microsyringe while stirring. After mixing for 25 minutes, add the stabilizer (organic phosphonate) and continue stirring for 10 minutes. Maintain a slight positive pressure (0.02 MPa) in the reactor during this addition process to prevent air from entering.

[0173] 3. Stability test:

[0174] 3.1 Transfer and Storage: Transfer the mixed solution to a stability test tank via a pipe. Filter the mixture using a 0.22μm filter cartridge during transfer. Seal the test tank and place it in a constant temperature and light environment. Mark the time.

[0175] 3.2 Centrifugation test: Immediately after the transfer is completed, take a 50ml sample and place it in a centrifuge. Centrifuge at 3000rpm for 30 minutes. Observe whether there is precipitation or stratification at the bottom of the centrifuge tube. If there is:

[0176] Sediment thickness > 0.5mm: judged as unqualified, returned to the reactor for re-mixing

[0177] Slightly turbid but no obvious stratification: Extend the test time to 48 hours and verify again;

[0178] 3.3. Long-term stability observation: Observe the liquid state in the test tank every 6 hours and record whether there is phase separation, color change or turbidity. After 24 hours, take samples again for infrared spectrum analysis and density test (standard value: 0.85-0.95g / cm 3 ).

[0179] 4. Quality confirmation records: The qualification criteria are: the matching degree between the infrared spectrum characteristic peak and the standard spectrum is ≥98%; no precipitation or stratification in the centrifugal test; no visible change in the 24-hour stability test; density deviation ≤±0.01g / cm 3 ; Calculate the infrared spectrum matching degree according to the following formula:

[0180] M=(1 / m){Σ m i＝1 [u i (1-|I i,t -I i,s | / I i,s )]}×100%; where M is the infrared spectrum matching degree; it indicates the similarity between the infrared spectrum of the sample and the standard spectrum. i is the weight of each characteristic peak: used to measure the importance of the i-th characteristic peak in the infrared spectrum in the overall matching evaluation. i,t It is the real-time spectrum intensity, which refers to the intensity value of the i-th characteristic peak in the sample infrared spectrum collected in real time during the detection process. This value will be affected by many factors such as sample concentration, instrument status, and detection environment. i,s is the standard spectrum intensity: it is the intensity value of the i-th characteristic peak in the infrared spectrum of the pre-set standard substance. The standard spectrum is usually a representative spectral data obtained by multiple precise measurements of high-purity, known-composition standard samples and data processing. It serves as a reference benchmark for comparison with the sample spectrum. Different standard substances have their own corresponding standard spectra, and these spectral data can be obtained from professional spectral databases (such as the NIST infrared spectrum database). m is the number of characteristic peaks, which indicates the total number of characteristic peaks selected in this infrared spectrum matching calculation. The selection of characteristic peaks needs to be determined based on the structural characteristics and analysis requirements of the target substance.

[0181] Record each infrared spectrum test result, centrifugal test phenomenon, and temperature / light data. Save parameters such as stirring speed, time, and additive amount during the mixing process. Regularly check the oxygen concentration in the reactor and maintain it below 2%.

[0182] Furthermore, in step S5, the high shear mixer is a high shear mixer equipped with a planetary stirring blade and a vacuum degassing function. The stirring resistance change is monitored by the torque sensor built into the mixer to judge the dispersion degree of the talcum powder and ensure complete dispersion. Ultrasonic dispersion auxiliary technology is adopted. After adding the surfactant, the ultrasonic device is started, and the cavitation effect and mechanical vibration of the ultrasonic wave are used to quickly and evenly disperse the surfactant in the system to improve the wettability and permeability of the system. The mixed liquid is homogenized using a high-pressure homogenizer equipped with a nano-scale homogenizing valve and a dynamic pressure compensation system. The opening of the homogenizing valve is automatically adjusted by the dynamic pressure compensation system to ensure that the material particle size is uniform and there is no agglomeration. The following steps are included:

[0183] 1. Mix talcum powder and dispersant:

[0184] 1.1. Establish a vacuum environment, turn on the vacuum degassing function of the high shear mixer, and increase the vacuum degree in the tank to 0.08MPa to prevent material oxidation and bubble mixing.

[0185] 1.2. Start the planetary agitator and set the speed to 500 rpm. Slowly add talcum powder (58 parts) through the screw conveyor. The feeding time is controlled within 10-15 minutes to avoid caking.

[0186] 1.3. After the talc powder is completely added, increase the speed to 800 rpm and add the dispersant (240 parts) at a uniform speed through a metering pump. The addition process lasts for 20 minutes.

[0187] 1.4 Torque monitoring and dispersion judgment: Real-time monitoring of torque sensor data:

[0188] Initial stage (0-20 minutes): The torque gradually rises to 150-200 N·m, indicating that the talc powder and the dispersant are initially mixed.

[0189] Mid-term stage (20-50 minutes): The torque stabilizes at 250-300 N·m, indicating that the talc powder is evenly dispersed.

[0190] Final stage (50-60 minutes): Torque fluctuation ≤ 5%, judged as complete dispersion.

[0191] If the torque is abnormal (such as a sudden increase or decrease), stop the machine immediately and check whether there is a block or equipment failure.

[0192] 2. Surfactant addition and ultrasonic-assisted dispersion:

[0193] 2.1. Addition of surfactant: Turn off the vacuum system, reduce the speed to 300 rpm, and add DuPont FSN-100 (2 parts) through the feeding port. The feeding time is ≤ 5 minutes.

[0194] 2.2. Ultrasonic dispersion start: Turn on the ultrasonic device, set the power to 400W, the frequency to 25kHz, and the action time to 30 minutes. Insert the ultrasonic probe 10-15cm below the liquid surface to ensure that the cavitation effect covers the entire mixing system.

[0195] 2.3. Stirring Parameter Adjustment: During ultrasonication, maintain a stirring speed of 400 rpm. The mechanical vibration and cavitation effect will synergistically promote surfactant diffusion. Samples should be taken every 10 minutes for observation. The system should show no obvious stratification and the surfactant droplet size should be ≤50 μm (measured by a laser particle size analyzer).

[0196] 3. Homogenization:

[0197] 3.1. High pressure homogenizer parameter setting:

[0198] 3.1.1, Pressure and circulation control:

[0199] First cycle: The pressure is set to 30 MPa, the flow rate is controlled at 50 L / h, and the material forms a high-speed jet (flow rate ≥ 100 m / s) when passing through the homogenizing valve.

[0200] Secondary circulation: The pressure is increased to 40 MPa to further break up the agglomerates and detect the particle size distribution (D50≤5μm).

[0201] Three cycles: The pressure is set at 50 MPa to ensure uniform particle size, D90 ≤ 10 μm. The particle size is predicted according to the following formula:

[0202] d=d0[1-γP / sqt(u)] 1 / (1+δT) ; In the formula, d is the average particle size of the material after homogenization (μm), which represents the particle size of the final product. d0 is the average particle size of the material before homogenization (μm), which reflects the particle size in the initial state. γ is the comprehensive crushing coefficient, which integrates factors such as equipment characteristics and material surface energy. It can be obtained by fitting small-scale experimental data. Different benchmark values are set for different materials and equipment, and then fine-tuned according to actual production data. u is the dynamic viscosity of the material (Pa·s), which is measured by a rotational viscometer under conditions close to the homogenization temperature. δ is the temperature influence coefficient, which reflects the degree of influence of temperature on particle size change. Its numerical value depends on the thermal sensitivity of the material itself and can be determined by comparing the homogenization test results at different temperatures. T is the real-time temperature of the homogenization process, which is obtained by real-time monitoring through the built-in temperature sensor of the equipment. P represents the homogenization pressure (unit: MPa), that is, the pressure value applied to the material during the homogenization process of the high-pressure homogenizer.

[0203] 3.1.2 Dynamic pressure compensation: When the system pressure fluctuation exceeds ±2%, the dynamic compensation system automatically adjusts the homogenizing valve opening. For example, when the pressure rises suddenly, the valve opening increases by 0.1mm to reduce fluid resistance; when the pressure drops suddenly, the valve opening decreases by 0.05mm to maintain shear force.

[0204] 3.2. Homogenization process monitoring: record homogenization pressure and flow data every 5 minutes. The pressure fluctuation is required to be ≤±1MPa and the flow rate is stable at 45-55L / h.

[0205] Perform particle size and viscosity tests. After three cycles, stop the machine and take samples:

[0206] Particle size detection: Laser particle size analyzer shows that the particle size distribution is concentrated in 2-8μm, and there are no particles larger than 10μm.

[0207] Viscosity test: The viscosity was measured by a rotational viscometer (25°C, 60 rpm) and was 75±10 mPa·s.

[0208] Density test: The value measured by the density meter is 0.90±0.03g / cm 3 .

[0209] If the test does not meet the standards, increase the number of cycles 1-2 times, or adjust the pressure to 55MPa (not exceeding the rated pressure of the equipment).

[0210] 4. Exception handling:

[0211] 4.1 Insufficient dispersion: This can be caused by torque consistently below 200 N·m or by talc precipitation observed during sampling. Solutions include: adding 5-10 parts of dispersant to improve system wettability; extending the stirring time by 20 minutes and increasing the speed to 900 rpm.

[0212] 4.2 Agglomeration after homogenization: This occurs when particle size testing reveals D90 > 10 μm, or when agglomerates are observed under a microscope. Solutions include: Check the homogenization valve for wear, replace it with a new one, and then re-homogenize; reduce the feed flow rate to 30 L / h and increase the shear time.

[0213] 5. End of operation: Turn off the high-pressure homogenizer, drain the remaining material, and clean the pipeline with an ethanol-water mixture (volume ratio of 1:1) for three cycles. Then rinse with purified water until the pH is neutral. Turn on the self-cleaning mode of the high-shear mixer and wipe the stirring blade and tank wall with a soft brush and detergent to avoid scratching the inner wall.

[0214] Furthermore, in step S6, the formulated flaw detection agent base is filtered through a 0.5μm filter cartridge equipped with an automatic backwash function to remove any impurities and large particles, ensuring product purity. A servo-driven, high-precision filling machine is used to inject the base agent into a pressure-resistant container. During the filling process, the filling volume and liquid level are monitored in real time to ensure filling accuracy.

[0215] A quantitative filler equipped with mass flow control and pressure compensation is used to inject 200 grams of tetrafluoroethane into the container. The filling process is carried out at a low temperature (5-10°C) to reduce the volatilization loss of tetrafluoroethane. The filling pressure is controlled at 0.6-0.8MPa (25°C). During the filling process, the pressure and temperature changes in the container are monitored in real time. The pressure compensation system automatically adjusts the filling speed to ensure a stable filling process.

[0216] The fuel nondestructive flaw detection agent of the present invention is easy to operate and directly displays images. It is non-flammable and has excellent comprehensive performance. It can quickly and sensitively detect small leaks. Using this flaw detection agent does not cause any damage to the unit and does not require power supply, black light lamp and other equipment.

[0217] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a fuel nondestructive testing agent, characterized in that: The following steps are involved: S1. Drying: Place the talc powder in a vacuum drying oven and dry it at 120±5°C for 24 hours to remove moisture to a moisture content of ≤0.1%; S2, ultrafine grinding: use air flow mill for ultrafine grinding, set the pressure to 0.8-1.0 MPa, grinding time 150 minutes; after grinding, pass through a 3000 mesh sieve; S3, classification: Use air flow classifier to perform particle size classification, and collect particles between 2-10 μm as qualified activated adsorbent; S4, dispersant preparation: in a reactor with a stirring device, 30 parts of mineral oil, 60 parts of trichloroethane, 5 parts of nitromethane and 5 parts of acetonitrile were added in sequence, the stirring speed was 300-500 rpm, and the mixture was mixed for 30 minutes; S5. Compounding and dispersion: Add the activated adsorbent to a high shear mixer, slowly add the dispersant while stirring, and continue stirring for 60 minutes; add the surfactant and continue stirring for 30 minutes; and homogenize the mixture using a high-pressure homogenizer; S6. Filling and adding propellant: inject the compounded flaw detection agent main agent into the pressure-resistant container through the filter device and seal it with a pressure cap; use a quantitative filling machine to inject tetrafluoroethane into the container; S7. Finished product inspection: Products are randomly sampled from each batch for sensitivity test, flammability test and corrosion test.

2. The method for preparing the fuel nondestructive flaw detection agent according to claim 1, characterized in that: Step S2 includes the following steps: S21. Raw material preparation: Confirm that the talc powder to be crushed has completed drying pretreatment and has a moisture content of ≤0.1%; S22, parameter setting: input the target particle size parameters into the system, set the target particle size range to 2-10μm, D90 value ≤10μm; set the initial crushing pressure parameter to 0.8-1.0MPa, and the grinding time to 150 minutes; S23, pulverizing operation: start the high-pressure gas supply system and adjust the gas pressure to a stable state; start the airflow pulverizer, start the feeding device, and slowly and evenly feed the talcum powder into the pulverizer feed port; start the ultrasonic vibrating screen and the dynamic image analyzer to collect particle images of the material at the pulverizer outlet; S24, real-time monitoring and automatic adjustment; S25, end of operation: when the grinding time reaches 150 minutes, or the material particle size has been stably tested to reach the target range, stop feeding talcum powder into the grinder; S26. Data recording: record key parameters and operating data.

3. The method for preparing the fuel nondestructive flaw detection agent according to claim 2, characterized in that: Step S24 includes the following steps: S24.

1. The particle size sensor monitors the material particle size data in real time and compares and analyzes it with the preset target particle size parameters. If the particle size deviates from the target range, the system automatically adjusts the pressure parameters of the air flow mill to optimize the pulverization effect by controlling the flow rate and pressure of the high-pressure gas. S24.

2. The ultrasonic vibrating screen screens the pulverized material in real time. Material that fails to pass the 3000-mesh screen is automatically returned to the pulverizer feed port for further pulverization. S24.

3. Dynamic image analyzer continuously collects images of material particle morphology and analyzes particle shape and size distribution information; S24.

4. The control system automatically adjusts the crushing parameters based on the feedback information from the dynamic image analyzer and the data from the particle size sensor after comprehensive judgment.

4. The method for preparing the fuel nondestructive flaw detection agent according to claim 1, characterized in that: Step S3 includes the following steps: S31, conveying the crushed talcum powder to the feed port of the classifier, turning on the air classifier, and starting the classifying impeller and air supply system; S32, the laser particle size analyzer built into the classifier continuously detects the particle size of the passing material; S33, adaptive adjustment: automatically adjust the air flow velocity and classifying impeller speed of the classifier according to the detection results of the laser particle size analyzer; S34, target particle collection: collect particles between 2-10 μm as qualified activated adsorbents; S35, intelligent sorting and return: For materials that do not meet the particle size requirements, the intelligent sorting system automatically identifies and sorts them out, and returns the sorted unqualified materials to the crushing process through the conveyor device; S36, particle size distribution test: Conduct detailed particle size distribution test on the collected qualified products; S37, end of operation: when the grading of a batch of products is completed, stop feeding.

5. The method for preparing the fuel nondestructive flaw detection agent according to claim 1, characterized in that: Step S4 includes the following steps: S41. Raw material preparation: prepare 30 parts of mineral oil, 60 parts of trichloroethane, 5 parts of nitromethane, and 5 parts of acetonitrile; prepare antioxidant and stabilizer; S42, dispersant preparation; S43. Stability test: Transfer the mixed solution to a stability test tank via a pipeline. Seal the test tank and place it in a constant temperature and constant light environment. Immediately after the transfer, take a 50 ml sample and centrifuge it at 3000 rpm for 30 minutes. Observe the bottom of the centrifuge tube for any precipitation or stratification. S43.

3. Long-term stability observation: Observe the liquid state in the test tank every 6 hours and record any phase separation, discoloration, or turbidity. After 24 hours, take another sample for infrared spectroscopy analysis and density testing. S44. Quality confirmation records: record each infrared spectrum test result, centrifugal test phenomenon, temperature and light data.

6. The method for preparing the fuel nondestructive flaw detection agent according to claim 5, characterized in that: Step S42 includes the following steps: S42.

1. Add the following materials in order: Start the cooling water supply to the reactor jacket and start the variable frequency agitator at 300 rpm. Using a metering pump, add the following: 30 parts mineral oil, 60 parts trichloroethane, and stir for 10 minutes; then add 5 parts nitromethane and stir for 5 minutes; then add 5 parts acetonitrile and stir for 5 minutes. S42.

2. Mixing process control: Increase the stirring speed to 500 rpm and continue mixing for 30 minutes; S42.

3. Addition of additives: After mixing for 15 minutes, add antioxidant via a micro syringe while stirring. After mixing for 25 minutes, add stabilizer and continue stirring for 10 minutes.

7. The method for preparing the fuel nondestructive flaw detection agent according to claim 1, characterized in that: Step S5 includes the following steps: S51. Mixing talcum powder and dispersant: Establish a vacuum environment, turn on the vacuum degassing function of the high shear mixer, increase the vacuum degree in the tank to 0.08 MPa, start the planetary agitator, set the speed to 500 rpm, and slowly add 58 parts of talcum powder via the screw conveyor. After the talcum powder is completely added, increase the speed to 800 rpm and simultaneously add 240 parts of dispersant at a uniform rate via the metering pump. The addition process continues for 20 minutes. Monitor the torque sensor data in real time: S52, surfactant addition and ultrasonic-assisted dispersion: Turn off the vacuum system, reduce the speed to 300 rpm, and add two parts of DuPont FSN-100 through the feed port; turn on the ultrasonic device, set the power to 400 W, the frequency to 25 kHz, and the action time to 30 minutes; S53, homogenization; S54, Abnormal handling: timely handle the problem of insufficient dispersion and agglomeration after homogenization; S55, end of operation: turn off the high-pressure homogenizer and discharge the residual material.

8. The method for preparing the fuel nondestructive flaw detection agent according to claim 7, characterized in that: Step S53 includes the following steps: S53.1, High pressure homogenizer parameter setting: S53.1.1, Pressure and Circulation Control: First cycle: the pressure is set to 30 MPa and the flow rate is controlled at 50 L / h; Secondary circulation: the pressure is increased to 40 MPa to further break up the agglomerates; Three cycles: the pressure is set at 50MPa to ensure uniform particle size of the material; S53.1.2, Dynamic pressure compensation: When the system pressure fluctuation exceeds ±2%, the dynamic compensation system automatically adjusts the homogenizing valve opening; S53.

2. Monitoring of homogenization process: record homogenization pressure and flow data every 5 minutes; conduct particle size and viscosity tests; after three cycles, stop the machine and take samples.

9. A fuel nondestructive flaw detection agent prepared using the method for preparing a fuel nondestructive flaw detection agent according to claim 1, characterized in that: The material components include: activated adsorbent, dispersant, surfactant and propellant; The proportion of each material component is: activated adsorbent: dispersant: surfactant: propellant ＝58:240:2:200。 10. The fuel non-destructive flaw detection agent according to claim 9, characterized in that: The activated adsorbent is talcum powder; the surfactant is DuPont FSN-100; the dispersant is a mixture of mineral oil, trichloroethane, nitromethane and acetonitrile, with a mixing ratio of 30:60:5:5; the propellant is tetrafluoroethane, and the added amount is 200 grams.

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