Lead and bismuth removal cleaning solution and its preparation method, usage method of lead and bismuth removal cleaning solution, lead and bismuth removal cleaning system

Abstract

This application relates to a lead-bismuth removal cleaning solution, its preparation method, its application method, and its cleaning system. The lead-bismuth removal cleaning solution provided in this application has low volume fractions of hydrogen peroxide and acetic acid, making it mild and safe. Furthermore, by rationally proportioning the volume fractions of hydrogen peroxide and acetic acid, the solution can accelerate the dissolution of lead and bismuth. Moreover, the weakly acidic nature of the solution can prevent excessive corrosion of the materials being cleaned, thus ensuring their roughness and achieving a good lead-bismuth removal effect.

Description

Technical Field

[0001] This invention relates to the field of surface treatment technology for metal alloy materials, specifically to a lead-bismuth removal cleaning solution and its preparation method, a method for using the lead-bismuth removal cleaning solution, and a lead-bismuth removal cleaning system. Background Technology

[0002] Liquid eutectic lead-bismuth alloy (LBE) is a candidate material for coolant and spallation target in advanced design systems (ADS) due to its good neutronics properties, low melting point, high boiling point, high thermal conductivity and strong chemical inertness.

[0003] However, the high temperature, high flow rate, and high density of LBE can adhere to stainless steel, causing corrosion to the reactor structure and reducing its load-bearing capacity. In severe cases, it can even endanger the safety of the reactor. Currently, the removal of lead bismuth adhering to stainless steel mainly uses high-concentration (volume fraction > 35%) cleaning solutions. These chemical solutions are not environmentally friendly and can cause pollution. Summary of the Invention

[0004] Based on this, this application provides a lead-bismuth removal cleaning solution, its preparation method, its application method, and a lead-bismuth removal cleaning system. The lead-bismuth removal cleaning solution provided in this application has a low concentration, is environmentally friendly, and has good cleaning effect.

[0005] A first aspect of this application provides a lead-bismuth removal cleaning solution, comprising a solvent and hydrogen peroxide in a volume fraction of 1% to 5% and acetic acid in a volume fraction of 1.2% to 7% in the solvent.

[0006] In one embodiment, the volume fraction ratio of the hydrogen peroxide to the acetic acid is 1:(1~1.5).

[0007] A second aspect of this application provides a method for preparing the lead-bismuth removal cleaning solution according to any embodiment of the first aspect of this application, comprising the following steps:

[0008] The lead-bismuth removal cleaning solution is prepared by mixing the hydrogen peroxide and acetic acid with a solvent according to volume fractions.

[0009] A third aspect of this application provides a method for using the lead-bismuth removal cleaning solution described in any embodiment of the first aspect of this application, comprising the following steps:

[0010] The material to be cleaned is immersed in the lead and bismuth removal cleaning solution, and cavitation bubbles are applied to the material to be cleaned using a cavitation jet process.

[0011] In one embodiment, the specific parameters of the cavitation jet process include: jet pressure of 10MPa~30MPa and jet distance of 20mm~50mm.

[0012] In one embodiment, the material to be cleaned is stainless steel.

[0013] A fourth aspect of this application provides a lead-bismuth removal cleaning system, comprising:

[0014] A cleaning apparatus for containing the lead-bismuth removal cleaning solution and the material to be cleaned as described in any embodiment of the first aspect of this application; and

[0015] A nozzle assembly is disposed inside the cleaning device and below the liquid surface of the lead-bismuth removal cleaning solution; it is used to apply cavitation bubbles to the material to be cleaned.

[0016] In one embodiment, the nozzle assembly includes:

[0017] The inlet section is used to introduce high-pressure water;

[0018] The outlet section is used to apply cavitation bubbles to the material to be cleaned;

[0019] The chamber section connects the inlet section and the outlet section; it is used to accelerate and depressurize the high-pressure water to generate the cavitation bubble.

[0020] In one embodiment, the lead-bismuth removal cleaning system further includes:

[0021] A high-pressure water inlet assembly includes a hydraulic pump and an overflow valve connected in sequence; the hydraulic pump is used to output high-pressure water; the overflow valve is connected to the inlet section pipe of the nozzle assembly, and the overflow valve is used to regulate the pressure of the high-pressure water.

[0022] In one embodiment, the lead-bismuth removal cleaning system further includes:

[0023] A nozzle moving stage, disposed outside the cleaning device, is used to move the nozzle assembly; and

[0024] A nozzle holder for holding the nozzle assembly and connecting it to the nozzle moving stage.

[0025] In one embodiment, the cleaning device includes:

[0026] A cleaning tank is used to contain the lead-bismuth removal cleaning solution and the material to be cleaned as described in any embodiment of the first aspect of this application; and

[0027] A material holder is disposed on the wall of the cleaning tank for fixing and holding the cleaning material.

[0028] The lead-bismuth removal cleaning solution provided in this application has a low volume fraction of hydrogen peroxide and acetic acid, which makes it mild and safe. At the same time, the lead-bismuth removal cleaning solution of this application can accelerate the dissolution of lead and bismuth by reasonably proportioning the volume fractions of hydrogen peroxide and acetic acid. Furthermore, the weakly acidic lead-bismuth removal cleaning solution can avoid excessive corrosion of the material to be cleaned, thereby ensuring its roughness and achieving a good lead-bismuth cleaning effect. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the lead-bismuth removal cleaning system provided in this application;

[0030] Figure 2 This is a schematic diagram of the nozzle assembly provided in this application.

[0031] In the diagram, 10-cleaning device; 101-cleaning tank; 102-material holder for cleaning; 20-material to be cleaned; 30-nozzle assembly; 301-inlet section; 302-chamber section; 303-outlet section; 40-nozzle moving platform; 50-nozzle holder; 60-high-pressure water inlet assembly; 601-hydraulic pump; 602-relief valve; 603-motor; 604-pressure gauge; 70-water storage assembly; 701-filter; 702-water storage tank. Detailed Implementation

[0032] The following detailed description, in conjunction with specific embodiments, provides a more complete and clear account of the lead-bismuth removal cleaning solution, its preparation method, its application method, and its cleaning system. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0034] In this article, "one or more" refers to any one, two or more of the listed items.

[0035] In this application, terms such as "first aspect," "third aspect," "fourth aspect," and "fifth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," "fourth," and "fifth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0036] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0037] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0038] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0039] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0040] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows for temperature fluctuations within the precision range controlled by the instrument.

[0041] In this application, "cavitation" refers to the phenomenon where a liquid undergoes a local pressure reduction during flow, and when the liquid pressure is less than its local saturated vapor pressure, the liquid locally vaporizes and turns into gas.

[0042] A first aspect of this application provides a lead-bismuth removal cleaning solution, comprising a solvent and hydrogen peroxide in a volume fraction of 1% to 5% and acetic acid in a volume fraction of 1.2% to 7% in the solvent.

[0043] Understood, in this application, the volume fraction of hydrogen peroxide can be selected from any value between 1% and 5%. Specifically, the volume fraction of hydrogen peroxide includes, but is not limited to, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%. The volume fraction of acetic acid can be selected from any value between 1.2% and 7%. Specifically, the volume fraction of acetic acid includes, but is not limited to, 1.2%, 1.5%, 1.8%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, or 7%.

[0044] The lead-bismuth removal cleaning solution provided in this application has a low volume fraction of hydrogen peroxide and acetic acid, which makes it mild and safe. At the same time, the lead-bismuth removal cleaning solution of this application can accelerate the dissolution of lead and bismuth by reasonably proportioning the volume fractions of hydrogen peroxide and acetic acid. Furthermore, the weakly acidic lead-bismuth removal cleaning solution can avoid excessive corrosion of the material to be cleaned, thereby ensuring its roughness and achieving a good lead-bismuth cleaning effect.

[0045] In one example, the volume fraction ratio of hydrogen peroxide to acetic acid is 1:(1~1.5). It is understood that the volume fraction ratio of hydrogen peroxide to acetic acid can be selected from any value between 1:(1~1.5). Specifically, the volume fraction ratio of hydrogen peroxide to acetic acid includes, but is not limited to, 1:1, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, or 1:5.

[0046] In one example, the solvent is water.

[0047] A second aspect of this application provides a method for preparing the lead-bismuth removal cleaning solution according to any embodiment of the first aspect of this application, comprising the following steps:

[0048] The lead-bismuth removal cleaning solution is prepared by mixing the hydrogen peroxide and acetic acid with a solvent according to volume fractions.

[0049] In one example, the mixing temperature is 30°C to 35°C. Understandably, the preparation temperature can be any value between 30°C and 35°C. Specifically, the preparation temperature includes, but is not limited to, 30°C, 31°C, 32°C, 33°C, 34°C, or 35°C.

[0050] Understandably, the above preparation method can also be used to prepare a mixture at the preparation temperature; the mixture can then be further diluted to prepare the lead-bismuth removal cleaning solution described in the first aspect of this application.

[0051] A third aspect of this application provides a method for using the lead-bismuth removal cleaning solution described in any example of the first aspect of this application, comprising the following steps:

[0052] The material to be cleaned is immersed in the lead and bismuth removal cleaning solution, and cavitation bubbles are applied to the material to be cleaned using a cavitation jet process.

[0053] In one example, the specific parameters of the cavitation jet process include: jet pressure of 10MPa~30MPa and jet distance of 20mm~50mm.

[0054] Understandably, the "jet pressure" mentioned in this application refers to the pressure range at the point of release of the air-bubble-containing medium, rather than the pressure range reaching the surface of the material to be cleaned. Specifically, the jet pressure can be any value between 10 MPa and 30 MPa. Specifically, the jet pressure includes, but is not limited to, 10 MPa, 12 MPa, 15 MPa, 18 MPa, 20 MPa, 22 MPa, 25 MPa, 28 MPa, or 30 MPa. The "jet distance" mentioned in this application refers to the distance between the location of the release of the air-bubble-containing medium and the surface of the material to be cleaned. Specifically, the jet distance includes, but is not limited to, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, or 50 mm.

[0055] Preferably, the specific parameters of the cavitation jet process include: jet pressure of 18MPa~25MPa and jet distance of 20mm~30mm.

[0056] In one example, the cavitation jet duration is 5 to 10 minutes. Preferably, the cavitation jet duration is 7 to 8 minutes.

[0057] In one example, the material to be cleaned is stainless steel.

[0058] Traditional lead and bismuth removal cleaning technologies mainly include mechanical cleaning, chemical cleaning, and ultrasonic cleaning. Mechanical cleaning mainly uses manual grinding, scraping, and wiping methods, which are time-consuming and labor-intensive, and the surface finish after cleaning is low. The biggest problem with chemical cleaning is that it will cause environmental pollution, as high-concentration chemical solutions are not environmentally friendly. Ultrasonic cleaning has low energy utilization, and its main energy is lost in the form of heat, causing the system to heat up.

[0059] Based on this, please refer to Figure 1 A fourth aspect of this application provides a lead-bismuth removal cleaning system, comprising:

[0060] Cleaning apparatus 10 is used to contain the lead-bismuth removal cleaning solution and the material to be cleaned 20 as described in any example of the first aspect of this application; and

[0061] The nozzle assembly 30 is disposed inside the cleaning device and below the liquid surface of the lead-bismuth removal cleaning solution; it is used to apply cavitation bubbles to the material to be cleaned.

[0062] Please see Figure 2 In one example, the nozzle assembly 30 includes:

[0063] Inlet section 301 is used to introduce high-pressure water;

[0064] Outlet section 302 is used to apply cavitation bubbles to the material to be cleaned;

[0065] The chamber section 303 connects the inlet section 301 and the outlet section 302; it is used to accelerate and depressurize the high-pressure water to generate cavitation bubbles. Preferably, the nozzle assembly 30 is a pike-shrimp cavitation nozzle. In this case, the high-pressure water accelerates and depressurizes after passing through the chamber section of the pike-shrimp cavitation nozzle. When the liquid pressure decreases below the local saturated vapor pressure, cavitation occurs. After the cavitation jet flows through the outlet section, it acts on the surface of the workpiece. The cavitation effect caused by the collapse of the cavitation bubble acts on the lead-bismuth alloy adhesion layer on the surface of the workpiece, eventually causing the adhered lead-bismuth alloy to break and fall off.

[0066] In one example, the lead-bismuth removal cleaning system further includes:

[0067] A nozzle moving stage 40, disposed outside the cleaning device 10, is used to move the nozzle assembly 30; and

[0068] Nozzle holder 50 is used to hold the nozzle assembly 30 and is connected to the nozzle moving stage 40.

[0069] In one example, the cleaning device 10 includes:

[0070] Cleaning tank 101 is used to contain the lead-bismuth removal cleaning solution as described in any example of the first aspect of this application and the material 20 to be cleaned; and

[0071] A material holder 102 is disposed on the wall of the cleaning tank for fixing and holding the material 20 to be cleaned. In the specific cleaning steps, the material 20 to be cleaned is fixed by the material holder 102, and a lead-bismuth removal cleaning solution containing 1%~5% hydrogen peroxide and 1.2%~7% acetic acid (by volume) is added to the cleaning tank 101. Simultaneously, to facilitate cavitation bubble formation, it is necessary to ensure that both the nozzle assembly 30 and the material to be cleaned in the cleaning tank 101 are below the surface of the lead-bismuth removal cleaning solution. The nozzle holder 50 is used to hold the nozzle assembly 30 and is connected to the nozzle moving stage 40 located outside the cleaning device 10. In this way, the external nozzle moving stage 40 can move the nozzle assembly 30 in the x, y and z directions through the nozzle holder 50 so that the jet can cover all the areas to be cleaned on the surface of the material to be cleaned. At the same time, it is also convenient to adjust the target distance between the nozzle assembly 30 and the surface of the material to be cleaned, so as to adjust the jet distance and make the collapse of cavitation bubbles occur on the surface of the material to be cleaned. The cavitation effect is used to decompose the lead-bismuth alloy on the surface of the material to be cleaned, thereby improving the cleaning effect.

[0072] In one example, the lead-bismuth removal cleaning system further includes:

[0073] A high-pressure water inlet assembly 60 includes a hydraulic pump 601 and an overflow valve 602 connected in sequence. The hydraulic pump 601 outputs high-pressure water. The overflow valve 602 is connected to the inlet section of the nozzle assembly 30 and is used to regulate the pressure of the high-pressure water. Understandably, the hydraulic pump 601 can also be electrically connected to a motor 603, which provides mechanical energy to the hydraulic pump 601.

[0074] In one specific example, the high-pressure water introduction component 60 further includes:

[0075] A pressure gauge 604 is positioned between the overflow valve 602 and the inlet section of the nozzle assembly 30, and is used to monitor the pressure value of the high-pressure water. The high-pressure water inlet assembly 60 includes a hydraulic pump 601, an overflow valve 602, and a pressure gauge 604 connected in sequence via pipes. The pressure gauge 604 is connected to the inlet section of the nozzle assembly 30. In the specific cleaning process, a motor 603 provides mechanical energy to the hydraulic pump 601, enabling it to pump water and output high-pressure water. The high-pressure water flows through pipes sequentially through the overflow valve 602 and the pressure gauge 604, and the pressure reaching the inlet section of the nozzle assembly 30 is regulated by the motor 603 and the overflow valve 602.

[0076] In one example, the lead-bismuth removal cleaning system further includes:

[0077] A water storage assembly 70 includes a filter 701 and a water storage tank 702 connected in sequence; the filter 701 is used to filter water, and the water storage tank 702 is used to store the filtered water. A hydraulic pump 601 in the high-pressure water inlet assembly 60 draws water from the water storage tank 702 and outputs high-pressure water.

[0078] In one more specific example, the cleaning method for the material to be cleaned includes the following steps:

[0079] S10. Prepare a lead-bismuth removal cleaning solution, wherein the lead-bismuth removal cleaning solution comprises 1% to 5% hydrogen peroxide and 1.2% to 7% acetic acid by volume, and control the temperature of the lead-bismuth removal cleaning solution to be 30°C to 35°C.

[0080] S20. Fix the material to be cleaned 20 using the material holder 102, and add the lead-bismuth removal cleaning solution prepared in step S10 into the cleaning tank 101. Simultaneously, to ensure the formation of cavitation bubbles, it is necessary to ensure that both the nozzle assembly 30 and the material to be cleaned in the cleaning tank 101 are below the surface of the lead-bismuth removal cleaning solution.

[0081] S30. After being filtered by filter 701, the water flows into water storage tank 702. Motor 603 acts as a prime mover to input mechanical energy into hydraulic pump 601. The hydraulic pump draws water from water storage tank 702 and converts the mechanical energy into the pressure energy of the water flow. The high-pressure water flows through the pipeline in sequence through overflow valve 602 and pressure gauge 604, and finally flows into the inlet section of nozzle assembly 30. Adjusting the frequency converter of motor 603 and overflow valve 602 controls the inlet pressure of nozzle assembly 30.

[0082] S40. The nozzle holder 50 is used to hold the nozzle assembly 30 and is connected to the nozzle moving stage 40 located outside the cleaning device 10, so that the external nozzle moving stage 40 can move the nozzle assembly 30 in the x, y and z directions through the nozzle holder 50, so that the jet can cover all the areas to be cleaned on the surface of the material to be cleaned; at the same time, the target distance between the nozzle assembly 30 and the surface of the material to be cleaned is adjusted.

[0083] S50. Remove the material to be cleaned, observe the surface morphology, and evaluate the cleaning effect.

[0084] In the above-mentioned cleaning methods, the combination of chemical cleaning and cavitation jet cleaning is beneficial for the decomposition of lead and bismuth, thus enhancing the cleaning effect. Simultaneously, cavitation jet cleaning causes the collapse of cavitation bubbles to occur on the surface of the material to be cleaned, allowing for excellent cleaning results even with a low volume fraction of lead and bismuth removal cleaning solution. Furthermore, the cleaning method provided in this application is simple to operate, has good cleaning effect, high cleaning efficiency, and low environmental pollution.

[0085] The following are specific embodiments. Unless otherwise specified, the raw materials used in the embodiments are all commercially available.

[0086] Example 1

[0087] Example 1 provides a lead and bismuth removal cleaning solution and its cleaning method, including the following steps:

[0088] (1) Select a 30% hydrogen peroxide solution and a 40% acetic acid solution by volume, add them to warm water to prepare a mixture; the temperature of the mixture is 35℃.

[0089] (2) Place the stainless steel workpiece to be cleaned in the mixture prepared in step (1), inject an appropriate amount of clean water into the cleaning tank, and prepare the cleaning solution; make the volume fraction of hydrogen peroxide in the cleaning solution 1% and the volume fraction of acetic acid 1.33%. Cover the nozzle assembly used to generate the jet with the cleaning solution to form an artificial submersion condition.

[0090] (3) Tap water from the water source flows through the filter into the water storage tank. The motor acts as the prime mover, inputting mechanical energy into the hydraulic pump. The hydraulic pump draws water from the water storage tank, converting the mechanical energy into the pressure energy of the water flow. The high-pressure water flows into the cavitation nozzle through the main pipeline. There is an overflow valve and a pressure gauge on the main pipeline. Adjusting the frequency converter of the motor and the overflow valve controls the nozzle inlet pressure to 17.5 MPa.

[0091] (4) Adjust the movement of the nozzle moving stage to change the distance between the nozzle assembly and the stainless steel workpiece surface, i.e. the target distance, so that the target distance is 35 mm; keep the target distance so that the cavitation jet of the nozzle assembly can act on the stainless steel workpiece surface for a period of time, the duration of which is 10 min.

[0092] (5) Remove the stainless steel workpiece and evaluate the cleaning effect.

[0093] Example 2

[0094] Example 2 provides a lead and bismuth removal cleaning solution and its cleaning method, including the following steps:

[0095] (1) Select a 30% hydrogen peroxide solution and a 40% acetic acid solution by volume, add them to warm water to prepare a mixture; the temperature of the mixture is 35℃.

[0096] (2) Place the stainless steel workpiece to be cleaned in the mixture prepared in step (1), inject an appropriate amount of clean water into the cleaning tank, and prepare the cleaning solution; make the volume fraction of hydrogen peroxide in the cleaning solution 5% and the volume fraction of acetic acid 6.67%. Cover the nozzle assembly used to generate the jet with the cleaning solution to form an artificial submersion condition.

[0097] (3) Tap water from the water source flows through the filter into the water storage tank. The motor acts as the prime mover, inputting mechanical energy into the hydraulic pump. The hydraulic pump draws water from the water storage tank, converting the mechanical energy into the pressure energy of the water flow. The high-pressure water flows into the cavitation nozzle through the main pipeline. There is an overflow valve and a pressure gauge on the main pipeline. Adjusting the frequency converter of the motor and the overflow valve controls the nozzle inlet pressure to 17.5 MPa.

[0098] (4) Adjust the movement of the nozzle moving stage to change the distance between the nozzle assembly and the stainless steel workpiece surface, i.e. the target distance, so that the target distance is 35 mm; keep the target distance so that the cavitation jet of the nozzle assembly can act on the stainless steel workpiece surface for a period of time, the duration of which is 10 min.

[0099] (5) Remove the stainless steel workpiece and evaluate the cleaning effect.

[0100] Example 3

[0101] Example 3 provides a lead and bismuth removal cleaning solution and its cleaning method, including the following steps:

[0102] (1) Select a 30% hydrogen peroxide solution and a 40% acetic acid solution by volume, add them to warm water to prepare a mixture; the temperature of the mixture is 35℃.

[0103] (2) Place the stainless steel workpiece to be cleaned in the mixture prepared in step (1), inject an appropriate amount of clean water into the cleaning tank, and prepare the cleaning solution; make the volume fraction of hydrogen peroxide in the cleaning solution 1% and the volume fraction of acetic acid 1.33%. Cover the nozzle assembly used to generate the jet with the cleaning solution to form an artificial submersion condition.

[0104] (3) Tap water from the water source flows through the filter into the water storage tank. The motor acts as the prime mover, inputting mechanical energy into the hydraulic pump. The hydraulic pump draws water from the water storage tank, converting the mechanical energy into the pressure energy of the water flow. The high-pressure water flows into the cavitation nozzle through the main pipeline. There is an overflow valve and a pressure gauge on the main pipeline. Adjusting the frequency converter of the motor and the overflow valve controls the nozzle inlet pressure to 20 MPa.

[0105] (4) Adjust the movement of the nozzle moving stage to change the distance between the nozzle assembly and the stainless steel workpiece surface, i.e. the target distance, so that the target distance is 30 mm; keep the target distance so that the cavitation jet of the nozzle assembly can act on the stainless steel workpiece surface for a period of time, with a duration of 8 min.

[0106] (5) Remove the stainless steel workpiece and evaluate the cleaning effect.

[0107] Example 4

[0108] Example 4 provides a lead and bismuth removal cleaning solution and its cleaning method, including the following steps:

[0109] (1) Prepare a lead and bismuth removal cleaning solution with an acetic acid volume fraction of 1% and a hydrogen peroxide volume fraction of 1.33%.

[0110] (2) Place the stainless steel workpiece to be cleaned in the lead-bismuth removal cleaning solution prepared in step (1). Cover the nozzle assembly used to generate the jet with the lead-bismuth removal cleaning solution to create an artificial submersion condition.

[0111] (3) Tap water from the water source flows through the filter into the water storage tank. The motor acts as the prime mover, inputting mechanical energy into the hydraulic pump. The hydraulic pump draws water from the water storage tank, converting the mechanical energy into the pressure energy of the water flow. The high-pressure water flows into the cavitation nozzle through the main pipeline. There is an overflow valve and a pressure gauge on the main pipeline. Adjusting the frequency converter of the motor and the overflow valve controls the nozzle inlet pressure to 8MPa.

[0112] (4) Adjust the movement of the nozzle moving stage to change the distance between the nozzle assembly and the stainless steel workpiece surface, i.e. the target distance, so that the target distance is 60 mm; keep the target distance so that the cavitation jet of the nozzle assembly can act on the stainless steel workpiece surface for a period of time, the duration of which is 10 min.

[0113] (5) Remove the stainless steel workpiece and evaluate the cleaning effect.

[0114] Comparative Example 1

[0115] Comparative Example 1 provides a lead and bismuth removal cleaning solution and a cleaning method thereof, comprising the following steps:

[0116] (1) Prepare a lead and bismuth removal cleaning solution with an acetic acid volume fraction of 10% and a hydrogen peroxide volume fraction of 15%.

[0117] (2) Place the stainless steel workpiece to be cleaned in the lead-bismuth removal cleaning solution prepared in step (1). Cover the nozzle assembly used to generate the jet with the lead-bismuth removal cleaning solution to create an artificial submersion condition.

[0118] (3) Tap water from the water source flows through the filter into the water storage tank. The motor acts as the prime mover, inputting mechanical energy into the hydraulic pump. The hydraulic pump draws water from the water storage tank, converting the mechanical energy into the pressure energy of the water flow. The high-pressure water flows into the cavitation nozzle through the main pipeline. There is an overflow valve and a pressure gauge on the main pipeline. Adjusting the frequency converter of the motor and the overflow valve controls the nozzle inlet pressure to 17.5 MPa.

[0119] (4) Adjust the movement of the nozzle moving stage to change the distance between the nozzle assembly and the stainless steel workpiece surface, i.e. the target distance, so that the target distance is 35 mm; keep the target distance so that the cavitation jet of the nozzle assembly can act on the stainless steel workpiece surface for a period of time, the duration of which is 10 min.

[0120] (5) Remove the stainless steel workpiece and evaluate the cleaning effect. Test method: Remove the stainless steel workpiece after cleaning in the examples and comparative examples, measure the 3D micromorphology of the workpiece surface using a three-dimensional profile measuring instrument to observe the surface roughness of the stainless steel workpiece, and obtain the surface roughness by the linear roughness method; identify and calculate the cavitation area by performing grayscale, binarization and morphological processing on the micromorphology images; and test the weight change of the stainless steel workpiece before and after cleaning, and calculate the lead bismuth removal rate by the weight change of the lead bismuth.

[0121] The corresponding test results are shown in Table 1:

[0122] Table 1

[0123]

[0124] As shown in Table 1, in Examples 1 to 3 of this application, the surface roughness of the workpiece after cleaning is 0.971 to 1.272, indicating that the cleaning solution and cleaning method provided in this application cause low damage to the workpiece. Simultaneously, the lead and bismuth removal rate is high, and there is a large cavitation area, indicating that the cleaning solution and cleaning method provided in this application cover a large area in a single treatment. Further, in the cleaning method provided in Example 4 of this application, the inlet pressure is low and the target distance is large, resulting in a low lead and bismuth removal rate. In this case, to improve the lead and bismuth removal rate on the workpiece surface, it is only necessary to further increase the cleaning duration. In Example 3 of this application, by optimizing the concentration of the cleaning solution and the cleaning process parameters, the surface roughness of the workpiece after cleaning is low, and the lead and bismuth removal rate is the highest, demonstrating excellent cleaning effect. Simultaneously, it has a large cavitation area, maximizing the coverage area in a single treatment. Comparative Example 1 did not use the cleaning solution provided in this application, and the surface roughness of the workpiece after cleaning was 6.018, indicating a high degree of damage to the workpiece.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method of using a lead bismuth removal cleaning solution, characterized by, Includes the following steps: The material to be cleaned is immersed in a lead and bismuth removal cleaning solution, and cavitation bubbles are applied to the material to be cleaned using a cavitation jet process. The lead-bismuth removal cleaning solution includes a solvent and hydrogen peroxide at a volume fraction of 1% to 5% and acetic acid at a volume fraction of 1.2% to 7% in the solvent; the volume fraction ratio of hydrogen peroxide to acetic acid is 1:(1 to 1.5). The parameters of the cavitation jet process include: jet pressure of 10MPa~30MPa, jet distance of 20mm~50mm, and cavitation jet time of 5min~10min.

2. The method of using a lead and bismuth removal cleaning solution according to claim 1, wherein, The preparation of the lead and bismuth removal cleaning solution includes the following steps: The lead-bismuth removal cleaning solution is prepared by mixing the hydrogen peroxide and acetic acid with a solvent according to volume fractions.

3. The method of using a lead and bismuth removal cleaning solution according to claim 1 or 2, wherein The material to be cleaned is stainless steel.

4. A lead-bismuth removal cleaning system, characterized in that, include: A cleaning apparatus for containing the lead-bismuth removal cleaning solution and the material to be cleaned in the method of using the lead-bismuth removal cleaning solution according to any one of claims 1 to 3; and A nozzle assembly is disposed inside the cleaning device and below the liquid surface of the lead-bismuth removal cleaning solution; it is used to apply cavitation bubbles to the material to be cleaned.

5. The lead-bismuth removal cleaning system according to claim 4, characterized in that, The nozzle assembly includes: The inlet section is used to introduce high-pressure water; The outlet section is used to apply cavitation bubbles to the material to be cleaned; The chamber section connects the inlet section and the outlet section; it is used to accelerate and depressurize the high-pressure water to generate the cavitation bubble.

6. The lead-bismuth removal cleaning system according to claim 5, characterized in that, Also includes: A high-pressure water inlet assembly includes a hydraulic pump and an overflow valve connected in sequence; the hydraulic pump is used to output high-pressure water; the overflow valve is connected to the inlet section pipe of the nozzle assembly, and the overflow valve is used to regulate the pressure of the high-pressure water.

7. The lead-bismuth removal cleaning system according to any one of claims 4 to 6, characterized in that, Also includes: A nozzle moving stage, located outside the cleaning device, is used to move the nozzle assembly; as well as A nozzle holder for holding the nozzle assembly and connecting it to the nozzle moving stage.

8. The lead-bismuth removal cleaning system according to any one of claims 4 to 6, characterized in that, The cleaning device includes: A cleaning tank is used to contain the lead-bismuth removal cleaning solution and the material to be cleaned in the method of using the lead-bismuth removal cleaning solution according to claim 1; and A material holder is disposed on the wall of the cleaning tank for fixing and holding the cleaning material.

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