Ultra-clean cleaning method for transmission system

Abstract

The invention discloses an ultra-clean cleaning method for a transmission system. The ultra-clean cleaning method comprises the following steps that a temporary circulation pipeline system is established to be connected with a to-be-cleaned pipeline; washing with water; degreasing and cleaning; discharging the liquid, adding chemicals to neutralize the degreasing liquid, and washing with water; adding chemicals for pickling; discharging the liquid, adding chemicals to neutralize the pickling solution, and washing with water; carrying out passivation; discharging the solution and adding chemicals to neutralize the passivation solution; high-purity water is used for flushing; washing with high-purity water until acceptance is qualified; and filling nitrogen and packaging. An exhaust valve is arranged at the highest point of the circulating pipeline system, a drain valve is arranged at the lowest point, and pressure and flow detection modules are configured; during cleaning, the exhaust valve is controlled to discharge regularly according to whether cleaning dead angles appear or not; according to whether a cleaning blind end appears, the drainage valve is controlled to discharge at regular time; according to the pressure and flow detection module, the flow speed during flushing and circulation is controlled, so that dead corners, blind ends and corners are treated and cleaned in a targeted mode, and the effect of cleaning an ultra-long and high-fall pipeline better is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline cleaning, and in particular to an ultra-clean cleaning method for a transmission system. Background Art

[0002] In some special industries such as basic physics research and aerospace, in order to strictly control the quality of products or experiments, the production or experimental systems must be cleaned with extremely high cleanliness requirements to eliminate the impact and interference of impurities on product quality or experimental data. We call this ultra-clean cleaning.

[0003] When cleaning a transmission system with an extra-long length and a high drop, such as a single pipeline with a length of about 1,700 meters and a drop of about 500 meters, the main technical problems are as follows:

[0004] 1) In order to fill the system to prevent cleaning dead corners and reduce scouring and corrosion at the bottom of the pipeline, theoretically, the cleaning liquid needs to be injected at a low level and discharged at a high level, so an ultra-clean pump with a head of more than 500 meters is required. Pumps that meet this requirement need to be customized, and the procurement cost is very high, which does not meet the requirements of engineering economy and efficiency. Therefore, the cleaning liquid can only be injected from the top of the pipeline, and the design adds a control system and process for the injection process to reduce scouring and corrosion at the bottom of the pipeline.

[0005] 2) Because the pipeline is too long, has turns, diameter changes, and drops, there is an uneven local flow rate, and the formulation of the agent and the cleaning time need to be considered comprehensively.

[0006] 3) Due to the height difference of 500 meters, the static pressure at the lower part of the pipeline is about 50 bar relative to the higher part. Will the surface roughness at the lower part be higher than that at the higher part? Summary of the invention

[0007] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an ultra-clean cleaning method for a transmission system, which can better clean ultra-long and high-drop pipelines, meet the cleaning cleanliness standard, and the surface roughness of the entire system Ra≤0.4um.

[0008] The ultra-clean cleaning method of the transmission system according to the first embodiment of the present invention comprises the following steps:

[0009] S1: Establish a temporary circulation pipeline system and connect it to the pipeline to be cleaned;

[0010] S2: water washing;

[0011] S3: adding chemicals for degreasing and cleaning, and controlling the normal circulation of the circulation pipeline system;

[0012] S4: draining the liquid and adding chemicals to neutralize the degreasing liquid, and washing with water until the pH value of the washing water reaches a first preset value;

[0013] S5: adding chemicals for pickling, and controlling the normal circulation of the circulation pipeline system;

[0014] S6: draining the liquid and adding chemicals to neutralize the pickling liquid, and washing with water until the pH value of the washing water reaches a second preset value;

[0015] S7: adding chemicals for passivation, and controlling the circulation pipeline system to circulate normally;

[0016] S8: draining and adding chemicals to neutralize the passivation liquid;

[0017] S9: Use high-purity water for open-circuit flushing until the pH value of the drainage reaches a third preset value, and then perform forward and reverse cycle flushing;

[0018] S10: The particle content in the water meets the acceptance criteria;

[0019] S11: After the inside of the pipeline is dried to the standard with high-purity nitrogen, the nitrogen filling port is temporarily sealed with a sealing film. Among them, the highest point of the circulation pipeline system is provided with an exhaust valve, the lowest point of the circulation pipeline system is provided with a shower valve, and the circulation pipeline system is equipped with a pressure detection module and a flow detection module; and during flushing, according to whether there is a gas blockage phenomenon to form a cleaning dead corner, the exhaust valve is controlled to discharge at a fixed time; according to whether there is a cleaning blind end, the shower valve is controlled to discharge at a fixed time; according to the values ​​of the pressure and flow detection modules, the flow rate during flushing and / or circulation is controlled.

[0020] The ultra-clean cleaning method of the transmission system according to the first aspect of the embodiment of the present invention has at least the following beneficial effects: ultra-clean cleaning is achieved by degreasing, pickling, passivation and high-purity water flushing, and at the same time, by appropriately controlling the exhaust valve, shower valve and cleaning flow rate, the cleaning dead corners, blind ends and bends are targetedly treated, thereby achieving better cleaning of extra-long and high-drop pipelines, meeting the cleaning cleanliness standards, and the surface roughness of the entire system Ra≤0.4um.

[0021] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method of performing S1 includes: connecting the pump system to the pipeline to be cleaned through a temporary pipeline to form a temporary circulation pipeline system, and hanging a monitoring sample tube in the circulation pipeline system for determining the cleaning status of each process.

[0022] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method for performing S2 includes: starting the cleaning pump, opening the valve, first checking the leakage, and flushing with water after confirming that there is no leakage point. The exhaust valve and the shower valve are discharged once every at least 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipeline to be cleaned has branches, switching and forward and reverse cycle cleaning are performed in turn.

[0023] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method of performing S3 includes: adding medicine for degreasing cleaning after leak testing, and ensuring the normal circulation of the system, switching the forward and reverse circulation by the valve during the circulation cleaning, the exhaust valve and the shower valve are discharged once every at least 20-40 minutes, and the discharge time is at least 2-5 minutes, and when the pipeline to be cleaned has branches, switching and forward and reverse circulation cleaning are performed in turn;

[0024] The method for performing S4 includes: after degreasing is completed, the degreasing agent is discharged to the neutralization tank with clean nitrogen or compressed air, the neutralization agent is added to the neutralization tank until the pH value in the neutralization tank is 6-9, and the neutralized cleaning waste liquid is discharged. When the pipeline to be cleaned has branches, the system branches are switched to discharge and neutralize in turn according to the above method;

[0025] Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, flush the inner wall of the pipe with water, and discharge the flushing water to the designated location until the pH of the flushing water is 6-920-40 minutes for 2-5 minutes.

[0026] Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, perform open-circuit flushing on the inner wall of the pipe. The flushing water is discharged directly to the designated location. When the drainage pH is 8, it can be switched to circulating flushing. During the circulating flushing, the valve switches between forward and reverse circulation. The exhaust valve and the shower valve discharge at least once every 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipe to be cleaned has branches, forward and reverse circulation flushing is performed in turn.

[0027] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method for performing S5 includes: calculating the circulation volume and the amount of medicine added according to the inner diameter and length of the pipeline to be cleaned, adding a pickling agent into the circulating cleaning tank to prepare a pickling solution, adding the pickling agent and circulating it in the system, switching the forward and reverse circulation through the valve during the circulation cleaning, the exhaust valve and the shower valve are discharged at least once every 20-40 minutes, and each discharge lasts at least 2-5 minutes, and when the pipeline to be cleaned has branches, switching and forward and reverse circulation flushing are performed in turn.

[0028] According to the ultra-clean cleaning method of the transmission system described in the first aspect of the present invention, the method of performing S6 includes:

[0029] After the pickling is completed, the pump station is adjusted to a self-circulating state, and the pickling agent in the system is discharged to the neutralization tank with clean nitrogen or compressed air. The neutralizing agent is added to the circulating neutralization tank until the pH in the neutralization tank reaches 6-9, and the neutralized cleaning waste liquid is discharged. When the pipeline to be cleaned has branches, the system branches are switched to discharge and neutralize in turn according to the above method;

[0030] Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, flush the inner wall of the pipe with water, and discharge the flushing water to a designated location until the pH of the flushing water is 6-9.

[0031] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method of performing S7 includes: adding a passivation agent into the circulating cleaning tank to prepare a passivation solution, the passivation agent is added and circulated in the system, and the valve is used to switch the forward and reverse circulation during the circulation cleaning. The exhaust valve and the shower valve are discharged once every at least 20-40 minutes, and the discharge time is at least 2-5 minutes. When the pipeline to be cleaned has branches, the forward and reverse circulation flushing is switched in turn;

[0032] The method for performing S8 includes: adjusting the pump station to a self-circulating state after the passivation is completed, discharging the passivation agent in the system to the neutralization tank with clean nitrogen or compressed air, adding a neutralizing agent to the circulating neutralization tank until the pH in the neutralization tank reaches 6-9, discharging the neutralized cleaning waste liquid, and when the pipeline to be cleaned has branches, switching the system branches in turn for discharge and neutralization according to the above method;

[0033] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method for performing S9 includes: opening a high-purity water source and starting a cleaning pump to perform circulation flushing on the inner wall of the pipeline, switching the forward and reverse circulation through the valve during the circulation flushing, the exhaust valve and the shower valve discharge once every at least 20-40 minutes, and each discharge lasts at least 2-5 minutes, and when the pipeline to be cleaned has branches, the forward and reverse circulation flushing is switched in turn, and when the pH value, turbidity and conductivity of the inlet and return liquids are the same, it can be switched to high-purity water open-circuit flushing, and the flushing water is directly discharged to a designated location.

[0034] According to the ultra-clean cleaning method for a transmission system described in an embodiment of the first aspect of the present invention, the method for performing S10 includes: after the high-purity water flushing is completed, detecting whether the particulate matter content in the water meets the acceptance standard.

[0035] According to the ultra-clean cleaning method of the transmission system described in the embodiment of the first aspect of the present invention, the method of performing S11 includes: after the water quality test is qualified, the connection port with the pump station is removed, a blind plate seal is installed on the pipeline interface not related to nitrogen drying, high-purity nitrogen is introduced into the pipeline to perform nitrogen drying, and the nitrogen filling port is temporarily sealed with a sealing film.

[0036] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0038] Figure 1 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0040] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] In the description of this application, "several" means one or more, "more" means at least two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0042] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application after combining the specific content of the technical solution.

[0043] Reference Figure 1The ultra-clean cleaning method of the transmission system of the first embodiment of the present application is applied to the ultra-clean cleaning of pipelines that are super long, have turns, have diameter changes, have drops, and have local flow rate imbalances. The ultra-clean cleaning method of the transmission system includes the following steps:

[0044] S1: Establish a temporary circulation pipeline system and connect it to the pipeline to be cleaned;

[0045] S2: water washing;

[0046] S3: Add chemicals for degreasing and cleaning, and control the normal circulation of the circulation pipeline system;

[0047] S4: draining the liquid and adding chemicals to neutralize the degreasing liquid, and washing with water until the pH value of the washing water reaches a first preset value;

[0048] S5: Add chemicals for pickling and control the normal circulation of the circulation pipeline system;

[0049] S6: draining the liquid and adding chemicals to neutralize the pickling liquid, and washing with water until the pH value of the washing water reaches a second preset value;

[0050] S7: Add chemicals for passivation and control the normal circulation of the circulation pipeline system;

[0051] S8: Drain the liquid and add chemicals to neutralize the passivation liquid.

[0052] S9: Use high-purity water for open-circuit flushing until the pH value of the drainage reaches a third preset value, and then perform forward and reverse cycle flushing;

[0053] S10: The particle content in the water meets the acceptance criteria;

[0054] S11: After the inside of the pipeline is dried to the standard with high-purity nitrogen, a sealing film is used to temporarily seal the nitrogen filling port.

[0055] Among them, an exhaust valve is provided at the highest point of the circulation piping system, and a shower valve is provided at the lowest point of the circulation piping system. The circulation piping system is configured with a pressure detection module and a flow detection module; and during flushing, the exhaust valve is controlled to discharge at a fixed time according to whether air blockage occurs to form a cleaning dead corner; the shower valve is controlled to discharge at a fixed time according to whether there is a cleaning blind end; and the flow rate during flushing and / or circulation is controlled according to the values ​​of the pressure detection module and the flow detection module.

[0056] Reference Figure 1The ultra-clean cleaning method of the transmission system of the first aspect of the present application realizes ultra-clean cleaning by degreasing, pickling, passivation and high-purity water flushing. At the same time, by appropriately controlling the exhaust valve, the shower valve and the cleaning flow rate, the cleaning dead corners, blind ends and bends are targetedly treated to achieve better cleaning of ultra-long and high-drop pipelines, meet the cleaning cleanliness standards, and the surface roughness of the entire system Ra≤0.4um.

[0057] It should be noted that before S1, it is necessary to manually clean the openings and flange surfaces of the cleaning pipeline, as well as the valves and gaskets involved in the circulation cleaning. The manual treatment methods include: manual scrubbing and degreasing → water flushing → manual scrubbing and pickling → water flushing → manual scrubbing and passivation → water flushing. A sealing film is provided at the connection between the circulation pipeline system and the pipeline to be cleaned for temporary sealing.

[0058] In some embodiments of the present application, the method of performing S1 includes: connecting the pump system to the pipeline to be cleaned through a temporary pipeline to form a temporary circulation pipeline system, and hanging a monitoring sample tube in the circulation pipeline system for determining the cleaning status of each process.

[0059] It is understandable that the establishment of a circulating piping system can prepare for chemical cleaning, and a monitoring sample tube can be hung in the system to monitor the cleaning effect in real time as a reference for determining the cleaning status of each process.

[0060] In some embodiments of the present application, the method for performing S2 includes: starting the cleaning pump, opening the valve, checking for leaks first, and flushing with water after confirming that there are no leaks. The exhaust valve and the shower valve are discharged at least once every 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipeline to be cleaned has branches, switching and forward and reverse cycle cleaning are performed in turn.

[0061] It is understandable that water flushing is used to remove dust, sand, particulate impurities and detached oxides that may be introduced during pipeline welding and installation, and to perform system pressure test and leak detection. It should be noted that the pressure of the temporary cleaning system is increased to about 1.2 times the pressure of the normal operation of the pump, and the leakage of the cleaning system is checked, and leak detection is sprayed with a spray bottle filled with leak detection liquid. The flushing water for open circuit flushing can be discharged directly, and the water outlet at the return liquid port is clear, and the water flushing work can be completed.

[0062] In some embodiments of the present application, the method for performing S3 includes: adding chemicals for degreasing and cleaning after leak testing, and ensuring the normal circulation of the system, switching the forward and reverse circulation through the valve during the circulation cleaning, the exhaust valve and the shower valve are discharged at least once every 20-40 minutes, and the discharge time is at least 2-5 minutes. When the pipeline to be cleaned has branches, alternate switching and forward and reverse circulation cleaning are performed.

[0063] It is understandable that degreasing can remove the residual oil in the pipe wall. When the test reaches the end point judgment standard, when the difference in alkali concentration between two tests within half an hour is less than 0.1%, the degreasing process can be ended. It should be noted that in order to prevent impurities in the raw materials from entering the system, when preparing the degreasing agent, first stir the degreasing agent evenly in the liquid preparation tank with warm water, filter out impurities through a 1μm filter bag, and then slowly add the filtered agent to the circulating cleaning tank.

[0064] More specifically, degreasing: prepare (0.5-1% NaOH + 0.5-1% NaCO3 + 0.1% OP-10) degreasing solution, and the total cleaning time is 2-3 hours, until the inner wall of the pipe mouth is wiped with a dust-free white cloth specially used in a Class 1000 clean room. The white cloth is not dirty, and there is no blue bright spot when detected by ultraviolet light, which means it is qualified.

[0065] In some embodiments of the present application, the method for performing S4 includes: after degreasing is completed, the degreasing agent is discharged to the neutralization tank with clean nitrogen or compressed air, a neutralizing agent is added to the neutralization tank until the pH value in the neutralization tank is 6-9, and the neutralized cleaning waste liquid is discharged. When the pipeline to be cleaned has branches, the system branches are switched to discharge and neutralize in turn according to the above method;

[0066] Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, flush the inner wall of the pipe with water, and discharge the flushing water to a designated location until the pH of the flushing water is 6-9.

[0067] It is understandable that neutralizing the degreasing liquid can facilitate waste liquid treatment, preferably using nitric acid for neutralization, draining the degreasing agent, and neutralizing the waste liquid to neutrality to end the degreasing liquid neutralization process. It should be noted that in order to deal with the heat release during neutralization, which may cause waste liquid overflow, chemical leakage, and environmental pollution, temporary cofferdams should be made in the cleaning pump station and raw material storage area, and quicklime, sand, etc. should be prepared to bury and absorb the overflow solution. During neutralization, the pump station should be kept in circulation and the drug should be added slowly to prevent the neutralization process from releasing heat too quickly and causing the waste liquid to overflow the tank.

[0068] It is understood that the water flushing after degreasing is used to remove the residual degreasing liquid left in the pipeline after degreasing. When the pH value of the return liquid is neutral, and the pH value, turbidity and conductivity of the inlet and return liquids are the same, the water flushing work can be ended and the acid cleaning step can be entered.

[0069] In some embodiments of the present application, the method for performing S5 includes: calculating the circulation volume and the amount of chemicals added according to the inner diameter and length of the pipe to be cleaned, adding a pickling agent into the circulating cleaning tank to prepare a pickling solution, adding the pickling agent and circulating it in the system, switching the forward and reverse circulation through the valve during the circulating cleaning, the exhaust valve and the shower valve are discharged at least once every 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipe to be cleaned has branches, switching and forward and reverse circulation flushing are performed in turn.

[0070] It is understandable that the chemical reaction between the pickling solution and the oxide is used to generate soluble substances to remove the stains and oxides remaining on the inner wall of the pipe. The concentration of the liquid includes the use of: nitric acid: 3-12%, hydrofluoric acid: 0.8-1.5%, and corrosion inhibitor: 0.3%. When the difference in acid concentration between two consecutive tests is less than 0.1%, it means that the monitoring sample tube has met the cleaning requirements. It should be noted that if impurities in the raw material enter the system, when preparing the pickling agent, the pickling raw material is first filtered out of the impurities through a 1μm rod filter element, and then the filtered agent is slowly added to the circulating cleaning tank. If the local agent concentration is high, corrodes the metal and causes over-washing, the pickling agent is slowly added when it is prepared to ensure uniform circulation. Each branch is replaced in turn at a fixed time, and the forward and reverse cycles are switched. During the pickling process, the cleaning flow rate in the pipeline is controlled within the required range.

[0071] More specifically, pickling: prepare (3-12% HNO3 + 0.8-1.5% HF + 0.3% corrosion inhibitor) pickling solution, the total cleaning time is 2-3 hours, check that the color of the hanging piece is uniform, the inner wall is visually metallic in color, there is no dirt, no signs of corrosion, wipe the inner wall with a dust-free white cloth specially used in a Class 1000 clean room, the white cloth is not dirty, and the surface roughness test Ra≤0.4um, which is qualified.

[0072] In some embodiments of the present application, the method for performing S6 includes: adjusting the pump station to a self-circulating state after the pickling is completed, discharging the pickling agent in the system to the neutralization tank with clean nitrogen or compressed air, adding a neutralizing agent to the circulating neutralization tank until the pH in the neutralization tank reaches 6-9, discharging the neutralized cleaning waste liquid, and when the pipeline to be cleaned has branches, switching the system branches in turn for discharge and neutralization according to the above method;

[0073] Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, flush the inner wall of the pipe with water, and discharge the flushing water to a designated location until the pH of the flushing water is 6-9.

[0074] It is understandable that neutralizing the pickling liquid can avoid harm to the environment. Add the neutralizing agent to the circulation tank, test the pH value while adding the neutralizing agent, stir the agent evenly by self-circulation of the pump station, neutralize the pH in the circulation tank to 6-9, open the drain valve, close the self-circulation valve, and discharge the neutralized cleaning waste liquid to the designated location.

[0075] It can be understood that water flushing after pickling can remove the remaining pickling residue and detached particles after the system is pickled, and the water flushing work can be ended when the pH value, turbidity and conductivity of the inlet and return liquids are the same.

[0076] In some embodiments of the present application, the method for performing S7 includes: adding a passivation agent into a circulating cleaning tank to prepare a passivation liquid, adding the passivation agent and circulating it in the system, switching the forward and reverse circulation through the valve during the circulating cleaning, the exhaust valve and the shower valve are discharged at least once every 20-40 minutes, and the discharge time is at least 2-5 minutes. When the pipeline to be cleaned has branches, forward and reverse circulation flushing is performed in turn.

[0077] It can be understood that passivation uses the strong oxidizing property of acid to form a very thin, dense, good covering and strong adhesion passivation film on the metal surface. This film exists relatively independently and is usually a compound of oxygen and metal. It plays the role of completely isolating the metal from the corrosive medium, preventing the metal from directly contacting the corrosive medium, so that the metal basically stops dissolving and forms a stable passive state to achieve the effect of preventing corrosion. Among them, the liquid and concentration of nitric acid used are better: 33-34%

[0078] It should be noted that if impurities in the raw materials enter the system, when preparing the passivation agent, the pickled raw materials should first be filtered through a 1μm rod filter to remove the impurities, and then the filtered agent should be slowly added to the circulating cleaning tank.

[0079] More specifically, passivation: prepare 33-34% HNO3 passivation solution, the total passivation time is 20-40 minutes, check that the color of the hanging piece is uniform, the inner wall is visually metallic, there is no dirt, no corrosion marks, wipe the inner wall with a dust-free white cloth specially used in a class 1000 clean room, the white cloth is not dirty, the surface roughness test Ra≤0.4um, and no blue spots appear within 30 seconds of the blue spot test, which is qualified.

[0080] In some embodiments of the present application, the method for performing S8 includes: adjusting the pump station to a self-circulating state after the passivation is completed, discharging the passivation agent in the system to the neutralization tank with clean nitrogen or compressed air, adding a neutralizing agent to the circulating neutralization tank until the pH in the neutralization tank reaches 6-9, discharging the neutralized cleaning waste liquid, and when the pipeline to be cleaned has branches, switching the system branches to discharge and neutralize in turn according to the above method;

[0081] It is understandable that neutralizing the passivation liquid can avoid harm to the environment. Add the neutralizing agent to the circulation tank, test the pH value while adding the neutralizing agent, stir the agent evenly by self-circulation of the pump station, neutralize the pH in the circulation tank to 6-9, open the drain valve, close the self-circulation valve, and discharge the neutralized cleaning waste liquid to the designated location.

[0082] In some embodiments of the present application, the method for performing S9 includes: opening a high-purity water source and starting a cleaning pump to perform a circulation flushing on the inner wall of the pipeline, switching the forward and reverse circulation through the valve during the circulation flushing, and discharging the exhaust valve and the shower valve at least once every 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipeline to be cleaned has branches, the forward and reverse circulation flushing is switched in turn. When the pH value, turbidity, and conductivity of the inlet and return liquids are the same, it can be switched to open-circuit flushing with high-purity water, and the flushing water is directly discharged to a designated location.

[0083] It is understandable that high-purity water flushing can remove the residual passivation liquid and detached particles left after the system passivation, maintain the cleanliness of the pipeline, and fully replace the residual reagents on the inner surface. The positive and reverse cycles are flushed until the pH value, turbidity and conductivity of the inlet and return liquids are the same. It should be noted that the flushing in S1 to S9 above is all done with high-purity water.

[0084] It is understandable that high-purity water is used for open-circuit flushing and replacement until the acceptance criteria for particulate matter content in the water are met. If it fails, high-purity water needs to be continuously added and drained for replacement. More specifically, the visible spectrum and particulate matter detection of pipeline flushing water are qualified. Among them, resistivity detection: the resistivity difference of the water quality at the inlet and outlet of the circulating cleaning loop is <= 4MΩ. Particulate matter detection in water: suspended particles in the sample must reach Level 50. Spectral detection: The spectra of water samples before and after flushing are consistent. If the cleaning equipment and accessories are not clean enough, the pump station and temporary connecting pipelines must be cleaned and tested with white cloth before being put into use. The pipeline interface should be protected in advance during disassembly and assembly, and the gasket should be cleaned in advance.

[0085] More specifically, high-purity water replacement and particle size detection are carried out. During the flushing process, samples are taken from the inlet and outlet to detect the resistivity. The total flushing time is 1 hour and 20-40 minutes. The resistivity difference between the inlet and outlet is ≤4MΩ. The absorption spectrum and particle quantity detection both meet the ultra-clean cleaning quality indicators.

[0086] Furthermore, after S9, we cooperate with the owner to dry the tank body, and seal and package the cleaned pipes and equipment to prevent contamination in preparation for installation and use.

[0087] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0088] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. An ultra-clean cleaning method for a transmission system, characterized in that: The following steps are involved: S1: Establish a temporary circulation pipeline system and connect it to the pipeline to be cleaned; S2: water washing; S3: adding chemicals for degreasing and cleaning, and controlling the normal circulation of the circulation pipeline system; S4: draining the liquid and adding chemicals to neutralize the degreasing liquid, and washing with water until the pH value of the washing water reaches a first preset value; S5: adding chemicals for pickling, and controlling the normal circulation of the circulation pipeline system; S6: draining the liquid and adding chemicals to neutralize the pickling liquid, and washing with water until the pH value of the washing water reaches a second preset value; S7: adding chemicals for passivation, and controlling the circulation pipeline system to circulate normally; S8: draining and adding chemicals to neutralize the passivation liquid; S9: Use high-purity water for open-circuit flushing until the pH value of the drainage reaches a third preset value, and then perform forward and reverse cycle flushing; S10: The particle content in the water meets the acceptance criteria; S11: After the inside of the pipeline is dried to the standard with high-purity nitrogen, a sealing film is used to temporarily seal the nitrogen filling port; Among them, an exhaust valve is provided at the highest point of the circulation piping system, and a shower valve is provided at the lowest point of the circulation piping system. The circulation piping system is configured with a pressure detection module and a flow detection module; and during flushing, the exhaust valve is controlled to discharge at a fixed time according to whether air blockage occurs to form a cleaning dead corner; the shower valve is controlled to discharge at a fixed time according to whether a cleaning blind end exists; and the flow rate during flushing and / or circulation is controlled according to the values ​​of the pressure detection module and the flow detection module.

2. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S1 includes: connecting the pump system to the pipeline to be cleaned through a temporary pipeline to form a temporary circulation pipeline system, and hanging a monitoring sample tube for determining the cleaning status of each process in the circulation pipeline system.

3. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S2 includes: starting the cleaning pump, opening the valve, checking for leakage first, and flushing with water after confirming that there is no leakage point. The exhaust valve and the shower valve are discharged at least once every 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipeline to be cleaned has branches, switching and forward and reverse cycle cleaning are performed in turn.

4. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S3 includes: adding medicine for degreasing cleaning after leak testing, and ensuring the normal circulation of the system, switching the forward and reverse circulation by the valve during the circulation cleaning, the exhaust valve and the shower valve discharge once every at least 20-40 minutes, and each discharge lasts at least 2-5 minutes, and when the pipeline to be cleaned has branches, switching and forward and reverse circulation cleaning are performed in turn; The method for performing S4 includes: after degreasing is completed, the degreasing agent is discharged to the neutralization tank with clean nitrogen or compressed air, the neutralization agent is added to the neutralization tank until the pH value in the neutralization tank is 6-9, and the neutralized cleaning waste liquid is discharged. When the pipeline to be cleaned has branches, the system branches are switched to discharge and neutralize in turn according to the above method; Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, flush the inner wall of the pipe with water, and discharge the flushing water to a designated location until the pH of the flushing water is 6-9.

5. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S5 includes: calculating the circulation volume and the dosage according to the inner diameter and length of the pipeline to be cleaned, adding a pickling agent into the circulation cleaning tank to prepare a pickling solution, adding the pickling agent and circulating it in the system, switching the forward and reverse circulation through the valve during the circulation cleaning, the exhaust valve and the shower valve are discharged once every at least 20-40 minutes, and the discharge time is at least 2-5 minutes. When the pipeline to be cleaned has branches, switching and forward and reverse circulation flushing are performed in turn.

6. The ultra-clean cleaning method of the transmission system according to claim 5, characterized in that: The method for performing S6 includes: adjusting the pump station to a self-circulating state after the pickling is completed, discharging the pickling agent in the system to the neutralization tank with clean nitrogen or compressed air, adding a neutralizing agent to the circulating neutralization tank until the pH in the neutralization tank reaches 6-9, discharging the neutralized cleaning waste liquid, and when the pipeline to be cleaned has branches, switching the system branches in turn for discharge and neutralization according to the above method; Then turn on the water source and start the cleaning pump, open the valve, check for leaks first, and after confirming that there are no leaks, flush the inner wall of the pipe with water, and discharge the flushing water to a designated location until the pH of the flushing water is 6-9.

7. The ultra-clean cleaning method of the transmission system according to claim 6, characterized in that: The method for performing S7 includes: adding a passivation agent into the circulation cleaning tank to prepare a passivation solution, the passivation agent is added and circulated in the system, the valve is used to switch the forward and reverse circulation during the circulation cleaning, the exhaust valve and the shower valve are discharged once every at least 20-40 minutes, and the discharge time is at least 2-5 minutes, and when the pipeline to be cleaned has branches, the forward and reverse circulation flushing is performed in turn; The method for performing S8 includes: adjusting the pump station to a self-circulating state after the passivation is completed, discharging the passivation agent in the system to the neutralization tank with clean nitrogen or compressed air, adding a neutralizing agent to the circulating neutralization tank until the pH in the neutralization tank reaches 6-9, discharging the neutralized cleaning waste liquid, and when the pipeline to be cleaned has branches, the system branches are switched to be discharged and neutralized in turn according to the above method.

8. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S9 includes: opening a high-purity water source and starting a cleaning pump to perform a circulation flushing on the inner wall of the pipeline. During the circulation flushing, the forward and reverse circulation is switched by the valve. The exhaust valve and the shower valve discharge once every at least 20-40 minutes, and each discharge lasts at least 2-5 minutes. When the pipeline to be cleaned has branches, the forward and reverse circulation flushing is switched in turn. When the pH value, turbidity and conductivity of the inlet and return liquids are the same, it can be switched to high-purity water open-circuit flushing, and the flushing water is directly discharged to a designated location.

9. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S10 includes: after the high-purity water flushing is completed, detecting that the content of particulate matter in the water meets the acceptance standard.

10. The ultra-clean cleaning method of the transmission system according to claim 1, characterized in that: The method for performing S11 includes: after the water quality test is qualified, the connection port with the pump station is removed, a blind plate seal is installed on the pipeline interface not related to nitrogen drying, high-purity nitrogen is introduced into the pipeline for nitrogen drying, and the nitrogen filling port is temporarily sealed with a sealing film.

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