Environment-friendly degreasing agent and cleaning method for super-large ethylene oxide heat exchange pipe

Abstract

The application provides an environment-friendly degreasing agent and a cleaning method for super-large ethylene oxide heat exchange pipes, and relates to the technical field of chemical equipment.The environment-friendly degreasing agent comprises an emulsifier NP-10, sodium gluconate, fatty alcohol polyoxyethylene ether sodium sulfate, coconut oil diethanolamide and water.The environment-friendly degreasing agent can effectively emulsify, disperse and strip stubborn oil stains on the inner wall of the super-large ethylene oxide heat exchange pipe, has an excellent decontamination effect on a small amount of oil stains accumulated by machine oil, lubricating oil and workshop dust, has an excellent rust removal effect on trace rust, chelates metal ions and prevents secondary pollution.Therefore, the degreasing agent can meet the stringent requirements of the large or super-large ethylene oxide heat exchange pipe on degreasing and cleaning, conforms to the environmental protection production standard, can be directly discharged after use, significantly improves the cleaning efficiency and cleanliness, and greatly reduces the subsequent complicated treatment process of waste liquid.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, and more specifically, to an environmentally friendly degreasing agent and a cleaning method for ultra-large ethylene oxide heat exchange tubes. Background Technology

[0002] With the continuous advancement of the petrochemical industry, the manufacturing technology of large and ultra-large ethylene oxide reactors has become increasingly mature, and such equipment is widely used in chemical enterprises. After the ethylene oxide reactor is manufactured, its heat exchange tubes must undergo rigorous degreasing and cleaning to meet the stringent requirements of specific process environments. Existing degreasing agents generally contain non-environmentally friendly components, such as phosphates or recalcitrant organic solvents. These substances can easily cause environmental problems such as water pollution and soil degradation during use, and are difficult to achieve uniform and efficient degreasing effects in the cleaning of large equipment. Residues may affect the safety of subsequent processes. In addition, traditional degreasing agents have poor biodegradability, which does not meet the urgent needs of modern industry for green chemistry and sustainable development. Summary of the Invention

[0003] This invention aims to solve the problems of water pollution and soil degradation caused by degreasing agents during the cleaning process.

[0004] To address the above problems, this invention provides an environmentally friendly degreasing agent and a cleaning method for ultra-large ethylene oxide heat exchange tubes.

[0005] In a first aspect, the present invention provides an environmentally friendly degreasing agent comprising emulsifier NP-10, sodium gluconate, sodium fatty alcohol polyoxyethylene ether sulfate, coconut oil diethanolamide, and water.

[0006] Optionally, by weight, it comprises 15 to 25 parts of emulsifier NP-10, 10 to 20 parts of sodium gluconate, 5 to 15 parts of sodium fatty alcohol polyoxyethylene ether sulfate, 5 to 15 parts of coconut oil diethanolamide, and 40 to 50 parts of water.

[0007] Secondly, the present invention provides a cleaning method for ultra-large ethylene oxide heat exchange tubes, using an environmentally friendly degreasing agent as described above for degreasing and cleaning.

[0008] Optionally, the following steps are included: S1: Use an environmentally friendly degreasing agent dissolved in water at 20℃ to 40℃ to form a degreasing washing solution to rinse the ultra-large ethylene oxide heat exchange tubes; S2: Use compressed air to purge the ultra-large ethylene oxide heat exchange tubes to remove the liquid accumulated inside the tubes; S3: Insert a sponge bullet into one end of the ultra-large ethylene oxide heat exchange tube, and use an air gun to fire the sponge bullet out from the other end of the ultra-large ethylene oxide heat exchange tube.

[0009] Optionally, steps S1 to S3 may be repeated once or multiple times until the inside of the ultra-large ethylene oxide heat exchange tube is clean.

[0010] Optionally, the sponge bullet is cylindrical, and its diameter is 5mm to 7mm larger than the inner diameter of the ultra-large ethylene oxide heat exchange tube.

[0011] Optionally, the length of the sponge bullet is 1.2 to 1.5 times the diameter of the sponge bullet.

[0012] Alternatively, the density of the sponge bullet is between 70d and 75d.

[0013] Optionally, in S1, a high-pressure water gun with a pressure ≥450MPa is used to flush the ultra-large ethylene oxide heat exchange tubes.

[0014] Optionally, in S1, the mass ratio of the environmentally friendly degreasing agent to water is 1:8 to 1:12.

[0015] The beneficial effects of this invention's environmentally friendly degreasing agent and cleaning method for ultra-large ethylene oxide heat exchange tubes are as follows: Through the rational formulation of the environmentally friendly degreasing agent, a novel, efficient, and neutral degreasing agent is prepared. It can effectively emulsify, disperse, and peel off stubborn oil stains from the inner wall of ultra-large ethylene oxide heat exchange tubes. It has an excellent cleaning effect on small amounts of oil stains accumulated inside the heat exchange tubes, such as machine oil, lubricating oil, and workshop dust, and also has an excellent removal effect on trace amounts of rust. Simultaneously, it chelates metal ions to prevent secondary pollution. Therefore, this degreasing agent can meet the stringent requirements for degreasing and cleaning of large or ultra-large ethylene oxide heat exchange tubes, complies with environmental protection production standards, and can be directly discharged after use, significantly improving cleaning efficiency and cleanliness, and greatly reducing the cumbersome subsequent waste liquid treatment procedures. Attached Figure Description

[0016] Figure 1 This is a schematic flowchart of a cleaning method for an ultra-large ethylene oxide heat exchanger tube according to an embodiment of the present invention. Detailed Implementation

[0017] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this invention's description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0019] In related technologies, traditional cleaning methods, such as liquid filling, circulating rinsing, and wiping, are time-consuming, labor-intensive, and material-intensive when it comes to degreasing and cleaning large or ultra-large ethylene oxide heat exchange tubes, and they are difficult to meet their stringent cleaning requirements.

[0020] To address the problems existing in the aforementioned related technologies, embodiments of the present invention provide an environmentally friendly degreasing agent and a cleaning method for ethylene oxide heat exchange tubes.

[0021] An embodiment of the present invention provides an environmentally friendly degreasing agent comprising emulsifier NP-10, sodium gluconate, sodium fatty alcohol polyoxyethylene ether sulfate, coconut oil diethanolamide, and water.

[0022] Specifically, emulsifier NP-10, as a nonionic surfactant, primarily functions to emulsify oily contaminants. By reducing the surface tension at the oil-water interface, it disperses water-insoluble oil into tiny droplets, thereby achieving stable dispersion in the aqueous phase and facilitating removal from the heat exchanger tube surface. Emulsifier NP-10 is used to provide the primary emulsifying capability. For example, it can be added to the formulation in different proportions to meet varying degrees of oil emulsification requirements. In one implementation, emulsifier NP-10 can be added to water to form a preliminary emulsion system.

[0023] Sodium gluconate, as a chelating and dispersing agent, can form stable complexes with metal ions in water, preventing them from redepositing onto the heat exchanger tube surface during cleaning. It also assists in dispersing oil stains and improving overall cleaning efficiency. Sodium gluconate is used to enhance the chelating and dispersing properties of degreasing agents. For example, it can be dissolved in water to complex hardness ions, preventing them from interfering with the action of other active components. In another implementation, sodium gluconate can be pre-mixed with emulsifier NP-10 to improve its dispersibility in water.

[0024] Sodium fatty alcohol polyoxyethylene ether sulfate (AES), as an anionic surfactant, possesses excellent wetting, penetrating, and emulsifying properties. It can rapidly penetrate into the interior of oil contaminants, reducing the adhesion between oil and the heat exchanger tube surface, and promoting oil removal and dispersion. Sodium fatty alcohol polyoxyethylene ether sulfate is used to provide excellent wetting and penetrating effects. For example, it can be directly added to degreasing agent formulations to reduce the surface tension of the solution, thereby allowing the degreasing agent to better penetrate the oil contaminant. In one implementation, it can act as an auxiliary surfactant, synergistically working with the emulsifier NP-10.

[0025] Coconut oil diethanolamide (6501), as a nonionic surfactant and foam stabilizer, enhances the emulsifying and detergency of degreasers. Furthermore, it helps generate adequate foam, allowing the degreaser to remain on the inner wall of heat exchange tubes for a longer time, thus improving degreasing efficiency, and it also exhibits good biodegradability. Coconut oil diethanolamide is used to further enhance the detergency of degreasers and stabilize foam. For example, it can be added to formulations to enhance emulsification and ensure effective adhesion of the degreaser to the surface being cleaned during the cleaning process. Alternatively, it can be used as a thickener to adjust the viscosity of the degreaser.

[0026] Water serves as both the dispersion medium and solvent for the degreasing agent, dissolving and diluting the aforementioned active components to form a homogeneous degreasing detergent solution. Water is inexpensive to use and does not introduce additional contaminants, facilitating large-scale cleaning operations. Water acts as the primary solvent and dispersion medium, carrying all the aforementioned active components. For example, the components can be added to the water in a specific order, and stirred to ensure thorough dissolution and mixing. In one implementation, the water can be preheated to a specific temperature to accelerate the dissolution process of the components.

[0027] In this embodiment, a novel, efficient, and neutral degreasing agent is prepared through the rational formulation of environmentally friendly degreasing agents. It effectively emulsifies, disperses, and removes stubborn oil stains from the inner wall of ethylene oxide heat exchange tubes. It has excellent cleaning effects on small amounts of oil stains accumulated inside the heat exchange tubes from machine oil, lubricating oil, and workshop dust, and also has excellent removal effects on trace amounts of rust. Simultaneously, it chelates metal ions to prevent secondary pollution. Therefore, this degreasing agent can meet the stringent degreasing and cleaning requirements of large or ultra-large ethylene oxide heat exchange tubes, complies with environmental protection production standards, and can be directly discharged after use. It significantly improves cleaning efficiency and cleanliness, and greatly reduces the cumbersome subsequent waste liquid treatment procedures.

[0028] Optionally, by weight, it comprises 15 to 25 parts of emulsifier NP-10, 10 to 20 parts of sodium gluconate, 5 to 15 parts of sodium fatty alcohol polyoxyethylene ether sulfate, 5 to 15 parts of coconut oil diethanolamide, and 40 to 50 parts of water.

[0029] Specifically, NP-10, an emulsifier, is a nonionic surfactant whose main function is to reduce the surface tension at the oil-water interface and promote the emulsification and dispersion of oil contaminants. When its dosage is controlled at 15 to 25 parts, it ensures that the degreaser has sufficient emulsifying ability to effectively peel off and disperse oil contaminants on the surface of the ultra-large ethylene oxide heat exchanger tube, while avoiding insufficient emulsification due to insufficient dosage or waste of raw materials due to excessive dosage. In addition to NP-10, those skilled in the art can also choose other nonionic surfactants, such as fatty alcohol polyoxyethylene ethers (AEO series) or alkyl glycosides (APG), to achieve similar emulsifying effects.

[0030] Sodium gluconate, as an excellent chelating and dispersing agent, functions in degreasing agents by chelating metal ions in water, preventing them from interfering with the performance of surfactants, and helping to disperse oil and solid particles, making them less prone to redeposition. Limiting its dosage to 10 to 20 parts maximizes its chelating and dispersing effect, significantly improving the overall cleaning efficiency of the degreasing agent. In other embodiments, other chelating agents such as ethylenediaminetetraacetic acid (EDTA) and its salts, or nitrotriacetic acid (NTA) and its salts, may also be considered.

[0031] Sodium fatty alcohol polyoxyethylene ether sulfate, as an anionic surfactant, can synergistically work with emulsifier NP-10 to further enhance the wetting, penetration, and detergency of the degreaser, and help maintain the stability of the degreaser system. Its dosage, ranging from 5 to 15 parts, ensures good detergency performance while maintaining system homogeneity and preventing stratification. Those skilled in the art can also use other anionic surfactants such as sodium dodecyl sulfate (SLS) or α-olefin sulfonate (AOS).

[0032] Coconut oil diethanolamide, as a nonionic co-surfactant, primarily functions as a solubilizer, foam stabilizer, and thickener. It promotes the uniform dissolution and dispersion of the active ingredients and enhances degreasing ability. When used in amounts of 5 to 15 parts, it effectively improves the overall performance of the degreasing agent, allowing each component to function fully. In practical applications, other alkanolamide compounds, such as laurylamide DEA, or amphoteric surfactants such as cocamidopropyl betaine, can also be selected.

[0033] Water serves as the primary solvent and diluent, with its dosage controlled between 40 and 50 parts. This ensures that all active ingredients are fully dissolved and evenly dispersed, forming a degreasing agent with suitable flowability. This dosage range guarantees both the effective concentration of the degreasing agent and facilitates subsequent preparation of a degreasing detergent solution for cleaning operations. In actual preparation, deionized water, softened water, or appropriately treated tap water can be selected as needed.

[0034] In this optional embodiment, precise control of the degreasing agent's performance is achieved by accurately defining the weight proportions of each component in the environmentally friendly degreasing agent. The emulsifier NP-10, sodium gluconate, sodium fatty alcohol polyoxyethylene ether sulfate, coconut oil diethanolamide, and water work synergistically within their respective defined weight proportions. This results in a degreasing agent that not only possesses highly efficient emulsifying, chelating, dispersing, and detergency capabilities, thoroughly removing stubborn oil stains from ultra-large ethylene oxide heat exchange tubes, but also effectively avoids poor degreasing effects or raw material waste caused by improper component ratios. This optimized degreasing agent, while ensuring compliance with the stringent degreasing and cleaning requirements of large ethylene oxide heat exchange tubes, significantly reduces production costs and improves cleaning efficiency and economic benefits, thereby effectively solving the technical problems of unclear degreasing agent formulations, unstable performance, and difficulty in cost control in existing technologies.

[0035] Another embodiment of the present invention provides a cleaning method for ultra-large ethylene oxide heat exchange tubes, which uses the environmentally friendly degreasing agent described above for degreasing and cleaning.

[0036] Specifically, this environmentally friendly degreaser, through its rationally formulated components, effectively meets the requirements for removing oil and impurities from the inner walls of heat exchange tubes, thereby achieving rapid emulsification, dispersion, and peeling of the oil. In the cleaning process, the environmentally friendly degreaser is prepared as a working solution and applied to the inner walls of the heat exchange tubes through circulating rinsing or immersion. Its synergistic effect allows it to quickly penetrate the oil, reducing the adhesion between the oil and the tube wall, and chelating metal ions in the water to prevent secondary contamination. Because this degreaser is specifically designed for the stringent degreasing requirements of ultra-large ethylene oxide heat exchange tubes, its decontamination efficiency is significantly improved, ensuring that the cleaned heat exchange tubes can pass visual inspection, endoscopic examination, and ultraviolet light inspection smoothly.

[0037] Furthermore, for ultra-large reactors with tube sheet diameters exceeding 9 meters and over 30,000 heat exchange tubes, this degreasing agent is more suitable for large-scale batch cleaning operations. Its environmentally friendly characteristics combined with highly efficient decontamination capabilities effectively reduce the time, manpower, and material resources required during the cleaning process. For example, in practical applications, by optimizing the concentration and action time of the degreasing agent, the cleaning cycle of a single heat exchange tube can be shortened while ensuring degreasing quality, thereby improving overall cleaning efficiency.

[0038] In this embodiment, not only is the problem that traditional methods cannot meet the needs of rapid and efficient degreasing and cleaning of large or ultra-large ethylene oxide heat exchange tubes solved, but the cleaning process is also made more environmentally friendly and economical, providing reliable technical support for the world's largest ethylene oxide project.

[0039] Optionally, such as Figure 1 As shown, it includes the following steps: S1: Use an environmentally friendly degreasing agent dissolved in water at 20℃ to 40℃ to form a degreasing washing solution to rinse the ultra-large ethylene oxide heat exchange tubes; S2: Use compressed air to purge the ultra-large ethylene oxide heat exchange tubes to remove the liquid accumulated inside the tubes; S3: Insert a sponge bullet into one end of the ultra-large ethylene oxide heat exchange tube, and use an air gun to fire the sponge bullet out from the other end of the ultra-large ethylene oxide heat exchange tube.

[0040] Specifically, in step S1, the environmentally friendly degreasing agent is a cleaning agent used to remove oil and impurities. Its formulation emphasizes environmental friendliness and reduces pollution. In addition to the emulsifier NP-10, sodium gluconate, sodium fatty alcohol polyoxyethylene ether sulfate, coconut oil diethanolamide, and water components included in the aforementioned environmentally friendly degreasing agent, the environmentally friendly degreasing agent can also be other environmentally compliant composite cleaning agents with good degreasing performance. For example, it may contain nonionic surfactants, chelating agents, detergent builders, and water. The environmentally friendly degreasing agent is dissolved in water at 20°C to 40°C. This temperature range is suitable for the degreasing agent to exert its optimal activity, ensuring its activity while avoiding excessive energy consumption. Water temperature control can be achieved through heating devices (such as electric heating rods or steam coils) or cooling devices (such as cooling coils or chillers). The environmentally friendly degreasing agent is thoroughly mixed with water to form a uniform degreasing washing solution to ensure cleaning effectiveness. This mixing process can be completed through stirring, circulating pump mixing, or other methods. Subsequently, the ultra-large ethylene oxide heat exchange tubes are rinsed with the degreasing detergent. This rinsing process can be carried out by pumping the degreasing detergent into the heat exchange tubes using a low-pressure or high-pressure water pump, or by soaking, circulating rinsing, or other methods.

[0041] In step S2, compressed air is used to purge the ultra-large ethylene oxide heat exchange tubes to remove accumulated liquid inside. Compressed air purging is an effective way to use a high-speed airflow to carry away residual liquid and loose dirt from the tubes. This step can be achieved by using an air compressor to provide high-pressure gas, which is then introduced into the heat exchange tubes through nozzles or pipes for purging. The purging method can be unidirectional or reciprocating to ensure that the accumulated liquid and loose dirt are thoroughly removed.

[0042] In step S3, a sponge bullet is inserted into one end of the ultra-large ethylene oxide heat exchange tube, and an air gun is used to eject the sponge bullet from the other end of the tube. The sponge bullet is a cylindrical or similarly shaped cleaning tool with a certain degree of elasticity and adsorption capacity. Its material can be polyurethane sponge, polyethylene sponge, or other elastic materials with adsorption and scraping capabilities. The air gun is a device that uses compressed gas to propel an object at high speed. It can be a specially designed industrial air gun or a jet device connected to a compressed air source, capable of providing sufficient thrust to propel the sponge bullet through the heat exchange tube. By manually or mechanically inserting the sponge bullet into the tube opening, and then applying air pressure at the other end using the air gun, the sponge bullet is propelled by air pressure through the entire inner cavity of the heat exchange tube, thereby achieving physical scraping and adsorption cleaning.

[0043] In this optional embodiment, firstly, rinsing is performed by dissolving an environmentally friendly degreaser in water at a specific temperature to form a degreasing detergent solution. This effectively dissolves and washes away most of the soluble oil and loose impurities inside the heat exchange tubes, laying the foundation for subsequent cleaning while balancing the activity of the degreaser and the energy consumption of the operation. Secondly, compressed air purging can quickly remove residual liquid and loosened dirt from the tubes, preventing them from adversely affecting the subsequent cleaning effect. This method is simple to operate and suitable for batch processing of large-scale heat exchange tubes. Finally, sponge bullets are introduced in conjunction with an air gun for physical cleaning. The sponge bullets, propelled by air pressure, pass through the heat exchange tubes at high speed. Relying on their own adsorption and scraping effects, they can thoroughly remove stubborn oil and impurities adhering to the tube walls, achieving deep cleaning of individual heat exchange tubes. This three-step sequential cleaning process effectively solves the problems of low cleaning efficiency and incomplete cleaning caused by the large diameter of large or ultra-large ethylene oxide heat exchanger tube sheets and the large number of heat exchanger tubes. It significantly improves the cleaning speed and cleanliness, meets the stringent degreasing and cleaning requirements, and has higher efficiency and better cleaning effect compared with traditional cleaning methods.

[0044] Optionally, steps S1 to S3 may be repeated once or multiple times until the inside of the ultra-large ethylene oxide heat exchange tube is clean.

[0045] Specifically, this repetitive operation aims to gradually remove stubborn dirt and residues that may be present on the inner wall of the ultra-large ethylene oxide heat exchanger tube by performing multiple complete cleaning cycles. The number of repetitions can be flexibly set according to actual cleaning needs and the degree of dirt on the ultra-large ethylene oxide heat exchanger tube. For example, a fixed number of repetitions can be preset, such as performing two or three complete steps S1 to S3; or, the number of repetitions can be dynamically adjusted based on real-time monitoring results during the cleaning process. Repeating steps S1 to S3 means that each repetition includes rinsing with degreasing detergent, purging with compressed air, and pushing out sponge bullets. This complete cycle ensures that the degreasing agent fully acts on the dirt and effectively removes the detached dirt through mechanical and pneumatic actions, avoiding the incomplete cleaning problems that may occur when only a single step is repeated.

[0046] "To the point of cleanliness of the ultra-large ethylene oxide heat exchanger tube" means that the repeated cleaning operation is stopped when the inner wall of the ultra-large ethylene oxide heat exchanger tube reaches a preset cleanliness standard. The methods for determining the cleanliness standard can be varied. For example, visual inspection can be performed using an endoscope to observe the inside of the ultra-large ethylene oxide heat exchanger tube to confirm the absence of visible dirt residue; alternatively, ultraviolet (UV) light detection can be used to observe the fluorescence reaction to determine the presence of organic residue; or, sampling and analysis of the cleaned ultra-large ethylene oxide heat exchanger tube can be performed, such as wiping and sampling followed by chemical analysis, to ensure that its surface meets specific cleanliness requirements. Furthermore, the cleanliness of the ultra-large ethylene oxide heat exchanger tube can be determined by monitoring the liquids or gases discharged during the cleaning process, such as detecting their turbidity, pH value, or the content of specific contaminants. When these indicators reach a stable level or a preset cleanliness threshold, the ultra-large ethylene oxide heat exchanger tube can be considered clean.

[0047] In this optional embodiment, to address the issue that a single cleaning may not completely remove stubborn oil and dirt, this application introduces a mechanism for repeatedly executing steps S1 to S3, effectively improving the cleanliness of ultra-large ethylene oxide heat exchange tubes. Repeating the entire cleaning process allows the three core steps of degreasing and rinsing, removing accumulated liquid, and pushing away dirt to work synergistically, repeatedly peeling and removing dirt from the tube walls, thereby gradually breaking down and thoroughly removing stubborn stains that may remain after a single cleaning. Simultaneously, setting the condition for stopping repetition as achieving cleanliness inside the ultra-large ethylene oxide heat exchange tube makes the cleaning process highly flexible and targeted. Operators can determine whether the cleanliness standard has been met based on the actual degree of dirt on different ultra-large ethylene oxide heat exchange tubes through detection methods, thus deciding whether to continue repeating the cleaning, avoiding unnecessary over-cleaning, and effectively saving time and resources. This on-demand repetitive strategy not only ensures that all ethylene oxide heat exchange tubes meet stringent degreasing and cleaning requirements, but also optimizes cleaning efficiency while maintaining cleanliness. It is particularly suitable for cleaning the numerous heat exchange tubes in large or ultra-large ethylene oxide reactors.

[0048] In some specific embodiments, white sponge bullets are preferable for ease of observation and comparison.

[0049] Choose a high-pressure water gun with a rat head for easy rinsing of the heat exchange tubes.

[0050] Optionally, the sponge bullet is cylindrical, and its diameter is 5mm to 7mm larger than the inner diameter of the ultra-large ethylene oxide heat exchange tube.

[0051] Specifically, the cylindrical structure of the sponge bullet refers to its main body being a cylinder with a circular cross-section. This geometric design aims to achieve a high degree of matching with the circular cavity structure of the ultra-large ethylene oxide heat exchange tube. By using a cylindrical sponge bullet, it is ensured that it can uniformly contact the entire inner wall surface of the ultra-large ethylene oxide heat exchange tube when moving inside the tube, thereby ensuring that all parts of the tube wall are thoroughly wiped and cleaned. For example, highly elastic sponge material can be injection molded using precision molds, or cylinders can be precisely cut from large pieces of sponge using CNC cutting technology to achieve the required shape accuracy. Alternatively, sponge material can be wound and bonded to form a cylindrical structure with a specific diameter and length. Simultaneously, this technical solution limits a specific dimensional difference range between the diameter of the sponge bullet and the inner diameter of the ultra-large ethylene oxide heat exchange tube. Specifically, the outer diameter of the sponge bullet should be 5 mm to 7 mm larger than the inner diameter of the ultra-large ethylene oxide heat exchange tube. This dimensional relationship is based on the compressive elastic properties of the sponge material and the requirements of the cleaning operation. For example, if the inner diameter of an ultra-large ethylene oxide heat exchange tube is 20 mm, the diameter of the sponge bullet can be selected from 25 mm to 27 mm. This size matching can be achieved by: precisely calculating and controlling the mold or cutting dimensions of the sponge bullet based on the pre-measured inner diameter of the ultra-large ethylene oxide heat exchange tube during manufacturing; or by preparing a series of sponge bullets with different diameters for ultra-large ethylene oxide heat exchange tubes of different specifications, and selecting the appropriate bullet based on the actual tube diameter before cleaning.

[0052] In this optional embodiment, the shape of the sponge bullet and its matching relationship with the inner diameter of the ultra-large ethylene oxide heat exchange tube are optimized, thereby effectively solving the problem of low cleaning efficiency and poor cleaning effect caused by improper size of the sponge bullet. Specifically, the sponge bullet is designed as a cylinder, which can perfectly fit the circular cavity structure of the ultra-large ethylene oxide heat exchange tube. This ensures that the sponge bullet can evenly and comprehensively conform to the tube wall when moving inside the tube, avoiding cleaning blind spots caused by shape mismatch, thus ensuring the cleaning effect of all parts of the tube wall. At the same time, by setting the diameter of the sponge bullet to be 5mm to 7mm larger than the inner diameter of the ultra-large ethylene oxide heat exchange tube, the sponge bullet can obtain an appropriate amount of compression after being inserted into the tube cavity. This appropriate amount of compression allows the sponge bullet to rely on its own elasticity to tightly conform to the inner wall of the ultra-large ethylene oxide heat exchange tube, generating sufficient friction to effectively scrape off stains and impurities on the tube wall, ensuring the cleanliness of the cleaning. Furthermore, this size design avoids excessive compression of the sponge bullets due to excessive diameter, which could lead to difficulty in pushing them inside the tube or jamming. Excessive interference would dramatically increase the friction between the sponge bullet and the tube wall. This size design ensures smooth and efficient cleaning operations. Conversely, if the diameter is too small, the interference would be insufficient, resulting in insufficient friction between the sponge bullet and the tube wall or an inability to effectively adhere to the tube wall, affecting the cleaning effect. Therefore, this solution significantly improves the cleaning effect of ultra-large ethylene oxide heat exchange tubes while ensuring efficient cleaning operations, meeting the requirements for rapid and efficient degreasing and cleaning of large-scale ultra-large ethylene oxide heat exchange tubes.

[0053] Optionally, the length of the sponge bullet is 1.2 to 1.5 times the diameter of the sponge bullet.

[0054] Specifically, the geometric proportions of the sponge bullets are defined, specifically the range between their length and diameter. This proportion aims to optimize the movement and cleaning efficiency of the sponge bullets within ultra-large ethylene oxide heat exchange tubes. In actual manufacturing, the length and diameter of the sponge bullets can be ensured to meet this proportional requirement through precise mold forming or cutting processes. For example, CNC cutting equipment can be used to process the sponge material to achieve high-precision dimensional control; alternatively, customized molds can be used for foaming molding, thereby directly obtaining sponge bullets with a specific length-to-diameter ratio during the production process.

[0055] In this optional embodiment, the problems of jamming, misalignment, and incomplete cleaning that may occur when cleaning the inner wall of the ultra-large ethylene oxide heat exchanger tube are effectively solved. This solution, by reasonably limiting the ratio of the sponge bullet's length to its own diameter, balances the smoothness of the cleaning operation with the cleaning effect on the inner wall of the ultra-large ethylene oxide heat exchanger tube. Combined with the already defined sponge bullet diameter parameters, this ensures the successful completion of the cleaning operation for the ultra-large ethylene oxide heat exchanger tube. Specifically, the length of the sponge bullet is limited to 1.2 to 1.5 times its own diameter. This allows the length to be adjusted to fit the diameter, avoiding problems such as difficulty in insertion, jamming, and excessive friction between the sponge bullet and the tube wall caused by excessive length. This ensures smooth passage of the sponge bullet through the ultra-large ethylene oxide heat exchange tube, improving cleaning efficiency. Conversely, it avoids problems such as insufficient contact area with the inner wall, insufficient friction between the sponge bullet and the tube wall, and inability to fully remove residual dirt caused by excessive length. This ensures effective cleaning of the tube wall by the sponge bullet, consistently meeting the degreasing and cleaning requirements of the ultra-large ethylene oxide heat exchange tube. This solution, combined with the aforementioned limitation that the diameter of the sponge bullet is 5mm to 7mm larger than the inner diameter of the ultra-large ethylene oxide heat exchange tube, ensures stable movement and efficient cleaning of the sponge bullet within the tube.

[0056] Alternatively, the density of the sponge bullet is between 70d and 75d.

[0057] Specifically, the density of a sponge bullet refers to its mass per unit volume, a key physical parameter for measuring the compactness of the sponge bullet material, directly affecting its hardness, elasticity, and abrasion resistance. In the cleaning process of ethylene oxide heat exchange tubes, the density of the sponge bullet determines the pressure distribution and scraping ability when in contact with the tube wall. To achieve a specific density range, various materials and processes can be employed. For example, polyurethane foam materials with different expansion ratios can be selected. By adjusting the polyurethane formulation (such as the proportions of isocyanate, polyol, foaming agent, catalyst, etc.) and foaming process (such as temperature, pressure, and mixing speed), the pore structure and closed-cell ratio of the foam can be precisely controlled to obtain the target density. Alternatively, ethylene-vinyl acetate copolymer (EVA) foam or natural rubber foam can be used. By adjusting their crosslinking degree, foaming agent dosage, and molding conditions, the required density range can be achieved. These materials can all be precisely controlled in production to ensure that the density of the sponge bullet remains stable between 70d and 75d to meet the specific requirements of cleaning operations.

[0058] In this optional embodiment, by limiting the density range of the sponge bullets, various cleaning problems caused by unsuitable sponge bullet density are effectively solved, thereby better adapting to the cleaning needs of ultra-large ethylene oxide heat exchange tubes. Limiting the density of the sponge bullets to between 70d and 75d ensures that the sponge bullets achieve the appropriate hardness for cleaning ethylene oxide heat exchange tubes. Specifically, this density range avoids the problem of excessive hardness due to excessive density, which could scratch the inner wall of the ethylene oxide heat exchange tube, ensuring the structural integrity of the ethylene oxide heat exchange tube. It also avoids the problem of reduced adsorption performance of the sponge bullets due to excessive density, thus reducing the cleaning effect of the heat exchange tube. Furthermore, this density range avoids the problem of insufficient hardness due to excessively low density, which could reduce cleaning ability, and also avoids the phenomenon that excessively low density could easily cause the sponge bullets to break inside the heat exchange tube. This ensures that the sponge bullets have sufficient cleaning ability to effectively scrape off residual oil and impurities on the tube wall, thereby guaranteeing the cleaning effect of the ethylene oxide heat exchange tube. Meanwhile, sponge bullets within this density range can maintain a stable structural shape and are not prone to excessive deformation during the process of passing through ethylene oxide heat exchange tubes. This avoids the problem of sponge bullets getting stuck in the ethylene oxide heat exchange tubes and causing the cleaning operation to be interrupted, thus ensuring the efficient and smooth progress of the cleaning operation and meeting the operational requirements for batch cleaning of a large number of ultra-large ethylene oxide heat exchange tubes.

[0059] Optionally, in S1, a high-pressure water gun with a pressure ≥450MPa is used to flush the ethylene oxide heat exchange tubes.

[0060] Specifically, a high-pressure water gun is a cleaning device that pressurizes water through a pump and then sprays it out at extremely high speed and with great impact. Its core function lies in converting mechanical energy into the kinetic energy of the water flow, generating a powerful impact force. This serves as a conveying and pressurizing device for the cleaning medium, providing sufficient energy to peel away dirt. The high-pressure water gun can be driven by a reciprocating pump, which pressurizes the water to the required pressure through the reciprocating motion of a piston, forming a high-speed jet through the nozzle. Alternatively, the high-pressure water gun can employ a system combining a centrifugal pump and multi-stage pressurization, progressively increasing the water pressure through the rotation of multiple impellers, ultimately spraying a high-pressure water jet through a dedicated nozzle. The pressure ≥450MPa refers to the minimum impact pressure value of the water jet from the high-pressure water gun when it acts on the target surface. This pressure value provides sufficient mechanical impact force to overcome the adhesion between stubborn oil stains and the inner wall of the ethylene oxide heat exchanger tube, achieving effective peeling. This pressure can be ensured by selecting an industrial-grade high-pressure water pump with sufficient rated output pressure and designing appropriate pipelines, valves, and nozzles to ensure the system can output a stable working pressure of no less than 450 MPa; or by precisely controlling the speed or piston stroke of the high-pressure pump and combining it with real-time monitoring and feedback adjustment by a pressure sensor to ensure the water flow pressure is always maintained at 450 MPa or higher. The purpose of rinsing the ethylene oxide heat exchange tubes is to introduce high-pressure water flow into the interior of the ethylene oxide heat exchange tubes, allowing it to fully contact the oil stains on the inner wall and generate mechanical action, thereby removing the dirt. This can be achieved by inserting the nozzle of a high-pressure water gun (e.g., a rotary nozzle or direct nozzle equipped with forward and / or backward spray holes) into one end of the ethylene oxide heat exchange tube and moving it along the length of the tube, so that the high-pressure water flow covers the entire inner wall surface; or by using an automated or semi-automated cleaning device that can precisely control the nozzle's feed speed and rotation angle to ensure uniform and thorough cleaning.

[0061] In this optional embodiment, the high-pressure water gun generates a powerful, focused water jet. When this water jet impacts the inner wall of the ethylene oxide heat exchange tube at an extremely high pressure of no less than 450 MPa, it provides enormous kinetic energy and shear force. This powerful physical impact is sufficient to overcome the strong adhesion between stubborn oil stains and the tube wall, thereby effectively peeling off and removing contaminants, solving the problem that traditional low-pressure rinsing is ineffective at removing stubborn oil stains. Simultaneously, in step S1, the environmentally friendly degreasing agent is dissolved in water at 20°C to 40°C to form a degreasing washing solution, which is used to rinse the ethylene oxide heat exchange tube. The physical action of the high-pressure water jet combined with the chemical action of the environmentally friendly degreasing agent—the degreasing agent softens and dissolves the oil stains, while the high-pressure water jet provides a strong mechanical flushing force, quickly carrying away the softened oil stains—creates a synergistic effect, significantly improving cleaning efficiency and thoroughness. This not only speeds up the cleaning of individual heat exchange tubes, but also significantly shortens the overall cleaning cycle for the numerous heat exchange tubes in ultra-large ethylene oxide reactors, improving operational efficiency and ensuring the thoroughness of the degreasing process, thereby meeting stringent degreasing and cleaning requirements.

[0062] Optionally, in S1, the mass ratio of the environmentally friendly degreasing agent to water is 1:8 to 1:12.

[0063] Specifically, this mass ratio defines the concentration of the environmentally friendly degreasing agent in water during the preparation of the degreasing detergent solution. This ratio is a key parameter to ensure the effective functioning of the degreasing agent. Specifically, this mass ratio can be precisely controlled in several ways. For example, an automated mixing system can be used to precisely control the amount of environmentally friendly degreasing agent and water added via a flow meter or metering pump, to prepare a degreasing detergent solution conforming to this ratio in real time or in batches. Another method is to strictly weigh and mix according to a preset weight or volume ratio during batch preparation, ensuring that the concentration of the degreasing detergent solution prepared each time is within this range. Furthermore, online concentration monitoring devices, such as conductivity meters or refractometers, can be used to monitor the prepared degreasing detergent solution in real time, and the amount of environmentally friendly degreasing agent or water added can be adjusted based on the monitoring results to maintain its mass ratio within the range of 1:8 to 1:12. The purpose of setting this mass ratio is to provide a detergent solution with stable and efficient degreasing capabilities for subsequent rinsing steps.

[0064] In this optional embodiment, by specifying the mixing ratio of the environmentally friendly degreasing agent and water in the heat exchange tube rinsing step S1, the mass ratio of the environmentally friendly degreasing agent to water is controlled between 1:8 and 1:12, thereby balancing the degreasing effect and raw material utilization rate, and solving various problems caused by improper mixing ratios. This mixing ratio range ensures that all effective degreasing components in the environmentally friendly degreasing agent are fully dispersed and dissolved in the water, allowing them to fully exert their degreasing and cleaning effects, ensuring the degreasing capacity of the degreasing washing solution, and thus meeting the stringent degreasing requirements of ethylene oxide heat exchange tubes, especially those in ultra-large equipment, ensuring that the cleanliness of the heat exchange tubes after cleaning meets the usage requirements. At the same time, this mixing ratio range avoids unnecessary waste caused by excessively high degreasing agent concentration and the problem of degreasing agent residues on the inner wall of the heat exchange tube, thereby reducing the workload of subsequent cleaning treatments and effectively controlling cleaning costs. In addition, this formulation avoids the problem of insufficient degreasing capacity due to excessively low degreasing agent concentration, which fails to meet cleaning requirements. It can adapt to the high-efficiency cleaning needs of large-scale and ultra-large ethylene oxide heat exchange tubes, taking into account cleaning efficiency, cleaning quality and cleaning cost.

[0065] In some specific embodiments, after cleaning the ethylene oxide heat exchange tube, the cleanliness of the outer surface of the sponge bullets is visually inspected twice to determine whether the ethylene oxide heat exchange tube is clean and qualified. If there is no significant change in the color of the sponge bullets between the two cleanings, the cleaning is considered qualified. After cleaning the ethylene oxide heat exchange tube, a light transmission method is required to confirm that no sponge bullets remain inside the ethylene oxide heat exchange tube.

[0066] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An environmentally friendly degreasing agent, characterized in that, It includes emulsifier NP-10, sodium gluconate, sodium fatty alcohol polyoxyethylene ether sulfate, coconut oil diethanolamide, and water.

2. The environmentally friendly degreasing agent according to claim 1, characterized in that, By weight, it comprises 15 to 25 parts emulsifier NP-10, 10 to 20 parts sodium gluconate, 5 to 15 parts sodium fatty alcohol polyoxyethylene ether sulfate, 5 to 15 parts coconut oil diethanolamide and 40 to 50 parts water.

3. A cleaning method for ultra-large ethylene oxide heat exchange tubes, characterized in that, Degreasing and cleaning are performed using the environmentally friendly degreasing agent as described in claim 1 or 2.

4. The cleaning method for ultra-large ethylene oxide heat exchange tubes according to claim 1, characterized in that, Includes the following steps: S1: Dissolve the aforementioned environmentally friendly degreasing agent in water at 20°C to 40°C to form a degreasing washing solution, and rinse the ultra-large ethylene oxide heat exchange tubes. S2: Use compressed air to purge the ultra-large ethylene oxide heat exchange tube to remove the liquid accumulated inside the tube; S3: A sponge bullet is inserted into one end of the ultra-large ethylene oxide heat exchange tube, and the sponge bullet is fired from the other end of the ultra-large ethylene oxide heat exchange tube using an air gun.

5. The cleaning method for ultra-large ethylene oxide heat exchange tubes according to claim 4, characterized in that, Repeat steps S1 to S3 once or more until the inside of the ultra-large ethylene oxide heat exchange tube is clean.

6. The cleaning method for ultra-large ethylene oxide heat exchange tubes according to claim 4, characterized in that, The sponge bullet is cylindrical, and its diameter is 5mm to 7mm larger than the inner diameter of the ultra-large ethylene oxide heat exchange tube.

7. The cleaning method for ultra-large ethylene oxide heat exchange tubes according to claim 6, characterized in that, The length of the sponge bullet is 1.2 to 1.5 times the diameter of the sponge bullet.

8. The cleaning method for ultra-large ethylene oxide heat exchange tubes according to claim 4, characterized in that, The density of the sponge bullet is between 70d and 75d.

9. The cleaning method for ultra-large ethylene oxide heat exchange tubes according to claim 4, characterized in that, In step S1, a high-pressure water gun with a pressure ≥450MPa is used to flush the ultra-large ethylene oxide heat exchange tube.

10. The cleaning method for the ultra-large ethylene oxide heat exchange tube according to claim 4, characterized in that, In step S1, the mass ratio of the environmentally friendly degreasing agent to water is 1:8 to 1:12.

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