Cleaning method of paint conveying and mixing system

Abstract

The invention provides a cleaning method of a paint conveying and mixing system, and relates to the technical field of automobile coating. The cleaning method comprises the steps that firstly, a compressed air source is connected to purge a circulating tank and a system pipeline connected with the circulating tank; 2, carrying out circulating cleaning on the circulating tank and the system pipeline by using a glycol ether solvent; step 3, passivating and neutralizing the system pipeline; fourthly, a lipid oily solvent is used for conducting circulating cleaning on the circulating tank and the system pipeline; and fifthly, pure water is used for conducting circulating cleaning on the circulating tank and the system pipeline, and a compressed air source is connected to blow-dry the system.

Description

Technical Field

[0001] The present application relates to the technical field of automobile painting, and in particular to a method for cleaning a paint conveying and mixing system. Background Art

[0002] The paint delivery and mixing system of the paint shop is the core component of the painting production line. It integrates functions such as paint storage, precise mixing, stable transportation, efficient filtration and temperature control to ensure that the paint is delivered to the painting station in the best condition to meet the needs of efficient, accurate and environmentally friendly painting operations.

[0003] The cleaning of the newly built paint delivery and mixing system in the paint shop is extremely important, as it is directly related to the coating quality and production efficiency. Before the system is put into use, thorough cleaning can remove impurities, grease and previously existing chemicals in the pipes, tanks and equipment, etc., to prevent these pollutants from mixing into the new paint and affecting the adhesion, gloss and durability of the coating; at the same time, cleaning is also a key step to prevent blockage and ensure smooth operation of the system, which helps to extend the service life of the equipment, reduce maintenance costs, and ensure the stability and reliability of the coating process.

[0004] At present, acrylic oily cleaning resins or polyester water-based cleaning resins are mostly used to clean newly built paint delivery and mixing systems. However, resin cleaning has the disadvantages of high viscosity and slow circulation, which affects the cleaning effect and efficiency. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a method for cleaning a paint delivery system to solve the technical problems that acrylic oily cleaning resins or polyester water-based cleaning resins have high viscosity and slow circulation, which affects the cleaning effect and efficiency.

[0006] In order to solve the above technical problems, the embodiments of the present application provide the following technical solutions:

[0007] The present application provides a method for cleaning a paint conveying and mixing system, the method comprising: a first step of connecting a compressed air source to purge a circulation tank and system pipelines connected thereto;

[0008] Step 2: Using glycol ether solvent to circulate and clean the circulation tank and the system pipeline;

[0009] The third step is to passivate and neutralize the system pipeline;

[0010] Step 4: Use lipid oily solvent to circulate and clean the circulation tank and the system pipeline;

[0011] Step 5: Use pure water to circulate and clean the circulation tank and the system pipelines, and connect a compressed air source to blow dry the system.

[0012] In some modified implementations of the present application, the second step is specifically:

[0013] Add the glycol ether solvent into the circulation tank to ensure that the liquid level is above the stirring blade, install a 5μm filter bag in the system pipeline, replace the filter bag every 4 hours, and after circulating and cleaning with a circulation pump for 24 hours, drain the solvent in the system into an empty paint barrel and transfer it to a hazardous waste area for treatment.

[0014] In some modified implementations of the present application, the second step is performed at least twice.

[0015] In some modified implementations of the present application, in the third step, an external container is used instead of the circulation tank, and an external pneumatic pump is used instead of the circulation pump, and is connected to the system pipeline.

[0016] In some modified implementations of the present application, the third step is specifically:

[0017] Citric acid or nitric acid is added to the external container, and diluted with pure water to a pH of 3-4, and circulated through the external pneumatic pump until passivation is completed. Sodium carbonate or sodium bicarbonate is added to the external container to neutralize to a pH of 6-7, and the liquid in the external container is directly discharged to a sewage treatment station through a pit for treatment.

[0018] In some modified implementations of the present application, the third step further includes:

[0019] At least two sections of pipeline scraps are used as test samples to be passivated synchronously with the system pipeline. The test samples are taken out every hour and passivation test is performed on the test samples using a passivation test reagent. After passing, the passivation is judged to be completed and the cycle ends.

[0020] In some modified implementations of the present application, the fourth step is specifically:

[0021] Add the lipid oily solvent into the circulation tank to ensure that the liquid level covers the stirring blade, install a 5μm filter bag in the system pipeline, replace the filter bag every 4 hours, and after circulating and cleaning with a circulation pump for 24 hours, drain the solvent in the system into an empty paint barrel and transfer it to a hazardous waste area for treatment.

[0022] In some modified implementations of the present application, the fourth step is performed at least twice.

[0023] In some modified implementations of the present application, before executing the third step, the method further includes:

[0024] After the glycol ether solvent is discharged, use pure water to circulate in the system at least once and then discharge it, and connect a compressed air source to blow the system dry and wait for passivation treatment.

[0025] In some modified embodiments of the present application, the glycol ether solvent is ethylene glycol butyl ether solvent; and / or,

[0026] The lipid oily solvent is butyl acetate solvent.

[0027] Compared with the prior art, the cleaning method of the paint delivery system provided in the present application first purges the system with compressed air to ensure that the cleaning solvent used subsequently can more effectively contact the inner wall of the system pipe and the inner wall of the tank. The glycol ether solvents can effectively remove grease, impurities and preliminary residues inside the system due to their good solubility and permeability, and lipid oily solvents can further dissolve and remove more stubborn stains, ensuring comprehensive cleaning of the system, and can achieve deep cleaning of different levels of the system, improving the cleaning effect and efficiency; passivation treatment is performed between the two cleaning steps to form a protective film on the surface of the system, and the pre-cleaning can avoid the influence of impurities in the system on the passivation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become easy to understand. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0029] Figure 1 The flowchart of the cleaning method of the paint conveying and mixing system provided by the embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0030] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by technicians in the field to which this application belongs.

[0032] Example

[0033] Reference Figure 1 , an embodiment of the present invention provides a method for cleaning a paint conveying and mixing system, the cleaning method comprising:

[0034] The first step is to connect the compressed air source to purge the circulation tank and the system pipelines connected to it;

[0035] Among them, before cleaning and passivation, the system pipeline is connected to the compressed air source, and the circulating tank and its connected system pipeline are purged by compressed air. The purging time can last for 1 hour. To ensure the cleanliness of the purging, white non-woven fabric can be tied to the return pipe port of the system pipeline 5 minutes before the end of the purging. According to the cleanliness of the white non-woven fabric, it is determined whether the purging time needs to be extended. After the purging, the inner wall of the circulating tank and the internal agitator and stirring blades are wiped clean. After purging, the mud, sand, grease, welding slag and rust remaining in the system pipeline, tank body and valve during the installation and construction process can be removed, ensuring that the cleaning solvent used later can more effectively contact the inner wall of the system pipeline and the inner wall of the tank body, reducing the interference of impurities on the cleaning solvent, thereby improving the cleaning effect; at the same time, purging first can also check the installation quality of the system pipeline, help to discover potential problems and deal with them in time, and create favorable conditions for the subsequent cleaning process.

[0036] Step 2: Using glycol ether solvent to circulate and clean the circulation tank and the system pipeline;

[0037] Among them, glycol ether solvents have good solubility, low volatility and chemical stability. They can efficiently dissolve and remove pollutants such as grease, impurities, etc. in system pipes and tanks. Through circulating cleaning, they can ensure that the solvent contacts and penetrates every corner of the system pipes and tanks to achieve comprehensive cleaning. This cleaning method can also improve the cleaning effect and reduce cleaning time and cost.

[0038] The third step is to passivate and neutralize the system pipeline;

[0039] Among them, after the system is initially cleaned with glycol ether solvents, the system pipelines are passivated, and a thin, dense and highly adhesive passivation film is formed by allowing the metal surface to react with the oxidizing medium. This can enhance the corrosion resistance of the material; the neutralization treatment can balance and adjust the pH in the system to ensure that the system is in a stable state.

[0040] Step 4: Use lipid oily solvent to circulate and clean the circulation tank and the system pipeline;

[0041] Among them, in the second step of cleaning, glycol ether solvents can preliminarily remove most of the grease, impurities and residues in the system pipes, tanks and valves due to their good solubility and permeability. In this step, lipid oily solvents are used for deep and comprehensive cleaning, which can further dissolve and remove difficult-to-remove stubborn stains, thereby improving the overall cleaning efficiency.

[0042] Step 5: Use pure water to circulate and clean the circulation tank and the system pipelines, and connect a compressed air source to blow dry the system.

[0043] Among them, the final circulation cleaning with pure water can completely remove the residual solvents and impurities in the system, ensure the cleanliness inside the system, prevent the residual solvent from adversely affecting the subsequent coating quality, and ensure that the system is free from corrosion.

[0044] Specifically, the cleaning method provided in this embodiment is applied to the cleaning of a newly built paint supply and mixing system in a paint shop, mainly for cleaning the system pipelines of the paint supply and mixing system, and the process also includes the cleaning of the circulation tank. Of course, the above method steps can also be used to clean the paint mixing tank of the paint supply and mixing system. The paint mixing tank can store glycol ether solvents or lipid oily solvents and transfer them to the circulation tank.

[0045] According to the above, an embodiment of the present invention proposes a method for cleaning a paint conveying and mixing system. First, the system is purged with compressed air to ensure that the cleaning solvent used subsequently can more effectively contact the inner wall of the system pipeline and the inner wall of the tank. Glycol ether solvents can effectively remove grease, impurities and preliminary residues inside the system due to their good solubility and permeability. Lipid oily solvents can further dissolve and remove more stubborn stains, ensuring comprehensive cleaning of the system. It can achieve deep cleaning of different levels of the system and improve the cleaning effect and efficiency. Passivation treatment is performed between the two cleaning steps to form a protective film on the surface of the system, and the pre-cleaning can avoid the influence of impurities in the system on the passivation effect.

[0046] For further information, see Attachment Figure 1 In the specific implementation, the second step is specifically as follows: add the glycol ether solvent into the circulation tank to ensure that the liquid level does not exceed the stirring blade, install a 5μm filter bag in the system pipeline, replace the filter bag every 4 hours, and after circulating and cleaning for 24 hours through a circulation pump, drain the solvent in the system into an empty paint barrel and transfer it to a hazardous waste area for treatment.

[0047] Specifically, in the technical solution adopted by the present invention, glycol ether solvents are used as the main cleaning medium in the second step of the cleaning operation to deeply clean the system; in order to ensure that the glycol ether solvent can fully contact and clean various positions inside the system, it is necessary to add a sufficient amount of solvent in the circulation tank to ensure that the liquid level at least covers the stirring blades of the agitator. The high-speed rotation and stirring of the stirring blades promote the mixing and tumbling of the fluid during the solvent circulation process, so that the solvent can more effectively dissolve and remove grease, impurities and residues in the system; a 5μm filter bag is installed on the system pipeline to intercept extremely small particles. To ensure the filtering effect, the filter bag is replaced after every 4 hours of circulation cleaning; the entire circulation cleaning process lasts for 24 hours, during which the circulation pump continues to work to promote the circulation of the solvent in the system. This continuous circulation action not only enhances the contact between the solvent and the inner wall and components of the system, but also promotes the dissolution and peeling of impurities in the system, thereby improving the cleaning effect; after the circulation cleaning is completed, the solvent is discharged into an empty paint barrel and transferred to a hazardous waste area for more rigorous and professional treatment.

[0048] Among them, in this embodiment, the second step of using glycol ether solvents to clean the system needs to be performed twice. After the first cycle of cleaning with glycol ether solvents is completed, the solvent in the system is emptied and the second cycle of cleaning with glycol ether solvents is repeated.

[0049] The glycol ether solvent used in the second cleaning process may be, but is not limited to, ethylene glycol butyl ether solvent.

[0050] Specifically, before executing the third step, the following steps are also included: after the glycol ether solvent is discharged, pure water is circulated in the system at least once before being discharged, and a compressed air source is connected to blow the system dry, and wait for passivation treatment. This can completely remove the solvent and other impurities remaining in the system, ensure that the system pipeline and the inner wall of the circulation tank are clean and free of dirt, provide a good foundation for the formation of the passivation film, and improve the passivation quality, and enhance the adhesion and corrosion resistance of the passivation layer.

[0051] For further information, see Attachment Figure 1 In a specific implementation, in the third step, an external container is used to replace the circulation tank, and an external pneumatic pump is used to replace the circulation pump, and is connected to the system pipeline.

[0052] Specifically, in order to prevent the circulation tank and the circulation pump from being corroded by acid, in the technical solution adopted by the present invention, when performing the passivation treatment in the third step, a medium-strong acid is used. Therefore, in this step, the circulation tank and the circulation pump of the system are not used to participate in the circulation of the system pipeline. Instead, an external container is used instead of the circulation tank, and an external pneumatic pump is used instead of the circulation pump, and they are connected to the system pipeline to realize circulation.

[0053] For further information, see Attachment Figure 1 In a specific implementation, the third step is specifically as follows: adding citric acid or nitric acid to the external container, diluting it with pure water to a pH of 3-4, circulating it through the external pneumatic pump until passivation is completed, adding sodium carbonate or sodium bicarbonate to the external container to neutralize it to a pH of 6-7, and then directly discharging the liquid in the external container through a pit to a sewage treatment station for treatment.

[0054] Specifically, in the technical solution adopted by the present invention, in the third step of cleaning the paint delivery system, citric acid or nitric acid is first added to an external container, and then diluted with pure water until the pH value of the solution is stabilized between 3-4, forming a medium-strong acid environment, and the solution is circulated to all corners of the system through an external pneumatic pump, aiming to passivate the system pipeline. After the passivation is completed, the system stops circulating. In order to neutralize the acidic solution and restore the pH of the system to a neutral range, an appropriate amount of sodium carbonate or sodium bicarbonate can be added to the external container. These two alkaline substances can effectively react with the acidic solution to adjust the pH value of the solution to between 6 and 7. After the system is neutralized, the liquid in the external container can be directly discharged to the sewage treatment station through a pit for further treatment and purification to ensure that the discharged wastewater meets the national or local environmental protection standards and does not cause adverse effects on the environment. .

[0055] For further information, see Attachment Figure 1 In a specific implementation, the third step also includes: using at least two sections of pipeline scraps as test samples to be passivated synchronously with the system pipeline, taking out the test samples every hour, and using a passivation test reagent to perform a passivation test on the test samples until the passivation is determined to be completed after passing the test and ending the cycle.

[0056] Specifically, in order to ensure that the passivation effect of the system pipeline in the third step can meet the standard, the technical solution adopted by the present invention uses two sections of pipeline scraps as test samples and installs them into the system pipeline, and passivation is performed synchronously with the system pipeline. The staff takes out the test samples every hour, and uses the passivation detection reagent to drip onto the test samples to detect the passivation effect. When the passivation effect of the test sample reaches the passivation standard, it can be judged that the passivation process of the entire system pipeline has been completed, and the cycle can be ended immediately, thereby ensuring that the entire system pipeline has good corrosion resistance, providing a basis for subsequent stable operation.

[0057] For further information, see Attachment Figure 1 In the specific implementation, the fourth step is specifically as follows: add the lipid oily solvent into the circulation tank to ensure that the liquid level does not exceed the stirring blade, install a 5μm filter bag in the system pipeline, replace the filter bag every 4 hours, and after circulating and cleaning with a circulation pump for 24 hours, drain the solvent in the system into an empty paint barrel and transfer it to a hazardous waste area for treatment.

[0058] Specifically, in the technical solution adopted by the present invention, after the passivation is completed, a lipid oily solvent is used as a cleaning medium to further clean the system pipeline and the circulation tank, which can further remove stubborn stains, grease, particles and impurities that may remain in the system. When performing this step, it is necessary to add a sufficient amount of lipid oily solvent to the circulation tank to ensure that the liquid level is above the stirring blade. The high-speed rotation and stirring of the stirring blade promotes the mixing and tumbling of the fluid during the solvent circulation process, so that the solvent can more effectively dissolve and take away the grease, impurities and residues in the system; a 5-micron filter bag is installed on the system pipeline, aiming to Effectively intercept and remove particles with a diameter greater than 5 microns, maintain the cleanliness of the cleaning solvent, and prevent impurities from re-entering the system. After every 4 hours of circulating cleaning, replace the filter bag; the entire circulating cleaning process lasts for 24 hours, during which the circulating pump continues to work to promote the circulation of the solvent in the system. This continuous circulation not only enhances the contact between the solvent and the inner wall and components of the system, but also promotes the dissolution and peeling of impurities in the system, thereby improving the cleaning effect; after the circulating cleaning is completed, the solvent is discharged into the empty paint barrel and transferred to the hazardous waste area for more rigorous and professional treatment. .

[0059] Among them, in this embodiment, the fourth step of using a lipid oily solvent to clean the system needs to be performed twice. After the first cycle of cleaning with the lipid oily solvent is completed, the solvent in the system is emptied and then the second cycle of cleaning with the lipid oily solvent is repeated.

[0060] The lipid oily solvent used in the fourth step of cleaning may be, but is not limited to, butyl acetate solvent.

[0061] It should be noted that in the description of this specification, the terms "upper", "lower", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does 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 cannot be understood as a limitation on the present invention; the terms "connect", "install", "fixed", etc. should be understood in a broad sense, for example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for cleaning a paint delivery system, characterized in that: include: The first step is to connect the compressed air source to purge the circulation tank and the system pipelines connected to it; Step 2: Using glycol ether solvent to circulate and clean the circulation tank and the system pipeline; The third step is to passivate and neutralize the system pipeline; Step 4: Use lipid oily solvent to circulate and clean the circulation tank and the system pipeline; Step 5: Use pure water to circulate and clean the circulation tank and the system pipelines, and connect a compressed air source to blow dry the system.

2. The method for cleaning the paint delivery system according to claim 1, characterized in that: The second step is specifically as follows: Add the glycol ether solvent into the circulation tank to ensure that the liquid level is above the stirring blade, install a 5μm filter bag in the system pipeline, replace the filter bag every 4 hours, and after circulating and cleaning with a circulation pump for 24 hours, drain the solvent in the system into an empty paint barrel and transfer it to a hazardous waste area for treatment.

3. The method for cleaning the paint delivery system according to claim 1 or 2, characterized in that: The second step is performed at least twice.

4. The method for cleaning the paint delivery system according to claim 1, characterized in that: In the third step, an external container is used to replace the circulation tank, and an external pneumatic pump is used to replace the circulation pump, and is connected to the system pipeline.

5. The method for cleaning the paint delivery system according to claim 4, characterized in that: The third step is specifically as follows: Citric acid or nitric acid is added to the external container, and diluted with pure water to a pH of 3-4, and circulated through the external pneumatic pump until passivation is completed. Sodium carbonate or sodium bicarbonate is added to the external container to neutralize to a pH of 6-7, and the liquid in the external container is directly discharged to a sewage treatment station through a pit for treatment.

6. The method for cleaning the paint delivery system according to claim 5, characterized in that: The third step also includes: At least two sections of pipeline scraps are used as test samples to be passivated synchronously with the system pipeline. The test samples are taken out every hour and passivation test is performed on the test samples using a passivation test reagent. After passing, the passivation is judged to be completed and the cycle ends.

7. The method for cleaning the paint delivery system according to claim 1, characterized in that: The fourth step is specifically as follows: Add the lipid oily solvent into the circulation tank to ensure that the liquid level covers the stirring blade, install a 5μm filter bag in the system pipeline, replace the filter bag every 4 hours, and after circulating and cleaning with a circulation pump for 24 hours, drain the solvent in the system into an empty paint barrel and transfer it to a hazardous waste area for treatment.

8. The method for cleaning the paint delivery system according to claim 1 or 7, characterized in that: The fourth step is performed at least twice.

9. The method for cleaning the paint delivery system according to claim 1, characterized in that: Before executing the third step, the method further includes: After the glycol ether solvent is discharged, use pure water to circulate in the system at least once and then discharge it, and connect a compressed air source to blow the system dry and wait for passivation treatment.

10. The method for cleaning the paint delivery and mixing system according to claim 1, characterized in that: The glycol ether solvent is ethylene glycol butyl ether solvent; and / or, The lipid oily solvent is butyl acetate solvent.

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