CN-121992415-A - Chemical pipeline rust removal neutral cleaning agent and application method thereof

Abstract

The invention discloses a chemical pipeline rust removal neutral cleaning agent and a use method thereof, which relate to the technical field of maintenance and cleaning of chemical equipment, the cleaning agent mainly comprises diammonium hydrogen citrate and ammonium hydrogen fluoride, the balance is water, the pH value is neutral, the scale on the inner wall of the pipeline is effectively removed by chelating diammonium hydrogen citrate and auxiliary activation of ammonium hydrogen fluoride under the near neutral pH environment, and the use method comprises two modes of static soaking and dynamic circulating cleaning, and can be flexibly selected according to working conditions. The invention can realize good rust removal effect, simultaneously control the corrosion to various metal materials such as carbon steel, chromium-molybdenum steel, stainless steel and the like to be very low, and the waste liquid after cleaning is nearly neutral, is environment-friendly and easy to treat, and has the advantages of high safety, simple and convenient operation and wide applicability.

Inventors

• FANG CHAO
• JI GUANGCHENG

Assignees

• 山东福佑德环保工程有限公司

Dates

Publication Date

20260508

Application Date

20260225

Claims (10)

1. 1. The chemical pipeline rust removal neutral cleaning agent is characterized by comprising the following components in percentage by mass: 2% to 5% of diammonium hydrogen citrate; ammonium bifluoride 0.01% to 0.1%; The balance being water; the cleaning agent is configured to act on the inner wall of the metal pipeline in a circulating flow cleaning mode under the conditions that the pH value is 5 to 7 and the temperature is normal temperature to 70 ℃.
2. 2. The chemical pipeline rust removing neutral cleaning agent according to claim 1, wherein the mass percentage concentration of the diammonium hydrogen citrate is 3-5%.
3. 3. The neutral detergent for rust removal of chemical pipelines according to claim 1, wherein the concentration of ammonium bifluoride is 0.03-0.05% by mass.
4. 4. The neutral detergent for rust removal of chemical pipelines according to claim 1, wherein the detergent has a pH value of about 6 in a use state.
5. 5. The neutral detergent for rust removal of chemical pipelines according to claim 1, further comprising a corrosion inhibitor, wherein the mass percentage concentration of the corrosion inhibitor is 0.1-0.3%.
6. 6. The neutral detergent for rust removal of chemical pipelines according to claim 1, further comprising an auxiliary organic acid, wherein the concentration of the auxiliary organic acid is 0.1-0.3% by mass, and the auxiliary organic acid is citric acid.
7. 7. A method for using a chemical pipeline rust removal neutral cleaning agent, which is applicable to the chemical pipeline rust removal neutral cleaning agent according to any one of claims 1 to 6, and is characterized by comprising the following specific steps: step one, contacting a metal pipeline part or system to be cleaned with the cleaning agent; Controlling the temperature of the cleaning process to be in the range of normal temperature to 70 ℃; and thirdly, rinsing the metal pipeline parts or the system after the cleaning is finished.
8. 8. The method for using the neutral detergent for rust removal of chemical pipelines according to claim 7, wherein in the first step, the metal pipeline components or systems to be cleaned are contacted with the detergent in a static soaking mode; the temperature of the static soaking is 60-70 ℃; the time of the static soaking is 5 to 12 hours.
9. 9. The method for using the neutral detergent for rust removal of chemical pipelines according to claim 7, wherein in the first step, the specific mode of contacting the metal pipeline components or systems to be cleaned with the detergent is dynamic circulation cleaning; the dynamic circulation cleaning is carried out at normal temperature; The time of the dynamic cycle cleaning is 7 to 16 hours; and after the dynamic circulation cleaning, the method further comprises a standing soaking step, wherein the standing soaking time is 8-15 hours.
10. 10. The method of claim 7, wherein in the third step, the metal pipe component or system is made of at least one of carbon steel, chromium-molybdenum steel and stainless steel; The chromium-molybdenum steel is fifteen chromium-molybdenum steel or twelve chromium-molybdenum steel; The stainless steel is 304 stainless steel or 316 stainless steel; The cleaning agent is used for carrying out rust removal treatment on an online industrial pipeline system formed by the materials in a dynamic circulation cleaning process, and the flowing state of the cleaning agent is full pipe flowing.

Description

Chemical pipeline rust removal neutral cleaning agent and application method thereof Technical Field The invention relates to the technical field of maintenance and cleaning of chemical equipment, in particular to a chemical pipeline rust removal neutral cleaning agent and a use method thereof. Background In the process industry of chemical industry, petroleum industry, metallurgy industry and the like, the inner wall of a metal pipeline is easy to corrode and form scale layers such as rust, oxide skin and the like due to long-term transportation of various mediums. The scale layers not only reduce the effective flow area of the pipeline and increase the energy consumption, but also can pollute products, block valve instruments and even cause pipeline perforation due to scale corrosion, thereby causing safety and environmental protection accidents. Therefore, chemical cleaning and rust removal are carried out on the in-service pipeline at regular intervals or in overhauling period, and are key links for guaranteeing production safety, improving energy efficiency and prolonging service life of equipment. At present, the chemical cleaning technology of the pipeline is mainly divided into two major categories of strong acid cleaning and environment-friendly cleaning. Although the strong acid (such as hydrochloric acid and nitric acid) is used for cleaning, the rust removal is rapid and thorough, the corrosion to a metal matrix is strong, the hydrogen embrittlement and the over-cleaning are easy to occur, the waste liquid treatment difficulty is high, and the environmental protection risk is high. In order to overcome the above drawbacks, environmental protection type cleaning technology is continuously developed. For example, patent publication No. CN103320801B discloses a long-life low-foam cleaning and rust-preventing two-in-one metal cleaning agent, the pH value of which is neutral, and the functions of cleaning and inter-process rust prevention are both achieved by compounding a plurality of surfactants, rust-preventing film forming agents and pH buffering agents in the formulation. In another example, the neutral cleaning prefilming agent technology guided by the concept of supermolecular chemistry claims to remove dirt through molecular recognition and form a protective film on the metal surface, thereby realizing no or low corrosion in the cleaning process. In addition, products such as ferrous sulfide scale neutral cleaning agents developed by domestic enterprises are also used for solving the problem of safe cleaning of specific scales. Although the safety of the existing environment-friendly cleaning agent is improved, the technical path of the environment-friendly cleaning agent is mostly dependent on complex surfactant compounding, polymer chelation or specific film forming mechanism. In practical application, especially when treating high-temperature oxide scale or stubborn rust scale on the inner wall of a pipeline with compact structure and strong adhesive force, the proposal often faces a contradiction that if extremely mild (such as strict neutral pH) is pursued, the chemical cleaning force is often insufficient, the cleaning period is long and the efficiency is low, and if more active ingredients are introduced to enhance the cleaning force, the broad-spectrum low corrosion characteristic on various metal materials (especially sensitive alloy steel) can be sacrificed, or the formula and the process become complex. Therefore, a new technical scheme is needed, and the problems that various industrial pipeline materials such as carbon steel, alloy steel and the like are efficiently derusted under the mild condition close to neutrality, and meanwhile, the corrosion rate is strictly controlled below the industrial safety standard (such as less than or equal to 6g/m < 2 >. H) can be solved. In summary, in the prior art, the field of chemical cleaning of pipelines has obvious limitations in terms of both "efficient cleaning" and "very low corrosion". The present invention is directed to solving the limitations of the prior art described above. Disclosure of Invention The invention aims to make up the defects of the prior art, provides a chemical pipeline rust removal neutral cleaning agent and a use method thereof, can effectively remove rust on the inner wall of a pipeline under a mild condition close to neutrality through the synergistic effect of diammonium hydrogen citrate and a trace amount of ammonium hydrogen fluoride, simultaneously controls the corrosion on various metal materials such as carbon steel, chromium molybdenum steel, stainless steel and the like at a very low level, solves the problem that high-efficiency cleaning and low corrosiveness are difficult to be compatible, and is easy to treat, safe and environment-friendly. The invention provides a chemical pipeline rust removal neutral cleaning agent for solving the technical problems, which comprises the following components in per