1. Application in Chelating Cleaning
Chelating agents, also known as complexing agents or ligands, utilize the complexation (coordination) or chelation of various chelating agents (including complexing agents) with scaling ions to generate soluble complexes (coordination compounds) for cleaning purposes.
Surfactants are often added to chelating agent cleaning to promote the cleaning process. Commonly used inorganic complexing agents include sodium tripolyphosphate, while commonly used organic chelating agents include ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA). Chelating agent cleaning is not only used for cooling water system cleaning but has also seen significant development in the cleaning of difficult-to-dissolve scales. Due to its ability to complex or chelate metal ions in various difficult-to-dissolve scales, it offers high cleaning efficiency.
2. Application in Heavy Oil Fouling and Coke Fouling Cleaning
In petroleum refining and petrochemical plants, heat exchange equipment and pipelines often suffer from severe heavy oil fouling and coke deposition, requiring frequent cleaning. The use of organic solvents is highly toxic, flammable, and explosive, while general alkaline cleaning methods are ineffective against heavy oil fouling and coke.
Currently, heavy oil fouling cleaners developed domestically and internationally are primarily based on composite surfactants, consisting of a combination of several nonionic and anionic surfactants, along with inorganic builders and alkaline substances. Composite surfactants not only produce effects such as wetting, penetration, emulsification, dispersion, solubilization, and foaming but also have the ability to absorb FeS₂. Generally, heating to above 80°C is required for cleaning.
3. Application in Cooling Water Biocides
When microbial slime is present in cooling water systems, non-oxidizing biocides are used, along with low-foaming nonionic surfactants as dispersants and penetrants, to enhance the activity of the agents and promote their penetration into cells and the mucus layer of fungi.
Additionally, quaternary ammonium salt biocides are widely used. These are some cationic surfactants, with the most common being benzalkonium chloride and benzyldimethylammonium chloride. They offer strong biocidal power, ease of use, low toxicity, and low cost. Besides their functions of stripping slime and removing odors from water, they also have corrosion inhibition effects.
Furthermore, biocides composed of quaternary ammonium salts and methylene dithiocyanate not only have broad-spectrum and synergistic biocidal effects but also prevent the growth of slime.
Post time: Sep-02-2025