Why should the cleaning and pre-filming of the circulating cooling water system be carried out?

Circulating cooling water system, whether it is a new system or an old system, must carry out system cleaning and pre-film work before driving for normal dosing. Cleaning and pre-membrane work is called pre-membrane treatment for chemical treatment of circulating water system. For the new system, it is inevitable that there will be debris, sundries and lime soil left in the system during the installation of equipment and pipelines. Sometimes the corrosion and oil contamination of cooling equipment are also very serious, if these debris and oil stains are not cleaned, it will affect the next pre-film treatment. The cooling equipment of the old system also often has dirt, slime and metal corrosion products, which seriously affects the equipment life and heat exchange efficiency. Therefore, the importance of cleaning work, for the new system, can improve the pre-film effect, reduce the generation of corrosion and scaling; For the old system, it can improve the heat exchange efficiency, improve the process operating conditions, ensure a long production cycle, reduce energy consumption and extend the service life of the equipment. Therefore, cleaning is an essential link in the operation of circulating water system. The prefilming of the circulating water system is to improve the film-forming effect of the corrosion inhibitor. Usually, a higher amount of corrosion inhibitor is added at the initial stage of the circulating water. After the film is formed, the concentration of the agent is reduced to maintain the film, that is, normal treatment. The purpose of this pre-film treatment is to quickly form a metal protective film on the metal surface to improve the corrosion inhibition effect of the corrosion inhibitor. Practice has also proved that in the same system, the corrosion inhibition effect of the equipment that has passed the pre-film and the pre-film is very different when the same corrosion inhibitor is used. Therefore, the pre-membrane work at the initial stage of circulating water start-up must be highly valued.