Precautions for shutting down circulating cooling water systems

Once in operation, the circulating cooling water generally keeps flowing continuously; only the system that needs to be cooled is shut down. Under normal circumstances, the circulating cooling water cannot be stopped, as a protective layer is formed on the surface of the equipment after the system has been cleaned and pre-coated, and the corrosion and scale-inhibiting agents present in the water continue to reinforce this protective layer while the system remains in operation. If parking, drain the water from the pipes; if driving again after more than 72 hours, the pre-coating needs to be cleaned ； If protection against leakage is not in place, parking is generally not allowed; allowing the water to circulate continuously can reduce corrosion of the piping and equipment by the water.

The water pump is fine; the main issue is the corrosion protection of the entire system. Contact the pharmaceutical manufacturer to develop a plan.

Implement strict accident management by earnestly applying the \"four no-lets-go\" principle, learning from past incidents, identifying the causes of accidents, and formulating preventive measures to reduce and eliminate various types of accidents, thereby ensuring the safety of property and employees’ lives and promoting production development. In the event of an accident, report it immediately to the supervisor and dispatch team. I. Circulating Water System 1. Reasons for excessive parameters in circulating water quality (1) The formula of the water quality stabilizer does not match the requirements of the water quality; this formula must be determined through simulation tests, as failing to change it will affect the quality of the circulating water. (2) The quality of the medication is unstable. (3) Chemical dosing is not carried out in a timely manner, and the amount of chemical added does not correspond to the requirements determined by water quality tests. (4) The amount of water filtered is small. (5) Dust gets blown into the circulating water system. (6) Wash away dirt in circulating water. 2. Treatment methods: (1) Select a water quality stabilizer formula suitable for the water quality. (2) Ensure the stable quality of the medication. (3) Implement strict water management, conduct tests on circulating water as required, and add chemicals in a timely manner. (4) Adjust the filtration water volume as needed. (5) Strengthen management to prevent materials and dust from entering the circulating water. (6) Prevent the manual washing of dirt in circulating water. 3. Once the circulating water returns to normal operation, scaling occurs severely on the heat exchange equipment and pipes; it is therefore necessary to continuously add chemicals to the system for water treatment in order to control scaling and corrosion and keep everything within the normal operational parameters. Reaction equation: (1) Formation of scale 　　　 △ Ca(HCO3)2 → CaCO3↓+H2O+CO2↑ After aeration, the CO2 dissolved in water escapes, so the pH value of the water increases. Ca(HCO3)2 + 2OH- → CaCO3↓ + 2H2O + CO32-; 2PO43- + 3Ca2+ → Ca3(PO4)2↓ + 6Cl-. (2) Principle of metal corrosion: Microcell theory – Anode region: Fe – 2e → Fe2+; Cathode region: 1/2O2 + H2O + 2e → 2OH-. When ferrous ions and hydroxide ions meet in water, Fe(OH)2 precipitate is formed; further oxidation leads to the formation of Fe(OH)3. 4. What should be done if the consumption of circulating water suddenly increases while the amount of water returning is low? 1) Report it promptly to the dispatching department and workshop management. ? 2) Notify all water users to inspect the pipelines in order to find out the cause of the increased water flow. ? 3) Increase the water supply volume to strive for a balanced circulating cooling water volume.

The question isn’t very clear – why does the pump need to be stopped? Should the device be shut down or has an accident occurred? If it needs to be stopped, the power supply must be turned off and the water inside removed; the equipment also needs to be rotated daily

To maintain water quality stability, it is important to pay attention to changes in the pH value; it should generally remain within a certain range, and this range must be compatible with that of the chemicals used

For short-term parking of 2-4 days, no special precautions are needed; in winter, it is necessary to drain the water from the collection tank and the suction tank, but there is no need to drain the water in the pipes. For long-term parking, the entire row needs to be cleaned again and coated with a preservative film

This post was last edited by ray1513 on 2012-4-28 at 15:32 to ensure proper maintenance of the equipment during parking periods, as well as to address any issues related to the equipment and processes

This post was last edited by ray1513 on 2012-4-28 at 15:31. For short-term parking, reducing the flow rate of the circulating water can help; it’s best not to stop the water flow entirely, as this may lead to severe corrosion. Current treatment technologies for circulating water are based on processing the water that is in circulation. For long-term parking, it is necessary to take protective measures before stopping use; generally, the water also needs to be drained. In winter, anti-freezing measures must be taken

This post was last edited by ray1513 on 2012-4-28 at 15:32. In fact, parking the system can be used for maintenance, cleaning, and coating it, which in turn helps to prepare it for protection in the next phase. If these are not needed, it is possible not to shut down the system completely for 10 days, as complete shutdown causes severe corrosion to the system; the cooling tower can be turned off. If the system is to remain parked for an extended period, anti-corrosion measures are required.