Two common cleaning methods for cooling towers(Ⅰ)

The Cooling Tower has been exposed to the outside for many years, and the adsorption force of the fan is very strong, causing a large amount of sediment and dirt to enter the tower. Long-term operation will gradually reduce the heat dissipation capacity of the cooling tower, and the outlet hole of the water distributor is easily blocked. Sand and dirt can easily enter the cooling water system, which will directly affect the normal cooling of the cooling water system. In order to prevent the above situation from happening, the cooling tower must be cleaned regularly. , There are two common cleaning methods.

method Ⅰ

Shutdown cleaning is to follow the cleaning process for sterilization and algae cleaning—cleaning with descaling agent—premembrane—cleaning after cleaning. This solution requires about 8 days of cleaning time in the shutdown state, and the descaling rate is over 95%.
Cleaning procedure: water flushing—sterilizing algae cleaning—cleaning agent descaling cleaning—rinsing after cleaning—pre-membrane—cleaning after cleaning.
 
1. Water flushing The purpose of water flushing is to use a large flow of water to wash away loose dirt such as dust, sediment, shed algae and corrosion in the system as much as possible, and at the same time check the leakage of the system. The flow rate of the flushing water should be greater than 0.15m/s, and the flushing water in the system should be drained after the flushing is qualified.

2. Sterilization and algae cleaning The purpose of sterilization and algae cleaning is to kill the microorganisms in the system and peel off the biological slime attached to the surface of the equipment. After draining the flushing water, add bactericide and algicide to the system for cleaning, and stop cleaning when the turbidity of the system tends to balance.

3. Descaling and cleaning with cleaning solution The purpose of cleaning with cleaning solution is to use the cleaning agent to dissolve the scale and oxides in the system and then dissolve them in water to wash them away. Add the cleaning agent to the central air-conditioning system and use the circulation pump to circulate and clean it, and then empty it at the highest point and discharge the sewage at the lowest point, so as to avoid air resistance and blockage of the shower guide, which will affect the cleaning effect. During cleaning, the cleaning solution concentration, metal ion (Fe2+, Fe3+, Cu2+) concentration, temperature, pH value, etc. should be checked regularly, and the cleaning should be ended when the metal ion concentration tends to be flat.

4. Rinse after cleaning The purpose of this water rinsing is to wash away the remaining cleaning solution and impurities during cleaning. The purpose of rinsing is to continuously open the shower to wash away the impurities and residual liquid deposited in the short tube. Flushing is to constantly test the pH value and turbidity, and end the flushing when the pH value and turbidity tend to be flat.

5. Pre-film The purpose of pre-film is to form a complete corrosion-resistant protective film on the metal surface that is in an activated state after cleaning or on the metal surface that has been damaged by the protective film.

6. Clean up the cooler and evaporator after cleaning. After cleaning, the cooler and evaporator of the main engine should be opened and the cooler should be flushed with a special pipe-through pipe one by one. Because the water circulation system of the cooler is exposed to the atmosphere and heat The exchange temperature is high, so the fouling of the cooler will be more serious than other places. If necessary, the open circulation system connected to the cooler should be cleaned and descaled to ensure that each copper pipe in the cooler is unblocked. Rinse the evaporator with high-pressure water to thoroughly wash away the impurities deposited in the evaporator, and if necessary, clean the external circulation system of the evaporator separately. Cooling tower cleaning, because the cooling tower is exposed to the atmosphere, there will be a lot of sediment, algae, etc. attached to the surface of the cooling tower packing during operation, if it is not cleaned, these dirt will be washed into the cooler in the future operation to cause cooling The blockage of the heat exchange copper tube in the cooling tower will affect the heat exchange effect, so the cooling tower must be thoroughly cleaned.