Flow chart of cooling tower cleaning treatment scheme 1: shutdown cleaning
That is, according to the cleaning process, sterilization and algae removal cleaning? Cleaning agent. Cleaning? -Pre-movie? -Cleaning after cleaning. The scheme needs to be cleaned for about 8 days in the shutdown state, and the scale removal rate is above 95%.
Cleaning procedure: water washing? Sterilization and algae removal cleaning? Cleaning agent descaling cleaning? Rinse after cleaning? Before the movie? Cleaning after cleaning.
1, water flushing
The purpose of water washing is to wash away the loose dirt such as dust, sediment, algae and corrosion in the system as much as possible with large flow of water, and at the same time check the leakage of the system. The flow rate of flushing water should be greater than 0. 15m/s, and the flushing water in the system should be discharged after the flushing is qualified.
2, sterilization and algae cleaning
The purpose of sterilization and algae removal cleaning is to kill the microorganisms in the system and peel off the biological slime attached to the surface of the equipment. After the washing water is discharged, add sterilization and algaecide to the system for cleaning, and stop cleaning when the turbidity of the system tends to balance.
3, cleaning liquid descaling cleaning
The purpose of cleaning with cleaning solution is to dissolve the scale and oxide in the system with cleaning agent and then dissolve it in water to wash it off. Add the cleaning agent into the central air conditioning system and circulate it with a circulating pump to drain water at the highest and lowest points to avoid air resistance and drainage blockage, which will affect the cleaning effect. During cleaning, the concentration of cleaning solution, the concentration of metal ions (Fe2+, Fe3+, Cu2+), temperature, PH value, etc. Should be tested regularly, when the concentration of metal ions tends to be flat, the cleaning should be ended.
Step 4 rinse after cleaning
The purpose of this water washing is to wash away the residual cleaning solution and impurities in the cleaning process. Flushing is to disconnect the guide shower and wash away the impurities and residual liquid deposited in the short pipe. Flushing is to continuously test PH and turbidity, and end flushing when PH and turbidity tend to be flat.
5, prefilming
The purpose of prefilming is to form a complete corrosion-resistant protective film on the metal surface activated after cleaning or the metal surface with damaged protective film.
6. Cleaning after cleaning
Cooler evaporator cleaning. After cleaning, open the cooler and evaporator of the main engine, and rinse the coolers one by one with a special pipe opener. Because the water circulation system of the cooler is exposed to the atmosphere and the heat exchange temperature is high, the scaling of the cooler will be more serious than that in other places. If necessary, the cooler should be cleaned and descaled by an external open circulation system to ensure the smooth flow of copper pipes in the cooler. Rinse the evaporator with high-pressure water, thoroughly rinse off the impurities deposited in the evaporator, and if necessary, clean the evaporator with a separate external circulation system.
Cooling tower cleaning. Because the cooling tower is exposed to the atmosphere, there will be a lot of sediment, algae and so on. Attached to the packing surface of the cooling tower during operation. If it is not cleaned, these dirt will be washed into the cooler in the future operation, which will cause the blockage of the heat exchange copper tube in the cooler and affect the heat exchange effect. Therefore, the cooling tower must be thoroughly cleaned.
Option 2: Neutral cleaning without shutdown
Under the normal operation of the unit, neutral cleaning agent is added to the cooling water, and the chilled water system is circularly cleaned for about 30 days, then the cleaning liquid is discharged, and the cleaning process of the maintenance agent is finished. This scheme takes a long time to clean, but it can be carried out under the normal operation of the unit and will not affect the normal operation of the unit.
After all the maintenance and cleaning work of the cooling tower is completed, the cooling water and chilled water systems should be chemically maintained. Adding corrosion and scale inhibitors to chilled water system can form stable complexes with metal ions such as iron, copper and zinc to prevent the corrosion of oxygen and metal ions in water. Through chelation, inhibition and lattice distortion. It can prevent scaling salt in water from forming scale. So as to play the role of corrosion and scale inhibition. Add bactericide and algaecide into cooling water. Because the cooling water system is open, fungi and algae will be produced in the process of recycling. Bactericides and algaecides can inhibit the generation and survival of fungi and algae, thus playing a role in regulating water quality.
Application field of cooling tower (I) Iron and steel industry
According to the top ten domestic iron and steel enterprises, they are: Shanghai Baosteel Group, Shougang Group, Anshan Iron and Steel Group, Benxi Iron and Steel Group, Wuhan Iron and Steel Group, Panzhihua Iron and Steel Group, Guangzhou Iron and Steel Group, Taiyuan Iron and Steel Group, Jiangsu Shagang Group and Handan Iron and Steel Group. Maanshan Iron and Steel (Group) Co., Ltd., which ranks 1 1, has nearly 450,000 tons/hour cooling towers. (Note: The standard unit t/h is used below)
Cooling towers play an important role in these enterprises, providing a strong guarantee for enterprises to complete production tasks, and with the increasing scale of iron and steel enterprises, the demand for cooling towers is increasing.
Description: 15 The total tonnage of cooling towers in iron and steel enterprises is about 8.95 million t/h. ..
(2) Chemical industry
At present, the top three domestic chemical enterprises are Sinopec Group, China Petroleum and Natural Gas Group and China Sinochem Group. The chemical industry has developed vigorously in recent years and has increasingly become a pillar industry of the gross national product.
It is understood that Sinopec currently has H-share companies 1 0 in Zhenhai Refining and Chemical Company and A-share listed companies 10, including Yizheng Chemical Fiber, Shanghai Petrochemical, Yangzi Petrochemical, Qilu Petrochemical, Petrochemical, China Phoenix, Zhongyuan Oil and Gas, PetroChina Daming, Wuhan Petroleum and Taishan Petroleum, among which Yizheng Chemical Fiber and Shanghai Petrochemical also contain H-shares.
(3) Textile industry (chemical fiber, printing and dyeing)
Textile industry is one of the important pillar industries of China's national economy. According to the list of China textile and chemical fiber printing and dyeing industry 10 top enterprises published by China Textile Industry Association, the domestic textile and chemical fiber industry is mainly represented by China Yizheng Chemical Fiber Co., Ltd., China Shenma Group Co., Ltd., Jilin Chemical Fiber Group Co., Ltd., Zhejiang Huafeng spandex Co., Ltd. and Guangdong Xinhui Meida Nylon Co., Ltd..
The textile printing and dyeing industry is represented by Zhejiang Yongtong Printing and Dyeing Group Co., Ltd., Zhejiang Hangmin Industrial Group Co., Ltd., Zhejiang Meixinda Printing and Dyeing Group Co., Ltd., Shandong Dahai Group Co., Ltd., Hutai (Panyu) Textile Printing and Dyeing Co., Ltd., Tianlong Holding Group Co., Ltd., Zhejiang Hua Gang Printing and Dyeing Co., Ltd., Zhejiang Huzhou Dagang Textile Printing and Dyeing Group Co., Ltd., Zhejiang Wanhengsheng Printing and Dyeing Co., Ltd. and Zhejiang Shaoxing Huayu Printing and Dyeing.
As an important equipment of refrigeration system, cooling tower is widely used and an indispensable part in the production process. The cooling tower is mainly used in the constant temperature workshop of chemical fiber industry and the printing and dyeing wastewater treatment system of textile printing and dyeing owners. Only the textile and chemical fiber printing and dyeing industry needs 560 million yuan for the new tower every year, and the old tower is rebuilt at an average annual rate of 368 million yuan. A total of 928 million yuan.
Graphic diagram of annual demand of cooling tower in textile and chemical fiber printing and dyeing industry
(4) Pharmaceutical industry
The top 20 domestic pharmaceutical companies are Yang Zijiang Pharmaceutical Group, Livzon Pharmaceutical Group, jiangsu hengrui Pharmaceutical Group, Harbin Pharmaceutical Group, Guangzhou Baiyun Mountain Tianxin Pharmaceutical Co., Ltd., Qilu Pharmaceutical Co., Ltd., Shandong Lunan Pharmaceutical Company, Shanghai Xinxianfeng Pharmaceutical Company, Huabei Pharmaceutical, Yaoyou Pharmaceutical Co., Ltd., Shanxi Pude Pharmaceutical Co., Ltd., Jiangsu Haosen Pharmaceutical Co., Ltd., Jiangsu Lianyungang Haosen Pharmaceutical Co., Ltd. Shandong Ruiyang Pharmaceutical Co., Ltd., Suzhou Dong Rui Pharmaceutical Co., Ltd., Shanghai No.1 Biochemical Pharmaceutical Company, Jilin Weiwei Pharmaceutical Co., Ltd., North China Pharmaceutical Group Shaanxi Bokang Pharmaceutical Co., Ltd., Guizhou Baiyi Pharmaceutical Co., Ltd., North China Pharmaceutical Jintan Biotechnology Development Co., Ltd., Hunan Xiangbei willman Pharmaceutical Co., Ltd.
Cooling towers are used in various production lines in pharmaceutical industry. Almost every workshop has cooling tower equipment, cooling water 150t/h? 300 tons/hour. A large pharmaceutical company has an independent production line and corresponding cooling tower equipment, which is suitable for different types of products.
(vi) Paper industry
The top enterprises in the paper industry are Zhenjiang Jin Dong Paper Co., Ltd., Ningbo Zhonghua Paper Co., Ltd., Shandong Chenming Paper Group Co., Ltd., Shandong Bohui Paper Group, Hunan Yueyang Forest Paper Group Co., Ltd., Heilongjiang Starr Paper Co., Ltd., Zhejiang Jingxing Paper Co., Ltd., Shandong Taishan Paper Co., Ltd., Mudanjiang Hengfeng Paper Group Co., Ltd. and Shanghai Dongbao Yong Lian Paper Co., Ltd.
Take Zhenjiang Jin Dong Paper Co., Ltd. as an example: According to our investigation, the annual output of paper products in this factory is about 6.5438+0.8 million tons, and the total number of cooling towers used in its production process is about 45,000 t/h.
According to the statistics of the paper industry, the current domestic annual output is about 38 million tons. Based on this, it is estimated that the consumption of cooling towers for paper making and printing is at least about 500,000 t/h. ..
(seven) service industry (including hospitals, hotels, office buildings, subways, gymnasiums, cinemas, etc.). )