Application of electric tracing tape in freezing prevention of sewage pipeline

　　In the cold winter, the freezing problem of sewage pipe network is like a sword hanging over the head of municipal managers. When the temperature keeps below freezing point, the common drainage system faces severe challenges, ranging from poor drainage to pipe burst. The introduction of electric heat tracing technology provides a reliable solution to this seasonal problem. Through accurate temperature control, sewage can flow smoothly in severe cold and the normal operation of urban drainage system can be guaranteed.

　　There is an essential difference between the anti-freezing and heat tracing of sewage pipes and traditional water pipes. Sewage contains solid impurities and organic matter, and its fluidity and freezing characteristics are completely different from those of clean water. The measured data of a northern city shows that the domestic sewage begins to precipitate ice crystals at -5℃, which is higher than the freezing point of pure water. In view of this characteristic, the electric heat tracing system of sewage pipeline needs higher maintenance temperature and more uniform heat distribution. Engineering practice shows that it is ideal to maintain the temperature of sewage pipe wall at 8-10℃, which can prevent freezing and not accelerate the fermentation of organic matter due to excessive temperature. Self-regulating electric tracing belt shows its unique advantages in this application, and its calorific value can be automatically adjusted with the ambient temperature, which not only ensures the anti-freezing effect, but also avoids energy waste. The operation record of a sewage treatment plant shows that this intelligent regulation reduces the energy consumption of the system by 35% compared with the constant power tracing belt.

　　The installation of electric heat tracing for outdoor sewage pipes needs special consideration. Different from indoor pipelines, outdoor pipelines are directly exposed to snow and wind, and the heat loss is more serious. The scientific design scheme usually adopts the triple protection structure of "tracing belt+insulation layer+protective shell". The heat tracing belt is installed close to the bottom of the pipeline to ensure the upward conduction of heat; The thickness of insulation layer should be calculated and determined according to the local extreme low temperature; The outermost protective shell resists rain and snow erosion and mechanical damage. More ingeniously, the system adopts the temperature control strategy in different periods, which automatically increases the power during the most freezing period from late night to early morning, and maintains the basic temperature at other times, thus achieving a perfect balance between safety and energy saving.

　　The anti-freezing challenge of underground sewage pipe network is more complicated. These pipelines are usually buried in shallow depth, and the soil temperature is greatly affected by air temperature, and it is difficult to repair. The innovative solution is to lay the electric tracing belt synchronously with the pipeline, and add thermal insulation particles into the backfill to form a composite thermal insulation system. For key nodes such as inspection wells and sump pits, the heat tracing method of circular winding is adopted to ensure that these frozen parts are fully heated. The system is also equipped with a remote monitoring function, and managers can check the temperature of each pipe section in real time through the mobile APP to find abnormal situations in time.

　　The demand for electric heat tracing of industrial wastewater pipelines is more special. Wastewater from chemical and pharmaceutical industries is often corrosive, which puts forward higher requirements for heat tracing system. The special anticorrosive electric heat tracing tape adopts PTFE sheath and fully sealed structure, which can withstand acid and alkali corrosion. The case of a chemical plant shows that this kind of tracing belt has been running stably in wastewater environment with pH value of 2-11 for 5 years without corrosion. More complicated is the high-viscosity wastewater, whose fluidity drops sharply at low temperature and needs higher maintenance temperature. The solution is to use a heat tracing belt with higher power density and a thicker insulation layer. The operation data of food processing plants show that maintaining the wall temperature of oily wastewater at 15℃ can effectively prevent pipeline blockage.

　　The anti-freezing of lifting pumping station and sewage treatment facilities is equally important. The failure of these key nodes will lead to the paralysis of the whole system. The application of electric heat tracing system here is more detailed: miniature heat tracing elements are used in the bearing parts of pump body to maintain lubrication performance; Arrange an annular tracing belt around the level gauge to prevent false alarm; Increase heat tracing density in key parts of gate valve to ensure flexible operation. The system also incorporates intelligent control strategy, adjusting operation parameters in advance according to the weather forecast, and establishing a "thermal barrier" before the cold wave comes.

　　With the development of technology, the electric heat tracing system of sewage pipeline is becoming more intelligent and efficient. The new generation of products integrates the function of leakage detection, and the pipeline damage can be found in time by monitoring the change of electrical characteristics of the tracing belt; The self-diagnosis system can predict the aging trend of components and arrange maintenance in advance; Combined with the Internet of Things technology, the regional collaborative control is realized, and the power distribution is dynamically adjusted according to the actual load of each pipeline section. These innovations not only improve the system reliability, but also greatly reduce the operating energy consumption.

　　From the main pipe network of northern cities to the special needs of high altitude areas in the south, from septic tanks in residential areas to wastewater treatment facilities in industrial parks, electric heat tracing technology is providing a solid guarantee for the winter operation of sewage systems. It is not only a technical means to solve the freezing problem, but also an important part of modern urban capacity building. Today, with the frequent occurrence of extreme weather caused by climate change, the scientifically designed and reasonably installed electric heating system is guarding the smooth flow of urban underground pipelines in all seasons.