In modern industry and daily life, sewage pumps play an indispensable role. They are key equipment to ensure the smooth discharge of sewage and wastewater. Whether in urban sewage treatment plants, industrial production, construction projects, etc., sewage pumps are of great significance. This article will deeply explore the working principles, structural features, application areas, and maintenance key points of sewage pumps, helping readers to comprehensively understand this important equipment.
I. Working Principles and Structural Features
Working Principles
The working principle of a sewage pump is based on centrifugal force. When the motor drives the impeller to rotate at high speed, the blades in the impeller push the liquid to rotate, enabling the liquid to obtain centrifugal force. Under the action of centrifugal force, the liquid is thrown from the center of the impeller to the edge of the impeller and then discharged through the pump casing. At the same time, a negative pressure is formed at the center of the impeller, causing the liquid to be continuously sucked into the impeller from the suction port, thus achieving a continuous drainage process.
Structural Features
- Compact Design
Sewage pumps usually adopt a structure where the pump and the motor are integrated. This design makes the overall structure compact, occupying a small area and facilitating installation and maintenance. Especially in places with limited space, such as basements and subway drainage stations, the compact structural design has more advantages. - Multiple Impeller Options
Sewage pumps adopt a unique single – blade or double – blade impeller structure, which greatly improves the passage ability of dirt. It can effectively pass fibrous materials 5 times the diameter of the pump and solid particles with a diameter of about 50% of the pump diameter. This makes sewage pumps perform well when dealing with sewage containing impurities. - Good Sealing Performance
The mechanical seal uses a new type of hard and corrosion – resistant tungsten carbide material. At the same time, the seal is improved to a double – end face seal, allowing it to operate in the oil chamber for a long time. The pump can operate safely and continuously for more than 8000 hours. Good sealing performance can not only prevent liquid leakage but also protect the motor from being eroded by sewage, extending the service life of the equipment.
II. Application Areas
Urban Sewage Treatment
In the discharge system of urban sewage treatment plants, sewage pumps are one of the core equipment. They are responsible for collecting urban domestic sewage and industrial wastewater and transporting them to treatment facilities. After a series of treatments, the water is discharged up to standard. The sewage pumps in urban sewage treatment plants need to have the characteristics of large flow rate and high head to meet the needs of treating a large amount of urban sewage.
Building Drainage
In the construction field, sewage pumps are indispensable for the sewage discharge of high – rise buildings, as well as the drainage stations in basements and civil air defense systems. For example, in high – rise buildings, sewage needs to be lifted to the municipal sewage pipeline through sewage pumps. In basements, to prevent waterlogging, sewage pumps also need to be installed to timely discharge rainwater and domestic sewage.
Industrial Wastewater Treatment
During the industrial production process, a large amount of wastewater containing various impurities and chemical substances is generated. Sewage pumps can discharge these wastewaters into special sewage treatment facilities for treatment, avoiding environmental pollution. The properties of wastewater in different industrial fields are different. Therefore, it is necessary to select the appropriate material and model of sewage pumps according to the characteristics of the wastewater. For example, in the chemical industry, corrosion – resistant stainless – steel sewage pumps may be required.
Agricultural Irrigation and Drainage
In the agricultural field, sewage pumps can be used for the sewage discharge of farms and the irrigation of rural farmland. In farms, sewage pumps can timely discharge the sewage generated during the breeding process, maintaining the hygiene of the breeding environment. In agricultural irrigation, sewage pumps can transport water sources such as river water and well water to the farmland to meet the water needs of crop growth.
III. Selection Points
- Clarify the Usage Environment
First, it is necessary to understand the usage environment of the water pump and select the correct type of water pump, such as wet – type or dry – type. For example, in underwater working occasions, submersible sewage pumps need to be selected. In ground drainage occasions, ordinary sewage pumps or self – priming sewage pumps can be selected. - Accurately Calculate the Head
When calculating the required head of the water pump, it should be noted that the flat – ground transportation distance cannot be simply included in the head. The flat – ground transportation distance needs to be multiplied by the friction coefficient before being included in the head. At the same time, pipeline elbow wear, pipeline friction, etc. all need to be calculated. In actual situations, these factors are relatively complex, and it is recommended to leave an appropriate margin to ensure that the water pump can discharge water normally. - Consider Water Quality Factors
If a stainless – steel sewage pump is selected, it is necessary to clarify the pH value and particle diameter of the water quality, and select the appropriate stainless – steel material. Generally, 304 material is suitable for water quality with a pH value between 4 and 10. If it exceeds this range, it is recommended to use 316 or 316L stainless steel. - Ensure the Appropriate Working Range
The water pump must be used within the rated head range to ensure that the motor is not overloaded. For example, if the actual required head is 30 meters, a water pump with a standard head lower than 30 meters should not be selected, otherwise, the motor will be overloaded, and in severe cases, the motor will be burned out. - Ensure Unobstructed Pipelines
The water pump pipelines must be unobstructed. If the pipelines are blocked, it will also cause the motor to be overloaded and even burn out the motor.
IV. Maintenance Points
- Regular Inspection
Regularly inspect various components of the sewage pump, such as the impeller, sealing ring, cable, motor insulation, and screws. Inspect at least once a year. If any components are found to be damaged or aged, they need to be replaced in a timely manner. For example, the impeller may be worn after long – term use, affecting the sewage discharge effect. At this time, the impeller needs to be replaced in a timely manner. - Replace Oil and Sealing Parts
If water is found in the oil, drain it, replace the oil, sealing gasket, and tighten the plug. Regularly replace the sealing parts to ensure the sealing performance of the equipment, preventing liquid leakage and motor water ingress. - Avoid Bad Usage Habits
During the use of the sewage pump, some bad habits should be avoided. Do not use it without grounding. Protective grounding must be adopted to ensure personal safety during use. Do not install without a leakage protector to prevent safety accidents caused by electric leakage. Do not start the machine when the power supply is abnormal. Both too high and too low voltage will increase the motor temperature and shorten the service life. Do not use it in a muddy environment to avoid poor motor heat dissipation and winding burnout. Do not frequently turn the machine on and off. After stopping, wait until the water in the pipeline has completely flowed back (usually with an interval of about 5 minutes) before starting again. Do not leave it in the water without care after it is out of use. Start the machine once a week and run it for 5 – 10 minutes. When it is not used for a long time, place it in clean water and run it for a few minutes to clean the mud inside and outside the pump, then take it out of the water, dry it, and conduct a comprehensive inspection.
As an important drainage device, sewage pumps play a key role in various fields. By understanding their working principles, structural features, application areas, selection points, and maintenance methods, we can better select, use, and maintain sewage pumps, ensuring their efficient and stable operation and providing reliable drainage protection for production and life.
