In modern construction and industrial production, sewage discharge is a crucial process. However, due to topographical constraints, complex building structures, or insufficient sewage discharge height, traditional gravity drainage methods often fail to meet requirements. At this point, sewage lifting pumps, as efficient and reliable sewage discharge equipment, have gradually become the core solution to such problems. This article provides a comprehensive analysis of sewage lifting pumps from aspects including their working principles, classification, application scenarios, selection key points, and maintenance, allowing you to gain an in-depth understanding of this key equipment.​

I. Working Principle of Sewage Lifting Pumps​

A sewage lifting pump is a device that lifts sewage from a lower position to a higher position through mechanical means to achieve sewage discharge. Its working principle is mainly based on fluid mechanics and mechanical transmission principles.​

Typically, a sewage lifting pump consists of a water collection tank, pump body, motor, control system, and pipelines. When sewage enters the water collection tank, the liquid level sensor inside the tank monitors the sewage level in real-time. When the water level reaches the preset starting level, the control system automatically starts the motor, driving the pump body to operate. The pump body generates centrifugal force through the rotation of the impeller, sucking sewage into the pump and lifting it to the designated drainage pipeline or sewage treatment facility via a pressure pipeline. When the water level in the tank drops to the preset stop level, the control system automatically shuts down the motor, and the pump body stops working, waiting for the next startup.​

In addition, to ensure the stable operation of the sewage lifting pump and prevent malfunctions, modern sewage lifting pumps are usually equipped with various protection devices, such as overload protection, overheating protection, water shortage protection, and fault alarm functions.​

II. Classification of Sewage Lifting Pumps​

Sewage lifting pumps can be divided into multiple types according to different classification criteria. The following are several common classification methods:​

(1) Classification by Application Scenario​

• Domestic Sewage Lifting Pumps: Mainly used in residential buildings, such as sewage discharge in basement bathrooms, kitchens, and balconies. These pumps are usually small in size, flexible to install, and relatively weak in processing capacity, generally suitable for treating domestic sewage.​

• Commercial Sewage Lifting Pumps: Applicable to commercial places, such as hotels, restaurants, office buildings, and shopping malls. Due to the large sewage discharge volume in commercial venues, higher requirements are placed on the processing capacity and stability of sewage lifting pumps. Commercial sewage lifting pumps usually have larger water collection tanks and more powerful pump bodies, which can meet the discharge needs of large amounts of sewage.​

• Industrial Sewage Lifting Pumps: Used for discharging sewage generated during industrial production processes. Industrial sewage has complex components and may contain a large amount of suspended solids, sediments, and chemical substances, which place high demands on the corrosion resistance, wear resistance, and processing capacity of sewage lifting pumps. Industrial sewage lifting pumps usually require special design and manufacturing according to the specific nature of the sewage.​

(2) Classification by Pump Body Type​

• Centrifugal Sewage Lifting Pumps: Adopt a centrifugal pump body and transport sewage by generating centrifugal force through the rotation of the impeller. Centrifugal sewage lifting pumps have the advantages of large flow rate, high lift, and high efficiency, and are suitable for treating sewage with few suspended solids and sediments.​

• Self-priming Sewage Lifting Pumps: Possess self-priming function and can automatically suck in sewage without the need for priming. Self-priming sewage lifting pumps are suitable for treating sewage containing a certain amount of suspended solids and sediments, and are relatively convenient to install and use.​

• Submersible Sewage Lifting Pumps: The pump body and motor are directly installed in sewage, and the pump body is driven to operate by a submersible motor. Submersible sewage lifting pumps have the advantages of small floor space, flexible installation, and low noise, and are suitable for treating sewage with a large amount of suspended solids and sediments, as well as for use in places with limited space.​

 

(3) Classification by Control Method​

• Manually Controlled Sewage Lifting Pumps: Require manual operation to start and stop the pump body. These pumps are suitable for places with low requirements for sewage discharge, such as small family workshops.​

• Automatically Controlled Sewage Lifting Pumps: Realize automatic startup and shutdown through liquid level sensors and control systems. Automatically controlled sewage lifting pumps have the advantages of convenient operation and stable operation, and are suitable for most places.​

• Intelligently Controlled Sewage Lifting Pumps: On the basis of automatic control, additional functions such as remote monitoring, fault diagnosis, and automatic alarm are added. Users can monitor the operating status of the sewage lifting pump in real-time through devices such as mobile apps or computers, and obtain fault information in a timely manner for maintenance and repair. Intelligently controlled sewage lifting pumps are suitable for places with high requirements for sewage discharge, such as large commercial complexes and industrial plants.​

III. Application Scenarios of Sewage Lifting Pumps​

Sewage lifting pumps have a wide range of application scenarios, covering almost all places that need to lift sewage from a lower position to a higher position for discharge. The following are some common application scenarios:​

(1) Construction Field​

• Basement Drainage: In basement buildings, since the floor elevation of the basement is lower than that of the outdoor drainage pipeline, gravity drainage cannot be used to discharge sewage. At this time, it is necessary to install a sewage lifting pump to lift the sewage in the basement to the outdoor drainage pipeline.​

• Bathroom Drainage: For some buildings without sunken bathrooms, the sewage discharge of the bathroom needs to be realized through a sewage lifting pump. In addition, in some high-end residential buildings, sewage lifting pumps are also used to achieve same-floor drainage to improve the comfort of using the bathroom.​

• Kitchen Drainage: The sewage generated in the kitchen contains a large amount of oil stains and food residues, which easily block the drainage pipeline. Using a sewage lifting pump can lift the kitchen sewage to the outdoor drainage pipeline to avoid blockage of the drainage pipeline.​

• Balcony Drainage: Balcony drainage usually requires discharging sewage to the outdoor drainage pipeline. If the floor elevation of the balcony is lower than that of the outdoor drainage pipeline, it is necessary to install a sewage lifting pump to achieve drainage.​

(2) Industrial Field​

• Sewage Treatment Plants: In sewage treatment plants, a large amount of sewage needs to be lifted from each treatment unit to the next treatment unit. Sewage lifting pumps are one of the indispensable equipment in sewage treatment plants.​

• Industrial Production Workshops: The sewage generated in industrial production workshops contains various pollutants, and it is necessary to lift the sewage to sewage treatment facilities through sewage lifting pumps for treatment.​

• Mine Drainage: During mine mining, a large amount of mine water is generated. This mine water needs to be lifted to the ground through sewage lifting pumps for treatment and discharge.​

(3) Municipal Field​

• Urban Sewage Treatment: Urban sewage treatment plants need to lift the sewage collected in the city to treatment facilities for treatment. Sewage lifting pumps play an important role in urban sewage treatment.​

• Rainwater Discharge: In some cities, due to low-lying terrain or poor drainage pipelines, rainwater easily accumulates. Using sewage lifting pumps can lift rainwater to drainage pipelines to avoid urban waterlogging.​

(4) Other Fields​

• Hospital Drainage: The sewage generated in hospitals contains a large number of bacteria and pollutants, and it is necessary to lift the sewage to sewage treatment facilities through sewage lifting pumps for treatment.​

• School Drainage: The sewage generated in school buildings such as teaching buildings and dormitories needs to be discharged through sewage lifting pumps.​

• Hotel Drainage: The sewage generated in hotel areas such as guest rooms, restaurants, and kitchens needs to be discharged through sewage lifting pumps.​

IV. Key Points for Selecting Sewage Lifting Pumps​

Selecting a suitable sewage lifting pump is crucial to ensuring smooth sewage discharge and stable operation of the equipment. The following are some key points to consider during the selection process:​

(1) Sewage Flow Rate​

Sewage flow rate is one of the important parameters for selecting a sewage lifting pump. The flow rate of the sewage lifting pump needs to be determined according to the actual sewage discharge volume. Usually, the sewage flow rate can be estimated in the following ways:​

• Estimation based on the number of users: For households and commercial places, the sewage flow rate can be estimated based on the number of users. Generally, the daily sewage discharge per person is approximately 100-200 liters.​

• Estimation based on the number of equipment: For industrial production workshops, the sewage flow rate can be estimated based on the number of production equipment and operating time.​

• Actual measurement: If conditions permit, the sewage flow rate can be determined through actual measurement.​

(2) Lifting Head​

Lifting head refers to the height at which the sewage lifting pump lifts sewage from the water collection tank to the drainage pipeline or sewage treatment facility. The head of the sewage lifting pump needs to be determined according to the actual lifting height. When calculating the lifting head, the following factors need to be considered:​

• Height difference from the lowest water level of the water collection tank to the drainage pipeline: This is the main part of the lifting head.​

• Pipeline resistance loss: When sewage flows in the pipeline, resistance loss occurs, which needs to be calculated based on factors such as pipeline length, diameter, material, and sewage flow rate.​

• Safety margin: To ensure that the sewage lifting pump can meet the requirements in actual operation, a certain safety margin needs to be added to the calculated lifting head, usually 10-20%.​

(3) Sewage Nature​

The nature of sewage also has a great impact on the selection of sewage lifting pumps. A suitable sewage lifting pump needs to be selected according to factors such as the composition, concentration, temperature, and pH value of the sewage. For example:​

• Sewage containing a large amount of suspended solids and sediments: A sewage lifting pump with strong wear resistance and anti-clogging function should be selected, such as a submersible sewage lifting pump or a self-priming sewage lifting pump.​

• Sewage containing corrosive substances: A sewage lifting pump made of corrosion-resistant materials should be selected, such as a stainless steel sewage lifting pump.​

• High-temperature sewage: A sewage lifting pump that can withstand high temperatures should be selected, such as a sewage lifting pump with a high-temperature motor and seals.​

(4) Installation Environment​

The installation environment is also an important factor in selecting a sewage lifting pump. A suitable sewage lifting pump needs to be selected according to factors such as the space size, ventilation conditions, and temperature and humidity of the installation site. For example:​

• Places with limited space: A submersible sewage lifting pump or a small self-priming sewage lifting pump can be selected.​

• Places with poor ventilation conditions: A sewage lifting pump with good heat dissipation performance should be selected to avoid overheating of the motor.​

• Places with high temperature and humidity: A sewage lifting pump with moisture-proof and anti-corrosion performance should be selected.​

(5) Equipment Quality and Reliability​

Equipment quality and reliability are key factors in selecting a sewage lifting pump. A sewage lifting pump with reliable quality and stable performance should be selected to ensure long-term stable operation of the equipment. When selecting, the following aspects can be referred to:​

• Brand reputation: Choose sewage lifting pumps from well-known brands, which usually have higher quality standards and good after-sales service.​

• Product certification: Check whether the sewage lifting pump has passed relevant product certifications, such as ISO certification and CE certification.​

• User reviews: Understand other users' evaluations and usage experiences of the brand and model of sewage lifting pump through channels such as the Internet and social media.​

(6) After-sales Service​

After-sales service is also an important consideration in selecting a sewage lifting pump. A manufacturer or supplier with good after-sales service should be selected so that timely maintenance and repair can be obtained when the equipment malfunctions. When selecting, you can understand the manufacturer's after-sales service policy, maintenance response time, and spare parts supply.​

V. Maintenance of Sewage Lifting Pumps​

Regular maintenance is crucial to extending the service life of sewage lifting pumps and ensuring stable operation of the equipment. The following are some common maintenance items:​

(1) Daily Maintenance​

• Check the equipment operating status: Check the operating status of the sewage lifting pump every day, including the temperature, noise, and vibration of the motor, as well as whether there is water leakage or blockage in the pipeline.​

• Clean the water collection tank: Regularly clean the debris and sediments in the water collection tank to avoid affecting the normal operation of the sewage lifting pump. The cleaning frequency can be determined according to the water quality and discharge volume of the sewage, usually once a week.​

• Check the liquid level sensor: The liquid level sensor is a key component for the automatic control of the sewage lifting pump. Its sensitivity and accuracy need to be checked regularly. If a fault is found in the liquid level sensor, it needs to be repaired or replaced in a timely manner.​

• Check the control system: Regularly check the various functions of the control system, such as automatic start-stop and fault alarm, to ensure the normal operation of the control system.​

(2) Regular Maintenance​

• Replace lubricating oil: For some components that require lubrication, such as motor bearings and pump shafts, lubricating oil needs to be replaced regularly. The replacement frequency can be determined according to the equipment's instruction manual, usually every 6-12 months.​

• Check the pump body and impeller: Regularly check the wear of the pump body and impeller. If severe wear is found, it needs to be repaired or replaced in a timely manner. At the same time, it is also necessary to check whether the impeller is blocked, and if so, clean it in a timely manner.​

• Check the seals: Seals are key components to prevent sewage leakage. Their sealing performance needs to be checked regularly. If the seals are found to be aging or damaged, they need to be replaced in a timely manner.​

• Check the motor: Regularly check the insulation performance and winding temperature of the motor to ensure the normal operation of the motor. If a fault is found in the motor, it needs to be repaired or replaced in a timely manner.​

(3) Fault Handling​

If the sewage lifting pump malfunctions, it needs to be handled in a timely manner. The following are some common faults and handling methods:​

• Pump body does not start:​

Causes: Power failure, control system failure, liquid level sensor failure, motor failure, etc.​

Handling methods: Check whether the power supply is normal, whether the control system has fault prompts, whether the liquid level sensor works normally, and whether the motor has faults. Conduct corresponding repairs or replacements according to the cause of the fault.​

• Pump body starts but does not discharge water:​

Causes: Pipeline blockage, pump impeller blockage, insufficient lifting head, motor reverse rotation, etc.​

Handling methods: Check whether the pipeline is blocked, clean the debris in the pump impeller, check whether the lifting head meets the requirements, and adjust the rotation direction of the motor.​

• Motor overheats:​

Causes: Overload operation, poor heat dissipation, motor bearing failure, winding short circuit, etc.​

Handling methods: Check whether the operating load of the sewage lifting pump exceeds the rated load, clean the heat sink of the motor, check whether the motor bearing is normal, and check whether the winding is short-circuited. Conduct corresponding handling according to the cause of the fault.​

• Sewage leakage:​

Causes: Aging or damage of seals, loose pipeline connections, pump body cracking, etc.​

Handling methods: Replace the seals, fasten the pipeline connections, check whether the pump body is cracked, and if so, repair or replace it in a timely manner.​

VI. Conclusion​

As the core equipment for solving sewage discharge challenges, sewage lifting pumps play an important role in modern construction and industrial production. Through the introduction in this article, it is believed that you have gained a deeper understanding of the working principles, classification, application scenarios, selection key points, and maintenance of sewage lifting pumps. In practical applications, it is necessary to select a suitable sewage lifting pump according to specific needs and actual conditions, and conduct regular maintenance to ensure stable operation of the equipment and extend its service life.​