Five minutes to comprehensively understand industry knowledge about submersible pumps
The deep well submersible pump is a water lifting device composed of a submersible electric motor and a water pump, which integrates mechanical and electrical components and operates underwater.
Its characteristics are compact structure, convenient use, and low price. It has been widely used in agricultural irrigation, environmental protection, municipal engineering, water conservancy engineering, urban and industrial and mining enterprise water supply and drainage, industrial thermal power station conveying circulating water, dock lifting and lowering water level, water diversion engineering, drought resistance and drainage, etc.
It usually consists of a water pump body, motor, cable, pipeline, and controller, etc. Its main function is to extract groundwater or well water from deep wells and transport it to the ground, meeting the needs of people's daily life and production water.
1、 Working principle
Before using the deep well submersible pump, it is necessary to follow the instructions. Before starting the pump, the suction pipe and pump must be filled with liquid. After starting the pump, the impeller rotates at high speed, and the liquid inside rotates with the blades. Under the action of centrifugal force, it flies away from the impeller and shoots outward. The velocity of the injected liquid in the diffusion chamber of the pump casing gradually slows down, and the pressure gradually increases. Then, it flows out from the pump outlet and discharge pipe.
At this point, a vacuum low-pressure area is formed at the center of the blade due to the liquid being thrown towards the surrounding area, which is neither air nor liquid. The liquid in the liquid pool flows into the pump through the suction pipe under the action of atmospheric pressure on the pool surface. The liquid is continuously sucked up from the liquid pool and then continuously discharged from the discharge pipe.
2、 Factors to consider during selection
1. Depth of water well: Different depths of water wells require the use of submersible pumps with different powers. Generally speaking, the deeper the water well, the greater the required power. Because the water pump needs to overcome greater water pressure and resistance to extract water from the bottom of the well. Therefore, when selecting a submersible pump, it is necessary to choose the appropriate power based on the depth of the water well to ensure that the submersible pump can work normally.
2. The water quality and quantity of well water: Different types of submersible pumps need to be selected for well water with different water quality and quantity.
For example, if the well water contains a large amount of sediment and impurities, a submersible pump that can handle these impurities needs to be selected. If the well water volume is large, a submersible pump that can withstand large water flow rates needs to be selected to ensure that the submersible pump can work normally.
3. Usage environment and requirements: Suitable submersible pump models need to be selected according to specific circumstances. For example, if the operating environment is harsh, it is necessary to choose corrosion-resistant and wear-resistant submersible pumps; If long-distance water transportation is required, high head or high flow submersible pumps need to be selected.
In addition, it is also necessary to consider the usage requirements, such as selecting submersible pumps with automatic controllers that require timed automatic opening and closing.
3、 Structural Description
1. The Type A submersible pump unit consists of four main parts: a water pump, a submersible motor (including cables), a water delivery pipe, and a control switch.
The submersible pump is a single suction multi-stage vertical centrifugal pump: the submersible motor is a sealed water filled wet type, vertical three-phase squirrel cage asynchronous motor, and the motor and water pump are directly connected through claw or key cylinder couplings; Equipped with three core cables of different specifications: the starting equipment is made of air switches of different capacity levels and self coupling pressure reducing starters, the water supply pipe is made of steel pipes of different diameters, connected by flanges, and the high head electric pump is controlled by gate valves.
2. The submersible pump is equipped with a rubber bearing in each stage of the backflow casing. The impeller is fixed on the pump shaft with a conical sleeve, and the guide shell is connected by threads or bolts as a whole.
3. The upper part of the high head submersible pump is equipped with a check valve to prevent damage to the unit caused by water hammer during shutdown.
4. The upper part of the submersible motor shaft is equipped with a labyrinth type sand preventer and two reverse configured skeleton oil seals to prevent flowing sand from entering the motor.
5. The submersible motor adopts water lubricated bearings, with rubber pressure regulating film and pressure regulating spring installed at the bottom, forming a pressure regulating chamber to regulate pressure changes caused by temperature. The motor winding is made of polyethylene insulation, nylon sheathed water-resistant electromagnetic wire, and the cable connection method follows the QJ cable joint process. The insulation of the joint is removed and the paint layer is scraped off, connected separately, welded firmly, wrapped with a layer of raw rubber, and then wrapped with 2-3 layers of waterproof tape. The outer layer is wrapped with 2-3 layers of waterproof tape or a layer of rubber tape (bicycle inner tire) bonded with water glue to prevent water leakage.
6. The motor is sealed with precision stop bolts and the cable outlet is sealed with glue.
7. There is a water injection hole and a drain hole at the upper end of the motor, and a drain hole is drilled at the lower part.
The lower part of the motor is equipped with a thrust bearing, which has grooves for dry cooling. In contrast, it is a stainless steel thrust plate that bears the axial force of the water pump.