The most Comprehensive Scientific Knowledge Ntroduction of Water Pumps in the World

The basic structure and principle of fire pump

Today, we will take you to have a deep understanding of the basic structural principles and application characteristics of fire pumps.

Fire pumps, as an indispensable and important fluid equipment in the application system of modern fire water, are also widely used in various fields. Understanding its basic structural principles and application characteristics will help you better exert its effectiveness in actual operation.

1. Basic structure of water pump

•  Ordinary water pump: mainly composed of motor (stator coil, rotor motor shaft also called pump shaft, motor front cover, rear cover, front bearing, rear bearing, motor housing also called barrel, fan, fan cover), mechanical seal, impeller, pump body, flanges connected to the water inlet and outlet, etc. These parts work together to ensure that the water pump can efficiently transport liquid. It is the most widely used.

• Automatic water pump: Based on the original water pump function, electrical automatic control is added to cut off and connect the power supply to achieve automatic start and stop (simple control is generally: differential pressure switch, electronic integrated induction switch) and then combined with air pressure, water pressure, fluid blocking (air pressure tank, also known as pressure tank, expansion tank, check valve also known as one-way valve and other valves) to complete automatic start and stop.

2. The working principle of the water pump is centrifugal force

The motor drives the rotating impeller and the fixed pump casing. The impeller is the part that directly contacts the liquid. The impeller is driven by the motor to rotate at high speed, forcing the liquid between the blades to rotate as well. At the same time, due to the centrifugal force, the liquid moves radially from the center of the impeller to the outer edge. The liquid gains energy in the process of flowing through the impeller, and leaves the outer edge of the impeller at high speed and enters the volute pump casing. In the volute, the flow passage gradually expands and decelerates, and part of the kinetic energy is converted into static pressure energy, reaching a higher pressure, and finally flows into the delivery pipe along the tangential direction.

It can also be explained this way: the impeller of the water pump is fixed on the same axis as the motor, and the motor rotates synchronously with the impeller to generate centrifugal force. The volute of the flow channel inside the pump body is closely matched with the impeller. Under the action of centrifugal force, the liquid is thrown to the surroundings and a low-pressure area is formed in the center of the impeller. At this time, the liquid enters the pump under the action of the pressure difference, passes through the flow channel of the pump body and enters the pump cavity, and is squeezed out of the pump body outlet by the high-speed centrifugal force, and continues to squeeze at high speed to form pressure to achieve liquid transportation.

A water pump is a machine that transports water. It is driven by a high-speed rotating motor that drives the impeller fixed on the shaft. The impeller rotates synchronously to generate centrifugal force (electrical energy is converted into kinetic energy, and this continuous process delivers the water)!

3. Water Pump Application Characteristics

• Wide range of applications: Water pumps are suitable for conveying various liquids, such as water, oil, acid and alkali liquids (also called media), etc. According to different needs, different types of motors with different materials and different structures can be selected to combine into various types of pumps.
• Water pump motor: ordinary air-cooled motor (the motor generates heat when working, and the fan rotates on the same axis, generating wind to blow to the motor casing for cooling, so that the motor temperature is maintained in a certain range and long-term continuous operation is achieved. The air-cooled motor casing has heat dissipation ribs for better heat dissipation), and pumps used in chemical industry production and other industries are generally equipped with air-cooled explosion-proof motors, as well as shielded motors, submersible motors (water-cooled motors), etc. Different types of water pumps are selected according to different applications.

4. Classification and naming of pumps

• Water pumps classified and named according to their structural principles: reciprocating pumps, plunger pumps, piston pumps, diaphragm pumps, rotor pumps, screw pumps, liquid ring pumps, gear pumps, vane pumps, Roots pumps, roller pumps, cam pumps, peristaltic pumps, perturbation pumps, vane pumps, centrifugal pumps, axial flow pumps, mixed flow pumps, vortex pumps, jet pumps, jet pumps, water hammer pumps, vacuum pumps, volute pumps, hose pumps, worm pumps, shielded pumps, permanent magnet pumps, vertical pumps, and horizontal pumps.
• Pumps named by medium classification: clean water pump, submersible pump, sewage pump, seawater pump, hot water pump, hot oil pump, thick oil pump, engine oil pump, heavy oil pump, residual oil pump, asphalt pump, impurity pump, slurry pump, mortar pump, mortar pump, ash pump, mud pump, cement pump, concrete pump, powder pump, acid and alkali pump, air pump, steam pump, oxygen pump, ammonia pump, gas pump, blood pump, foam pump, emulsion pump, paint pump, sulfuric acid pump, hydrochloric acid pump, colloid pump, alcohol pump, beer pump, wine pump, chocolate pump, milk pump, starch pump, wort pump, toothpaste pump, brine pump, brine pump, alkali pump, molten salt pump, grease pump, pesticide pump, fertilizer pump, agent pump, gas-liquid pump, oil agent pump, chemical fiber pump, spinning pump, dosage pump, paint pump, pulp pump, pulp pump, insulin pump, thick slurry pump, air pump, water pump, oil pump
• Commonly used civil water pumps are classified and named according to the effect presentation and automatic control mode: variable frequency water pump, variable frequency constant pressure water pump, sewage lifting pump, circulation pump, booster pump, pipeline pump, shielded pump, return pump, intelligent water pump, adaptive water pump, variable frequency constant pressure water supply system.

5. High efficiency and stability

High-quality water pumps are characterized by high efficiency and low energy consumption, and can maintain stable performance during long-term operation.

6. Pump performance parameters

To select a pump, you must first understand the basic parameters of the pump you need, such as key flow rate, head, pressure rating, medium, temperature, density, viscosity, efficiency, and motor power.

• The flow rate is Q = how many M3/H (hour H/minute MIN/second S, how many tons of cubic M3 of water need to be transported), such as: Q = 10M3/10000L/H hour/MIN minute/S second. There are maximum flow and rated flow. In actual use, it is calculated according to the rated flow.
• The lift is H = meters M. The lift refers to the vertical height difference in meters. There are maximum lift and rated lift. In actual use, the rated lift is used for calculation.
• Rated flow and rated head values ​​refer to (for example, rated flow head is 8 cubic meters per hour, head is 25 meters, it can be understood that when the vertical height of the water pump outlet pipe is 25 meters, it discharges 8 tons of water per hour). It is reflected in the performance curve, flow, head, efficiency, cavitation margin, motor power, insert curve

7. Cavitation: Cavitation of water pump:

• Reveal the secret behind it: Have you ever wondered why your water pump sometimes makes strange noises? Or are you worried about whether the water pump has a problem? In fact, this may be cavitation of the water pump. Today, let’s take a deeper look at what cavitation of water pumps is. What is cavitation of water pumps? Cavitation refers to the process in which, during the operation of a water pump, due to a drop in local pressure, dissolved gases in the water precipitate when the pressure drops to a certain level, forming bubbles. When these bubbles enter the high-pressure area with the water flow, they will quickly burst, causing noise and vibration (cavitation can be understood as water bubbles hitting the impeller, and the collision produces erosion, which damages the impeller and pump cavity just like corrosion!

• The harm of cavitation: cavitation will not only affect the operation of the water pump and reduce its efficiency, but also damage the internal parts of the water pump. Long-term cavitation will cause corrosion of the metal surface inside the water pump, thus shortening the service life of the water pump.
• How to prevent cavitation?

8. To prevent cavitation, you can start from the following aspects

• Choose the right pump: Choose a pump with the right model and parameters according to actual needs to avoid cavitation caused by excessive or insufficient flow.
• Keep the water level normal: Make sure the water level of the pump is always within the normal range to avoid pressure drop due to low water level.
• Regular maintenance: Regularly maintain the pump to clean up internal impurities and sediments to prevent cavitation caused by blockage.
• Increase air pressure: By increasing the pressure of the water inlet (system pressure), the pump’s anti-cavitation ability can be improved.

By understanding the cavitation phenomenon of water pumps and taking corresponding preventive measures, we can ensure the normal operation of water pumps and extend their service life. If you find that your home water pump has abnormal sounds or vibrations, it is recommended to check it in time and take corresponding measures to avoid unnecessary losses.