The working principle and structure of centrifugal pump, the working principle of centrifugal pump

A centrifugal pump is a commonly used power device to transport liquids from a low-pressure area to a high-pressure area, and is commonly used in applications such as water supply, drainage, irrigation, industrial processes, etc. Its working principle and structure are as follows:

Working principle: The centrifugal pump uses the centrifugal force generated by the rotation of the impeller to suck the liquid from the inlet of the pump, and pushes the liquid to the outlet of the pump through the pump casing and outlet pipeline, so as to realize the transfer of liquid. When the motor drives the pump shaft to rotate, the impeller also rotates, and the liquid is carried into the gap between the blades under the action of the impeller, and then is pushed from the outlet of the blade to the outlet pipe by centrifugal force, thus forming a continuous fluid flow.

Structure: Centrifugal pumps are usually composed of the following main parts:

Pump casing (or pump body): The pump casing is the external casing of a centrifugal pump, usually made of cast iron, stainless steel, alloy steel and other materials, and its main role is to accommodate and support other pump components, and form the flow channel of the pump through the connection with other parts.

Impeller (or vane): The impeller is one of the most important components in a centrifugal pump and is usually made of materials such as cast iron, stainless steel, copper alloy, etc. The impeller generates centrifugal force by rotating to draw the liquid from the inlet of the pump and push it towards the outlet, thus enabling the delivery of liquid.

Pump shaft: The pump shaft is the part that connects the motor and the impeller, usually made of high-strength alloy steel or stainless steel, its main role is to transfer the rotation of the motor to the impeller, and is responsible for bearing the axial and radial load of the pump.

Guide vane (or deflector): The guide vane is located between the impeller and the pump casing, usually made of steel plate, cast iron and other materials, its main role is to guide the flow of liquid from the outlet of the impeller to the outlet of the pump casing, and control the flow and head of the pump by adjusting the angle of the guide vane.

Shaft seal: Shaft seal is a component in a centrifugal pump that is used to prevent the liquid in the pump from leaking out of the pump, usually composed of a sealing ring, a sealing surface, a packing, etc. Shaft seals create a seal between the pump shaft and the pump casing, preventing liquid leakage and also preventing external substances from entering the pump.

Bearing: The bearing is the part that supports the pump shaft of the centrifugal pump, usually located between the pump casing and the pump shaft, bears the axial and radial load of the pump shaft, and ensures the stable operation of the pump shaft. Common bearing types include rolling bearings and plain bearings, the selection and lubrication of which will vary depending on the specific pump design and operating conditions.

Pump base (or base): The pump base is the supporting structure of a centrifugal pump, usually made of steel, which is used to support the pump casing, impeller and pump shaft, and ensure the stable operation of the pump by being fixed with the ground or other foundations.

Inlet and outlet pipelines: Inlet and outlet pipelines are used to guide liquids into and out of centrifugal pumps, usually composed of pipes, flanges and connectors, etc., and their design and installation need to consider factors such as liquid flow, pressure and pipe size to ensure the performance and working effect of the pump.

The above are the main components of centrifugal pumps, different types and specifications of centrifugal pumps may have some additional structures and components, such as pump drive mode (motor, diesel engine, etc.), pump control system (switch, inverter, etc.), accessories (valves, flow meters, etc.), etc., these components will also vary according to specific application needs and design requirements.

Centrifugal pumps have many advantages such as wide range of performance, uniform flow, simple structure, reliable operation and convenient maintenance, so centrifugal pumps are the most widely used in industrial production. In addition to the reciprocating pumps commonly used in high-pressure and small flow or metering, vortex pumps and positive displacement pumps commonly used in liquid gas, and rotary lobe pumps commonly used in high-viscosity media, centrifugal pumps are used in most other occasions.

According to statistics, in chemical production (including petrochemical) units, the use of centrifugal pumps accounts for 70 80 of the total number of pumps.

How centrifugal pumps work.

Centrifugal pumps are mainly composed of impellers, shafts, pump casings, shaft seals and sealing rings. When the prime mover drives the pump shaft and impeller to rotate, the liquid moves in a circular motion with the impeller on the one hand, and is thrown out from the center of the impeller to the periphery under the action of centrifugal force, and the liquid obtains pressure energy and velocity energy from the impeller. As the liquid flows through the volute to the drain, part of the velocity energy is converted to static energy.

When the liquid is thrown out of the impeller, the center of the impeller creates a low pressure area, which forms a pressure difference with the pressure of the suction liquid surface, so that the liquid is continuously sucked in and discharged at a certain pressure.

The main components of centrifugal pumps.

Pump casings. There are two types of pump casings: axially split and radially split. Most single-stage pumps have a volute housing, and multistage pumps have radially split housings that are generally annular or round.

Generally, the inner cavity of the volute pump casing is a spiral liquid channel, which is used to collect the liquid thrown out of the impeller and lead it to the diffusion pipe to the pump outlet. The pump casing is subjected to the full operating pressure and the heat load of the liquid.

Impeller. The impeller is the only working component, through which the pump works on the liquid. There are three types of impellers: closed, open and semi-open.

The closed impeller consists of a blade, a front cover plate, and a rear cover plate. The semi-open impeller consists of a blade and a rear cover. The open impeller has only blades and no front and rear covers.

Closed impellers have higher efficiency and open impellers have lower efficiency.

Sealing rings. The function of the sealing ring is to prevent the internal and external leakage of the pump, and the sealing ring made of wear-resistant materials is embedded in the front and rear covers of the impeller and the pump casing, and can be replaced after wear.

shafts and bearings. One end of the pump shaft is fixed with an impeller, and one end is equipped with a coupling. Depending on the size of the pump, rolling bearings and plain bearings are available.

Shaft seals. There are generally two types of shaft seals: mechanical seals and packing seals. Generally, pumps are designed to be fitted with both packing seals and mechanical seals.

When the impeller rotates, it drives the blades in the impeller to drive the fluid to rotate together, generating centrifugal force, and the fluid is thrown along the blades to the impeller outlet under the action of force, and is fed into the outlet pipe.

As the impeller rotates repeatedly, the fluid is continuously sucked in and discharged, and the centrifugal pump is always in working condition.

Anhui Jiangnan pump valve.

Answer for you: 1) The impeller is driven by the pump shaft to rotate, and the work is done on the fluid located between the blades, and the fluid is thrown to the periphery by centrifugal action. When the fluid reaches the outer periphery of the impeller, the flow rate is very high.

2) The pump casing collects the liquid that is thrown from between the blades, and these liquids flow in the shell in the direction of the gradual expansion of the volute-shaped channel, so that the kinetic energy of the fluid is converted into static pressure energy and the energy loss is reduced. Therefore, the role of the pump casing is not only to collect liquid, it is also an energy conversion device.

3) Liquid suction principle: relying on the high-speed rotation of the impeller, the liquid in the center of the impeller is forced to be thrown away at a high speed, so as to form a low pressure in the center of the impeller, and the liquid in the low groove is continuously sucked up.

1. The working principle of centrifugal pump.

After the pump is running, under the action of the centrifugal force generated by the high-speed rotation of the impeller, the water in the impeller channel is thrown around, pressed into the volute, and the impeller inlet forms a vacuum, and the water of the pool is sucked in along the suction pipe under the outside atmospheric pressure to supplement this space. The inhaled water is then thrown out by the impeller and enters the outlet pipe through the volute. It can be seen that if the impeller of the Stuffy Qing centrifugal pump rotates continuously, it can continuously absorb and pressure water, and the water can be continuously raised from low to high or far away.

To sum up, a centrifugal pump is called a centrifugal pump because it lifts water to a high place due to the centrifugal force generated by the high-speed rotation of the impeller.

2. General characteristics of centrifugal pumps.

1) The flow direction of water along the centrifugal pump is sucked in along the axial direction of the impeller and flows out perpendicular to the axial direction, that is, the direction of the inlet and outgoing water flow is 90° to each other.

2) Since the centrifugal pump relies on the impeller inlet to form a vacuum to absorb water, it is necessary to pour water into the pump and the suction pipe before starting, or use a vacuum pump to pump air to discharge the air to form a vacuum, and the pump casing and water suction pipeline must be strictly sealed, and no air leakage is allowed, otherwise it cannot form a vacuum, and it will not be able to absorb water.

3) Because it is impossible to form an absolute vacuum at the impeller inlet, the suction height of the centrifugal pump cannot exceed 10 meters, plus the loss along the way caused by the water flow through the suction pipeline, the actual allowable installation height (the height of the pump axis from the suction water surface) is far less than 10 meters. If the installation is too high, it will not absorb water; In addition, since the atmospheric pressure in the mountains is lower than in the plains, the installation height of the same pump in the mountains, especially in the high mountains, should be reduced, otherwise it will not be able to absorb water.

Centrifugal pump is a common mechanical water pump, which is mainly composed of the following parts:

1.Pump body: The pump body is the main load-bearing part of the centrifugal pump, including the inlet, outlet, impeller and pump casing. The design and material of the pump body often depends on the use case and fluid characteristics of the pump.

2.Impeller: The impeller is the core component of a centrifugal pump, which is composed of a series of blades, which generate centrifugal force through the rotation of the motor to suck the liquid from the inlet, and then push the liquid to the outlet through the rotating blades.

3.Pump silver resistant grip shaft: The pump shaft is the part that connects the impeller and the motor, which bears the centrifugal force of the impeller and the rotational torque of the motor, and transports the liquid to the outlet.

4.Mechanical seals: Mechanical seals are usually composed of components such as static rings, moving rings, changqing springs, and gaskets to prevent liquid leakage and gas ingress.

5.Bearings: Bearings are used to support the pump shaft and impeller to reduce friction and wear between the shaft and the bearing.

The working principle of a centrifugal pump is to use the rotation of the impeller to draw the liquid from the inlet, and then generate centrifugal force to push the liquid towards the outlet. Specifically, when the motor starts, the impeller begins to rotate, and the liquid generates centrifugal force with the rotation of the impeller, forming a negative pressure area, so that the liquid enters the pump body from the inlet. As the impeller rotates, the liquid is compressed and accelerated, pushing it towards the outlet.

Eventually, the liquid flows out of the outlet, completing the process of liquid transfer. Fight hunger.

The structure and shape of the impeller varies according to different usage scenarios and the type of pump. Generally speaking, the impeller of centrifugal pump mainly includes two types: open impeller and closed impeller. There is a certain gap between the open impeller and the pump body, which can handle some liquids with larger particles, but the efficiency is relatively low; Closed impeller has a tight seal between the pump body and has high efficiency and flow rate, but is not suitable for handling liquids with larger particles.

Centrifugal pumps work by using centrifugal force to transport liquids. Its structure is mainly composed of motors, pump bodies, impellers, bearings, seals, etc.

The motor connects the impeller through a bearing, which rotates the impeller at high speed. As the impeller rotates, the liquid is drawn into the pump body and then pushed towards the outlet. The outlet of a centrifugal pump is usually connected to a pipe that transports the liquid to the point where it needs to be trained.

The impeller of a centrifugal pump usually has multiple blades, and the shape and number of blades can affect the performance of the pump. The outlet of a centrifugal pump is usually connected to a pipe to transport the liquid to where it is needed.

The efficiency and performance of a centrifugal pump depends on a variety of factors, such as the shape of the impeller, speed, flow rate, head, etc. Therefore, when choosing a centrifugal pump, it is necessary to select the appropriate pump type and parameters according to the specific use requirements and working conditions.

1. The working principle of the centrifugal pump is: The reason why the centrifugal pump can send the water out is due to the laughter of centrifugal force, before the water pump works, the pump body and the water inlet pipe must be filled with water to form a vacuum state, when the impeller rotates rapidly, the blades promote the water to rotate rapidly, and the rotating water flies away from the impeller under the action of centrifugal force, after the water in the pump is thrown out, the central part of the impeller forms a vacuum area, and the water of the water source is pressed into the water inlet pipe through the pipe network under the action of atmospheric pressure (or water pressure), so that the cycle is endless. It can achieve continuous pumping;

2. The basic structure of the centrifugal pump is composed of six parts, namely: impeller, pump body, pump shaft, bearing, seal vertical ring, stuffing box.

Centrifugal pumps are generally driven by electric motors, and the pump body and suction line are filled with liquid before starting the pump. When the impeller rotates at high speed, the impeller drives the liquid between the blades to rotate together, and due to the centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the impeller (the flow rate can be increased to 15 25m s), and the kinetic energy also increases. When the liquid enters the pump casing, due to the gradual expansion of the flow channel in the volute-shaped pump casing, the liquid flow rate gradually decreases, and part of the kinetic energy is converted into static pressure energy, so the liquid flows out along the discharge port at a higher pressure.

At the same time, a certain vacuum is formed at the center of the impeller because the liquid is thrown out, and the pressure PA at the liquid level is higher than that at the center of the impeller, so the liquid from the suction line enters the pump under the action of pressure difference. The impeller rotates constantly, and the liquid is continuously sucked in and pressed out. Because centrifugal pumps can transport liquids, mainly rely on the action of centrifugal force, they are called centrifugal pumps.

To put it simply, the centrifugal pump increases the kinetic energy of the liquid through the rotation of the impeller, and converts the kinetic energy into pressure potential energy at the outlet, so that the liquid can obtain a certain pressure and then carry out remote transportation.

The working principle of centrifugal pump is to use the rotation of the impeller to make the water centrifugal motion to work.

The basic structure of the centrifugal pump is composed of six parts, namely impeller, pump body, pump shaft, bearing, sealing ring, and stuffing box. The pump should be filled with water before starting, and the rotating impeller after starting drives the water in the pump to rotate at high speed, and the water is thrown out and pressed into the outlet pipe as a movement of dispersing the eggplant.

When the water is thrown out, the pressure near the impeller decreases, creating a zone of low pressure near the rotating shaft. The pressure here is much lower than atmospheric pressure, and the water outside is under the action of atmospheric pressure, rushing open the bottom valve from the inlet pipe into the pump. The incoming water is thrown out and pressed into the outlet pipe as the impeller rotates at high speed.

The impeller is constantly rotating at high speed under the drive of the power machine, and the water is continuously pumped from low to high.

Scope of application of centrifugal pumps

Centrifugal pumps can be widely used in aquaculture farms, electric power, metallurgy, coal, building materials and other industries to transport slurry containing solid particles. Such as hydraulic ash removal in thermal power plants, slurry transportation in metallurgical concentrators, coal slurry and heavy medium transportation in coal washing plants, etc. When the centrifugal pump is working, the pump needs to be placed on the trembling land, the suction pipe needs to be placed in the water, and the pump needs to be started by digging and renting.

Due to the limitation of the structure, the mud pump and the submerged centrifugal pump need to be placed on the water surface when working, and the pump is put into the water, so it must be fixed, otherwise, the motor falling into the water will cause the motor to be scrapped. Moreover, because the length of the long shaft is generally fixed, the installation and use of the pump is more troublesome, and the application occasions are subject to many restrictions.