Multistage centrifugal pump its parts and working principle

Multistage Centrifugal pump its parts and working principle

A multistage pump is a type of pump with multiple impellers arranged in series. This allows the pump to achieve higher pressure than a single-stage pump, while maintaining high efficiency. Multistage pumps are commonly used in applications where high head is required, such as water supply, fire protection, and industrial process pumping,Boiler Feed Water Supply,Hydroelectric Power Generation, Chemical Processing Industries,Offshore Oil and Gas Platforms,Desalination and Reverse Osmosis Systems,Advanced Monitoring and Control System.

A typical form of centrifugal pump with several impellers connected in succession on a single shaft is the multistage centrifugal pump. The following parts are visible in a multistage centrifugal pump's cross-section:

Suction port: Located on the left side of the pump, this port descends into the impeller's eye

Impeller: Receives kinetic energy from an external power source, such as a turbine, diesel generator, or electric motor, and the fluid flows out from the tip under centrifugal force.

Volute: The liquid's pressure increases in the volute.

Diffuser: Has the same function as the volute casing in a regular centrifugal pump.

Return passage channel: Guides the flow to the next impeller.

When it comes to conquering challenges of pressure and flow, multistage pumps rise to the occasion. Unlike their single-stage counterparts, these workhorses pack an extra punch. Imagine a team of collaborators, each adding their strength to the task. That's the essence of a multistage pump multiple impellers working in series to deliver fluids at significantly higher pressures. They're the go-to choice for demanding applications where regular pumps just can't keep up. Get ready to delve into the world of multistage pumps and discover how they tackle tough jobs across various industries.High-pressure fluids are delivered in big quantities using multi-stage centrifugal pumps with high capacity. Among the many uses for them are industrial condensate systems.Refineries,Pipelines,Water desalination,Delivering water to high-rise,buildings,Boiler feed water,Spraying,High-pressure cleaning,Water works,Heating,Fuel delivery,Oil and gas production.

A multistage pump is a type of pump that has multiple impellers arranged in series. This allows the pump to achieve a higher head than a single-stage pump, while also maintaining a high efficiency.

Multistage centrifugal pump, its parts and working principle

A multistage centrifugal pump is a type of centrifugal pump that has multiple impellers arranged in series within the same casing. Each stage (or impeller) adds more pressure to the fluid, making these pumps ideal for applications where high pressure is required, such as in water supply systems, boiler feed, and mining.

Key Parts of a Multistage Centrifugal Pump

Multiple Impellers: Unlike a single-stage pump, a multistage pump has several impellers, each placed along the shaft. As fluid moves through each impeller, it gains additional pressure, building up as it moves from one stage to the next.

Casing: The casing encloses all the impellers and helps direct the flow of fluid. It can be in a volute or diffuser design, each affecting the pressure conversion process slightly differently.

Shaft: The shaft connects all the impellers and is driven by a motor. It allows the transfer of energy from the motor to each impeller in the pump.

Suction and Discharge Nozzles: These nozzles serve as the entry and exit points for the fluid. The fluid enters through the suction nozzle and, after passing through all impellers, exits at a much higher pressure through the discharge nozzle.

Bearings and Shaft Seals: Bearings stabilize the shaft, allowing smooth rotation, while shaft seals or mechanical seals prevent fluid from leaking out along the shaft.

Working Principle of a Multistage Centrifugal Pump

The working of a multistage centrifugal pump relies on the sequential increase in pressure provided by each impeller stage. Here’s how it works:

Fluid Entry: The fluid enters the pump through the suction nozzle, where it encounters the first impeller. As the impeller spins, it accelerates the fluid and pushes it outward toward the casing.

Pressure Building in Stages: After the first impeller, the fluid, now at a higher pressure, moves to the next stage where the process repeats. With each impeller, the fluid gains additional pressure, and this pressure builds progressively with each stage.

Final Discharge: After passing through all stages, the fluid reaches the discharge nozzle at a high pressure, ready for applications requiring greater force, such as high-rise building water supply or industrial processes.

This staged design makes multistage centrifugal pumps highly efficient and adaptable for a range of high-pressure applications, making them essential in industries that need a reliable, powerful pump solution.

The working principle of a multistage pump is as follows:

working principle of a multistage pump

A multistage pump is a type of centrifugal pump that uses multiple impellers to generate higher pressures. The impellers are mounted in ring sections along a shaft, with each ring section containing an impeller, a suction casing, and a discharge casing. At suction line pressure, the fluid enters the pump inlet and moves through the impellers left to right.The impeller draws fluid in through the suction casing and discharges it through the discharge casing, where it then enters another ring section and the process repeats.The more impellers or stages a pump has, the higher the final discharge pressure will be. However, the flow range remains constant for a given RPM, even if the number of stages is changed while the dimensions and speeds remain the same. The purpose of the impeller and diffuser is to reduce speed and increase pressure. After the liquid comes out of the diffuser, it's drained into the housing and fed into the next impeller. This process is repeated until the liquid is discharged from the final impeller and leaves the pump through the outlet.

A multistage pump operates on the principle of transferring energy from a rotating impeller to the fluid it's moving, progressively increasing pressure with each stage. Here's a breakdown of the key components and their roles:

Impellers: The heart of the pump, these are rotary components with fan-like blades. As the shaft spins, the impeller blades push the fluid outwards due to centrifugal force.

Diffusers: These are channels located just after each impeller. They convert the high velocity imparted by the impeller into increased pressure for the fluid.

Stages: A multistage pump has multiple impellers and diffusers arranged in series. The fluid flows from the outlet of one impeller's diffuser into the inlet of the next impeller. With each stage, the pressure of the fluid progressively increases.

Pump Casing: This encloses the impellers, diffusers, and shaft, directing the flow of the fluid through the stages.

Here's how it works:

Liquid enters the pump through the suction inlet.

The rotating impeller imparts kinetic energy to the fluid, accelerating it outwards.

The diffuser converts this high velocity into increased pressure.

The fluid then exits the first stage and enters the inlet of the next impeller.

This process repeats in each stage, with the pressure rising incrementally with each pass through an impeller and diffuser.

Finally, the high-pressure fluid exits the pump through the discharge outlet.

By combining multiple stages, multistage pumps achieve significantly higher pressure outputs compared to single-stage pumps. This makes them ideal for tasks requiring high pressure for applications like:

Supplying water to high-rise buildings.

Feeding water to boilers in power plants.

Industrial processes requiring high-pressure fluids

The main parts of a multistage pump are:

Parts of List Multistage Pump

Impellers:

Impellers are the rotating parts of the pump that provide centrifugal force to the fluid. They are generally made of cast iron or stainless steel.

Diffuser:

Diffusers are the stationary parts of the pump that convert the kinetic energy of the fluid into pressure. They are generally made of cast iron or stainless steel.

Casing:

The casing is the housing that houses the impellers and diffusers. It is usually made of cast iron or stainless steel.

Shaft:

The shaft is the rotating shaft that connects the impellers to the motor. It is usually made of steel or stainless steel.

Bearings:

Bearings support the shaft and allow it to rotate smoothly. They are generally made of ball bearings or sleeve bearings.

Seals:

The seal prevents fluid from leaking out of the pump. They are generally made of rubber or synthetic material.

Motor:

The motor provides the power to rotate the impellers. This is usually an electric motor, but can also be a steam turbine or a gas turbine.

In addition to these main parts, there are several other components that can be found in a multistage pump, such as:

Volute:

The volute is the part of the casing that collects the fluid coming out of the impellers and directs it to the discharge port.

Suction and Discharge Valve:

Suction and discharge valves control the flow of fluid into and out of the pump.

Thrust Bearing:

Thrust bearing supports the axial thrust of the pump. It is usually located between the last impeller and the motor.

Cooling System:

The cooling system removes heat from the pump. This is usually a water-cooling system, but can also be an air-cooling system or a refrigerant-cooling system.

The number and type of components in a multistage pump will vary depending on the specific design of the pump. However, the main parts listed above are common to all multistage pumps.

Types of Multistage Pump

Vertical Multistage Pump:

Vertical Multistage Pump

In this configuration, the impellers are arranged vertically, making it suitable for applications where space is limited. Vertical multistage pumps are commonly used in buildings, water treatment plants and boiler feed systems.

Horizontal multistage pumps:

Horizontal multistage pump

These pumps are typically mounted horizontally and are used for a variety of applications, including water supply, fire protection, and industrial process pumping.

Axial Split Multistage Pump:

Axial Split Multistage Pump

This pump design has a split casing along the axis, allowing easy access to the impellers for maintenance and repair. Axial split multistage pumps are often used in large scale industrial applications including oil refineries, power plants and chemical processing plants.

Radial Split Multistage Pump:

Radial Split Multistage Pump

Unlike axial split pumps, radial split multistage pumps have a split casing perpendicular to the axis. This design facilitates maintenance and repair operations and is commonly found in applications such as oil and gas production, petrochemical plants, and water treatment facilities.

Barrel Multistage Pump:

Barrel Multistage Pump

This pump type consists of a barrel-shaped casing that houses a number of impellers. It is commonly used for high-pressure applications in industries such as oil and gas, power generation, and mining.

Ring Section Multistage Pump:

Ring Section Multistage Pump

In a ring section pump, the impellers are arranged in a ring shaped casing. This design allows handling of high pressures and is suitable for applications such as boiler feed water, petroleum refining and chemical processing.

Submersible Multistage Pump:

Submersible Multistage Pump

Designed to operate under water, submersible multistage pumps are often used in deep wells, offshore oil platforms, and wastewater treatment plants. These pumps are sealed and fitted with submersible motors for efficient water lifting.

Regenerative (peripheral) multistage pumps:

Regenerative (peripheral) multistage pumps

Also known as peripheral pumps, regenerative multistage pumps employ impellers with many small channels to generate high pressure. They are commonly used in applications such as pressure boosting, water circulation and small scale industrial processes.

Mixed Flow Multistage Pump:

Mixed Flow Multistage Pump

This type of multistage pump combines elements of both axial and radial flow, allowing for efficient fluid movement in a variety of applications, including irrigation, drainage systems, and wastewater treatment.

Modular Multistage Pump:

Modular Multistage Pump

Modular pumps consist of separate stages that can be assembled and stacked together according to the specific requirements of the application. They offer flexibility in terms of capacity and pressure, which makes them suitable for a variety of industries such as mining, water treatment, and oil and gas.

Here are some of the advantages of using multistage pumps:

They can achieve higher targets than single-stage pumps.

They are more efficient than single-stage pumps.

They are smaller and lighter than single-stage pumps of similar capacity.

They are less sensitive to changes in fluid properties.

Here are some of the disadvantages of using multistage pumps:

They are more expensive than single-stage pumps.

These are more complex to install and maintain.

They may be more prone to vibration.

Here are some of the applications where multistage pumps are commonly used:

Water supply.

Fire protection.

Industrial Process Pumping.

Chemical Processing.

Oil and gas production.

HVAC System.

Irrigation.

Here are some of the key factors to consider when choosing a multistage pump:

Required head.

Required flow rate.

Fluid Properties.

Operating conditions.

Budget.