Multistage centrifugal pumps have become quite popular due to their flexibility in handling various flow and head requirements, coupled with their energy efficiency. These pumps work by having the fluid pass through multiple impellers arranged in a series.
HERE’S A BREAKDOWN IN SIMPLER TERMS:
- Definition: Multistage pumps are pumps that have several impellers arranged in a series.
- Increasing Head: If a single-stage pump doesn’t provide enough head (pressure), adding more impellers in series (multistage) is a cost-effective way to increase the head.
- Flow Rate and Power: Adding stages doesn’t change the flow rate; it just increases power and head proportionally.
- Example: A ring-section pump is a type of multistage pump used in power stations and industries needing high pressures.
- Arrangement: Stages can be in tandem (one after the other) or back-to-back in pairs or groups for better axial thrust balancing.
- Advantages: Multistage pumps cover higher pressure ranges economically. They can be tapped downstream or have dummy stages for future pressure increases.
- Disadvantage: Too many stages can make the pump sensitive to external vibrations.
- Components: Each stage includes an impeller, a diffuser, and return guide vanes. An inlet casing is upstream of the first stage, and the last stage is in the discharge casing with a balancing device and shaft seal.
In simple terms, multistage pumps are like a series of pumps working together to provide the right pressure for various applications, such as in power stations or industries.
ABOUT MULTISTAGE CENTRIFUGAL PUMPS
Multistage centrifugal pumps are like a series of connected chambers that pump liquid. Imagine it as a chain of chambers. The liquid starts at one end with low pressure, goes through each chamber, and comes out at the other with higher pressure.
HERE’S A SIMPLER BREAKDOWN:
Chambers in Series: These pumps have multiple chambers (stages) lined up. Liquid goes through one stage, then into the next, and so on.
Pressure Increase: As the liquid moves through each stage, the pressure keeps going up. The more stages there are, the higher the final pressure when the liquid comes out.
Constant Flow: Interestingly, even though the pressure increases, the amount of liquid the pump can move (flow) stays the same.
Types: There are two main types based on how the shaft is positioned—horizontal or vertical.
In simple terms, multistage pumps are like a team of chambers working together to push liquid, and the more chambers they have, the stronger the push they can give.
8K MULTISTAGE CENTRIFUGAL PUMPS
8K series is a top-notch line of pumps designed to last long and work without causing problems. Originally made for boosting water pressure, purifying water, and handling hot water, many industries now use it because it performs well.
These pumps are industrial-grade and made with strong materials like stainless steel. They have special features like different seal options and a tough design with a separate bearing for extra support. The 8K series also uses tungsten carbide for certain parts, making sure it lasts a long time.
Simply put, you can rely on the 8K series to do its job well, no matter what you’re using it for.
MULTISTAGE CENTRIFUGAL PUMPS FEATURES
The pump has parts that touch the liquid made of high-quality stainless steel. It uses special rubber parts called Viton®, which can be changed for different needs. The pump is designed to work with standard motors easily. There’s a special feature at the top to let air out, preventing problems when starting. The pump is made to fit into existing systems easily. It has a special seal made of Silicon Carbide, Carbon, and Viton®. The parts inside are strengthened to avoid bending during use. The pump can handle temperatures from really cold to pretty hot.
MULTI STAGE PUMP PARTS
The multistage pump is a bit like the regular centrifugal pump but has some extra parts. One important part is called a diffuser, and it helps direct the liquid to the impeller or the next stage. For a side channel pump, there are special plates with a scalloped side channel and liquid parts.
In multistage centrifugal pumps, the impellers are facing the same way, and this creates a strong push called thrust. To handle this, there’s a special device called a thrust balance device, like a balance disc or drum, which makes the thrust less so that a regular-sized thrust bearing can handle it.
HOW MULTI STAGE PUMP WORK
A multistage pump works like this: one impeller passes the liquid to the next impeller, and the number of impellers depends on how much pressure is needed. The liquid goes through each impeller in a sequence from left to right.
These pumps have many uses, like pumping water to tall buildings, reverse osmosis (RO), supplying water to boilers, spraying, high-pressure cleaning, water treatment, heating, dealing with condensation, delivering fuel, and working in oil and gas production, power generation, mining, and other situations with high pressure and temperature.
WHAT ARE THE ADVANTAGES OF USING A MULTI STAGE PUMP
If we compare a Centrifugal Multistage Pump to a high-pressure duty pump, even though the multistage pump is more complex and costly, it’s likely a better fit hydraulically. It’s more efficient and reliable. With its hydraulic modules and the ability to add or adjust impellers, it can precisely meet the required duty point without compromise. The selection is closer to the ‘BEP’ (Best Efficiency Point), ensuring efficient and reliable operation.
Multistage pumps can be set up with an interstage bleed-off if there are multiple duty points needed. It might be possible to run a multistage pump at a lower speed than a single-stage centrifugal pump, offering efficiency advantages and running much quieter a critical consideration in today’s world. A 3 dBA increase represents a doubling of sound, and the sound scale is logarithmic.
VERTICAL MULTISTAGE CENTRIFUGAL PUMPS
Vertical multistage centrifugal pumps have a vertical shaft, with stages stacked on top of each other. These pumps are best for clean water applications due to small clearances. They work well for:
- High-pressure shower systems
- Boiler feedwater
- Desuperheater feed
These pumps are suitable for spaces with limited room. They can provide high-pressure output with a single pump body and motor. However, they can’t handle debris or solids and are sensitive to deadhead conditions.
Multistage pumps offer benefits like energy savings and versatility in handling different flow and head scenarios. If you’re considering one for your needs, consult with an engineer to ensure the right pump is selected for your specific use.
ADDITIONAL CENTRIFUGAL PUMPS
Centrifugal pumps are useful for moving large amounts of fluid at low pressure in industries. They are commonly used for pumping freshwater or liquids with some particles. Here are some popular centrifugal pump models that come with the pump, seal, and motor included. Most of these pumps operate at 3450 revolutions per minute (rpm), but there are also models available at 1725 rpm.
MULTISTAGE PUMP USED IN INDUSTRY
In India, the two most common types of multi-stage pumps used in industries are horizontal and vertical pumps. Kiron Hydraulic Needs offers a variety of multi-stage pumps and provides local technical support and on-site service engineering in Ireland to meet operational needs.