Pumps are essential equipment used in various industries, including agriculture, chemical, construction, mining, oil and gas, and wastewater treatment. There are different types of these available in the market, each designed for a specific application.
Choosing the right type for your industry is crucial in ensuring the success of your operations. In this comprehensive guide, we will discuss the differences between centrifugal, positive displacement, slurry, dredge, self-priming, and submersible pumps. Also, various examples of industries that use them, and top US companies that produce them.
What are Centrifugal, Positive Displacement, Slurry, Dredge, Self-Priming, and Submersible Pumps?
1. Centrifugal Pump:
It’s the most common type used in various industries. This uses centrifugal force to move fluid through an impeller. This generates kinetic energy, creating pressure which forces fluid out of the discharge port.
These products are suitable for fluids with low viscosity. They are perfect for high flow rate and low-pressure applications, like water supply, irrigation, and HVAC systems. Most centrifugal products may operate with a suction lift if they require priming.
Figure: Centrifugal stainless steel pump
2. Positive Displacement Pump (pd pump):
This works by trapping fluid. These are designed by using two or more mechanical parts. The fluid is then moved through the pump’s chambers for positive displacement work.
These are ideal for thick fluids. They can manage liquids with a high concentration of solids, like food items, chemicals, and oil. It’s also used in applications where the flow rate needs to be constant, such as dosing and metering.
Figure: The structure of positive displacement from researchgate.net
3. Slurry Pump:
This is built to withstand abrasive and corrosive liquids, such as mud, sand, and gravel. These fluids are typically found in mining, dredging, and wastewater treatment applications. These use impellers with wider vanes to reduce clogging. Also, reduces wear and tear from solids, ensuring a more extended service life.
Figure: Slurry with horizontal/vertical application
4. Dredge Pump:
This is designed primarily for dredging applications. They can push large volumes of solids, such as sediment in rivers, lakes, and harbors.
These are built to handle high-density slurries, including sand, gravel, and rocks. They are commonly used in the mining and construction industries.
Figure: Diver operated dredge electric powered by Eddy Pump
Figure: Diver operated dredge hydraulic powered
5. Self-Priming Pump:
It is mainly built to automatically create a suction vacuum to prime themselves without external intervention. The location of the tool should be above the fluid level for it to operate. These
include water transfer, drainage, and sewage treatment.
Figure: Trailer Mounted Self-Priming Slurry
6. Submersible Pump:
It is designed to be fully submerged in the fluid they are taking out. They are suitable for applications where fluid needs to be lifted. Examples include deep wells, boreholes and mines. They’re also used in sewage treatment, irrigation, animal waste, and drainage applications.
Figure: Submersible, dreamstime.com
The material and chemistry of the stainless steel pump offers greater chemical resistance. The addition of molybdenum to steel during production makes the steel more resistant to corrosion and oxidation.
How One Type of Pump is Different from the Other?
Centrifugal and positive displacement are two different categories that operate based on different principles.
The first is used to transport liquids. It does this by rotating an impeller, which increases the pressure and flow of the liquid.
Positive displacement pump works differently. They use a mechanical process to move liquid. This process involves trapping a fixed amount of liquid and then pushing it through the equipment.
Submersibles are built to work underwater. They are commonly used to push water out of flooded basements or water wells. Self-priming ones prime themselves. This creates a vacuum which allows them to draw water from below the suction line of the equipment.
There is a wide variety of submersible and self-priming. Centrifugal and positive displacement can also be either submersible or self-priming.
Dredge and slurry are similar in that they both can transport fluids with a high solids content. However, there are a few key variations among them.
Dredges are commonly used when pushing a mixture of water and solids. This mixture is too heavy to be moved by other types of equipment. Slurries are used for a different purpose. They transport a mixture of water and solids that have similar particle size and density.
These come in three varieties: positive displacement, centrifugal, and submersible.These are designed specifically for dredging applications.
Dredge typically has a higher flow rate and can handle bigger particles than other types. Positive displacement and centrifugal are beneficial for applications with a consistent fluid that don’t have microscopic solid or liquid. Large solids can disrupt the process, making these types of equipment less suitable. Submersible is used when it needs to operate underwater.
Self-priming is used when the equipment needs to prime itself before drawing out the solid and liquids.
Applications Where You Should Consider Eddy or DAE Pumps
Eddy Pump Corporation produces the EDDY Pump. It is made to manage abrasive and thick liquids with high solid content.
These are suitable for dredging, marine, mining, oil and gas, sewage/water treatment, and material handling (e.g. sand and gravel, fly ash pumping). Eddy Pump technology has an advanced design.
It is worth considering if your industry deals with abrasive, viscous fluids with high solids content. It offers improved efficiency, reduced downtime, total customer lifecycle cost, and longer service life.
DAE Pumps provide a range of options to meet any pump requirements.
These include submersible, centrifugal, positive displacement, self-priming, dewatering, dredge, and slurry.
If you need a pump for industrial use, it’s important to select the right one. It must be suitable for your application.
Frequently Asked Questions (FAQs)
1. What is the primary difference among positive displacement and centrifugal pumps?
Positive displacement draws fluid into a cavity. They then displace the fluid and force it out using suction.
Centrifugal and aerodynamic use a rotating impeller. This impeller draws the fluid into the pump and pushes it out of the pressure point at a higher speed.
2. What is the difference between a centrifugal and self-priming pump?
Centrifugals are not made to remove air from the suction line to a liquid level. This liquid level must have a geodetic height higher than the pump’s height. In contrast, self-priming is able to get rid of air from the suction line without external auxiliary equipment.
3. What is the difference between a submersible and centrifugal pump?
A submersible needs to be underwater in order to work. In contrast, a centrifugal pump must be above the water level for it to function.
4. What is striving or What is a suction lift?
This simply means that the maximum level of the pumped liquid is physically below the centerline of the pump impeller. Most centrifugal pumps can be operated at this condition if they may be primed first.
5. Why are pumps manufactured with stainless steel?
The advantages of using stainless steel is that stainless steel is strong, corrosion resistant. It has high heat resistance and requires little maintenance. This makes it an ideal material for surface and submersible ones.
6. What is the difference between a slurry and dredge pump?
Dredges are often employed in situations where the water and solids mixture is too heavy for other equipment. Examples include slurry, positive displacement, self-priming, centrifugal and submersible pumps. Slurries primarily transport a mixture of water and solids that have similar particle size and density.