Dynamic pumps which process movement of fluids in a systematic way are known as Centrifugal pumps. It may require one or more than one impellers. They are the most known among all industrial pump manufacturers because of their simple mechanics and design’s effectiveness. And as they are the most familiar ones, compared to the other pumps, they have lesser cost prices.
Composition
Impellers are the sets of rotary vanes and are the primary constituent of a centrifugal pump. These vanes produce centrifugal force to provide energy to the fluid and are meant to be inside a proper casing. The pump got two primary parts: the shaft and the impellers, along with the stuffing box, casing and bearings.
• Capacity: Amount of liquid discharged from a centrifugal pump in provided time.
• Total Head: The difference between the discharge pressures and pump suction.
• Suction Head: The difference between the level of liquid in the vessel and the pump’s centerline.
• Power: In given time, the energy utilized by the pump.
• Efficiency: The percentage measure of the effectiveness of a pump while transferring power used to form energy.
Features of Centrifugal pumps
There are a number of features that should be taken into consideration. There are a few key factors which set the quality of a pump.
• Impeller design
This design serves as the backbone of the pump’s performance. It is the main factor in a pump’s design and determines the flow type of a pump.
Closed impellers: As the vanes totally close off all the sides, water pumps of closed designs are the best.
Vortex impellers: These are the clog repellent impellers with unique semi-open impeller design, the best solution in case of stringy materials. Though these are 50% less efficient compared to other designs.
Open and semi-open impellers: Fewer chances of getting clogged and suits well in viscous medium.
Turbine impeller: These impellers have lower flow rates but generate high head and are used for regenerative turbine pumps.
• Material
Relying on media type, surrounding environment, and system requirement, these pumps are manufactured using various kinds of materials.
Cast iron: In correspondence to high-pressure ratings, Cast iron provides high durability, tensile strength, and abrasion.
Plastics: These provide resistance to corrosion and from attacks including chemicals. These materials are inexpensive comparatively.
Steel and stainless steel alloys: Most probably the best kind of material providing better tensile strength than plastics. Due to high-pressure ratings, it protects the pump from extensive corrosion and chemical attacks.
Pump Operations
• Axial flow pumps have the characteristics of low pressure and high flow. Behaving similarly like a boat propeller, these pumps draw the liquid in the impeller shaft’s parallel direction.
• Radial flow pumps have the characteristics of low flow and high pressure. There’s an acceleration of the liquid through the central part of the impeller and goes out along the blades of the impeller to the pump’s shaft maintaining right angles.
• Mixed flow pumps have combined attributes of both axial and radial flow pumps maintaining a medium flow and medium pressure. In these pumps, the liquid is forced out of the pump’s shaft creating angle more than 90 degrees. Pressure built in these pumps is equally divided into the liquid lifting process (axial flow pump) and developing a centrifugal force (radial flow pump).
Centrifugal pumps provide less pressure and greater flow rates compared to displacement pumps. So, as per industrial pump manufacturers, centrifugal pumps have a great demand in the market.