Centrifugal pumps are rotating machines, which use impeller force to trigger flow and pressure automatically to lift water and fluids to higher ground. This happens by converting kinetic energy to hydrodynamic energy of fluid flow. The rotational energy is brought about by the electric or engine mortar. Francesco Di Giorgio Martini, an Italian engineer in 1475, developed a mud-lifting machine, which was considered the first type of centrifugal pumps.
Let’s take a look at some of the common centrifugal pumps used today. Since they are used for different jobs, it’s important to know which one to use when.
Axial flow Pumps
It uses a propeller in a pipe, which is driven by a motor inside the tube, attached outside the pipe or using a right angle drive shaft, which pierces the pipe. The propeller continuously puts pressure on the fluid or gas forcing their flow parallel to the axis of rotation. Power required increases as the flow decreases. The highest power is achieved at zero flow rate. Therefore, the power required increases with the increase in flow.
- It has a high flow rate at a relatively low power.
- It is easily adjustable to run at peak efficiency by changing the pitch of the propeller.
The most common application of the axial-flow pump is the sewage niche ranging from commercial, industrial and municipal services. They are also used in transfer pumps to sail ballast. They can be used to lift water used for irrigation and pumping water from reservoirs.
Mixed/Radial Flow Pumps
This is a centrifugal pump with a mixed impeller. The impellers for high-speed pumps are fitted with a diffuser and a tubular casing while those of relatively low speed are fitted with a volute casing. Fluids or gasses enter through the axial plane, and then it is moved by the impeller and exits at the right angle to the shaft radially. This kind of pump operates in higher pressures than the axial flow pumps and offers higher discharge than the radial flow pumps.
- They are highly reliable and are not strenuous.
- They are best suited for industrial use since they are cost effective and require less power to move large volumes of fluid.
- This type of centrifugal pump is durable thus will be of great economic importance for an extended period.
This kind of pump is used in situations that require a high level of flow with low pressure applied. They are highly recommended for industrial use due to the low cost of operation and durability.
In this case, the peripheral impeller rotates in a large concentric casing channel with both an inlet and outlet. As the fluid repeatedly circulates between the impeller and the pipe surface, high energy is created. The energy created forces the fluid to move from the center of rotation to the outlet point. This kind of pump can pump fluids with high gas content better than any other type of centrifugal pump.
- They are not sophisticated and thus can be used in small scale pumping of water.
- They don’t use much energy as they utilize the momentum of the fluid.
Peripheral pumps are also used in pumping uncontaminated water or other uncontaminated fluids. They are mostly used for car-wash pumps or for pressure boosting purposes.
This is a type of pump that is controlled using a power switch. One will switch on the power switch in case water or fluid pumping is needed. It circulates water in loops when pumping and is available in several ranges of horsepower and performance rates. This type of pump is used to pump water from deep or shallow wells.
- They are easy to operate.
- They are cheap.
They can be used to pump water to households or sprinklers used for irrigation.
Why is safety training an important part of education for workers who work with centrifugal pumps?
The different types of centrifugal pumps are operated differently from the other due to the wide range of differences. Users of these pumps need to familiarize themselves with the various methods of operation to ensure that the pumps are not damaged or do not affect the people using them.
NTT offers Safety Training on Centrifugal Pumps of all Kinds
If you are a safety director, building engineer, superintendent, or if you require cross training on pumps and pumps systems, NTT Training offers a seminar that will enable you to calculate pump efficiency along with operation costs, maintain, install and troubleshoot centrifugal pumps as well as carry out centrifugal pump design, theory, distinctions, and operations. The in-depth centrifugal pumps seminar involves hands-on lab experiences that reinforce and demonstrate the practical techniques of troubleshooting and maintenance. To find out more on how you can attend the seminar, you can contact NTT Training in person, or chat online.