Pumps
Did you ever think about the impact pumps have on our lives? Can you imagine how much more difficult things would be without pumps?
Pumps play a very important role in our daily lives and in plenty of industries. You can think of pumps as the heart; that is the same way the heart circulates blood in our bodies, pumps circulate and move liquids and gases through systems and from one place to another.
Basic Working Principles of Pumps
The two most important factors that we will look into are pressure and mass flow rate.
Pressure: By definition, pressure is the force exerted divided by the area where the force is exerted. Pumps create pressure and this is what allows pumps to move gases and liquids through pipes.
Mass Flow Rate: It is the amount of liquid or gas that passes through a point per unit time. Pumps can regulate how much fluid to push through pipes per unit time and that is how pumps can control the mass flow rate.
But How Do Pumps Actually Work?
Suction: The first step is for the pump to pull the fluid into it. In order to do so, it creates a suction force just like how we use a straw to drink a drink.
Increasing the Fluid’s Pressure: The manner in which a pump increases the fluid’s pressure is that when the fluid is sucked into the pump it will hit the impeller blades that would be rotating at a high speed. As the fluid hits and passes through the impeller it gains velocity and pressure. Basically, what is happening is that the pump is converting the rotational energy, coming from a motor to rotate the impeller, into energy in the moving fluid. As you can see in the image, the main components that make up the pump are the following:
- The impeller: This is the rotating blades.
- The Casing: The airtight path that surrounds the impeller.
Discharge: Therefore, this increase in pressure propels the fluid forward for it to exit through the discharge. Hence, the fluid exits the pump with an increased pressure ready to be transported to the desired location through pipes.
Pumps in the Real World
Many industries rely on pumps, below are a few examples:
- Oil and Gas Industry: Pumps are utilized to extract natural gases from wells and to transport these products through pipelines in gas plants in order to end up with the final products such as gasoline and diesel.
- Automotive Industry: Pumps are a crucial part of many systems in a car; let’s start by taking a look at the fuel system. A fuel pump is found in a car’s fuel tank, and it is responsible for transporting fuel from the tank and sending it through the car’s fuel lines to the engine. Another very important system in a car is the cooling system, which keeps the engine cool and prevents it from overheating. The way this system operates is by circulating coolant/water throughout the coolant tubes in the engine to remove heat; this is achieved by the help of a water pump. The coolant would not flow throughout the engine if the water pump were not present, and the engine would overheat.
- Firefighting Trucks: To be able to effectively extinguish fires, these trucks are equipped with pumps that draw water and deliver it at a high pressure through hoses.
What are some examples of where pumps are used in our daily lives?
- HVAC Systems (Heating, Ventilation, and Air Conditioning): In this case, pumps are utilized in order to circulate water, refrigerants, and air through HVAC systems.
- Water Supply: It is thanks to pumps that we have a clean water supply to our houses for our everyday use and needs.
Check this out to see the role of pumps in water towers!
Electric Motor
The function of this electric motor is to provide the pump with rotational energy in order to rotate the impeller (blades).
Let’s have a look at how a DC electric motor works.
A DC electric motor converts electric energy, that is provided from a power source, into mechanical energy. A DC motor operates based on the principles of electromagnetism; that is the interaction between magnetic fields and electric current. A power source is connected to the two terminals as seen in the following image.
In the following image we can see only one armature; however, in an actual DC electric motor there are multiple armatures (coils) present
The metal case of a DC motor comprises of the following components:
Coil of wire (armature): Once we connect the motor to a power supply, an electric current will induce a flow through the armature. This will create an electromagnetic field around the wire.
Magnets: The magnetic field created around the wire will interact with the two magnets surrounding the armature and therefore a force will be exerted on the armature (the wired coil) and cause the coil to rotate.
Commutator: This is responsible for making sure that the coil is rotating continuously so the shaft rotates continuously. This continuous rotation of the armature (coil) and consequently rotation of the shaft is what generates the mechanical energy needed to operate the pump.
The following is a section view of a DC electric motor. We can see how we have multiple armatures (coils), a commutator, and a shaft; these make up what is known as the rotor. The two magnets on each side of the motor and the metal case of the motor make up what is known as the stator.
To conclude this section, take a look at this 3D animation to visualize how the electric motor drives the pump.
CHALLENGE
For your next challenge you are going to be asked to create and operate your own pump to transfer water all the way to the top of your mini house. However, in order to operate this pump you are going to need an electric motor which you can find in the kit.
In order to complete this challenge, take a look at our demonstration at how to create your own pump and how to operate it using the components in the kit.
DONE!
Congratulations on diving into the world of electric motors and pumps! These vital devices drive everything from industrial machinery to household appliances. Understanding their mechanics opens up a world of innovation and efficiency. Keep exploring their workings! Your knowledge in this area will fuel progress in engineering fields everywhere.