How Does a Blower Work?
The technology behind blowers, on the surface, seems to be very simple. The name alone implies its function to blow air much like an ordinary household fan used to move air during a heat wave in the summer. In actuality, there is far more science behind a blower than its simple name may imply. What is involved is an aspect of natural law that is one of the basic laws of physics.
If you watch the weather broadcast of a news channel, you are aware of high and low-pressure systems and their influence on the weather. Low pressure is caused by warm air rising to leave a large space under it. It produces high winds and warm air. A high-pressure system squeezes the air under it creating less pleasant conditions.
Blowers make use low pressure and high pressure. Air and fluid masses seek, as with nature, a balance and equilibrium. This is what blowers use to fulfill their function. Low pressure is air rising, which is the movement of hot air. It rises until it is cooled while cold air is heavy and moves downward. This is a simple description of weather where masses of hot and cold air change the climate. Blower systems work in much the same way by increasing or decreasing air pressure.
A good example of how a blower works is a hot air balloon, which rises and descends depending on the heated air blown into it. When the pilot of the balloon wants to rise, they heat the air in the balloon. As the temperature increases, the balloon slowly moves upward as if by magic. Like a low pressure system, it moves up regardless of the ambient temperature around it. If the balloon were heated continuously, it would rise until the air inside is cooled causing it to descend and slowly return to its launch point. This is very similar to the exchange that takes place between low and high-pressure air.
A blower functions in much the same way without the rising and descending. A very practical method of heating a house is to install a blower. Heat is the absence of cold where cold is the absence of heat. When you are too hot, you cool yourself with a cold drink, ice bag, or sitting in front of a fan. Though the normal household fan is not as technical as a blower, it serves the same function. If you are hot, the air pressure around you is low meaning the heat is rising inside you. To change that pressure, you turn on a fan that increases the air pressure and cools you. It is a miniature example of what happens on the planet with high and low-pressure systems seeking to maintain climatic balance.
Giving cold to a friend when they are warm changes the air pressure around them by removing low pressure. The same thing happens when are having a cup of hot coffee or hot soup. You blow on it to cool it, which is changing the air pressure. None of us think about air or fluid flow when we are cooling something. It is our reaction to an uncomfortable or unpleasant condition. What we don’t realize is that we are completing one of the laws of physics regarding high and low pressure.
Blowers, in their multiple uses, do the same thing as a household fan or space heater. In conditions that require low pressure, they remove high pressure by blowing air in. When the reverse is required, they blow the air out. If you visit a construction site in the summer, you will see huge fans placed around enclosed areas. These fans, or blowers, increase the air pressure making the conditions for the workers more comfortable and less oppressive.
The laws of physics that define the movement of fluids is a description of air flow. The rule of fluid dynamics is that a pressurized fluid seeks equilibrium with nearby bodies of fluids that have a different pressure. Air is constantly seeking to equalize itself by flowing from areas of high pressure to low pressure. When you pressurize the air by using a portable fan, you feel the highly pressurized air moving to an area of lower pressure, which is the space around you. The fan influences the direction of the flow while your body feels the force of the air.
Blowers are much like the household fan only much larger and more powerful. Instead of moving a small amount of air, they have the power to move large volumes of it and change the temperature of liquids. Though these units are larger and can move huge volumes of air or gases, they are a very economical means of changing temperatures.
Most large blowers are used in large industries because of their ability to produce a high pressure ratio with a large volume of gas flow. They are intended to remove hot fumes or harmful contaminates and come in two basic types – axial or centrifugal. The type that is chosen by a company depends on the space and type of gases to be moved.
As complicated as all of this may sound, blowers depend on the basic principle of low and high pressure, which constantly seek equilibrium. It is an aspect of nature that has been engineered into a device that has multiple uses in homes and industry.