The term pneumatic is used to describe a mechanical device that is powered by compressed air. Systems based on pneumatics rely on compressed air. The energy produced by pneumatic systems can be more flexible, less costly, more reliable, and less dangerous than that produced by devices powered other ways, such as with actuators or electric motors.
Pneumatics is a branch of mechanics that deals with the mechanical properties of gases. Air is a gas. This field focuses on using pressurized gas (compressed air) to produce mechanical motion and the application of such gases to produce motion.
Pneumatic devices work via the following general procedure:
- An air compressor is used to reduce the volume of air (which creates compressed air).
- Compressed air travels through a filter into pneumatic tubing.
- Valves control the flow of compressed air as it moves through the tubing.
- Upon reaching an actuator, the compressed air produces motion.
Many devices that people use in everyday life are based on pneumatics. This is true with devices used by consumers as well as in industrial applications.
Quite a few consumer products are based on pneumatics.
- air compressor - An air compressor is a pneumatic device that uses a motor or engine to convert power into pressurized air that can be stored in a tank as potential energy. When you use a coin-operated device at a gas station to put air in your car, you are using an air compressor. If you use a hand-held pump to put air in a bicycle tire, that is a very basic air compressor.
- exercise equipment - Exercise equipment, such as elliptical and resistance training machines, is powered by pneumatics. With these devices, a pneumatic cylinder creates resistance that can be adjusted with air pressure.
- pipe organs - Pneumatics even plays a role in some musical instruments. For example, pipe organs produce sound by pushing pressurized air through pipes that are chosen by pressing keys on a keyboard.
- air guns - Pneumatic air guns are toy guns, such as BB guns, that use a small amount of pre-compressed air as an energy source to put a projectile in motion.
- breast pumps - Some breast pumps that nursing mothers use to help them keep up with expressing breast milk when they are away from their babies use pneumatic technology.
- vacuum pump - A vacuum pump removes air molecules from a sealed container, leaving behind a partial vacuum. This concept is commonly used in at-home food preservation systems. Vacuum sealing food in bags or jars can greatly extend its shelf life.
- pneumatic delivery tubes - Pneumatic mail systems were once widely used to deliver letters through pressurized air tubes. This system is no longer commonly used in the mail but is often used in hospitals to quickly distribute and deliver medical samples and medications from one location to another.
- LEGO pneumatics - Even LEGOs can use pneumatics! There is a kind of Lego brick that uses air pressure to perform various actions using the pneumatics concepts. They are included in some LEGO education sets.
There are many uses for pneumatic systems in industrial applications, including ones that impact day-to-day life.
- air brakes - Air brakes on buses and trucks are formally known as compressed air brake systems. These systems use a type of friction brake in which compressed air presses on a piston and then applies the pressure to the brake pad that stops the vehicle. If you ever rode a school bus, you have benefitted from a pneumatic device.
- jackhammer - A handheld jackhammer is a tool that combines a hammer and a chisel. This type of tool is powered by compressed air. Any road or sidewalk that you have ever used likely required the use of a jackhammer to be constructed.
- compressed air engines - Compressed air engines, also called pneumatic motors, do mechanical work by expanding compressed air. The compressed air is converted to mechanical action by rotary or linear motion.
- pressure regulators and sensors - Pressure regulators are valves designed to automatically stop the flow of a liquid or gas when it reaches a certain pressure. Pressure sensors are used to measure the pressure of gases or liquids.
- pneumatic bladder - A pneumatic bladder is an inflatable bag technology that can be used to seal drains and ducts to contain chemical gases or spills, to stabilize cargo within a container or to float an artificial coral reef. They can be used in medical research, and have other applications as well.
- pneumatic cylinders - Pneumatic cylinders use the power of compressed gas to produce force and motion, either in a linear or rotating motion. They are commonly used in the construction of industrial equipment.
- pressure switches - Pneumatic pressure switches close an electrical contact when a certain amount of air pressure has been reached. The switch can be set up to make contact either when the pressure rises or when the pressure falls.
- barostat systems - A barostat system maintains constant pressure in a closed chamber. Barostatic balloons are used in the medical field of gastroenterology to study the human intestinal tract.
As you can see, you will likely encounter some type of pneumatic system on a regular basis in the course of your everyday life. Now that you are familiar with some common uses of pneumatics, explore other scientific concepts related to energy. Start by reviewing examples of electrical energy in action. From there, review some examples of chemical energy in everyday life.