The pneumatic system has played an essential role in the mechanical field and also it is being used in industrial automation solutions development. These systems are related to hydraulic systems however compressed air is used in these systems instead of hydraulic fluid. The term ‘Pneuma’ means air whereas Pneumatics means using compressed air to perform the specific task.
The atmosphere air when its volume is decreased through compression is called the compressed air, so pressure can be increased. Normally, compressed air is used as a working medium at 6 kg/sq mm to 8 kg/sq mm pressure. By using pneumatic systems, we can develop maximum force up to 50 kN. This article discusses an overview of a pneumatic system, working with applications.
What is Pneumatic System?
Pneumatic system definition: A system that uses compressed air for transmitting and controlling energy in various industries is known as a Pneumatic system. These systems mainly work by using a constant compressed air supply which is provided by an air compressor. The compressor takes the air from the atmosphere & stores it in a receiver which is known as a high-pressure tank. After that, this compressed air is supplied to the system through a series of valves or pipes.
Pneumatic System Construction
The construction of a pneumatic system can be done by using different components. Pneumatic system components mainly include Intake filter, compressor, cooler, separator, motor control center, receiver, pressure switch, secondary air treatment, control valve, and actuator. Pneumatic system line diagram is shown below.
Intake Filter
An intake filter is used to filter out the pollutants from the air which is also known as an air filter.
Compressor
The main function of this compressor is to reduce the volume of air & increase the air pressure.
Motor Control Center
The motor in this system is used to supply mechanical energy to the compressor because the motor function is to change the energy from electrical to mechanical.
Cooler
The cooler is used to decrease the temperature of the compressed air.
Separator
The separator is used to separate the moisture or water vapor within the air.
Receiver
The receiver in the system is a high-pressure tank, used to store the compressed air which is coming from the air coolers.
Air Treatment
The air treatment in the above system can be separated into three stages. So, in the first stage, the large size particles are banned from entering the compressor through an intake filter.
The air exiting from the compressor may have a high temperature, so it is treated in the next stage. In the final stage, the compressed air temperature is decreased with a cooler & the compressed air can be dried through a dryer.
Pressure Switch
Pressure switches in the above system are used to detect the increase or decrease in air pressure which are either changeable or not adjustable. These switches are used in vacuum or pressure applications.
Control Valve
The control valve in the above system is used to change the airflow direction.
Air Actuator
In a pneumatic system, the air actuator is an essential part and the main function of this is to use the compressed air energy which is also called pressure energy & change it into mechanical energy. So we can get the final output from the air actuator.
Pneumatic System Working Principle
At first, the air is taken directly from the atmosphere by using the air filter. This air is cleaned & purified within the air filter. These filters are essential because if the air is used directly from the atmosphere, it can damage the compressor. After that, the air can be supplied to the air compressor which is driven by the mechanical energy produced by the electric motor.
The air compressor increases the air pressure & decreases its volume. When the air pressure is increased, then its temperature can also be increased. Thus in the next step, compressed air is transmitted to the air coolers which reduces its temperature but its pressure will remain the same even after reducing its temperature.
After that, the air which is cooled is transmitted and stored within the receiver tanks. After that, this air can be transmitted to the air treatment chamber which is also known as filter regulator lubricator or FRL Once the air is moved into this chamber, then it is dried.
In a pneumatic system, this process is very important because the components used in the pneumatic system are delicate. If this air treatment is not used then the air might be wet & warm and it is transmitted directly to the receiver tank So, this will have a the serious impact on the remaining parts. So by using this, the system performance and efficiency can be increased.
The air from the air treatment is transmitted to the control valve to change the flow direction based on the requirements. Finally, the air actuator uses the energy of air and converts it into mechanical, thus we can get the final output from this actuator.
Difference between Pneumatic and Hydraulic System
The difference between a pneumatic system & a hydraulic system includes the following.
Pneumatic System | Hydraulic System |
| The pneumatic system works through air or gas. | The hydraulic system works through the fluid. |
| It generates less power. | It generates more power. |
| This process is very clean. | This process is not clean. |
| Simple to operate. | Not simple to operate. |
| Maintenance is easy. | Maintenance is not easy. |
| Initial & operating cost is less. | Initial & operating cost is high. |
| Simple complexity. | Medium complexity |
| Excellent reliability. | Good reliability. |
| High peak power. | Very high peak power. |
| Less size. | Very less size. |
| Good position accuracy. | Good position accuracy. |
| Fast speed | Speed is slow. |
| Utilities of this system are power, compressor, pipes, etc | Utilities of this system are pump, power, pipes, etc |
Pneumatic System Maintenance
Some common issues that occurred in the Pneumatic system are a slow movement of the actuator, less pressure, leaks from the air seal, Too much air choke, damaged filter, cylindrical drift, the flow of air direction not changing within the control valve, etc. To overcome all these issues, the maintenance of a pneumatic system is very important. So, the maintenance of the pneumatic system can be done like the following.
- For weekly once, airline filters need to Drain & check the water traps operation.
- For every 4 weeks, we need to check air leaks & seals.
- For every four weeks, need to add lubricant to mist lubricators.
- For weekly once, need to clean components & electric actuators externally.
- Need to check movements of components, pivot points & lubricate cylinders.
- For half-yearly, we need to change air filters.
- Need to clean and replace plugged silencer if required.
Advantages
The advantages of the pneumatic system include the following.
- Its design is simple.
- Efficient.
- High effectiveness.
- Availability of source is infinite.
- High reliability & durability.
- Safety aspects.
- Economical.
- Air can be stored.
- The transfer of power & speed is very simple to set up.
- High adaptability to the harsh environment.
- Simple selection of pressure & speed..
- Eco friendly.
Disadvantages
The disadvantages of the pneumatic system include the following.
- Relatively low accuracy.
- Low loading.
- The processing required before use.
- Uneven moving speed.
- Needs air-producing equipment installation.
- Easy to leak.
- Less operating pressure.
- Simple condenses.
- As compared to electricity, compressed air is costly.
- A silencer needs to install in each dump line because these systems will generate loud noise.
- When these systems need special pipes then the cost for installation will be increased.
- These systems are not upgradable.
Applications
The applications of the pneumatic system include the following.
- These systems are used in manufacturing industries like machine tools, automotive, domestic appliances & commercial appliances.
- These systems are used in processing industries like food processing, chemical, textiles, paper, petrochemical, etc.
- These are used in railway coaches, automobile braking systems, wagons & printing presses.
- These are used in industrial robots for different purposes like packing, filling, drilling, stamping, punching, hosting, clamping, etc.
- Assembly systems.
- Plastics machinery.
- Car washes.
- Test systems.
- Used to drive both rotary & linear and actuators.
- Coolant systems.
- Opening & closing the doors.
- Petroleum markets.
- These are used in different types of equipment for material handling.
- Medical equipment & logic controlling operations.
- In nut runners & power hammers.
- Used in machine tools operations.
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