Pneumatic System

Pneumatic technology is the study of behavior and applications of compressed air in our daily life and manufacturing automation specifically.

In pneumatic systems air is used as the medium which is easily available and can be exhausted into the atmosphere after completion of the assigned task.

Here are the components of Pneumatic system:

a) Air filters: The contaminants from the air is filter out by this.

b) Compressor: Air compressors generates compressed air. Air compressors can be diesel or electrically operated. Suitable capacity compressors may be used based on the requirements.

c) Air cooler:  Air temperature increases during compression operation. Therefore coolers are used to reduce the temperature of the compressed air.

d) Dryer: By using the dryer the water vapor or moisture in the air is separated from the air.

e) Control Valves: Control valves are used to regulate, control and monitor for control of direction flow, pressure etc.

f) Air Actuator: To obtain the required movements of mechanical elements of pneumatic system air cylinders and motors are used.

g) Electric Motor: Transforms electrical energy into mechanical energy. To drive the compressor it is used.

h) Receiver tank: The air receiver stored the compressed air coming from the compressor.

How does it work in system?

Case study-A double acting cylinder powered a plastic component is which to be embossed by using a die .When the cylinder rod has fully extended to the highest position and the preset pressure is optimized then the return of the die will be effected. To confirm full extension a roller lever valve is used. When the piston rod will reach the embossing position then and only then the signal for retracting will generate. Pressure gauge will indicate the pressure in the piston chamber

Used components for this task :

• double acting cylinder

• 3/2 push button valve

• 3/2 roller valve

• shuttle valve

• 5/3 pneumatic actuated direction control valve

• pressure sequence valve

• compressed air source

• pressure gauge and connecting piping

Working:

The above figure shows pneumatic circuit diagram for embossing application. The flow takes place through the valve when the push button valve (S1) is pressed, It will generate a signal which is sent to the control port 14 of the direction control valve (V2).

The extension of the cylinder will be caused due to left position of the direction control valve (V2) is switched-on and the flow enters at the piston-end of the cylinder (A).Due to DCV’s memory function Even if the push button is released the position of the DCV (V2) will not change . As the piston nears the end position, the roller valve (S2) is actuated and the pressure sequence valve (V1) connects pressure line. The pressure at the piston-side of the cylinder (A) increases during the embossing process. The pressure regulator (Z1) indicates this increase in pressure. The 3/2 valve of pressure sequence valve switches and the signal is applied to port 12 of the DCV (V2), when the pressure reaches to its pre-set value in the pressure sequence valve(V1). The right position of the DCV is achieved and the piston retracts. The roller valve (S2) is released and the signal at the control port 12 of the DCV (V2) is reset and the pressure sequence valve is also reset during the retracting movement.

Reasons to go with Pneumatic system:

• Unlimited Supply of Air 

Many factories that have production lines use the compressed air. Air is endless in nature and free of cost. Taking benefit of this property of air Manufacturers use it as a power supply for their tools and machinery. Once the air is used in factories it is released back in atmosphere. In this way air can be used repeated number of times and released back without any processing. Also it is easily transportable through pipes to various places.

• Proven Durability and Reliability 

Pneumatic controls are technically more long lasting and reliable. They can survive in the toughest manufacturing conditions. Pneumatic controls have proven to be more efficient as compared to other electromotive components that are electricity dependent. 

• Simple Design that Adapts to Harsh Environments 

Since the compresses air does not easily get affected by factors such as higher temperatures, dust and rusting, it has proven to be very durable. 

•  Processing is required before use

The efficiency of usage of air is determined by the available volume of compressed air. If the air gets heated, its volume varies. Hence, the efficiency may also vary due to such reasons. Hence the limitations must be taken into account. Processing is Required Before Use: 

Air contains components like water vapor that me lead to damaging of components due friction. Hence it is extremely crucial that this water vapor is removed, which implies that the air must be processed. 

• Pneumatic controls 

Pneumatic controls have revolutionized the way of working of many companies due to its various advantages and thus helped acquiring given efficient results.