The document provides an overview of reciprocating air compressors, including their classification, main components, and operational mechanics. It explains the differences between single-stage and multi-stage compressors, as well as single acting and double acting types. Additionally, it discusses various applications, advantages, and disadvantages of reciprocating air compressors.

1. Reciprocating Air
Compressor
By : Atif Razi

2. Contents
 Air Compressors
 Classification of Air Compressors
 Reciprocating Air Compressor
 Main Parts of Reciprocating Air Compressor
 Working of Reciprocating Air Compressor
 Types of Reciprocating Air Compressor
 Applications of Reciprocating Air Compressor
 Advantages & Disadvantages of Reciprocating Air Compressor

3. Air Compressor
 A mechanically operated
machine that rises the fluid
pressure by reducing its
volume is called a Compressor.
 If the compressor uses gas as a
working fluid, it is called a gas
compressor.
 If the compressor uses air as a
working fluid, it is called an
air compressor.
 So, an air compressor is a
device which sucks in air from
atmosphere, increases its
pressure by compressing it and
deliver to a storage level.

4. Air Compressor
According to Positive
Displacement/Working
Rotary
Lobe
Screw
Scroll
Vane
Liquid Ring
Reciprocating/Piston
Type
According to
Action/Piston Working
Single Acting
Double Acting
According to number
of Stages/Cylinder
Single Stage
Multi Stage
According to Dynamic
Displacement
Centrifugal
Axial
Turbo

5. Reciprocating Air Compressor
 Reciprocating of a machine means moving backward and forward (or
upward & downward) in a straight line.
 It is a famous type of air compressor which comes under the category
of positive displacement compressor.
 It is called a positive displacement air compressor because air is
first sucked in a chamber and then compression is achieved by
decreasing the area of the chamber by using piston which does
reciprocating motion.
 It compresses air due to the upward and downward motion of the
piston therefore it is also called a piston compressor.

6. Main Parts of Reciprocating Air
Compressor

7. Working

8. Working
 As power is On, the electric motor starts
rotating and also rotates the crankshaft
attached to it. The piston starts doing to and
fro motion inside the cylinder.
 As the piston moves downward (towards
BDC), the air from the atmosphere enters
into the chamber of the cylinder.
 Now the piston after reaching at BDC,
starts moving upward (i.e. towards TDC), the
compression of the air starts and its pressure
begins to increase.
 When the pressure inside the cylinder
increases above the pressure of the discharge
valve, the discharge valve opens and the
compressed air is delivered to a air storage
tank from where it is utilized for the work.

9. Single Stage Reciprocating Air
Compressor
 In single stage reciprocating air
compressor the compression of
the air takes place in a single
cylinder
 In the first stroke, it sucks the
air from the atmosphere and in
the second stroke it
compresses it and deliver it to
the storage tank.

10. Multi Stage Reciprocating Air Compressor
 In this types of compressor, the
compression of the air takes place
in two stages i.e. the air is first
compressed to some extent in one
cylinder and than it is transferred
to the second cylinder for further
compression.
 Finally the compressed air is stored
in a tank.
 There is an intercooler present in
between the two cylinders, which
is used to cool the air at constant
pressure before it is compressed in
the second cylinder.

11. Single Acting Reciprocating Air
Compressor
 In single acting reciprocating
air compressor, only single side
of the piston is used for the
compression of the air and
other side is connected to the
crankcase and not used for the
compression.

12. Double Acting Reciprocating Air
Compressor
 In double acting reciprocating
air compressor, both the sides
of the piston is used for the
compression of the air.
 When suction takes place at
one side than compression is
taking place at other side.
 Both suction and compression
takes place on each stroke of
the piston.

13. Applications
Refrigerators Gas distribution plants Oil Refineries Chemical Plants
Inflate the tires of
vehicles
Small Paint Jobs
Dust cleaning / Pressure
Washing
Carpentry/Woodworking Crafting Dry Cleaning Commercial Purposes Hand Tools

14. Advantages & Disadvantages of
Reciprocating Air Compressor
 Advantages :
 Optimal operating speed
 It is cheap compared to other
types of compressors.
 Easy to maintain.
 It is perfect for high-pressure
requirements
 It has high efficiency.
 Designed for continuous duty
 Disadvantages :
 These machines have a high
weight and large size which is a
big problem with them.
 It has a very high noise.
 The compressed air outlet
temperature is very high.
 Piston rings and valves are
extremely sensitive to the dirt
present in the fluid