Transcript Air Compressors

Air Compressors
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Introduction
• Air compressors are pumps that are
used to compress air at atmospheric
pressure to a very high pressure at
which it can perform work.
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Uses of Compressed Air
• Pneumatic tools
– hand grinders
– chisels
– screw drivers
• Operate pneumatic systems
• Cleaning machine parts and
components
• Start up large diesel engines
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Air is Compressible
• Compressed air is produce by reducing its
volume so as to increase the air pressure
Low
pressure
High
pressure
1.5 Bar
3.0 Bar
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Air Compressor
• It takes in atmospheric
air.
• Compresses the air so
as to increase the air
pressure.
• Transfers the
compressed air into an
air receiver.
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Reciprocating Air Compressor
• Works on principles of positive displacement
• Single-stage compressor operated by one
cylinder only
– normally up to 4 bars
• Multi-stage compressors are used for higher
operating pressure
– normally up to 15 bars for double stages
compressors
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Air Receiver
• To store compressed air.
• To stabilize compressed
air supply.
• To smoothen pressure
pulsation.
• To dry the compressed
air by allowing water
vapor to precipitate.
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Air
Flow
Receiver
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Reciprocating Air Compressor
Single-Stage
Double-Stage
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Parts of a Reciprocating
Compressor
• Pressure gauge
– indicate the pressure in the air receiver
• Start/Stop switch
– manually switch on or off the electric
motor
• Automatic cut in/out relay
– to start the motor automatically when the
pressure drop to the lower set point
– to stop motor automatically when the
system has reached the upper set pressure
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Parts of a Reciprocating
Compressor
• Suction filter
– to provide dust free air to the compressor
– paper filter is normally used
• Safety valve
– to ensure the pressure in certain equipment is
limited to preset value
– air will be relieved through this valve when
pressure is higher than the preset value
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Parts of a Reciprocating
Compressor
• Drain Valve
– to drain off water accumulated in the air
receiver due to condensation
• Air receiver
– storage tank for compressed air
– to maintain air pressure in the system
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Parts of a Reciprocating
Compressor
• Compressor block
– contain the working parts of a
compressor
– inlet valve & outlet valve
– piston
– crankshaft
– connecting roads
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Parts of a Reciprocating
Compressor
• Cooling fan
– air is blown over the finned compressor
block for cooling
– attached to the flywheel and rotate
together with the crankshaft
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Reciprocating Air Compressor
1. Pressure gauge
2. Start/stop switch
3. Auto cut in/out relay
4. Filter
5. Relief valve
6. Drain valve
7. Air receiver
8. Compressor block
9. Flywheel & cooling fan
10.Discharge line
11.Drive belt
12 .Guard
13.Motor
14.Power supply
15.Air supply line ms4.9 Air Compressors/Tieh SF
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Reciprocating Air Compressor
Single-Stage Reciprocating Air Compressor
• Vacuum is created when
piston moves downwards
• suction valve opens due to
atmospheric pressure
• air enters the cylinder via the
air filter
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Reciprocating Air Compressor
Operation of a Single-Stage in discharge stroke
• Volume of air is reduced when the
To air receiver
piston moves upward
• pressure increases and is now higher
than the pressure in the air receiver
• pressure of the higher side will force
open the discharge valve
• compressed air is discharged to the
air receiver
The 1st cycle completed and the next
cycles will start repeating
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Safety Precautions
• Ensure the safety valve installed is in good
working condition
• Well ventilated, dust free and dry
• Do not use it carelessly
• Do not use it for dusting clothes or hair
• Guard the eyes when cleaning
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Routine Maintenance of Compressors
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Clean the suction air filter
Check belt drive for slackness
Grease ball bearings
Check oil level
Check for oil leakage
Listen for noise
Inspected once every 12 months by Safety
Officer
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