1. Basic compressed air system
▶ Compressed air is widely used throughout industry and is considered one of the most useful and clean industrial utilities. The standard compressor installation consists of a compressor, a water-chilled after-cooler, and a receiver.
▶ A typical compressed air system consists of compression, cooling, storage, and distribution equipment as below;
▶ Intake filtering
: Incoming air must be filtered to remove dust and other contaminants.
▶ Compression
: The filtered air is compressed with motor-driven screw,
centrifugal, or reciprocating compressors.
▶ Cooling
: Compressing air raises its temperature dramatically, so cooling is required. Much of the energy "lost" in making compressed air is in the form of removed heat.
Cooling is also important in the process of drying air.
Much of the water vapor condenses as the air is cooled,
making it easy to drain away.
▶ Air Storage
: A tank called an air receiver typically is placed downstream of the cooler to provide surge capacity for the system.
Some systems provide additional receiver tanks in the process area to
accommodate widely available demand.
▶ Drying
: Cooled, pressurized air still carries a significant amount of moisture and
lubricants from the compression process, virtually all of which must be
removed before the air can be used. Drying compressed air can be very
energy intensive.
▶ Distribution
: A system of distribution pipes and regulators convey compressed air from the
central compressor plant to process areas. This system includes various
isolation valves, fluid traps, intermediate storage vessels, and even heat
trace on pipes to prevent condensation or freezing in lines exposed to the
outdoors. Pressure losses in distribution typically are compensated for by
higher pressure at the compressor discharge.
▶ Point of Use
: At the intended point of use, a feeder pipe with a final isolation valve, filter,
and regulator carries the compressed air to hoses that supply processes or
pneumatic tools. |
