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Classification of air compressors

Short answer

Air compressors raise pressure by reducing volume (positive displacement: reciprocating, rotary) or converting kinetic energy (dynamic: centrifugal, axial). Further classification includes stages, action, delivery pressure, capacity, cooling, and cylinder arrangement. Applications: pneumatic tools, braking systems, engine starting, spray painting, cleaning, process instrumentation.

What is an air compressor? Classify air compressors and state the applications of compressed air.

An air compressor is a machine that raises the pressure of air by reducing its volume (positive displacement type) or by converting kinetic energy into pressure (dynamic type).

Classification

  1. Principle of operation
    • Positive displacement: reciprocating (piston) and rotary (Roots blower, sliding vane, screw, lobe).
    • Dynamic (non-positive displacement): centrifugal and axial flow compressors.
  2. Number of stages: single-stage, two-stage and multi-stage.
  3. Action: single-acting (air compressed on one side of the piston) and double-acting (both sides).
  4. Delivery pressure: low (up to 10 bar), medium (10 to 80 bar) and high (80 to 1000 bar).
  5. Capacity: low (below 0.15 m³/s), medium (0.15 to 5 m³/s) and high (above 5 m³/s).
  6. Cooling: air-cooled (fins) and water-cooled.
  7. Cylinder arrangement: vertical, horizontal, V, W and radial.

Applications of compressed air

  • Pneumatic tools: drills, hammers, riveters, spray painting.
  • Operating pneumatic brakes in trucks and trains.
  • Starting diesel engines and supplying air to gas turbines.
  • Cleaning, sand-blasting, air-lift pumps and mine ventilation.
  • Process industries, food packaging and instrumentation air.

✓ Answer checked by Claude Opus 5.5 (high effort)

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