Compressor Questions and Answers
| 1 | Define compression ratio for a compressor? Ans : Compression ration = Absolute discharge pressure of last stage Absolute in take pressure |
| 2 | What are the different components of a compressed air system network? Ans. The different components that are available in a compressed air network are Intake air filters Inter-stage coolers After coolers Air dryers Moisture drain traps Receivers |
| 3 | List at least three different flow control methods adopted in a compressed air system? Ans. Various flow control methods are Automatic On/Off control Load and Unload Multi-step control Throttling control |
| 4 | Define “volumetric efficiency” of a compressor? Ans. Volumetric efficiency= Free air delivery , m3/min compressor displacement |
| 5 | What are the various instruments required for performance evaluation of compressed air systems by nozzle method? Ans. Various instruments required are Thermometers or Thermocouple Pressure gauges or Manometers Differential pressure gauges or manometers Standard nozzle Psycho meter Tachometer/Stroboscope Electrical demand analyzer |
| 6 | Define specific power requirement? Ans. The ratio of power consumption in kW to the volume delivered at ambient conditions. |
| 7 | During the a leakage assessment test, compressor was loaded for 7 minutes and unloaded for 20 minutes. If the actual free air delivered is 200 CFM then evaluate quantity of leakage. Ans. % leakage = (load time X 100) / ( load time + unload time) = (7×100) / (7+20) Leakage quantity = Actual FAD x % leakage = = (200×26)/100 = 51.85 cfm |
| 8 | What happens to power consumption when the temperature of the inlet air to the compressor rises by 8 degC? Ans. Power consumption increases by 2% |
| 9 | If the pressure setting of a compressor is reduced by 1 kg/cm2g, what impact it will have on power consumption? Ans. The power consumption reduces by 6-10% |
| 10 | What are the acceptable pressure drops in mains header and that in distribution system in a compressed air network? Ans. Typical acceptable pressure drop in industrial practice is 0.3 bar in mains header at the farthest point and 0.5 bar in distribution system. |