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Compressed air is air kept under a pressure that is greater than atmospheric pressure. It serves many domestic and industrial purposes. In Europe, 10 percent of all industrial electricity consumption is to produce compressed air—amounting to 80 terawatt hours consumption per year.〔(Paineilma hukkaa 15 hiilivoimalan tuotannon ) 〕〔http://isi.fraunhofer.de/isi-de/publ/download/isi04p20/compressed-air-benchmarking.pdf "Compressed Air System Audits and Benchmarking Results from the German Compressed Air Campaign "Druckluft effizient" "〕 == Uses == In industry, compressed air is so widely used that it is often regarded as the fourth utility, after electricity, natural gas and water. However, compressed air is more expensive than the other three utilities when evaluated on a per unit energy delivered basis.〔Yuan, C., Zhang, T., Rangarajan, A., Dornfeld, D., Ziemba, B., and Whitbeck, R. “A Decision-based Analysis of Compressed Air Usage Patterns in Automotive Manufacturing”, Journal of Manufacturing Systems, 25 (4), 2006, pp.293-300〕 Compressed air is used for many purposes, including: * Pneumatics, the use of pressurized gases to do work * * Pneumatic post, using capsules to move paper and small goods through tubes. * * Air tools * * HVAC control systems * Vehicle propulsion (''see'' compressed air vehicle) * Energy storage (''see'' compressed air energy storage) * Air brakes, including: * * railway braking systems * * road vehicle braking systems * Scuba diving, for breathing and to inflate buoyancy devices * Refrigeration using a vortex tube * Air-start systems in engines * Ammunition propulsion in: * * Air guns * * Airsoft equipment * * Paintball equipment The header piping up to the air dryers is exposed to moist, hot air (temperatures can reach well over 150 degrees F). Copper, stainless steel and other piping materials that are less corrosive are recommended. If plain carbon steel piping is installed, then rust particles can pass downstream and interfere with the operation of condensate valves and wye strainers. The riser piping should connect to the top of the header piping and be one pipe size larger than the compressor discharge piping and/or overhead header piping. A drip leg with a drain is needed to prevent water from flowing back to the compressor. Mount valves in the highest horizontal piping (this avoids the hazard of opening a closed valve in vertical piping, and releasing trapped condensate to flow back into air compressors). All of the header main compressed air piping should slope 1/8" to 1/4" per foot down and away from the point of origin. Gravity and airflow will then carry condensate to the low points where a drop leg should be installed to allow for removal at accessible drop legs and drain points. These drops should be installed every 50 to 70 feet in the system and be taken from the bottom of the main line to insure as much removal as possible. The inlet piping for air dryer(s) should connect to the bottom of the piping headers. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「compressed air」の詳細全文を読む スポンサード リンク
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