AirAtmosphere
The air is invisible, odorless, tasteless mixture of gases that surround the earth. The air surrounding the earth is called the atmosphere. It stretches over the land of about 400 km and is divided into several layers. The layer closest to the earth, which extends from sea level up to 30,000, is called LAMER atmosphere. In the troposphere extends from 30 000' 50 000. The layer extends from 50 000 to 200 miles is called the stratosphere. Layer beyond 200 nautical miles is called the ionosphere.
Air is a mixture of oxygen, nitrogen, carbon dioxide, hydrogen, sulfur, carbon dioxide and water vapor (moisture). It also contains a very small percentage of rare gases.
- Oxygenatmosphere at about 23% oxygen by weight. Oxygen is easily combined with many substances. When fuels such as wood, coal, or oil are burned, their carbon and hydrogen combine with oxygen in the atmosphere, forming carbon dioxide and water, respectively. Oxygen hi atmosphere is replenished from plants that absorb carbon dioxide and release oxygen.
- NitrogenAbout three-quarters of the earth's atmosphere consists of nitrogen.
Nitrogen gaseous element that is not readdy to combine with other substances. If in combination with other elements, nitrogen, as a rule, unstable. Nitrogen in conjunction with commercial hydrogen to form ammonia, the basis for most of fertilizers and important refrigerant (NH3 [R-717]). Liquid nitrogen is obtained by cooling, also special-purpose expenditure of the refrigerant.
- Carbon dioxideCarbon dioxide is 0.03% and 0.04% of the atmosphere. Carbon dioxide is a combination of carbon and oxygen. Absorbed by growing plants, he becomes one of the "building blocks" in the development of plant cells.
- HydrogenHydrogen (Hz), very light gas is not showing in weight percentage. Hydrogen is present in most fuels. When burned, it combines with oxygen to form water (H20) in steam and gaseous form.
- Sulphur dioxideSulfur dioxide, the most common of gaseous pollutants. It is formed from the combustion of fuels containing sulphur. Many large power plants now have facilities for removing sulphur from these sources of fuel and sulphur dioxide from the flue gas.
- Water vapor (moisture)the amount of water vapor in the atmosphere changes with temperature. It is not listed as a percentage, but rather, the term "relative humidity of the air."
- Rare gasesRare gases make up from 0.9% to 1.3% of the atmosphere (by weight). These gases include neon, argon, helium, krypton, and xenon.
in addition to these substances, the air contains a variety of contaminants. These vary significantly across regions and over time. However, contaminants in the air are of great importance in air conditioning...
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Air-Conditioning