Facts Concerning Cryogenic Gases That Should Be Understood

By Grace Rivas

Cryogenic gases are gases that are kept in either liquid or gaseous form at extremely low temperatures. They have boiling points of low than -150 degrees Celsius. At normal temperature and pressure, these substances exist in their gaseous form. They usually have 2 main characteristics. The first characteristic is, when liquefied, small quantities of liquid can melt into very large quantities of gas. The 2nd property is that they are very cold.

Because of their low temperatures, they condense the atmospheric air to create fog that can be seen by the eyes. When stored in tanks that are poorly insulated, they condense the surrounding air to form a mixture of air and liquid. According to the WHMIS criteria, they are classified as compressed gasses.

Each cryogenic material has its specific characteristics, even though most can be categorized in one of three categories. The categories are flammable and inert gasses and oxygen. Inert gas never reacts chemically with most other materials. Materials placed under the inert category include krypton, nitrogen, Oregon, and neon. Flammable gas undergoes combustion in air. Key examples are hydrogen, liquefied natural gas, and methane among many others. Most materials termed as non-combustible burn when upon mixing with liquid atmospheric oxygen. This means that precautions observed in handling oxygen should be different to those of other cryogenics.

These substances are used, stored, and transported in highly insulated containers. The containers are constructed in a manner as to endure quick changes in temperature and great differences in temperature. Examples of containers utilized include gas cylinders, laboratory liquid dewar flasks, and liquid dewar flasks. Gas cylinders comprise valves for filling up and dispensing the gas and pressure-regulating valves with frangible disks to act as backup protection.

There are several health hazards associated with these substances and precaution must be taken when handling them. The health hazards are classified into three groups, that is toxicity, asphyxiation, and extreme cold. The cold gas and its associated vapor can cause effects on the skin similar to thermal burns. Brief exposure that cannot affect skin can affect delicate tissues like eyes. Other effects include frostbite, pain, sticking on cold surface, and lung damage.

Many of these gases are usually heavier than air in the atmosphere. They therefore displace atmospheric air and settle on floors creating oxygen shortage. Oxygen deficiency may cause asphyxiation and eventually death. Therefore it is not advisable to handle these materials in enclosed spaces with poor ventilation. Materials such as carbon (II) Oxide are greatly toxic and may cause death in seconds if they leak out into the environment.

These substances have numerous uses in various governmental, industrial and domestic applications. To start with, liquefied forms are employed as fuels for rockets and other fast planes. Other applications comprise of blood and food preservation, electrical power transmission, magnetic resonance imaging, nuclear magnetic resonance spectroscopy, and forward looking infrared. Certain rare groups of blood need to be maintained under extremely cold temperature to remain valuable. They are used to make detectors too.

Of all Cryogenic gases, liquefied nitrogen gas is the most commonly utilized. It is legal for acquisition and can be bought from any place around the globe. Dewar flasks are apparently the best storage containers used.

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