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Industrial gases encompass a large number of products that are
gaseous at room temperature and pressure, and while they may actually be stored
as a liquid or solid they are commonly used in gaseous form. Gases have
unique properties and characteristics depending upon such variables as the
temperature, pressure, and volume to which they are subjected. Gases have low
densities, assume the volume of their containment (or dissipate to the
atmosphere), mix well with other gases, and are more compressible than solids
and liquids. Industrial gases are comprised of elements, molecular compounds,
or mixtures.
Industrial gas suppliers typically provide the gas as well as the
storage and processing equipment necessary to facilitate transportation and
proper usage. Industrial gas equipment may include storage tanks and
distribution systems, vaporizers and pressure vessels (dewars, cylinders, and
tanks), and cryogenic trailers. Each of these items typically include a means
of controlling pressure and flow.
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Physical Properties of Gases
As mentioned earlier, gases are compressible and as such,
knowledge of the pressure generated by a gas as it relates to temperature and
volume are critical to any application from both a performance and safety
perspective.
From a performance perspective, knowledge of the boiling point and
freezing point may be relevant but the auto-ignition temperature, the minimum
temperature required to ignite a gas or vapor in air without a spark or flame
present, is of paramount importance.
The flammable (or explosive) range is the range of a gas or vapor
concentration that will burn or explode if an ignition source is introduced.
Limiting concentrations are commonly called the lower explosive or flammable
limit (LEL/LFL) and the upper explosive or flammable limit (UEL/UFL).
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Application and Use of Gases
Industrial gases are used in a myriad of applications that are
dependent upon the many unique properties of specific gases. For example,
industrial gases are commonly used in manufacturing, especially in cutting and
welding applications. Acetylene gas is a highly flammable gas used in such
applications as the production of organic compounds such as neoprene and
rubber. It may also be pressurized to produce benzene. Oxygen acetylene torches
mix oxygen and acetylene gas in controlled amounts to produce an extremely hot
flame. Oxy acetylene welding is used to cut steel or weld iron, and can produce
a flame as hot as 6300° Fahrenheit. Other cutting devices include carbon
dioxide lasers. CO2 laser cutting uses a laser beam focused with a lens to cut
materials and is typically used for precision applications such as laser
surgery. Rare industrial gases such as argon are also commonly used in laser
applications.
Major applications include:
- Calibration Gas / Gas Standard - a defined gas concentration used to establish
the response curve of an analyzer.
- Chemical Process / Petrochemical - pure gases, gas mixtures, or gas standards for
reactions, water treatment, sterilization, instrumentation calibration,
heating, and processing in the chemical, petrochemical and pulp and
paper industries.
- Electronic and Semiconductor - specialized for microelectronic manufacturing
or semiconductor processing applications such as thin film deposition
(CVD, PVD), etching, RTP, packaging, or soldering.
- Environmental Monitoring - reference for compliance with regulatory
mandates.
- Food & Beverage / Packaging - food and beverages require gases for storage,
ripening, carbonation, to minimize oxidation, sustain freshness, and more.
- Laboratory / Analytical - used to ensure a uniform and/or inert
environment for research, quality control, analytical work, and other
laboratory needs.
- Laser Gas -
lasers require special gases to create a laser beam.
- Pharmaceutical / Medical Gas - used for patient care, surgical procedures, and
therapy.
- Welding / Thermal Process Gas - high temperature processes require gases with a
high energy content and low flash point.
Major Industrial Gases
While there are literally thousands of available industrial gases,
certain industrial gases are major elements of the world economy.
Major gases include:
Hydrogen (H) -
a colorless, highly flammable, gaseous element.
Nitrogen -
a nonmetallic element that constitutes nearly four-fifths of the air by volume.
It occurs as a colorless, odorless, almost inert, diatomic gas (N2), in
various minerals. Nitrogen is found in all proteins and used in a wide variety
of important manufactures
Air - a colorless,
odorless, tasteless, gaseous mixture; mainly nitrogen (approximately 78
percent) and oxygen (approximately 21 percent), with lesser amounts of argon,
carbon dioxide, hydrogen, neon, helium, and other gases.
For More information on Industrial Gases, check out IHS
GlobalSpec's Selection
Guide.
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