CANGAS Systems Company Limited, identified as the Beijing Key High-tech Corporation, is one of the initial companies involved in air separation industry. CANGAS is committed to continuously providing core value to customers in all industries. With 27,000 square meters’ production base, five national patents and ISO9001:2008 Certificate of Quality Management System Certification, CAN GAS has been an integration of R&D, design, manufacture, sales, service. Over the past ten years, CANGAS has successfully provided over 1000 sets of air separation systems for many industries in over 40 countries and regions.
CANGAS Systems have a range of PSA nitrogen & oxygen generators, membrane nitrogen & oxygen generators, nitrogen purification systems etc, and are widely used in industries of petroleum, oil & gas, chemicals, electronics, metallurgy, coals, pharmaceuticals, aerospace, autos, glass, plastics, food, medical treatment, grain, etc. With years research in air separation technology and rich solution experiences in various industries, CANGAS sticks to providing our clients with more reliable, more economical, more convenient professional gas solutions.
By now we have supplied CANGAS® systems for clients including GE USA, WILMAR International Singapore, DEGUSSA Group Germany, SAMSUNG, ORION Korea, China Petrol, Sinopec, etc. CANGAS has built up a global distributor system covering Russia, Bangladesh, Indonesia, Pakistan etc. During the 2008 Olympics, CANGAS was selected by Beijing Food Safety Test Center as the supplier for nitrogen generator to test the Olympic food.
We have an experienced professional team always ready to be at your service. The sales engineers carefully analyze your specified requirements and offer suitable solutions for you. The after-sale service system guarantees swift response to your problems within 24 hours and their resolutions in the shortest time. CANGAS is responsible for after-sales services to nitrogen/oxygen generators and other related equipment offered by us. Besides, CANGAS global distributor system can provide prompt professional localized service.
CANGAS is dedicated to supplying with our customers with more reliable, more economical and more convenient air separation solutions and professional service.
Cryogenics is the science that addresses the production and effects of very low temperatures. The word originates from
the Greek words 'kryos' meaning "frost" and 'genic' meaning "to produce." Under such a definition it could be used to
include all temperatures below the freezing point of water (0 C). However, Prof. Kamerlingh Onnes of the University
of Leiden in the Netherlands first used the word in 1894 to describe the art and science of producing much lower
temperatures. He used the word in reference to the liquefaction of permanent gases such as oxygen, nitrogen, hydrogen,
and helium. Oxygen had been liquefied at -183 C a few years earlier (in 1887), and a race was in progress to liquefy the
remaining permanent gases at even lower temperatures. The techniques employed in producing such low temperatures
were quite different from those used somewhat earlier in the production of artificial ice. In particular, efficient heat
exchangers are required to reach very low temperatures. Over the years the term cryogenics has generally been used to
refer to temperatures below approximately -150 C.
According to the laws of thermodynamics, there exists a limit to the lowest temperature that can be achieved, which is
known as absolute zero. Molecules are in their lowest, but finite, energy state at absolute zero. Such a temperature is
impossible to reach because the input power required approaches infinity.
However, temperatures within a few billionths of a degree above absolute zero have been achieved. Absolute zero is the zero
of the absolute or thermodynamic temperature scale. It is equal to -273.15 C or -459.67 F. The metric or SI (International
System) absolute scale is known as the Kelvin scale whose unit is the kelvin (not Kelvin) which has the same magnitude
as the degree Celsius. The symbol for the Kelvin scale is K, as adopted by the 13th General Council on Weights and
Measures (CGPM) in 1968, and not K. Thus, 0 C equals 273.15 K. The English absolute scale, known as the Rankine scale,
uses the symbol R and has an increment the same as that of the Fahrenheit scale. In terms of the Kelvin scale the
cryogenic region is often considered to be that below approximately 120 K (-153 C). The common permanent gases
referred to earlier change from gas to liquid at atmospheric pressure at the temperatures shown in Table 1, called the
normal boiling point (NBP). Such liquids are known as cryogenic liquids or cryogens. When liquid helium is cooled further
to 2.17 K or below, it becomes a superfluid with very unusual properties associated with being in the quantum mechanical
ground state. For example, it has zero viscosity and produces a film that can creep up and over the walls of an open
container, such as a beaker, and drip off the bottom as long as the temperature of the container remains below 2.17 K.
The measurement of cryogenic temperatures requires methods that may not be so familiar to the general public. Normal
mercury or alcohol thermometers freeze at such low temperatures and become useless. The platinum resistance
thermometer has a well-defined behavior of electrical resistance versus temperature and is commonly used to measure
temperatures accurately, including cryogenic temperatures down to about 20 K. Certain semiconducting materials, such
as doped germanium, are also useful as electrical resistance thermometers for temperatures down to 1 K and below, as long
as they are calibrated over the range they are to be used. Such secondary thermometers are calibrated against primary
thermometers that utilize fundamental laws of physics in which a physical variable changes in a well-known theoretical way with temperature.
The production of cryogenic temperatures almost always utilizes the compression and expansion of gases. In a typical air
liquefaction process the air is compressed, causing it to heat, and allowed to cool back to room temperature while still
pressurized. The compressed air is further cooled in a heat exchanger before it is allowed to expand back to atmospheric
pressure. The expansion causes the air to cool and a portion of it to liquefy. The remaining cooled gaseous portion is
returned through the other side of the heat exchanger where it precools the incoming high-pressure air before returning
to the compressor. The liquid portion is usually distilled to produce liquid oxygen, liquid nitrogen, and liquid argon. Other
gases, such as helium, are used in a similar process to produce even lower temperatures, but several stages of expansion
Cryogenics has many applications. Cryogenic liquids, such as oxygen, nitrogen, and argon, are often used in industrial and
medical applications. The electrical resistance of most metals decreases as temperature decreases. Certain metals lose all
electrical resistance below some transition temperature and become superconductors. An electromagnet wound with a
wire of such a metal can produce extremely high magnetic fields with no generation of heat and no consumption of
electric power once the field is established and the metal remains cold. These metals, typically niobium alloys cooled to
4.2 K, are used for the magnets of magnetic resonance imaging (MRI) systems in most hospitals.