INTRODUCTION :
INTRODUCTION Cryogenics may be defined as the branch of physics which deals with the production of very low temperature and their effect on matter. It may also be defined as the science and technology of temperatures below 120K. The word “cryo” is derived from a Greek word “kruos” which means cold.
Methods to Produce Low Temperatures :
Methods to Produce Low Temperatures Magnetism produces low temperatures. When a material is magnetized it becomes warm and cold when demagnetized in controlled atmosphere thus producing low temperatures. By compressing the gas, the gas is cooled releasing heat and later allowed to expand producing ultra low temperatures.
Cryogenics in fuels :
Cryogenics in fuels Fluids are stored at 93.5k(-180degree) or below Due to air friction ,it gets ignited Cools engine on expansion. On expansion pressure increases providing high thrust Satellite payload increases
Cryogenic Rocket Engines :
Cryogenic Rocket Engines Cryogenic rocket engines are one of the important applications in the field of cryogenics. The higher thrust levels required for a rocket engines are achieved when liquid oxygen and liquid hydrocarbons are used as fuel. But at atmospheric conditions, LOX and low molecular hydrocarbons are in gaseous state. Therefore these are stored in liquid form by cooling them down using cryogenics. Hence the name Cryogenic Rocket Engines.
VULCAIN 2 ROCKET ENGINE :
VULCAIN 2 ROCKET ENGINE THRUST -1359KN INLET CONDITIONS: LH2; Pressure=182.1bar Temperature=36k LO2: Pressure=153.9 Temperature=96.7k Combustion chamber pressure=117.3bar Thrust chamber mass=909kg
Cryogenic Heat Treatment :
Cryogenic Heat Treatment This is a process of treating metals, plastics, ceramics at temperatures below 120K to their crystal structures and properties. This increases their wear resistance, and life of metals and plastics. They are used in the field of super conductors, cryo microbiology, and space programs. Unlike other processes here permanent coating is completely impart through the metal surface. The symbol used to represent cryogenic heat treatment
In alloy steels:- :
In alloy steels:- In this process the alloy steels are treated to convert the entire austenite into a martensite matrix such it changes the molecular structure of the steel and forms an entirely new, more refined grain structure which partly relieves the thermal stresses. The number of countable carbides increase from 30,000 to 80,000 per square millimeter which forms a “super hard” surface on the metal. After deep cryogenic heat treatment
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Before CI Processing After CI Processing Comparative microphotographs (1000x) of steel samples show the change in microstructure produced by the controlled deep cryogenic process. Uniform, more completely transformed microstructure and less retained austenite at right, is related to improvements in strength, stability and resistance to wear. *Cryogenics International's Cryogenics International (CI) was granted a U.S. patent for its revolutionary new computerized deep cryogenic treatment systems. Cryogenics International now makes dramatic cost savings and increased productivity available to many people and industries around the world.
Advantages of Cryogenic Processing :
Advantages of Cryogenic Processing The following properties are attained to the materials treated:- Increases wear resistance Increases corrosion resistance Good dimensionality High strength Good quality Cost reduction in the material manufactured Lower stress corrosion Cryogenic heat treatment helps to reduce the stored stress in the metal by creating a unified bond between the crystals.
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This process is eco friendly in nature There is no waste deposition The nitrogen which used in the process is liquefied from the atmosphere and later released back into it thereby creating no imbalance to the ecosystem.
Cryogenic fuels :
Cryogenic fuels Cryogenics has made possible the commercial transportation of liquefied natural gas. Without cryogenics, nuclear research would lack liquid hydrogen and helium for use in particle detectors and for the powerful electromagnets needed in large particle accelerators. Such magnets are also being used in nuclear fusion research.
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Cryogenic cooling is often used in space telescopes that observe objects in infrared and microwave wavelengths. More efficient and compact cryocoolers allow cryogenic temperatures to be used in an increasing variety of military, medical, scientific, civilian, and commercial applications, including infrared sensors, superconducting electronics, and magnetic levitation trains.
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Cryogenics is used in artificial insemination to store semens and embryos. One such use in bio field is Cryosurgery. Cryosurgery sometimes is referred to as cryotherapy or cryoablation. It is a surgical technique in which freezing is used to destroy undesirable tissues. Liquid nitrogen, which boils at -196°C, is the most effective cryogen for clinical use. Temperatures of -25°C to -50°C can be achieved within 30 seconds if a sufficient amount of liquid nitrogen is applied by spray or probe. Cryogenics in biology
Other uses of cryogenics :
Other uses of cryogenics IN SPORTS:- Cryogenics are also used to treat many types of sports equipment, the most common being golf clubs. Because cryogenics increases the molecular density of treated materials, it improves the distribution of energy (in this case kinetic energy) through the object. The treatment also increases the rigidity of the metal, which in this case might affect the shaft of the golf club. Combined, the increases in kinetic energy distribution and rigidity of the shaft make for a longer and straighter drive.
Future of Cryogenics :
Future of Cryogenics Cryogenic rocket engine which will be used by NASA for its next manned moon mission. ICICLES
CONCLUSION :
CONCLUSION From this presentation it can be concluded as cryogenics can be applied to almost everywhere in every field. It finds its application in military, tooling industry, agricultural industry, aerospace, medical, recycling, household, automobile industry, cryogenics is found to improve the grain structure of everything treated be it metal or plastic or coils or engines or musical instruments or fiber. This field could be put to many other applications in various fields. Its reaches in the mentioned industries hold a good chance of extension. Hence Cryogenics proves to be very promising for the future in this world of materials.