Articles Posted in the " Cryogenics " Category

  • CRYOGENICS—MATERIALS OF CONSTRUCTION

    CRYOGENICS—MATERIALS OF CONSTRUCTION

     CRYOGENICS—MATERIALS OF CONSTRUCTION  MATERIALS OF CONSTRUCTION AT CRYOGENIC TEMPERATURES Ductility is measured from the energy required to break the specimen. Some data in this respect is given in table 3. TABLE 3: Change of ductility with low temperature Metal Crystal lattice Energy to break (FT lb.) at 700F Energy to break  (FT lb.) at 3000 […]


  • Liquefaction of Helium and Magnetic Cooling

    Liquefaction of Helium and Magnetic Cooling

    Liquefaction of Helium, Magnetic Cooling  Liquefaction of Helium by Collins’s Cryostat Principle (i)  Polytropic expansion for pre-cooling (ii) Throttling for liquefaction. Liquefaction of helium(Fig.4) uses normal boiling liquid nitrogen for pre-cooling before the helium enters the first cascade heat exchanger. Since helium liquefies at a lower temperature than that of even hydrogen, more number of […]


  • CRYOGENICS-LIQUEFACTION OF GASES-2

    CRYOGENICS-LIQUEFACTION OF GASES-2

    CRYOGENICS-LIQUEFACTION OF GASES-2 A modified Claude cycle is taken into consideration to design nitrogen liquefies to take the advantage of both the turbo-ex pander and Joule Thomson valve [Fig.3(a)]. Instead of three heat ex changers as in the Claude cycle, two numbers of heat ex changers are used in this liquefier. Last two heat ex […]


  • CRYOGENICS-LIQUEFACTION OF AIR

    CRYOGENICS-LIQUEFACTION OF AIR

    CRYOGENICS-LIQUEFACTION OF AIR Principle of Liquefaction Liquefaction of gases is achieved by employing. Joule Thomson expansion alone as in Linde’s process  or Isentropic expansion as well as Joule Thomson expansion as used in Claude’s process  Air liquefaction It is carried out with two processes. First is by Linde’s process and second is Claude’s process respectively. […]


  • CRYOGENICS- Liquefaction of gases

    CRYOGENICS- Liquefaction of gases

    CRYOGENICS- Liquefaction of gases PRINCIPLE OF LIQUEFACTION To achieve cryogenic temperatures, liquefaction of permanent gases is carried out. Principle involved in the liquefaction of a gas is one or two types of gas expansions. These are either throttling alone (Linde’s process) or adiabatic expansion followed by throttling (Claude’s process). Isotropic expansion (theoretical)/real expansion This type […]


  • Cryogenics

    Cryogenics

    CRYOGENICS INTRODUCTION Cryogenics involves the study of temperatures below -1500C.  It deals with how to produce these temperatures, and how materials behave at those temperatures. There are many areas of interest where we need cryogenic temperatures.  Applications include storage of large volumes of gases in small space in the liquefied form, preservation of insemination, very […]


  • Applications of Cryo-genics

    Applications of Cryo-genics

    DEFINITION OF CRYOGENICS It is a science which deals with creating and maintaining temperatures lower than -1500C. Liquefaction of air at -1910C Liquefaction of hydrogen at -2530C Magnetic cooling 0.001 K APPLICATIONS OF CRYOGENICS 1.Industrial applications i. Shrink fitting of metals ii. Liquid oxygen is used in welding iii. Liquid oxygen is used in the […]


  • * Throttling and Free Expansion Processes

    * Throttling and Free Expansion Processes

    Throttling and Free Expansion Processes  Throttling Process This is an expansion process at constant enthalpy. That it is found refrigeration and air-conditioning where the LIQUID is throttled. Further, process is also found in the liquefaction of gases. Throttling is an irreversible process. No work is obtained at the decrease of pressure. Thus, it is not […]


  • * Refrigeration Basics- Conventional & non -conventional

    * Refrigeration Basics- Conventional & non -conventional

     Refrigeration Basics-Conventional & non -conventional Refrigeration is lowering of temperature. Both conventional as well as non-conventional methods are used. Drying agent like silica gel is used in the drier cum filter to remove any moisture. Steel pipes are used with ammonia where copper pipes are used with halogenated hydrocarbon refrigerants. PIONEERS IN REFRIGERATION Jacob Parkinson […]


  • ** Cryogenics- Liquefaction of Gases-1

    ** Cryogenics- Liquefaction of Gases-1

    Cryogenics- Liquefaction of Gases-1 Cryogenics  involves the study of temperatures below -1500 C, how to produce them, and which materials behave at those temperatures. There are many areas of interest where we need cryogenic temperatures such as (i)   Storage of large volumes of gases in small space in the liquefied form (ii)  Preservation of insemination […]