Articles Posted in the " Cryogenics " Category

  • MATERIALS OF CONSTRUCTION AT CRYOGENIC TEMPERATURES

    MATERIALS OF CONSTRUCTION AT CRYOGENIC TEMPERATURES

      MATERIALS OF CONSTRUCTION AT CRYOGENIC TEMPERATURES   All materials do not work satisfactorily at cryogenic temperatures. Properties undergo a tremendous change from room temperature down to cryogenic temperatures. Mechanical, electrical, thermal, and magnetic properties are most affected. At cryogenic temperatures, properties of concern include permeability, thermal conductivity, specific heat, linear thermal expansion, thermal expansion coefficient, […]


  • MAGNETIC COOLING CLASS NOTES FOR ENGINEERING

    MAGNETIC COOLING CLASS NOTES FOR ENGINEERING

    Para MAGNETIC COOLING CLASS NOTES FOR ENGINEERING    Achieve cryogenic temperatures by magnetic cooling. It is achievable by demagnetization of a para magnetic salt. Magnetic cooling gives a temperature up to 0.001 K.   Magnetic Cooling Very Low temperatures of the order of 0.001 K are obtainable with magnetic cooling. Demagnetization of a para magnetic salt […]


  • LIQUEFACTION OF GASES MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS

    LIQUEFACTION OF GASES MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS

    LIQUEFACTION OF GASES MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS  When a gas is at a lower than its inversion temperature, cooling occurs on expansion. Thus, must bring gases below inversion temperatures before liquefaction. 1. When air expands at room temperature (a) Produce heating  (b) Cooling  produces (c) Neither heating nor cooling produces (d) None (Ans: […]


  • THROTTLING AND FREE EXPANSION PROCESSES CLASS NOTES

    THROTTLING AND FREE EXPANSION PROCESSES CLASS NOTES

      THROTTLING AND FREE EXPANSION PROCESSES CLASS NOTES  Expansion process at constant enthalpy is throttling. It is irreversible. No work on decrease of pressure. This is a necessity in liquefaction and vapor refrigeration. Free expansion is at constant internal energy. This is irreversible non flow process. No work available.   Throttling Process This is an […]


  • CRYOGENICS-LIQUEFACTION CLASS NOTES FOR ENGINEERING

    CRYOGENICS-LIQUEFACTION CLASS NOTES FOR ENGINEERING

     CRYOGENICS-LIQUEFACTION CLASS NOTES FOR ENGINEERING    Cryogenics  involves the study of temperatures below -1500C. It is of interest to know how to produce such temperatures. These temperatures are produced by liquefaction of gases. In addition , it is of interest is know which materials are suitable at these temperatures. There are many areas of interest […]