This document discusses cryogenics, which is the science of producing very cold temperatures below 123 K. Some key applications of cryogenics mentioned include space applications like rocket propulsion using liquid hydrogen and oxygen, medicine like cryosurgery and cell preservation, food processing like freezing foods, industrial gas production through cryogenic distillation of air, superconductivity in technologies like MRI machines, and high energy physics experiments like those at CERN.

1. CRYOGENICS

2. What is CRYOGENICS ?
 Kryo – Very cold (frost)
 Genics – to produce
 “Science and art of producing very cold”
 Cryogenics is the science and technology associated
with generation of low temperature below 123 K.
 National bureau of Standards, Colorado.

6. Applications
 SPACE
 MECHANICAL
 MEDICINE
 GAS INDUSTRY
 FOOD PROCESSING ………..

7. Space
 Rocket Propulsion
 Cryogenic engines are powered by cryogenic propellants
.
 Liquid Hydrogen is used as a fuel to propel the rocket.
 Liquid Oxygen is used as an oxidizer.

8. Space
 Cooling of Infra-Red (IR) sensor
 Cooling of IR detectors, Telescopes, Cold probes etc.
 Development of miniature and small cryocoolers for
satellites for an improved accuracy and reliability of earth
observation.
 Space simulations chambers are realistic environment for
air/space craft. The cold space is simulated at cryogenic
temperatures by use of LN2.

9. Space
 The levels of vacuum required in space simulation
chambers are very high.
 This is achieved by the use of cryopumps and turbo
molecular pumps.

10. Mechanical
Magnetic Separation
 Magnetic separation technique is used in variety of
applications like enhancing the brightness of kaolin,
improving the quality of ultra-high purity quartz etc.-
Superconducting Magnet ensures proper separation.

11. Mechanical
 Heat Treatment:
 The lives of the tools die castings & their dies, forgings,
jigs & fixtures etc, increase when subjected to cryogenic
heat treatment.
 The life of guitar strings increases by 4 to 5times with no
need for tuning.

12. Mechanical
 Cryogenic recycling:
 Turns the scrap into raw material by subjecting it to
cryogenics temperatures. This is mostly used for PVC,
rubbers.

13. Medicine

14. Cryo Surgery
 When a live tissue is frozen and maintained for
sometime in a frozen state, the blood supply to this
tissue is stopped and it dies due to lack of oxygen.
 When thawed the tissue turns into a blister and is slowly
eliminated either by dropping off as scab or getting
excreted.

15. Cryo Surgery
 Cryosurgery is a technique in which the harmful tissues
are destroyed by freezing them to cryogenic
temperature.
 Cryosurgery has shorter hospital stay, less blood loss,
and small recovery time.
 It is generally used in patients with localized prostate
and kidney cancer, skin disorders, retinal problems, etc.

16. Cryo Surgery
 Skin (cancer)
 Eye (removal of cataracts)
 Brain (Parkinson’s disease)
 Gynaecology
 Internal surgery

18. Cryo Surgery
Advantages:
 Lower chances of infection
 Smaller or no incision
 Shorter or no hospital stay
 Better cosmetic quality

19. Medicine
 Cell Preservation
 Cells and tissues can be kept indefinitely in a state of
suspended animation by storing in liquid nitrogen; but
cell death takes place during freezing and thawing.
 The mechanism of cell death is fully understood, but
related to formation of extracellular/ intercellular ice
crystals, migration of water across the cell membrane and
to changes in the salt concentration in the intracellular
fluid.
 Systems are developed to preserve blood cells, plasma
cells, human organs and animal organs at cryogenic
temperatures.

20. Medicine
 Still some cells can be frozen and thawed with high viability rate
by:
 Following a strict temperature – time protocol.
 Adding certain chemicals like glycerol .
 Applications
 Human erythrocytes and platelets
 Bull sperms
 Cattle and other livestock embryos
 Eye cornea and skin
 Many bacteria and fungi

21. Food Processing
 Preserving food at low temperature is a well-known
technique.
 Cooling of sea foods, meat (sea export), and milk products
for long time preservation is achieved by use of LN2.

22. Food Processing
 Freezing of marine products
 Faster cooling
 (cryo freezing, all cells are cooled simultaneously, water in the
material is frozen not the surroundings)
 Smaller ice crystals
 Low drip loss
 Better taste and flavor
 Individual Quick Freezing
 No additional freezing load
 Better consumer acceptance
 Simpler and lighter equipment

24. Food Processing
 Transportation of frozen foods
 Liquid N2 is sprayed on the top of the cabin
 Simpler and lighter equipments
 Better temperature control

26. Gas Industry
 Production of industrial gases-Cryogenic liquefaction and
distillation of air
 The transportation of gases across the world is done in liquid
state. This is done by storing the liquid at cryogenic temperature.
 The use of inert gases in welding industry has initiated higher
demand for gas production in the recent past.
 Cryogens like LOX, LH2 are used in rocket propulsion while
LH2 is being considered for automobile
 Liquid nitrogen is used as pre-coolant in most of the cryogenic
systems.

27. Gas Industry
 Steel industry – Oxygen is used in the production of steel.
Basic Oxygen Furnace (BOF)uses oxygen instead of air.
 Nitrogen and argon are primarily used to provide an inert
atmosphere in chemical, metallurgical and welding
industries.

28. Super Conductivity
 The Super conducting magnets for both NMR and MRI
machines (used for body scanning) are cooled by liquid
Helium.
 Maglev Locomotion
 Maglev Train runs on the principle of Magnetic
Levitation.
 The train gets levitated from the guide way by using
electromagnetic forces between superconducting magnets
on the vehicle and coils on the ground.
 This results in no contact motion and therefore no friction

29. Super Conductivity

30. High Energy Physics
 CERN is an organization for nuclear research in Europe which was
founded in 1954.
 It consists of a 27Km accelerator ring with four detectors.
 All the magnet systems (SC) and its accessories are kept at 1.9 K
using the liquid Helium.
 A liquid nitrogen layer (77 K) is used as shielding for liquid helium.
 It is an experiment seeking answers to Big Bang theory and
collision of atomic particles.

31. High Energy Physics
 ITER (International Thermonuclear Experimental Reactor)
is an engineering project for nuclear fusion reactor.
 The superconducting magnets are maintained at 4 K by
liquid helium.
 The experiments are carried out to enable mankind to
generate energy for future.