Liquid Nitrogen - Uses

Uses

Liquid nitrogen is a compact and readily transported source of nitrogen gas without pressurization. Further, its ability to maintain temperatures far below the freezing point of water makes it extremely useful in a wide range of applications, primarily as an open-cycle refrigerant, including:

• in cryotherapy for removing unsightly or potentially malignant skin lesions such as warts and actinic keratosis
• to store cells at low temperature for laboratory work
• in cryogenics
• as a backup nitrogen source in hypoxic air fire prevention systems
• as a source of very dry nitrogen gas
• for the immersion freezing and transportation of food products
• for the cryopreservation of blood, reproductive cells (sperm and egg), and other biological samples and materials
  • to preserve tissue samples from surgical excisions for future studies
• as a method of freezing water pipes in order to work on them in situations where a valve is not available to block water flow to the work area - nowadays replaced by electrical heat pumps
• in the process of promession, a way to dispose of the dead
• for the cryonic preservation in the hope of future reanimation.
• to shrink-weld machinery parts together
• as a coolant
  • for CCD cameras in astronomy
  • for a high-temperature superconductor to a temperature sufficient to achieve superconductivity
  • for vacuum pump traps and in controlled-evaporation processes in chemistry.
  • to increase the sensitivity of infrared homing seeker heads of missiles such as the Strela 3
  • to temporarily shrink mechanical components during machine assembly and allow improved interference fits
  • for computers
• in food preparation, such as for making ultra-smooth ice cream. See also molecular gastronomy.
• in container inerting and pressurisation by injecting a controlled amount of liquid nitrogen just prior to sealing or capping.
• as a cosmetic novelty giving a smoky, bubbling "cauldron effect" to drinks. See liquid nitrogen cocktail.
• as an energy storage medium.
• branding cattle.