Many industrial production processes require rapid cooling and freezing capabilities. Liquid nitrogen (LIN) and carbon dioxide (CO2) are extremely effective cooling agents due to the low boiling point of LIN (-196°C) and the low sublimation point of CO2 (-78.5°C). Liquid carbon dioxide converts to solid carbon dioxide snow at –79ºC (–109ºF). In combination with snow horns or specially designed nozzles, this CO2 snow, also known as dry ice, is a flexible, easy-to-use cooling medium.
In addition, LIN and CO2 are environmentally sound alternatives to conventional cooling processes, which often involve potentially harmful refrigerants, large quantities of water or dust and fumes. Because they are inert, these gases also eliminate the risk of fire or explosion.
LIN and CO2 are commonly used to increase productivity and enhance quality in concrete mixing, asphalt paving, rubber hose production, glass production, plastic film blowing, grinding, welding and machining. Cryogenic condensation with LIN is also an effective way of purifying waste air and recovering valuable volatile organic compounds (VOC).
In the manufacture of aluminium, dross cooling with argon eliminates fumes and dust, while increasing recovery rates. The benefits of LIN in extrusion plants include higher production rates, improved surface finish and increased die lifetime.
Cryogenic solutions are also extremely popular in the food industry. LIN and CO2 are gentle, effective ways of quickly lowering the temperature of food products to facilitate processing or preserve quality. Dry ice (i.e. solid carbon dioxide) is a convenient cooling agent for smaller batches, whereas cryogenic, liquid gases are an eco-friendly, flexible and low-noise way of maintaining the precise temperature of entire trucks during transit.
Linde also offers innovative cryogenic cooling solutions for reactor cooling and freeze drying in the pharma industry.