Dry Ice
Dry ice – what is it?
Dry ice is frozen carbon dioxide (commonly also called carbonic acid) in solid form. It is called «dry» because it evaporates straight without melting or becoming liquid – it sublimates. In a first step gaseous carbonic acid is liquefied by compressing it and then turned into a solid state of aggregation through high-speed expansion. Pure, white, frozen carbonic acid snow will form which is then highly compressed in the respective hydraulic presses and pressed into ice blocks or pellets. The pressure and temperature applied determine the state of aggregation of the carbonic acid, i.e. whether it is gaseous, liquid or solid.
Dry ice evaporates straight without melting, i.e. it passes the liquid form. Carbon dioxide is one of the few gases which can turn solid. When heated from a temperature of –78.5°C (194.65 K) to 0°C (273.15 K) dry ice has a cooling power of about 640kJ/kg; this is approximately three times the cooling power of conventional ice.
The more important advantage, however, may be that after the vaporisation process «nothing» is left over unlike when using traditional water ice. If heat is added, the dry ice will immediately turn into gas. During the dry ice blasting process –78°C-cold dry ice pellets are “shot” at high velocity onto the surfaces to be cleaned.
- Dry ice has a temperature of about -78.5° Celsius
- Dry Ice weighs about 700 kg/m³
- Dry Ice is water-free
- Dry Ice passes the liquid state: from ice to gas
- Dry Ice evaporates upon impact (energy conversion)
- Dry Ice is oxygen-free (anti-bacterial)
- Dry Ice is non-toxic