Dry-Ice refers to carbon dioxide in its solid state (frozen carbon dioxide). The maximum temperature of dry ice is - 78.5 ºC and normally its density is 1.56 g/cm³. Dry-Ice comes with an advantage of removing the heat of the water with an efficiency that is twice as much as the water ice. Generally available in block, slices and pellets, Dry-Ice changes directly from solid to gaseous state in normal atmospheric conditions without going through a wet liquid stage.
Distinct from regular water ice, which exists at temperatures of 32°F (0°C) and below, dry ice is extremely cold, hence, useful for freezing. Carbon dioxide vapor is substantially heavier than air and in confined, poorly ventilated spaces it can displace air, causing asphyxiation. However, it is extremely popular and widely used because of it can be simply converted its frozen form with the help of dry-ice manufacturing gas plants and is safe & easy to handle using insulated gloves.
Dry-Ice Plant Process
The various stages in the production process of dry-ice by a high quality Dry-Ice Gas Plant are:-
- The first step of the process of making dry-ice consists of
compressing and cooling gaseous CO2 under high pressure to produce
liquid CO2 and removing any excess heat.
- The CO2 gas is further cooled until it condenses into a 100%
- The next step is to reduce the pressure over the liquid carbon
dioxide by sending it through an expansion valve.
- Finally, the liquid CO2 is then allowed to expand to atmospheric
pressure to produce CO2 snow. Part of the liquid sublimates (changes
directly from a solid to a gas), causing the remainder to freeze
- The dry ice is then compressed hydraulically under a large press
to form blocks, slices or pellets.
- After processing, dry-ice is stored in an insulated container as the thicker the insulation, the slower it will sublimate. The sublimation of Dry Ice to Carbon Dioxide gas may result in expansion or possibly explodation of an airtight container.