Dry ice
Dry ice is produced from liquid CO2. 2.5 kg of carbon dioxide is required to produce 1 kg of dry ice. Carbon dioxide is liquefied at a pressure of 5.1 bar. It is stored in bottles in this liquid state. When liquid carbon dioxide is exposed to sudden pressure decrease, the occurring rapid evaporation through sublimation cools the substance so much that it freezes and forms finely powdered snow, the compression of which results in the formation of dry ice. The constituted compact snow is then pressed into blocks or extruded under pressure into pellets or nuggets. This ice is very similar to normal water ice, but its properties are significantly different.
Properties
- does not contain water
- three times colder than ice-water
- tasteless and odourless
- no end product is created due to sublimation
- germ and bacteria free
- non-toxic in small quantities
- non-flammable
- heavier than air
- has no electric charge (dipolar)
- non-reactive (does not react with its environment)
Surface-friendly
The applied technology is not abrasive! It does not remove material from the surface to be cleaned in contrast to sandblasting and other particle spraying methods.
Environmentally friendly
No chemicals are deployed, it is a 100% environmentally friendly method. Dry ice cleaning has a much smaller environmental burden compared to the regular use of solvents and chemicals.
Minimal amount of waste is generated
Since dry ice cleaning does not involve the use of any solvent, only the fallen dirt needs to be removed. As for the sprayed material (dry ice), it sublimates. There is no water or other media either.
Safe solution
It is non-toxic, non-acidic, non-alkaline, and no solvents are used. It does not endanger the employees; only simple occupational health and safety equipment is required. It does not damage the machinery, not even the delicate, sensitive parts!
Hardening the surface
The dry ice pellets are sprayed on the surface to be cleaned by applying a large amount of air with high pressure. Impurities harden and become brittle due to the low temperature. This condition reduces their flexibility and adhesiveness, making them easier to remove.
Temperature difference, thermal shock
On account of the sudden local “freezing”, the dirt particles shrink and crack, as a result of which the dirt to be removed separates from the base surface.
Shock wave
The dry ice particles hit the surface at high speeds. The removal of dirt is also favoured by the kinetic energy induced by the particles.
Explosive sublimation
During the transformation of dry ice, the very cold pieces of ice, in contact with the relatively warm surface to be cleaned, turn into gas almost immediately. This process is accompanied by an increase in the volume of the gas (the volume of which is several hundredfold), which can actually be regarded as a micro-explosion of carbon dioxide.This explosion repels the contamination that has already been dissolved and the contamination particles are swept off the surface with the help of the compressed air. The greater the temperature difference between the surface to be cleaned and the dry ice is, the more effective the dry ice cleaning will be! After the cleaning is over, the surface remains dry and does not require any kind of treatment. The sprayed material sublimates, and no by-products or hazardous waste are produced.
Advantages:
Cost-cutting and productivity-increasing:
- Downtimes can be shortened.
- There is no need to disassemble or reassemble before and after cleaning.
- The cleaning takes place on site, the technology utilised is completely mobile.
