Dry Ice Blasting Explained
Dry Ice Blasting is a relatively new cleaning process, used primarily in industrial cleaning applications. It is an environmentally friendly process that can clean a wide variety of components very effectively without the use of chemicals or abrasion. It does this by using small pellets of solid carbon dioxide (commonly known as dry ice) propelled by compressed air at the high velocity of 150 m/sec (492 ft/s) through a hand held lance to impact and clean the surface quickly and thoroughly.
Dry ice is made by liquefying CO2 (carbon dioxide) under pressure and then allowing it to expand rapidly. In this process part of the CO2evaporates and thus cools the remainder to such an extent that it freezes and creates CO2 snow at a temperature of -79°C (-110°F) Dry ice pellets with a diameter of 3 mm are obtained by pressing the CO2 snow through an appropriate die and then be loaded into insulated containers for transportation to site ready for use.
The Dry Ice Blasting process is superior to blasting with sand or glass bead and other types of industrial cleaning methods for a number of reasons, not least because there is no residue left after cleaning as the pellets sublimate (convert directly from solid pellet to a vapour (CO2) leaving only the product that has been removed from the cleaned surface to recycle or dispose of – no water, no chemicals or grit.
Cleaning with Kinetic Energy
Dry ice cleaning works on the principle of 3mm pellets of dry ice being propelled at 150 m/sec (492 ft/sec) onto a contaminated surface.
Cleaning with Thermal Energy
This causes the contaminated layers to freeze (ice is at CO2 -79°C / -110°F), so rapidly that the unwanted layer contracts, weakens
The dry ice pellets penetrate the cracks in the contaminants surface that the thermal shock has created and then explode.