Process of dry ice blast cleaning:
Dry ice blasting works like high pressure blasting without any damage to the surface. The temperature of dry ice is -109.3°F or -78.5°C , known to be fast and effective cleaning method, blasting at a supersonic speed causes the material to be removed from the surface to shrink, looses its adhesions and leaving behind the surface. As the dry ice particles penetrates the material to be removed, they come in contact with the warmer subsurface, thus converting itself down into carbon dioxide gas which is 800 times greater in volume and expands behind the material to be ventilated into the atmosphere. This process of dry ice blasting is non-toxic and non-corrosive as the dry ice particle impact the surface being cleaned, they sublimes into the atmosphere leaving behind the removable material to be disposed off.
Replacing sand blasting:
Now a days sand blasting is being replaced by ice blasting as it is soft enough leaving the surface undamaged. Using a sandblaster is similar to using ice pick where as ice blasting is similar to using a spatula. Sand cuts away the contaminant where as ice blasting lifts it away. Sandblasting creates fugitive dust which is toxic, creates a huge amount of mess and shortens the life of all near by moving parts, whereas dry ice blasting reduces equipment damage in two ways. First, dry ice blasting process is non-abrasive; it quickly removes contaminants without damaging the surface. Thus the equipments integrity, luster and tolerance are preserved and the equipment need not to be replaced for the next process. Second, the equipment can be cleaned while at their original place. This prevents from accidental bumps, drops and damages while moving to and fro the cleaning area.
Replacing steam and water blasting:
It is amongst the fastest methods of cleaning, water blasting has limited applications. On steel surfaces it cannot create any specific surface profile which is a key parameter for painting. Also the use of water causes flash rusting which makes paint application difficult and risky. Furthermore the use of water blasting on welding lines, motors and machine tools results in severe electrical problems. Thus they are now being replaced by dry ice blasting for following reasons. Electrical parts and generators can start working without waiting for them to dry. Dry ice blasting removes more algae, sea slimes, sea weeds and mussels on boat than water blasting which causes the organic matter to reattach earlier. Molds and mild dew removals are complete and with less chances of regeneration.
Replacing environmentally damaged solvents:
Solvent management and disposals are costly issues for any kind of business. Dry ice blasting is once again playing a tremendous role in replacing environmentally damaged solvents. These chemicals include methyl chloride, perchlorethane, orthodichlorobenzene, cresylic acid, trichlorithane and caustic solution. It dissolves away unwanted materials in just one step, with simultaneous cleaning of numerous objects with differing geometries. It also provides safe in place cleaning without leaving any wastes as it evaporates completely. When dry ice replaces hazardous chemical cleaners the disposal cost of that chemical is eliminated. Tinker Air Force Base has reported it eliminated hazardous waste disposal associated with 17,000 gallons of chemicals they no longer need to use each year because of dry ice cleaning.
Looking at so many advantages of dry ice blasting, there are some drawbacks as well which can be worked upon. Firstly, it produces huge amount of noise leading to noise pollution but is now being replaced by silent machines as well. Protective earphones can be used to eliminate this problem. Secondly, it produces large amount of carbon dioxide which needs to be ventilated into the atmosphere. Thirdly, effective cleaning can occur in a straight line of sight from the dry ice jet nozzle. Sometimes parts need to be disassembled for the same reason.