Dry Ice Cleaning - What is this?
Introduction
Dry ice blasting is a relatively new cleaning process using solid CO2 pellets (known as dry ice). It is primarily used for industrial use in a variety of applications. The pellets sublimate (convert directly from a solid blast pellet to a vapor (CO2) leaving no residue.
Today, the dry ice cleaning method is quickly becoming favored for environmental as well as production reasons. Because of tremendous environmental regulations, industry has needed to minimize wastes. Also, there is a growing consciousness that many are placing now on the global environmental impact of their production practices. However, these benefits are accentuated due to the tremendous performance gains through dry ice blasting -- little or no production downtime, quality of clean and minimized damaged to equipment.
What Is Dry Ice
Dry ice pellets are made by taking liquid carbon dioxide (CO2) from a pressurized storage tank and expanding it at ambient pressure to produce snow. The snow is then compressed through a die to make hard pellets.
What Is Dry Ice Blasting
It is a process in which dry ice particles are propelled to supersonic speed, to impact and clean a surface. The particles are accelerated by compressed air, just as with other blasting systems.
The micro-thermal shock (caused by the dry ice temperature of -79º C), the kinetic energy of dry ice pellets and the air pressure break the bond between the coating and the substrate. It pops off the coating from inside out and the air stream removes it from the surface.
Industries can utilize the dry ice blasting cleaning method through equipment that fires the pellets through a blasting gun. Upon impact the dry ice sublimates (vaporizes). There are many major benefits to this cleaning process. To read of them in detail, see our Dry Ice Blasting Benefits page.
Dry Ice Blasting Compared to Traditional Methods
The following two charts give a helpful perspective of how dry ice blasting compares with the traditional cleaning methods --
CIP, blasting, solvents, and others:.
|
Dry Ice Blast Cleaning Comparison Chart
|
|
Blasting
Cleaning Technique |
Waste for Disposal |
Abrasive |
Toxic |
Electrically Conductive |
Performance Comparison |
|
Dry
Ice |
No
|
No
|
No
|
No
|
Excellent
|
|
CIP/Chemical
|
Yes
|
No
|
Yes
|
Yes
|
OK
|
|
Steam
|
No
|
No
|
No
|
Yes
|
Poor
|
|
Solvents
|
Yes
|
No
|
Yes
|
Yes
|
Limited
|
|
Sand
|
Yes
|
Yes
|
No*
|
No
|
OK
|
|
Glass Beads
|
Yes
|
Yes
|
No*
|
No
|
OK
|
|
Walnut Shells
|
Yes
|
Yes
|
No*
|
No
|
Limited
|
|
* Each
of these blast cleaning materials becomes contaminated upon
contact if used to clean hazardous objects. When that happens, these
materials are then classified as toxic waste requiring safe disposal. |
|
Cleaning
Method Comparison |
|
Issue |
Traditional |
Dry
Ice Blasting |
|
Equipment
Downtime |
Cleaned
in dedicated cleaning area; Disassembly/reassembly; Drying time required |
Equipment
can be cleaned in place; Dry process - equipment restart immediately
after cleaning |
|
Hazardous Waste |
Cleaner becomes and treated as a secondary contaminant |
No
additional contaminant; Dry ice sublimates with contact with targeted
surface |
|
Labor
Hours |
Intensive
hand scrubbing; Lengthy cleanings; Follow-up cleaning-up can be lengthy |
Dramatically
reduced - often completed in a quarter of time or better |
|
Quality of Cleaning |
Poor to average |
Excellent |
|
Potential Equipment Damage |
Grit
abrasions; Grit contamination; Movement of equipment to and from cleaning
area |
No
equipment damage; Preventive maintenance very realistic as labor hours
are significantly less |
|
Safety |
Health
threats from solvents; Water-based cleaning pose hazards around electrical
equipment; Threats to environment |
Standard
safety precautions; Dry process - safe around electrical equipment |
|
Cost |
Cleaner
becomes additional hazardous waste; expensive solvents; Additional
labor |
Minimal - cost of dry ice |