Dry Ice Blasting Equipment

Dry ice blasting machines use dry ice pellets as the cleaning media and work by bringing the dry ice and the item to be cleaned together. The dry ice pellets are solid until they reach the surface; they then quickly sublimate, which is to say, from the solid state, they go directly to the gas state. The extreme pressure created by this phase change blasts the item's surface clean. Three primary types of dry ice blasting equipment exist: cooperative feeding, non-cooperative feeding, and two-fluid; new technologies continue to emerge. In addition, every machine requires an air supply: the delivery system needs a large volume of compressed air and the appropriate dry ice pellets.

Although the first machine able to perform dry ice blasting was created in the 19th century, it took until the early 1980s for the machines to properly come onto the market. Cooperative feeding machines force the dry ice under pressure through the hoses and nozzles using the kinetic energy that comes from a rotating drum, and cleaning is done pneumatically. Non-cooperative feeding machines don't use a rotating drum, unlike cooperative feeding machines. Instead of kinetic energy, they use high mechanical sealing. Two-fluid machines introduce the dry ice through one hose and nozzles, with high-velocity air through the other, creating a more powerful cleaning effect with the ability to set desired aggressiveness levels.

Types of Machines

There are three types of machines that can be used for dry ice cleaning, and they have subtle differences in the way that they control and deliver media. The lower mass or first-generation machines use a motor and gearbox to push out the ice from the hopper while using an airstream to carry the ice to the target. These systems disperse the ice unequally and are unsuitable for larger jobs.

As part of the next development stage, a company spent six years in research and development to develop a method of controlling the ice flow and also manufacture an agitator that would offer a positive dry ice feed. Eventually, they patented a vibrator design that can flow and feed the dry ice; this is the current system used on modern dry ice machines. The machines feed the ice into an airstream in the nozzle and are, therefore, a less efficient means of delivering the ice. Their advantage is mainly in their compact size, which allows portability.
The top level of development is based upon a relatively simple concept that uses a venturi principle to transport the ice. Another company has devised and patented a system capable of handling more significant amounts of dry ice and is more energy efficient. In these machines, the air and ice reach the surface through very gentle action; in doing so, it becomes more of a radiant heat and sudden temperature cooling that does the cleaning. This type of machine can handle more air, which equals more ice flow, but they are currently less mobile and cost more than the other systems. However, new portable machinery is also being developed using similar principles.