Le cryogenic cleaning is an innovative and environmentally friendly cleaning technology that uses solid particles solid of carbon dioxide (CO2), commonly called Carbon dioxide ice or dry ice, as a cleaning agent. These particles are propelled at high speed onto the surfaces to be cleaned using a pneumatic projection system. Upon impact, dry ice undergoes sublimation instantaneous, going directly from solid state to gaseous state, without passing through a liquid state. This phenomenon creates a thermal shock on the contaminated surface, which makes it possible to detach particles or layers of dirt without damaging the surface.

This process is extremely effective at removing various types of contaminants, such as greases, oils, waxes, production residues, and even certain coatings without the need for chemical solvents, water, or abrasive methods. It is therefore particularly suitable for cleaning sensitive parts or in environments where water use is prohibited or undesirable.

The speed at which dry ice particles are propelled depends largely on the system used, as well as several adjustable parameters, such as pressure, air volume, and nozzle type. In general, dry ice blasting systems can be classified into two main categories based on their design and projection speed:

• Bitube or venturi system : These systems can achieve projection speeds of between 60 and 120 meters per second (m/s). They are often used for general cleaning applications where effective dirt removal is required without specific projection speed requirements. See bitube cryogenic machine
• Mono-tube system with supersonic nozzle : These systems are capable of propelling dry ice particles at speeds exceeding 290 m/s, thus offering increased cleaning capacity for more demanding tasks or for particularly difficult surfaces to clean. See mono-tube dry ice blasting machine

In addition to its advantages in terms of efficiency and environmental respect, dry ice blasting is also valued for its ability to significantly reduce le downtime of industrial equipment, since it can often be performed without disassembling machines or equipment. This method also contributes to extending of the lifespan of assets by avoiding premature wear related to more abrasive cleaning methods.

The origin of dry ice blasting, also known as "dry ice blasting", dates back to the 1950. However, it was only developed and commercialized as an industrial cleaning technique from the 1980. This method was invented and explored as an alternative to traditional cleaning techniques, which used chemical solvents, pressurized water, or abrasive methods that could damage surfaces or be harmful to the environment.

The fundamental discovery behind dry ice blasting is the ability of dry ice to sublimate, that is to pass directly from solid to gaseous state without passing through a liquid state, when in contact with surfaces to be cleaned. This unique property allows effective removal of contaminantswithout leaving residues, unlike traditional cleaning methods which can leave secondary waste or require additional cleaning.

The introduction of this technique revolutionized many industries by offering a non-abrasive cleaning, water-free et environmentally de friendlysolution. Dry ice blasting proved particularly useful in sectors such as aerospace, automotive, food and beverage, plastics, or foundry, and electronics, where equipment and component cleanliness is crucial and where water or solvent use can pose safety, quality, or environmental issues.

Since its introduction, dry ice blasting technology and equipment have evolved considerably, offering increased efficiency, better ergonomics for operators, and greater adaptability to a wide range of industrial cleaning applications.

Dry ice blasting works in three main stages, based on the use of dry ice in the form of pellets or particles:

1. Projection : Dry ice particles are placed inside a dry ice blasting machine, then accelerated high speed using a jet compressed air through a specially designed projection nozzle. This acceleration allows particles to strike the surface to be cleaned with great kinetic energy (Ec=1/2 mV²)
2. Thermal shock : The impact of dry ice particles on the surface creates a thermal shock that weakens the bond between the dirt and the surface. The temperature difference between dry ice (approximately -78.5 °C) and the surface causes rapid thermal contraction of the dirt layer, making it easier to detach.
3. Sublimation : At the moment of impact, dry ice passes directly from solid to gaseous state (sublimation), increasing its volume considerably, at a ratio of 1 to 400 or 1 to 700 (depending on ambient temperature). This change of state causes rapid expansion that helps "blow" dirt off the surface without abrasion or damage, leaving the surface clean and dry, without water or solvent residue.

This process allows effective cleaning without using chemicals, without generating secondary waste, and without damaging surfaces, making it an ecological and safe cleaning method for many industrial applications.

Dry ice blasting and sandblasting are two industrial cleaning methods, but they differ in their principles, media used, and impacts on treated surfaces:

Cleaning media:

• Dry ice blasting: Uses solid dry ice particles that sublimate upon contact with surfaces.
• Sandblasting: Uses solid abrasive particles such as corundum, glass, or roughness agents.

Mechanism of action:

• Sandblasting: Acts through abrasive mechanical action, where solid particles strike the surface and physically erode or remove dirt, paint, rust, etc.
• Dry ice blasting: Works through thermal shock and sublimation, where the cold contact of dry ice particles with the surface creates a thermal shock that weakens contaminants before sublimation expels them from the surface.

Effects on the surface:

• Dry ice blasting: Non-abrasive, does not deteriorate the treated surface and leaves no secondary residue, as sublimated dry ice disperses into the atmosphere.
• Sandblasting: Potentially abrasive, can alter the surface texture or cause damage if improperly applied. Generates secondary waste (worn abrasive particles and removed materials) that must be collected and disposed of.

Applications:

• Dry ice blasting: Ideal for precision cleaning, sensitive equipment, environments where water or residues are problematic.
• Sandblasting: Better suited for removing thick coatings, rust, or surface preparation before painting or coating, where abrasion is necessary.

Environmental and safety considerations:

• Dry ice blasting: More eco-friendly, reduces chemical contamination risks and minimizes operator exposure to hazardous chemicals.
• Sandblasting: Can generate harmful dust and waste, requiring strict control measures for operator safety and environmental protection.

In summary, the choice between dry ice blasting and sandblasting depends on the nature of the dirt to be removed, the type of surface to be cleaned, environmental considerations, and specific cleaning objectives. Moreover, sandblasting generates a lot of dust and you generally cannot clean on-site.

Upon impact with a surface, dry ice undergoessublimation, passing from solid to gaseous state without becoming liquid. This process releases carbon dioxide (CO₂), a natural component of air, which participates in essential ecological cycles such as photosynthesis. Although CO₂ is a greenhouse gas, its release in this context does not introduce chemical pollutants into the environment, integrating into natural cycleswithout directly contributing to climate warming.

During dry ice blasting, contaminants are removed from the surface in an efficient and controlled manner. Here is a precise and concise explanation of what happens to the contaminants:

• Dry contaminants : After detachment from the surface by dry ice blasting action, these particles fall by gravity. They can be collected on a prepared surface, such as a plastic tarp, facilitating their removal. Disposal is then carried out simply using an industrial vacuum, or by direct collection for reprocessing or appropriate disposal.
• Viscous contaminants : For more adherent substances, such as grease or oils, the cryogenic method also detaches them, but their collection requires specific planning. The process is carried out by guiding these contaminants from their initial location (point A) to a predefined collection point (point B), where they can then be treated or cleaned further, for example, using high-pressure cleaning or other appropriate methods to ensure complete removal.

This strategic approach to contaminant removal ensures that dry ice blasting does not merely move dirt from one point to another, but contributes to effective waste ecological management.

The Cryoblaster ATX is designed for cleaning operation withdry et clean air (available in most factories).

Although the ATX series includes a micron filter as standard, an additional air dryer will be necessary in exceptional circumstances:

– absence of de treatment of compressed air at customer site,
– rental of a compressor without compressed air treatment system

You should always purge the compressed air lines before connecting them to your ATX unit. This will eliminate water and dirt that may be present (see methodology in your ATX User Manual).