Applications

This method is ideal for situations where there is:

• a very tough build up, such as baked-on product
• electrical or sensitive componentry
• too much downtime in cleaning
• a dry environment, such as a milk powder drier
• requirements for no secondary waste, such as water or sand.

What are some examples of dry ice blasting outcomes?

Waffle factory brings new life back to old molds without water or chemical

A bakery and foodservice factory cuts costs and downtime while increasing productivity by 80%

Chocolate facility reduces cleaning time by 60%, and reduces maintenance costs and downtime

Wooden brewing vessels thoroughly cleaned without affecting flavor

Bakery uses dry ice blasting to reduce cleaning labor from 25 to 2 people

What are the benefits?

Dry ice blasting has many benefits that make it an excellent cleaning method for the food industry. The top 10 include:

1. Zero secondary waste  
2. Zero water
3. Zero chemical
4. A sustainable cleaning method
5. Non-conductive
6. Sanitise as you clean
7. Reduce plant downtime
8. Non-abrasive
9. Deep clean in place
10. Odour-free cleaning

Read more about these benefits here.

How much does dry ice blasting cost?

Every dry ice blasting job is different which makes it difficult to have a standard price that will be accurate for all situations.

However, there are some key factors that make up the price of a dry ice blasting job. By looking at each of these you can get an approximate value of work.

We wrote an article explaining these factors: read it here.

The science behind how it works

(All information in this section is retrieved from Coldjet.)

Dry ice blasting combines three primary factors to remove contaminants:

• Pellet Kinetic Energy
• Thermal Shock Effect
• Thermal Kinetic Effect

Pellet Kinetic Energy

Dry ice is accelerated by compressed air through a nozzle at supersonic speeds. When the dry ice collides with the substrate being cleaned it creates a kinetic effect. This effect has the largest contribution to the cleaning process when substrates are at ambient temperatures or below.

Even at high impact velocities and direct head-on impact angles, the kinetic effect of solid CO₂ pellets is minimal when compared to other media (grit, sand, PMB). This is due to the relative softness of a solid CO₂ particle (1.5 – 2 on the Mohs Scale of Hardness), which is not as dense and hard as other blasting media. Also, the pellet changes phase from a solid to a gas, almost instantaneously, upon impact. Very little impact energy is transferred into the coating or substrate, so the dry ice cleaning process is considered to be non-abrasive.

Thermal Shock Effect

The temperature (-109°F / -78.9°C) of the dry ice causes thermodynamic shock, which causes the contaminant to embrittle and shrink. The resulting micro-cracking helps break the bond between the surface and the contaminant.  The instantaneous sublimation (phase change from solid to gas) of dry ice upon impact absorbs maximum heat from the very thin top layer of the surface contaminant.  Maximum heat is absorbed due to latent heat of sublimation.  The very rapid transfer of heat into the dry ice from the coating top layer creates an extremely large temperature differential between successive micro-layers within the contaminant. This sharp thermal gradient produces localized high shear stresses between the micro-layers. The shear stresses produced are also dependent upon the contaminant’s thermal conductivity and thermal coefficient of expansion / contraction, as well as the thermal mass of the underlying substrate. The high shear produced over a very brief period of time causes rapid micro-cracking between the layers leading to the failure of the bond between the contaminant and surface of the substrate.

Thermal Kinetic Effect

Upon impact, the combined impact energy dissipation and extremely rapid heat transfer between the pellet and the surface causes the dry ice particles to sublimate, or expand instantly, and return to the natural gas state. During this phase transition from solid to gas, the volume of dry ice expands up to 800 times in a few milliseconds and lifts the contaminant off of the substrate. This is effectively a “micro-explosion” at the point of contact. 

The “micro-explosion” aids in the lifting of thermally-fractured coating particles from the substrate. This is because of the dry ice particle’s lack of rebound energy, which tends to distribute its mass along the surface during the impact. The CO₂ gas expands outward along the surface and its resulting “explosion shock front” effectively provides an area of high pressure focused between the surface and the thermally fractured contaminant particles. This results in a very efficient lifting force to carry the particles away from the surface.

You could buy your own machine.

This is a good idea if you plan to do a routine small job, such as a quick clean at the end of every shift. For a job like this, it is unlikely bringing in a contractor will be cost-effective. 
 

You could use a different chemical-free method of cleaning.

Steam cleaning and pressure washing are also chemical-free methods of cleaning. 

Dry or wet steam cleaning is good for cleaning oily or waxy surfaces.  This method of cleaning generally requires 3 phase power, so ensure this is available before planning to start.

Pressure washing is the cheapest option. It is perfect for situations where the soil will easily remove and water is no issue. Pressure washing generally requires a drain for the water to wash down. 
 

You could use abrasive blasting.

Sand blasting, soda blasting, and bead blasting are all examples of abrasive cleaning. They are very effective in cleaning and will remove everything including paint and rust. Abrasive blasting cleans back to bare metal but it creates a lot of mess and is extremely harsh on sensitive equipment, such as seals or wiring.
 

You could use chemical cleaning.

To remove the kind of build-ups that dry ice blasting is used for, you would need very strong, harsh and toxic chemicals. This process often involves a lot of soaking, water and downtime for your plant.

Often there are solutions that are cheaper by the hour, but they will nearly always take a lot longer than dry ice blasting would for the same job.