A. Unlike other types of blasting media that have a “chiseling” effect, dry ice
blasting actually penetrates the contaminant utilizing kinetic energy from the high-velocity
dry ice particles, creating an explosion upon striking the substrate and lifting
the unwanted material from the surface. This non-abrasive process is commonly referred
to as “impact flushing”.
Q2. How do I store dry ice?
A. Air is the worst enemy of dry ice. Dry ice should be kept in a well-insulated
container available from your ice supplier. Since dry ice is extremely cold (109°
below zero), storing the product in a normal freezer may slow sublimation minimally,
but will not significantly prolong its’ shelf life.
Q3. How long can I store dry ice?
A. We recommend that fresh dry ice be used within 3-5 days. Properly insulated dry
ice can be stored for periods over 10 days. However, the ice loses its’ integrity
after extended periods of time, becoming soft and powder-like. This not only creates
problems with inconsistent feeding of the blasting equipment (due to density loss),
it may also exhibit unsatisfactory cleaning results.
Q4. Where do I get dry ice?
A. There is typically more than one supplier in your area. Your local Phoenix representative
will be more than
happy to help you find an ice distributor near you. Contact them for more information.
Q5. How are dry ice pellets produced?
A. Dry ice is manufactured using liquid carbon dioxide (CO2).
Liquid CO2 is
stored in a bulk tank at 300 psi. To form dry ice pellets, the liquid CO2 is sent
through an orifice
or expansion valve into a chamber. The pressure drop, created going through
the orifice, causes the liquid to flash into gas and dry ice snow. The dry ice
snow is then compressed into rice-sized pellets and the gas is
vented to atmosphere or recovered to be reused. The conversion from liquid to
solid is approximately 46%.
Q6. What kind of safety equipment do I need?
A. For most applications: Ear plugs or muffs (or both), safety glasses, face shield,
gloves, long sleeve shirt, long pants, and safety shoes. For specialized cleaning
jobs in confined spaces or no ventilation, a self-contained breathing apparatus,
respirator, jumpsuit or special clothing may be required. Check your company’s safety
policy and regulations for detailed specifications.
Q7. How much dry ice will I use?
A. 2-3 pounds per minute is normally sufficient for most cleaning. Phoenix blasting
units have a variable ice rate that can be adjusted for more or less, depending on
the specific application.
Q8. Does using more ice per minute speed up my removal rate?
A. Contrary to popular belief, more is NOT better when it comes to dry ice for the
majority of applications. User experience and trial tests will determine exactly
what you need to get the job done, and you’ll save a monetary bundle in the process.
Q9. What is the cost of operation?
A. Operation costs will depend on the feed rate (ice usage setting) and cost per
pound of the ice. An on-site demo is the best way to determine your actual projected
cost of operation. Contact your representative to schedule.
Q11. How do I get training on my new Phoenix blasting unit?
A. Upon delivery of your newly purchased system, we will provide start-up assistance
and safety training at your facility. Start-up may include classroom and hands-on
instruction, if so desired.
Q12. Why would I use dry ice cleaning instead of a traditional blasting media?
A. Positive reasons for incorporating dry ice processes are numerous. First, with
government bans and regulations increasing on chemical cleaning, dry ice is an environmentally
safe and effective alternative to current cleaning methods, approved even in the
food industry. Also, you will increase revenue by lower disposal costs, not to mention
the high-end expense savings from product replacement damage incurred over time by
blasting with less friendly, abrasive media like sand, water, soda, walnut shell,
bead, etc. In addition, most applications can be cleaned on-line without disassembly,
and without the worry of any grit entrapment or residue, freeing up hours of employee
labor, ultimately saving your business countless time and money. So you may want
to ask yourself… why wouldn’t I use dry ice cleaning?
Q13. Does dry ice blasting freeze the contaminate?
A. No. This is a common misconception regarding the technology. Contaminants are
not frozen in place, and then struck with a hammer to crack and fall to the floor.
One should keep in mind that this is a cleaning (not freezing) process. The contaminate
is penetrated and removed from the substrate being blasted.
Q14. Where does the contaminant go?
A. It moves from an undesirable location to an area where it can be dealt with more
easily. If it is dry, it usually falls to the floor where it is swept away or vacuumed
during normal maintenance. If it is a wet substance like grease, you take a methodical
approach similar to hosing down a driveway. You start at one end and guide it to
a collection point where it can be vacuumed or squeegeed up.
Q15. What type of dry ice do I need?
A. Rice style pellets.
Q16. Can you use dry ice to clean hot tools on-line?
A. Absolutely. In fact, with most applications involving hot tooling, the removal
rate is actually increased due to thermal shock. A cool tool will typically take
a bit longer to clean.
Q17. What is the power supply and how much will I need?
A. Since Phoenix cleaning systems are 100% pneumatic, no electrical cords or outlets
are necessary. All you need is cool, dry compressed air for easy operation. Most
results can be achieved between a range of 60 CFM @ 60 psi up to 220 CFM @ 100 psi,
depending on the application. (High-pressure units naturally require more for high-end
Q18. Will dry ice cleaning damage my substrate?
A. Typically, No. Dry ice cleaning is a non-abrasive process. It will not etch or
profile any substrate that is “harder” than the ice itself. With softer surfaces
such as wood, drywall, soft plastic, etc., damage can sometimes occur if the parameters
on the machine are set incorrectly (i.e. blast pressure too high, ice rate too high,
wrong nozzle choice). For this reason, Phoenix has designed our control systems to
be completely variable, thereby accommodating most delicate applications.
Q19. Does dry ice cleaning cool the substrate?
A. Yes, but generally not as much as you might think. The amount of cooling depends
upon three main factors:
a) mass of the targeted surface
b) dwell time
c) ice usage rate
Normally, however, cooling is not a cause for concern. The decreases are minimal,
with most substrates
reaching ambient temperature in a matter of minutes after cleaning is completed.
Q&A - Frequently Asked Questions about Dry Ice Blasting Equipment