TPT September 2007

5. Carbon dioxide as a solvent Advanced research and a high number of tests have been carried out in order to ensure Fismet cleaning machines are of the highest standard. Two issues are continually at the top of the R&D agenda: operator safety and environmental protection. In particular, recent research has focussed on the use of carbon dioxide to solve tube- cleaning problems. Carbon dioxide is becoming one of the most attractive substitutes to chlorinated and CFC solvents. This is because it has an extraordinary solvent power compared to 1.1.1. trichloroethane (TCA), used in the past and now widely banned. Cleaning using carbon dioxide does not cause the increase of total carbon dioxide in the air. In fact the quantity used in the industrial cleaning process is mostly recovered, as residual of other productions; after use, it is definitively scattered. The benefits of carbon dioxide include non-flammability, non- combustion, and non-corrosion. Therefore, it is possible to verify that carbon dioxide is a high value alternative to traditional cleaning systems, even because it is easy to find and has a very low purchase cost.

‹ Figure 10 : Solid (as ice pellets) carbon dioxide sandblast equipment

In industrial cleaning, carbon dioxide can be used in every one of its four states. It can easily achieve changing temperatures and pressures during each of these four states. The four states are supercritical (allowing chemical extraction and removal of organic contaminants); liquid (for degreasing); snow (for removal of microscopic contaminant particles and lightly organic contaminants); and ice (for strong removal of organic and inorganic contaminants). In tube cleaning technology, the use of carbon dioxide is highly appreciated, mostly in manufacturing sectors such as medical, aeronautical, aerospace, and nuclear. It is also highly beneficial to sectors that have recently raised required cleaning parameters, such as automotive, air conditioning, heating and heat exchanger applications.

fi Figure 9 : Semi-solid (as snow crystals) carbon dioxide system

Fismet Industriale Srl – Italy Fax : +39 02 335 03251 E-mail : info@fismet.com Website : www.fismet.com

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S eptember /O ctober 2007