| 摘要 |
<p>A method for removing, condensing and collecting propellants, e.g. chlorofluoro-carbons (CFCs) in an environmentally friendly manner from foam materials, e.g. insulant materials from old (discarded) refrigerators, district heating tubes and other materials for which the method is suitable. The method is based on the fact that the decomposition of the foam materials and accordingly the liberation of the propellant in the foam takes place in a liquid medium, e.g. water. In case the temperature of the liquid medium is equal to or above the temperature corresponding to the boiling point of the propellant at the actual pressure, the propellant is liberated from the foam as a gas. The propellant gases are conducted through one or several liquid media, e.g. water and/or one or several ''cold traps'' in which the temperature is below the temperature corresponding to the boiling point of the propellant gases at the actual pressure which causes that the propellant condenses. In case the temperature of the liquid medium is below the temperature corresponding to the boiling point of the propellant at the actual pressure, immediately upon liberation the propellant will condense when entering into contact with the liquid medium and be located in the process container according to the density of the materials. The condensed propellant and the non-condensed gases are optionally conducted to a succeeding treatment.</p> |
