Process for the removal of blowing agents / ozone depleting substances from rigid foam in refrigeration equipment

摘要

A process for the removal of ozone depleting substances (ODS) from foam insulating material of refrigerator equipment carcasses 4 involves (after degassing and removing the compressor unit) removing the top and bottom of the carcass, placing the remaining shell 4 within an hermetically sealed enclosure 14 (seals 15) and grinding down the foam insulant with a series of rotating augers 7 and brushes (positioned at the end of flexible driving shafts 8 and driven by gear train 10, 11) so as to produce a concentrated mixture of ODS vapours which may be subsequently collected. The concentration of the vapours is increased by filling any void spaces within the carcass with bulk material or an inflatable air bag 18. This also serves to facilitate the removal of any vapours which are released from the foam (and which are additionally recycled to the enclosure so as to minimise loss to the atmosphere). Foam residue falls in to hopper mill 9, underneath which outlet 13 (which may carry mill driveshaft 12) is positioned. A relationship between clamps 16, flexible bellows 6 and a switch within lid 1 allows the sideways oscillation of the carcass so as to ensure the removal of all foam. Augers may be arranged in an offset double row and may also have a quick-release nature so as to be removed and replaced with augers of different sizes. An interlocking system 3 prevents enclosure lid 1 being open until the ODS vapour concentrations reach a pre-determined level.