Patent ID: 6076537
Filing Date: 2000-06-20
Classification: C23G

Abstract:
A solvent extraction and cleaning system, comprising:a generally closed product containing vessel having a port for the introduction and extraction of solvent, the vessel being configured to allow introduction and removal of solvent;a reservoir for storing solvent, the reservoir being connected to the vessel to enable transfer of solvent between the vessel and the reservoir to thereby permit solvent contact with the product within the vessel to clean the product;a pump for creating a vacuum pressure to evaporate the solvent within the vessel and for withdrawing air from the vessel to thereby dry the product within the vessel; anda controller, the controller regulating the vacuum pressure within the vessel, the controller monitoring the vacuum pressure within the vessel so that at a predetermined vacuum pressure, if the concentration of solvent within the vessel exceeds a predetermined level, the controller temporarily enables gas to enter the vessel to provide a carrier for the evaporated solvent, so as to temporarily reduce the vacuum pressure within the vessel, and the controller then sequentially enables the vacuum pressure to again build within the vessel and then enables the gas to enter the vessel until the concentration of solvent within the vessel is sufficiently low.