Abstract: A semicontinuous process for solvent dewaxing a waxy petroleum oil feed stream including the steps of: diluting of the waxy oil feed stream with solvent; feeding cold oil/solvent/wax mixture to a filter to remove the wax and obtain an oil/solvent filtrate stream; contacting the oil/solvent filtrate stream with a selective semipermeable membrane to selectively transfer solvent through the membrane to obtain a solvent-rich permeate; and periodically directing a warm stream of recovered solvent onto the membrane surface to wash the membrane and remove impurities therefrom.

Abstract: A fluid treatment device is described which includes a cylindrical housing with fluid inlet and outlet means at or adjacent opposite ends. Particulate material for treating fluid flowed through the device, is disposed within the housing, between the inlet and outlet means. A helical baffle is disposed within the housing in the particulate material. The baffle extends axially along the housing and the free edges of its fins are in contact with the housing. The baffle serves to impose a helical path on fluid flowing through the device so that, when the device is mounted with its axis horizontal and with a volume of particulate material less than the volume of the space within the housing, fluid flows through the particulate material most of the time and not entirely along the void as would be the case if the baffle were not present.

Abstract: A reverse osmosis water purification system has a feed water line and outlets for reject and product water. Instead of wasting the reject water by allowing it to flow to a drain, the reject water is returned to the water feed line downstream of the reverse osmosis system so that is can be used for other purposes. A section of the water feed line has a flow restrictor which estabishes a dynamic pressure drop. Feed water for the reverse osmosis system is taken off the feed line upstream of the restrictor and reject water is returned downstream of the restrictor, thereby reducing the water wastage due to the reverse osmosis process.

Abstract: A three element reverse osmosis filter cartridge assembly has a pre-filter section for solid particles, a reverse osmosis membrane filter section which produces product water and waste water from feed water circulated thereto via the pre-filter section, and a post-filter section for filtering the product water. These sections are disposed in coaxial, concentric relationship. The pre-filter section forms a replaceable outside sheath which is slideable onto and off the membrane section. The post-filter section is a tubular body containing carbon or other particles which is removably disposed in a central opening inside the membrane section. The membrane section has a support ring defining one end of the cartridge assembly which is disposed in sealing relationship with a ring which holds filter media layers of the pre-filter section. The pre-filter section has another ring at the end thereof opposite to said first ring and defines the opposite end of said pre-filter section.

Abstract: A reverse osmosis water purification system produces product water in response to pressurized feed water from a water supply line. The unit also produces waste or drain water. The purified product water is supplied to a reservoir wherein the pressure of the water increases when the reservoir becomes filled or when waste water is used to pressurized the product water and enable it to be withdrawn at a tap or faucet.