Vacuum pressure applied to a hydrostatic chamber causes a rise of carrier liquid from an underlying flow stream to an equilibrium level in a hydrostatic column passage and stacking of floating liquid thereabove for separation from the carrier liquid by overflow into siphoning passages conducting the floating liquid to a recovery container vented to atmosphere. The liquid conducted through the siphoning passages seals the hydrostatic chamber, within which an adjusted vacuum pressure maintains recovery operation under established hydrostatic relationships for a given set of dynamic flow conditions.

A system for oil and water separation by siphon and vacuum means, upon an oil tanker vessel; the system including in one design a relatively small, sealed tank upon a deck of the vessel, a hand controlled vent valve on a top of the tank, an outlet end of a siphon line entering the tank while an inlet end of the siphon line may run into a collection or other tank, and discharge lines from lower and upper ends of the sealed tank being connected to pumps for discharging oil at a top and water at the bottom.

A collapsible container for separating oil and water and containing and transporting the separated oil is provided. The container is manufactured of a water impervious material and has a plurality of chambers, capable of holding oil and water, which are attached to each other serially along a linear axis. Located at opposite ends of the container are an input chamber and an output chamber. Intermediate the input and output chambers is at least one intermediate chamber. Substantially vertically disposed baffles, having an opening at their lower edges, are provided within the container defining the connecting walls between the input chamber and the adjoining intermediate chamber and the connecting walls between adjacent intermediate chambers. A baffle, also substantially vertically disposed, having an opening at its upper edge, is provided within the container defining the connecting wall between the output chamber and the intermediate chamber located farthest from the input chamber. An inlet allowing an oil and water mixture to enter the inlet chamber is provided. In addition, an outlet attached to the outlet chamber is provided to allow material within the outlet chamber to exit the container.

An oil recovery apparatus and method, particularly for removing oil and grease from the discharge of dishwashing machines or the like, provides a small size assembly employing the same principle as in U.S. Pat. No. 4,051,024. This apparatus and method employs single rotating discs of plastic or plastic coated material and each disk has a pair of scraper blades arranged to scrape opposite sides of the rotating blade. Exterior of the container for the oil recovery apparatus is at least one filter basket adapted to receive the flow into the strainer container of large particles of food and other waste such as cigarette butts and the like. Each filter is disposed for the ready cleaning of accumulated matter from the basket. There is shown plural filters, valve controlls, auxiliary heating and disc support means to be more fully described.

Removal from the surface of bodies of water of oily and floating matters is conducted by preliminarily increasing the concentration of the oily and floating matters in the upper water layers by separating a liquid surface layer sufficiently thick to contain substantially all of the oily and floating matters, simultaneously giving the separated layer a relative speed so as to forward it to subsequent treatment steps with a minimum of or no turbulence, and introducing the separated layer into a basin having a horizontal size relative to the cross-section where the initial separation occurred such as to substantially reduce the relative velocity of the liquid flow, where the level of the liquid in the basin is kept near to the average level of the body of water outside the basin. The water in the basin is caused to have a downward flow direction by sucking from the bottom of the basin, leaving the already separated oil at the surface, thereby increasing its concentration. An upper liquid layer is then withdrawn from the basin surface. The upper liquid layer is forwarded to further decantation treatment where the liquids withdrawn from the surface layers are passed at low speed through an array of communicating tanks from which the water deposited at the bottom is sucked out and discharged while the oil is withdrawn and sent to store. An apparatus facilitating the method and the present invention is also disclosed.