Centrifuge for separation of oil from water

Claim 1

A centrifuge for the separation of substantially immiscible liquids forming a mixture of light and heavy liquids comprising a casing, liquid inlet means into said casing for admission thereto of a mixture of said light and heavy liquids, a rotor within said casing, means for journalling said rotor, said rotor having three stages, said first stage comprising a multiplicity of axially and radially extending surface members spaced apart sufficiently to permit relatively large drops of the light liquid to flow as drops and streams radially toward the axis of said rotor as the heavy liquid is forced to migrate radially outwardly toward the casing under the influence of centrifugal forces, means adjacent to radially inward ends of said surface members for permitting flow of (said) separated light liquid from radially inward portions of said rotor and from said casing, the second stage comprising means defining relatively long substantially radially narrow axial passages extending lengthwise (and centrally) of the rotor(,) for receiving flow of unseparated light and heavy liquids from said first stage, the length and number of said passages being sufficient to cause coalescence of (relatively small drops of) substantially the remainer of said light liquid from small drops to (form) larger drops thereof during axial flow of said light and heavy liquids in a direction away from said first stage, a third stage downstream of said second stage comprising a multiplicity of axially and radically extending surface members and means for receiving flow of heavy and light liquids from said second stage, said surface members being spaced apart sufficiently to permit the relatively large drops received from said second stage to separate from said heavy liquid and to flow radially inwardly as said drops are displaced from said heavy liquid under the influence of centrifugal forces, means for removing said drops of light liquid from said rotor and casing and outlet means for removing the heavy liquid from said casing adjacent to said third stage.

Claim 10

A method of separating a lighter liquid substantially immiscibly mixed with a heavier liquid comprising the steps of rotating said liquids to subject them to high centrifugal forces, moving said liquids axially through a first zone wherein relatively large drops of said lighter liquid are displaced substantially radially inwardly by said heavier liquid and brought into contact with spaced radial and axial surface members, removing said displaced lighter liquids, causing the remainer of said heavier liquid and lighter liquid to move axially through a second zone where centrifugal and fluid shear forces act to effect coalescence of said lighter liquid into larger drops or a film, releasing said film, drops, and heavier liquid into a third zone wherein said film forms large drops and impinging said drops on spaced radial and axial surface members and removing said heavier liquid outwardly of said surface members while removing said lighter material inwardly of said members.

Claim 11

A method of separating a lighter liquid substantially immiscibly mixed with a heavier liquid comprising the steps of rotating said liquids to subject them to high centrifugal forces, moving said liquids axially through a first zone wherein relatively large drops of said lighter liquid are displaced substantially radially inwardly by said heavier liquid and brought into contact with spaced radial and axial surface members, removing said displaced lighter liquids, causing the remainer of said heavier liquid and lighter liquid to move axially through a second zone where centrifugal and fluid shear forces act to effect coalescence of said lighter liquid into larger drops or a film, releasing said film, drops, and heavier liquid into a third zone wherein said film forms large drops and impinging said drops on spaced radial and axial surface members and removing said heavier liquid outwardly of said surface members while removing said lighter material inwardly of said members.