Vacuum seal

A vacuum sealing arrangement to seal an area in which a pressure differential exists comprising a rotor member rotatable within said area, said rotor member having a first sealing face orthogonal to the axis of rotation of said rotor member and defining a gap with a second sealing face, said first and second sealing faces defining said area in which said seal is to be created, said first sealing face having at least one fluid flow path into which a sealing fluid can be supplied to be held by counterbalanced centrifugal and pressure differential forces to create said seal within said gap between said first and second sealing faces, wherein said flow paths each comprises a groove provided in said first sealing face.

A liquid concentrator having a compressor connected between an evaporator and a condenser, both operating under vacuum, said compressor having a shaft with a rotor mounted thereon, said rotor having a first sealing face orthogonal to the axis of rotation of said rotor member and defining a gap with a second sealing face, said first and second sealing faces defining an area in which a pressure differential exists and in which a seal is to be created, said first sealing face having at least one fluid flow path into which a sealing fluid can be supplied to be held by counterbalanced centrifugal and pressure differential forces to create said seal within said gap between said first and second sealing faces.

A liquid concentrator having a compressor connected between an evaporator and a condenser, both operating under vacuum, said compressor having a shaft with a rotor mounted thereon, said rotor having a first sealing face orthogonal to the axis of rotation of said rotor and defining a gap with the second sealing face, said first and second sealing faces defining an area in which a pressure differential exists and in which a seal is to be created, said first sealing face having at least one fluid flow path into which a sealing fluid can be supplied to be held by counterbalanced centrifugal and pressure differential forces to create said seal within said gap between said first and second sealing faces and wherein a separator is connected between said evaporator and said compressor, said separator supplying steam to said compressor which in turn supplies pressurized steam to said condenser, a proportion of said steam being recycled from said condenser to said separator.