Abstract: A ballast water treatment system for treating ballast water for a vessel has a pathway for navigable raw water to the tank and a discharge for discharging water back to the body of navigable raw water. A back washable filter in the pathway receives the raw water and screens sediment from the raw water to produce initially processed water which contains at least some marine organisms. A UV or other biocidal device is connected between the filter and the ballast tank, for disabling or killing the marine organisms in the initially processed water to produce treated ballast water for the main outlet to the ballast tank.

Abstract: A ballast water treatment system for treating ballast water for a vessel has a pathway with for navigable raw water for to the tank and a discharge for discharging water back to the body of navigable raw water. A back washable filter in the pathway receives the raw water and screens sediment from the raw water to produce initially processed water which contains at least some marine organisms. A UV or other biocidal device is connected between to the filter and the ballast tank, for disabling or killing the marine organisms in the initially processed water to produce treated ballast water for the main outlet to the ballast tank.

Abstract: A centrifugal separator for purifying liquids containing impurities, has a main fluid conduit forming a passage with an inlet for receiving raw liquid to be purified, and first and second outlets. A discharge conduit is in the passage and is connected to the first outlet. A stator is positioned in the fluid passage for imparting an initial swirling axial movement to the raw liquid. A rotor positioned in the fluid passage upstream of the discharge conduit and downstream of the stator, imparts a further swirling axial movement to the raw water in the fluid passage for causing solids in the raw liquid to migrate outwardly. Clean liquid enters the discharge conduit to exit the separator via the first outlet, and solids laden liquid passes the discharge conduit and exits the separator via the second outlet.

Abstract: A centrifugal separator for purifying liquids containing impurities, has a main fluid conduit forming a passage with an inlet for receiving raw liquid to be purified, and first and second outlets. A discharge conduit is in the passage and is connected to the first outlet. A stator is positioned in the fluid passage for imparting an initial swirling axial movement to the raw liquid. A rotor positioned in the fluid passage upstream of the discharge conduit and downstream of the stator, imparts a further swirling axial movement to the raw water in the fluid passage for causing solids in the raw liquid to migrate outwardly. Clean liquid enters the discharge conduit to exit the separator via the first outlet, and solids laden liquid passes the discharge conduit and exits the separator via the second outlet.

Abstract: An apparatus and method for treating water to be supplied to a ballast tank uses a water pathway having a main inlet for connection to a body of navigable open raw water containing sediment and marine organisms, and a main outlet for connection to the vessel's ballast tank(s). A centrifugal separator is provided in the pathway and has a separator inlet for receiving the raw water. The centrifugal separator separates sediment with some water from the raw water to produce initially processed water which contains at least some marine organisms. The separator has a first outlet for returning the sediment with some water to the body of raw water and a second outlet for supplying the initially processed water to the pathway.

Abstract: An apparatus and method for treating water to be supplied to a ballast tank uses a water pathway having a main inlet for connection to a body of navigable open raw water containing sediment and marine organisms, and a main outlet for connection to the vessel's ballast tank(s). A centrifugal separator is provided in the pathway and has a separator inlet for receiving the raw water. The centrifugal separator separates sediment with some water from the raw water to produce initially processed water which contains at least some marine organisms. The separator has a first outlet for returning the sediment with some water to the body of raw water and a second outlet for supplying the initially processed water to the pathway.